A Case of X-Linked Moesin-Associated Immune Deficiency in a Pediatric Patient

Background: X-Linked Moesin-Associated Immune Deficiency (X-MAID) is a rare severe combined immunodeficiency (SCID) subtype that can present at any age due to its variability. Depending on severity, patients demonstrate failure to thrive, recurrent bacterial and viral infections, and increased susceptibility to varicella zoster. It has been characterized by marked lymphopenia with hypogammaglobulinemia and impaired T-cell migration and proliferation. Case Presentation: This is a report of a Cuban 7-year-old male with poor weight gain and facial dysmorphia. He had a history of recurrent bacterial gastrointestinal infections and pneumonia beginning at 4 months of age. He additionally had 4-6 upper respiratory tract and ear infections annually. While still living in Cuba, he was admitted for a profound EBV infection in the setting of significant leukopenia. A bone marrow biopsy confirmed no malignancy. After he moved to the United States, his laboratory work-up revealed marked leukopenia with low absolute neutrophil and lymphocyte count with low T and B cells, very low immunoglobulin levels IgG, IgA, and IgM, and poor vaccination responses to streptococcus pneumonia, varicella zoster, and SARS-CoV-2. Genetic testing revealed a missense pathogenic variant c.511C>T (p.Arg171Trp) in the moesin (MSN) gene associated with X-MAID. He was managed with Bactrim and acyclovir prophylaxis, and immunoglobulin replacement therapy, and considered for hematopoietic stem cell transplantation. Discussion(s): Diagnosis of X-MAID should be considered in patients with recurrent infections and profound lymphopenia. As with SCID, early diagnosis and intervention is of utmost importance to prevent morbidity and mortality. This case demonstrates the importance of genetic testing in identifying this disease as it may prompt an immunologist to consider HSCT if conservative management is suboptimal. In the current literature, HSCT appears promising, but the long-term outcomes have yet to be described.Copyright © 2023 Elsevier Inc.

Characterization of Adaptive Immune Responses to SARS-CoV-2 Updated Bivalent Booster

Bivalent COVID-19 vaccines that contain two mRNAs encoding Wuhan-1 and Omicron BA.4/5 spike proteins are successful in preventing infection from the original strain and Omicron variants, but the quality of adaptive immune responses is still not well documented. This study aims at characterizing adaptive immune responses to the bivalent booster vaccination in 46 healthy participants. Plasma and PBMC were collected prior and three weeks after bivalent booster. We measured anti-N, anti-S, and RBD IgM, IgA, IgG plasma titers against original, Omicron BA.1, and BA.5 variants (pending) as well as total anti-S IgG titers and surrogate Virus Neutralization capacity against the Alpha, Delta, and BA.1 variant. With spectral flow-cytometry we identified peripheral blood B-cells specific for the RBD of the S-protein of the original and BA.1 variants. T-cell-specific responses were assessed by cytokine release assay after stimulation with SARS-CoV-2 peptides from the original, BA.1, BA.4, and BA.5 variants (pending). Finally, we performed TRB and IGH repertoire studies on sorted CD4+, CD8+, CD19+ lymphocytes, to study breadth of SARS-CoV-2 specific clonotypes (pending). 27/46 participants were analyzed;9 had SARS-CoV-2 infection (COVID+), while 18 are infection naive (COVID-). In both groups, median time since last dose of SARS-CoV-2 vaccine (3rd or 4th) was 11 months. All subjects were positive for anti-S IgG prior to bivalent booster. The COVID + group displayed anti-S IgG pre-booster levels and neutralization against BA.1 higher than the COVID- group. Significant increase post-boost of total anti-S IgG and BA.1 neutralizing activity was detected in the COVID- but not in the COVID+ group;however, no difference in neutralization activity post-boost was detected between the two groups. Furthermore, the COVIDgroup showed significant increase in the frequency of CD19+ and CD27+ switched memory B-cells specific for BA.1 RBD in post-boost compared to pre-boost samples. However, post-boost frequencies of the same B-cells were higher in the COVID+ compared to the COVID- group. These preliminary findings confirm that among individual immunized with the original COVID-19 mRNAvaccine, prior COVID infection provides increased protection against SARS-CoV-2 variants. They also demonstrate that booster immunization with the bivalent vaccine induces robust adaptive immune responses against Omicron variant.[Formula presented][Formula presented]Copyright © 2023 Elsevier Inc.

IRF2BP2 mutation with autoimmune enteropathy, immune deficiency, and respiratory failure

Case history: We present the case of a 31-year-old Hispanic male with history of recurrent bronchiectasis, invasive aspergillosis, and severe persistent asthma, who is now status post lung transplant for end-stage lung disease. He initially presented at 7 years of age with diarrhea, failure to thrive, and nearly absent immunoglobulin levels (IgG < 33 mg/dL, IgA < 7 mg/dL, IgM = 11 mg/dL, IgE = 4 IU/dL) necessitating IVIG treatment. Small intestinal biopsy showed villous atrophy consistent with autoimmune enteropathy. Sweat chloride was reported as indeterminate (44 me/dL). Initial WBC, platelet, and T- and NK-cell counts were within normal range, and B-cell count and percentage were borderline low. Most recently, he was found to have increased immature B-cell count (CD21low), decreased memory B-cells, and poor pneumococcal vaccine antibody response. Patient has been hospitalized numerous times with increasingly severe bronchiectasis, pneumonitis, and COVID-19 infections twice despite vaccination, leading to respiratory failure and lung transplantation. Family history is negative for immune deficiency and lung diseases. Discussion(s): Of these 3 VUSs (see the table), the one in IRF2BP2 has the most pathogenic potential due to its autosomal dominant inheritance, its location in a conserved domain (Ring), and previous case reports of pathogenic variants at the same or adjacent alleles 1-3. Baxter et al reported a de novo truncating mutation in IRF2BP2 at codon 536 (c.1606CinsTTT), which is similar to our patient's mutation. This patient was noted to have an IPEX-like presentation, with chronic diarrhea, hypogammaglobulinemia, and recurrent infections. Variant Functional Prediction Score for our variant predicts a potentially high damage effect. There are 2 other case reports of heterozygous mutations in loci adjacent to this allele;one (c.1652G>A)2 with a similar clinical phenotype to our patient and the other (C.625-665 del)3 with primarily inflammatory features and few infections. Impact: This case highlights a variant in IRF2BP2 associated with severe hypogammaglobulinemia, recurrent pulmonary infections, and autoimmune enteropathy. [Table presented]Copyright © 2023 Elsevier Inc.

Mastocytosis and COVID19 infection and vaccination: A pediatric series

Introduction: Mastocytosis encompasses a heterogeneous group of diseases characterized by an accumulation of clonal mast cells (MC) in the skin and/or internal organs, and symptoms of MC activation. This MC activation can be elucidated by several factors, including infections or vaccination. Objective(s): We present our experience with COVID infection and vaccination in a series of 133 patients with pediatric mastocytosis. Method(s): Between January 1998 and December 2022, 133 pediatric patients have been referred to our hospital owing to clinically suspected MC disorder, mainly with mastocytosis in the skin. The final diagnoses of mastocytosis were established by the presence of typical skin lesions together with an increase of MC numbers in a biopsy from lesional skin or activating KIT mutations in lesional skin tissue. Serum baseline tryptase and total immunoglobulin E levels were measured, and patients underwent a comprehensive allergy workup to confirm atopic status and history of anaphylaxis. Regarding vaccination, REMA's (Spanish Network on Mastocytosis) protocol was followed. Result(s): 13 patients with COVID infection were identified, of which 25 (56,8%) were female and 0% had symptoms of MC activation. All of them had an asymptomatic or mild course of COVID infection. None of the patients experimented MC activation symptoms during viral illness. Regarding COVID vaccination, all patients received premedication with antihistamine 60 minutes prior vaccination. No one experimented immediate reactions and only one patient (0,75%) referred worsening of MC activation symptoms (baseline pruritus, urtication and brain fog) only after the first doses, recovering without changes in his treatment (oral cromoglycate and antihistamine) in two months. Discussion(s): Although MC have been implicated in the pathogenesis of cytokine storm in COVID19, there is no clinical evidence of SARSCoV- 2-induced MC activation, perhaps related to the fact that bone marrow MC lack angiotensin-converting enzyme 2 receptors.

Surveillance of anti-SARS-CoV-2 antibodies in plasma pools and in immunoglobulin medicinal products manufactured since 2020 has shown high neutralizing activity against SARS-CoV-2 and current variants

Background: Patients with primary and secondary immunodeficiencies have shown an impaired humoral immune response to COVID-19 vaccination. It is therefore of paramount importance to investigate anti-SARS-CoV-2 antibody levels in plasma pools and in immunoglobulin (IgG) products used to treat these patients. AIM: To assess the evolution of anti-SARS-CoV-2 antibodies (S protein) in plasma pools and IgG products and its neutralizing activity to original-type virus (Wuhan) and the variants of concern (VOC), including Omicron. Method(s): Healthy donors plasma pools collected in the US and Europe, and the subsequent intravenous (Flebogamma DIFand Gamunex-C, Grifols) and subcutaneous (Xembify, Grifols) IgG manufactured batches were followed from March 2020. Anti-SARS-CoV-2 S protein IgG titers were determined in plasma pools and in IgG batches by ELISA. Neutralization assays analyzed the capacity of IgG products to neutralize original-type virus and VOC (Alpha, Beta, Delta, Omicron BA.1 and BA.5), using pseudo viruses expressing S protein. Results were expressed as the dilution producing 50% neutralization (ID50). Result(s): In plasma pools, anti-SARS-CoV-2 S antibodies continuously increased throughout the study period regardless of the geographic origin. In the US, the first positive plasma pools were collected at the end of 2020. Since July 2021, an exponential increase over 30-fold of anti-SARS-CoV-2 S antibodies was reported. This trend continued increasing until the end of study period. Similarly, IgG products showed a similar evolution of anti-SARS-CoV-2 S antibodies. As expected, IgG batches released at the end of 2020 presented low SARS-CoV-2 neutralization activity. However, IgG products manufactured since August 2021 showed high neutralization activity against original-type virus and the rest of VOC. Regarding Omicron BA.5, a 5 to 10-fold increase was observed over time. Conclusion(s): This study reported the onset of elevated anti-SARS-CoV-2 antibody titers in plasma pools and IgG products since mid-2021, reflecting the evolution of the pandemic and vaccine campaigns. Intravenous and subcutaneous IgG products efficiently neutralized the current circulating VOC, Omicron BA.5. Further research is warranted to assess whether a clinical protective titer against SARS-CoV-2 and passive immunization is achieved in patients with immunodeficiencies treated with IgG products.Copyright © 2023 Elsevier Inc.

Establishment of an infrastructure for rapid pandemic response at the Frederick National Laboratory

The sudden onset of the 2019 SARS-CoV-2 pandemic required agile development of standards and efficient validation of assays to assess prevalence of infection as well as immune responses to infection and vaccination. Leveraging their experience in HPV serology and standards, the Vaccine, Immunity and Cancer Directorate (VICD) at the Frederick National Laboratory for Cancer Research (FNCLR) pivoted to address this unmet need in SARS-Co-V2 serology clinical testing and research. This standardization effort required the collection and processing of large volumes of blood from SARS-Co-V2 infected and uninfected individuals into serum and peripheral blood mononuclear cells (PBMCs). Collaborations with specimen collection sites across the United States were established. Following qualification for anti-SARS-CoV-2 IgG and IgM levels in independent laboratories, VICD assembled reference evaluation panels, which were used to assist the FDA's performance evaluation of commercial assays submitted for EUA approval. To date, 185 different shipments of the standard or validation panel have been sent to both domestic and international labs. These materials are also available to the SARS-CoV-2 serology community for assay calibration and performance evaluation which greatly facilitates assay data harmonization. In addition, the NCI Serological Sciences Network (SeroNet) was born from this initiative and expertise, resulting in the establishment of Capacity Building Centers (CBCs) for sample collection from different healthy, cancer and immunocompromised cohorts at Mount Sinai, Arizona State University, the University of Minnesota, and Northwell Feinstein. The NCI and FNLCR simultaneously collaborated to develop a network of investigators focused on advancing research on the immune response to SARS-CoV-2 infection and vaccination among diverse and vulnerable populations, including cancer patients. Their research has resulted in over 326 peer-reviewed publications. The CBC's have enrolled patients in longitudinal studies, resulting in a centralized collection of annotated, well characterized serum, PBMCs and clinical data. Numerous cancer cohorts, but predominantly Multiple Myeloma, are included. Furthermore, technology development was supported at the CBC's. Based upon this success, the VICD in collaboration with NCI is pursuing an even more innovative effort in pandemic preparedness to establish a Center for Serology and Data Emergency Preparedness (CESDEP);a global network able to activate and pivot to address pandemic-level threats, while continuing to expand the development of immunological assays that can inform clinical decisions for cancer and other immunocompromised patients.

Determination of the Effects of Prenatal Remdesivir Exposure on Placenta Morphology, Placental IgG Transfer, and Fetal Growth in a Humanized Mouse Model

Remdesivir (RDV) is an antiviral medication used most recently for the treatment of COVID-19. Although no adverse effects were observed on perinatal parameters in reproductive and development toxicology studies at doses up to four-fold clinical area under the curve (AUC) exposures, some researchers have reported that therapeutic levels of RDV may impair early embryogenesis, as observed by in vitro studies. In addition, the influence of prenatal RDV exposure on maternal IgG transfer in the placenta is still unknown. Administration of RDV in pregnant humanized mouse model (Tg32), which expresses the human Fc gamma receptor and transporter (FCGRT) gene, was used to further evaluate potential effects on IgG transfer and concurrent perinatal endpoints. Animals were dosed daily from gestational days (GDs) 10- 14 with 25 mg/kg RDV (GS-5734) via intravenous injection (n=3-5 per group). Concurrent vehicle control animals were dosed intravenously with 12% sulfobutyl ether- beta-cyclodextrin in water (pH3.5;NaOH/HCl). All animals were administered 2 mg/kg human IgG via intravenous injection on GD 14. Placentae and fetuses were collected from dams on GD 14, 15, 16, and 18 and evaluated using histopathology and qPCR for inflammation markers. No abnormal morphologies (necrosis/apoptosis) of placentae were observed between the concurrent control and RDVdosed groups. Additionally, no differences in maternal body weights were observed. There were no statistically significant differences in placenta weights. There were no statistically significant changes in pregnancy parameters (implantation sites and dead fetuses/litter) and fetal weights between the RDV-dosed group and concurrent controls at GD 14, 15, 16, and 18. No changes were observed in transcript levels of inflammation markers in the RDV-dosed group when compared to the concurrent control group. There was a slightly lower ratio of fetal IgG level to maternal IgG levels in the RDV-dosed group;however, no statistically significant differences were observed between the RDV-dosed group and concurrent controls on GD 14, 15, 16, and 18. Our results suggest that a daily dose of 25 mg/kg RDV on GDs 10-14 in humanized mice did not cause adverse effects on placenta and fetal development. (Funded by the Perinatal Health Center of Excellence: E0300201.).

Anti-SARS-CoV-2 antibodies important in diagnostics of acute hepatitis in children

The most common causes of acute hepatitis in children are hepatitis A and autoimmune hepatitis. Hepatitis in the course of Wilson's disease is sporadically registered in adolescents. An increase of activity of aminotransferases both in the course of multisystem inflammatory syndrome in children (MIS-C) and in the course of COVID-19 has been observed. Hepatitis is common in children with MIS-C and is associated with a more severe presentation and persistent elevation of liver function tests. To date, no cases of acute hepatitis in children due to COVID-19 have been reported. We present 2 cases of acute hepatitis in children where the only cause seems to be a previous asymptomatic SARS-CoV-2 infection.Copyright © 2023 Termedia Publishing House Ltd.. All rights reserved.

Detection of SARS-CoV-2 Antibodies in Matched Pregnant Women and Newborn Blood

Objective: The factors affecting the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies from mother to newborn and the duration of seropositivity rates in these infants have not yet been clearly demonstrated. The objectives of this study were (1) to assess the levels of SARS-CoV-2 spike-specific immunoglobulin G (IgG) in women infected in the pregnancy period and newborns born to these women and (2) to search the transplacental transfer ratio of spike-specific IgG. Method(s): Seventy pregnant women with symptomatic SARS-CoV-2 infection and their newborns were prospectively followed. Anti-SARS-CoV-2 immunoassay was used for the detection of the in vitro quantitative determination of total antibodies to the SARS-CoV-2 spike protein. Discussion(s): Spike-specific IgG was demonstrated in 89.1% (44 of 46) of pregnant women infected more than 14 days before delivery and in 92.6% (43 of 44) of their newborns. Median transfer ratio of spike-specific Ig was 0.87 (interquartile range [IQR], 0.34-0.90), 1.0 (IQR, 0.9-0.29), and 0.81 (IQR, 0.02-1.0) in first trimester (n = 4), second trimester (n = 14), and third trimester (n = 28) pregnant women, respectively. Antibody transfer ratio was correlated with time elapsed from infection (p < 0.001). Peak antibody transfer ratio above 1 was observed at a median 60 to 120 days after the infection from delivery. Antibody transfer ratio was high in pregnant women infected more than 60 days before delivery (p < 0.001). Transfer ratio was significantly higher in the severe-critically symptomatic women (n = 15) than the mild-moderately symptomatic women (n = 55) (p = 0.001). At 3 months, 18 of 25 infants (72%) had spike-specific IgG. Conclusion(s): Timing from infection to delivery and severity of maternal infection are critical in assessing the antibody generation and transport. Higher antibody transfer ratio can be detected in neonates when SARS-CoV-2 infection is present for more than 60 days before birth. Maternally derived antibody can persist for 3 months after birth.Copyright © 2023. The Author(s).

Seroprevalence of SARS-CoV- 2 in children of school-going age in district Swabi, Pakistan

Introduction: Earlier estimates of SARS-CoV- 2 do not accurately account for the extent of undiagnosed infections in children, who typically experience mild or asymptomatic disease. The purpose of this study was to estimate the seroprevalence of SARS-CoV- 2 antibodies in children from District Swabi, one of the populous districts of Pakistan, and to identify symptoms most frequently associated with seropositivity. Methodology: We used ELISA to test for the presence of antibodies, IgM and IgG, in blood samples collected from 246 children of school-going age (5-16 years old) selected randomly from the district of Swabi, Pakistan. This study was approved by Khyber Medical University, Peshawar, Ethical Board, and Advanced Studies Review Board. Data were collected on a purposefully built questionnaire. Result(s): Overall, 2.0% of our participants were seropositive for IgM, whereas 23.1% were seropositive for IgG. Older age, female gender, and contact history were significantly associated with higher seropositivity. Symptoms associated with seropositivity were: fever (98.0%), cough (90.0%), sore throat (79.0%), coryza (68.0%), myalgia (61.0%), loss of sense of smell and taste (49.0%), and vomiting or diarrhoea (8.0%). Although 77.6% of our IgG seropositive participants recalled experiencing flu-like symptoms, none of the participants in this study had visited the doctor or were tested for SARS-COV- 2. We found IgG titres to be significantly higher in symptomatic children. Conclusion(s): The number of undiagnosed infections in children may be substantially larger than the official accounts. Sparse data are available regarding coronavirus disease in children, particularly in low middle-income countries (LMIC). The most frequently symptoms were fever, cough, sore throat, coreza, myalgia, loss of sense of smell and taste and lastly vomiting and diarrhoea. Serological studies provide valuable insight into the immunological status of a population, and can prove vital when considering future strategies.

The efficiency of COVID-19 vaccines among taiwanese patients with varied comorbidities

Background/Aims: The global pandemic of COVID-19 has caused tremendous loss of human life since 2019. Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is one of the best policies to control the pandemic. The vaccination efficacy in Taiwanese patients with different comorbidities is elusive and to be explored. Method(s): Uninfected subjects who received 3-doses of mRNA vaccines (Moderna, BioNTech), non-replicating viral vector-based vaccines (AstraZeneca, AZ) or protein subunit vaccines (Medigen COVID-19 vaccine, MVC) were prospectively enrolled. SARSCoV2- IgG spike antibody level was determined (Abbott [SARS-CoV- 2 IgG II]) within 3 months after the last dose of vaccination. Charlson Comorbidity Index (CCI) was applied to disclose the association of vaccine titer and underlying comorbidities. Result(s): A total of 824 subjects were enrolled in the current study. The mean age was 58.9 years and males accounted for 48.7% of the population. The proportion of CCI with 0-1, 2-3 and>4 was 52.8% (n = 435), 31.3% (n = 258) and 15.9% (n = 131), respectively. The most commonly used vaccination combination was AZ-AZ-Moderna (39.2%), followed by Moderna-Moderna-Moderna (27.8%) and AZAZ- BioNTech (14.7%), respectively. The mean vaccination titer was 3.11 log BAU/mL after a median 48 days of the 3rd dose. Subjects of male gender, lower body mass index, chronic kidney disease, higher CCI, and receiving AZ-AZ based vaccination were likely to have a lower titer of antibody. There was a decreasing trend of antibody titer with the increase of CCT (trend P<0.001). Linear regression analysis revealed that AZ-AZ-based vaccination (beta: 0.341, 95% confidence intervals [CI]: 0.144, 0.21, P<0.001) and higher CCI (beta: - 0.055, CI: - 0.096, - 0.014, P = 0.009) independently correlated with low IgG spike antibody levels. Conclusion(s): Patients with more comorbidities had a poor response to 3 doses of COVID-19 vaccination. Further studies are warranted to clarify the efficacy of booster vaccination in the population. The vaccine titer did not differ between patient with or without chronic liver disease.

Determination of antibodies to SARS-CoV-2 in patients with coronavirus infection

COVID-19, caused by the novel SARS-CoV-2 virus, poses major challenges for global public health. The detection of antibodies in blood serum is one of the important methods for diagnostics of COVID-19 patients. The main aim was to study the dynamics of the appearance of neutralizing antibodies and antibodies to the SARS-CoV-2 proteins in COVID-19 patients sera. Material and methods. The blood sera of four groups of people were studied: "intact" donors (blood sera were collected in 2016-2019);patients with a laboratory-confirmed diagnosis of acute respiratory viral infection;patients with influenza (antibodies to the influenza virus have been identified) and patients with a PCR confirmed diagnosis of COVID-19. Blood sera were analyzed in ELISA with commercial kits for detection of IgG to SARS-CoV-2 (N, S) proteins and total antibodies to RBD of protein S and in neutralization test (NT). Results and discussion. Antibodies to SARS-CoV-2 were not detected in paired blood sera of people from groups 1-3 by ELISA and NT. At the time of hospitalization of patients with COVID-19 in the sera of 12 (19%) patients antibodies to SARS-CoV-2 were absent when they were determined by NT and ELISA. In blood sera taken 4-9 days after hospitalization, neutralizing antibodies and antibodies to at least one viral protein were detected in ELISA. Conclusion. At the time of hospitalization, the overwhelming majority of patients had a humoral immune response to the SARS-CoV-2. In the dynamics of observation, the levels of antibodies to SARS-CoV-2 proteins increased, to a greater extent to RBD.Copyright © 2022 Geotar Media Publishing Group

Effect of Covid-19 on nasal allergies: A study from hilly regions of Himachal Pradesh

Background: The World Health Organization (WHO) designated SARS-CoV-2 infection as coronavirus disease 2019 (Covid-19).Due to the government implication of Covid-19 specific guideline of using mask, there could be a significant decrease in the allergic rhinitis. Objective(s): Present study aims to analyze the changes in the trends of nasal allergies from hilly regions of Himachal Pradesh following Covid-19 pandemic. Method(s): The prospective data obtained from January 2022 to November 2022 was compared from the retrospective data available between January 2019 to November 2019. Prospectively, a total of 596 patients were included in the study. All these patients underwent Skin prick tests for common allergens. All these patients also underwent testing for total IgE levels in biochemistry lab of the hospital by chemiluminescence method.The results were compared with retrospective dataof 728 age sex match patients. Result(s): A significant difference in the allergen sensitivity was observed. The number of patients who were sensitized during Covid was comparatively less than those during Pre covid period.Dust mite, Cockroach, Peanut and Wheat revealed a non-significant odds ratio indicating that they were not true predictors for sensitization and non-sensitization. Whereas Grass pollen, Mould mix and Pine mix revealed a significant odds ratio. Usage of mask found to have an impact on improvement in symptoms. Majority of the patients who did not use mask had no improvement in symptoms. Majority of the patients had high IgE levels in pre covid period whereas it was normal for majority of them during covid. Conclusion(s): In our study, allergic rhinitis incidence decreased throughout the pandemic period. After pandemic, there was a noticeably decreased level of sensitivity to grass pollen, mould, and pine mix. Use of face masks lead to significant decrease in symptoms of allergic rhinitis.Copyright © 2022, Anka Publishers. All rights reserved.

Rituximab and Covid-19 Vaccines, Are They Fit for Purpose?

Background/Aims Since the COVID-19 outbreak the rheumatology community have been concerned about the risk of SARS-CoV-2 infection in patients prescribed immunosuppressing medications. Data suggests that patients receiving Rrtuximab are at increased risk of developing severe outcomes from COVID-19 (1). In our unit all patients receiving rituximab were selected to receive a targeted vaccination and booster programme with all patients receiving at least 2 vaccinations and up to 3 booster vaccinations. We studied the efficacy of the COVID-19 vaccines in rituximab patients, by checking the the Roche Elecsys Anti-SARS-CoV-2-S (Spike) IgG/IgM total antibody levels post vaccination. Our aim was to assess the vaccination response in patients receiving rituximab and to offer advice on continued shielding or alternatively passive immunization with tixagevimab/cilgavimab in those patients who did not mount a response. Methods Taking 39 patients currently on rituximab therapy, we measured Anti- SARS-CoV-2-S (Spike) antibody levels post vaccination. We recorded whether the test was positive or negative, and the numerical result. We recorded rituximab dates of administration and dates of vaccines. We also recorded diagnosis, co-prescribed DMARDs, immunoglobulin levels, white cell and lymphocyte counts. We took record of whether or not the patient subsequently contracted COVID-19, required a hospital admission, ICU or died. Results Of our 39 patients, 21 had Anti-SARS-CoV-2-S (Spike) antibody levels checked. Of these patients, 7 (33%) had a negative spike protein result. Of the patients with a positive result, 8 (38%) had an antibody level between 0-250U/ML, and only 6 (28.6%) had a level >250U/ML (The manufacturer advises that a level above 0.8U/ML is a positive result). Of patients with a negative result, 1 patient had received 3 vaccines, 5 patients had received 4, and 1 patient had 5. All of the patients had received a vaccine >4 weeks prior to receiving the drug. Two patients were co-prescribed Belimumab, 3 were co-prescribed low-dose methotrexate and 2 were not on additional disease modifying agents. The diagnoses of these patients were, 2 patients with SLE, 4 with SPRA, and 1 MPO Vasculitis. There were no significant findings in lymphocyte count, white cell count or immunoglobulin levels. Conclusion These findings suggest that our current COVID-19 vaccination and booster programme may not provide adequate response in patients receiving rituximab therapy. Despite this being a small cohort, these results show that 33% of patients have not mounted a vaccine response and this is concerning. We suggest that vaccine response should be checked in all patients receiving rituximab therapy and those patients who do not mount a vaccine response should be offered passive immunity and advised of possible additional risks regarding COVID-19 exposure.

Neutralising antibodies (NAbs) against SARS-CoV-2 in BNT162b2 vaccine recipients with a history of advanced HIV infection: cPass as a simpler alternative to gold-standard tests

Background: Established SARS-CoV-2 NAb tests are labor-intensive. We prospectively measured NAbs vs Wuhan-1 and Omicron BA.2 using the novel GenScript cPass assay and examined correlations with responses measured by gold-standard plaque reduction neutralisation test (PRNT) (Cotugno, Ruggiero et al. Cell Rep 2021) and with anti-Spike IgG quantified by Roche Elecsys. Given the paucity of data, we selected BNT162b2 vaccine recipients with a history of advanced HIV infection (prior AIDS-defining conditions and/or nadir CD4 <200 cells). Method(s): In Mar 2021-Apr 2022, 55 PWH received 2 vaccine doses median 3 weeks apart [IQR 3-3] and a 3rd dose 27 weeks later [23-31]. Plasma samples (n=147) were stored immediately before dose-1 (T0), median 4 weeks [3-5] after dose-2 (T1) and median 13 weeks [9-19] after dose-3 (T2) for batch testing. Result(s): Participants' characteristics: 74% male, 85% white, all on ART, 82% HIV-RNA <50 cps/ml;median age 55 years, ART duration 7 years, nadir CD4 83 cells [36-211], current CD4 440 cells [270-710], CD4:CD8 ratio 0.6 [0.4-1.0];73% had a history of advanced HIV infection;15% received a COVID-19 diagnosis during the study. At T0, T1 and T2, proportions with quantifiable anti-S IgG (>0.8 U/ml) were 11/49 (22%), 50/54 (93%) and 43/43 (100%), respectively;their median anti-S IgG titres were 30 [15-124], 15949 [596-3389] and 8527 [3146-17190] U/ml. Proportions showing Wuhan-1 neutralisation by cPass were 6/50 (12%), 45/53 (85%) and 40/43 (93%), with median neutralisations of 67% [47-70], 97% [91-98] and 98% [98-98] and corresponding NAb titres of 1332 [792-1436], 5354 [3529-6187] and 6242 [5765-6766] U/ml. At T2, 25/28 (89%) showed BA.2 neutralisation by cPass (median 83% [68-93];NAb titre 7836 [3172-12173] U/ml) (Fig 1A). Two participants lacking NAbs at T2 had a history of advanced HIV infection. cPass data were highly correlated with anti-S IgG titres (rho 0.82;p<0.0001) and with PRNT data for both Wuhan-1 (n=27, Fig 1B) and Omicron BA.2 (n=28, Fig 1C). Conclusion(s): cPAss offers a simple methodology for measuring SARS-CoV-2 NAbs. Despite prior advanced HIV infection, neutralising activity improved with successive vaccinations and most participants showed NAbs against both Wuhan-1 and Omicron BA.2 after 3 vaccine doses. (Figure Presented).

Hospital Protection Correlates in Outpatient Covid-19 Convalescent Plasma Recipients

Background: High titer COVID-19 convalescent plasma (CCP) reduces hospitalizations among immunocompetent outpatients. This study evaluated recipient post-transfusion S receptor binding domain (S-RBD) IgG antibody levels and the association of progressing to hospitalization among unvaccinated outpatients with COVID-19 treated with CCP or control plasma. Method(s): This analysis focused on participants from a multicenter doubleblind, randomized, controlled trial comparing treatment of outpatients with COVID-19 convalescent plasma (CCP) or control plasma without SARS-CoV-2 antibodies. Participants with confirmed SARS-CoV-2 infection were transfused within 9-days of symptom onset between June 2020 and October 2021 (n=110 vaccinated control;n=105 vaccinated CCP;n=464 unvaccinated control;n=472 unvaccinated CCP;total n=574 control and n=577 CCP recipients). All subjects had specimens collected the day prior to transfusion (D-1), within 30 minutes after transfusion (D0), 14 (D14), 28 (D28), and 90 (D90) days post-transfusion. Ancestral SARS-CoV-2 S-RBD was measured by an in-house validated ELISA. All 54 COVID-19-related hospitalizations occurred within 2 weeks of transfusion. Result(s): Post-transfusion anti-S-RBD IgG levels on D0 were significantly greater for CCP (median=4 titer,log3) compared to control (median=2 titer,log3;p< 0.001) recipients. Neither sex nor age impacted antibody levels following CCP treatment at D14, D28, and D90. Vaccinated recipients had greater titers than unvaccinated recipients prior to transfusion with little change in titers post-transfusion. Unvaccinated recipients had low antibody titers on D-1 with CCP recipients exhibiting a significant increase in titer from D-1 to D0 compared to controls (mean fold change=1.89;p< 0.001). Among unvaccinated recipients, those who received CCP transfusion late ( >5 days after symptom onset) and had low D0 antibody levels (< 4.24 titer, log3) had the greatest proportion of hospitalizations (5.5%). In contrast, those who received CCP transfusion early (< 5 days after symptom onset) with high D0 antibody levels ( >4.24 titer, log3) had no hospitalizations. Unvaccinated CCP recipient anti-S-RBD IgG antibody levels on D0 correlated with donor anti-S-RBD IgG antibody levels (r=0.30, p< 0.001). Conclusion(s): Among unvaccinated outpatients with COVID-19, CCP recipient antibody dilutional titers after transfusion over 540 titer correlated with protection against hospitalization when transfusion occurred within 5 days of symptom onset. (Figure Presented).

Secondary infections in critically ill patients with COVID-19: effects of intravenous IgM-enriched immunoglobulin therapy

Introduction: Critically ill patients with severe COVID-19 have an increased risk of bacterial and fungal superinfections due to a dysregulated immune response characterized by lymphopenia and low immunoglobulins levels. The intravenous immunoglobulins are involved in pathogen/toxin scavenging and inhibition of inflammatory mediators gene transcription with anti-apoptotic effects on immune system cells. This research aimed to describe the effects of intravenous IgM-enriched immunoglobulins in COVID-19 patients with sepsis due to secondary infections and low IgM levels. Method(s): We performed an observational retrospective study, including patients admitted to our intensive care unit (ICU) between March 2020 and February 2021 with severe COVID-19 and sepsis due to a superinfection (known or suspected) treated with intravenous IgM-enriched immunoglobulins. We collected demographic data and comorbidities. We noted hemodinamic data, antimicrobial and adiuvant therapies, laboratory results at ICU admission (T0), at the beginning (T1) and at the end (T2) of the IgM-enriched immunoglobulins infusion and at ICU discharge (T3). Result(s): In our cohort of 36 patients (Table 1) the prevalence of documented secondary infections was 83%. We observed a significant reduction of leukocytes from T0 to T3 (10.4 [8.3-14.5] x 103/ mmc vs 7.1 [4.8-11.2] x 103/ mmc, p < 0.01) and the SOFA score from T0 to T2 (7 [6-19] vs 5 [3-7], p < 0.01) and from T0 to T3 (7 [6-10] vs 4 [2-9], p < 0.01);from T1 to T2 (7 [6-9] vs 5 [3-7], p < 0.01) and from T1 to T3 (7 [6-9] vs 4 [2-9], p < 0.01). Cardiovascular SOFA showed a statistically significant reduction from T1 to T2 (4 [3-4] vs 0 [0-3], p < 0.01). Conclusion(s): The IgM-enriched immunoglobulins could improve organ function, as evidenced by the reduction of the SOFA score. Although the latest Surviving Sepsis Campaign guidelines suggest against using of IgM-enriched immunoglobulins, our study supports its use as an adjunctive therapy in COVID-19 patients with septic shock.

Ace2 Substrate Cleavage Effect Associated with Covid-19 Patient Plasma Immunoglobulin

Background: Many mechanisms responsible for COVID-19 pathogenesis are well-known, but COVID-19 includes features with unclear pathogenesis, like autonomic dysregulation, coagulopathies, and high levels of inflammation. The SARS-CoV-2 spike protein receptor binding domain (RBD) receptor is angiotensin converting enzyme 2 (ACE2). We hypothesized that some COVID-19 patients may develop immunoglobulins (Igs) that have negative molecular image of RBD sufficiently similar to ACE2 to yield ACE2-like catalytic activity - ACE2-like 'abzymes'. Method(s): To explore this hypothesis, we studied 67 patients hospitalized with COVID-19 who had disodium ethylenediaminetetraacetate (EDTA) anticoagulated plasma samples available, obtained about 7 days after admission. We used commercially available fluorometric ACE2 assays (Abcam), and a SpectraMax M5 microplate reader (Molecular Devices), measuring Relative Fluorescent Unit (RFU, Ex/Em = 320/420 nm;RFU) in a kinetic mode every 20 min at 37C. ACE2 inhibitor provided in the assay kit was used for additional controls. In some control experiments, we added Zn2+ to plasma, or conducted serial dilutions to decrease Zn2+. To deplete Igs, we passed plasma samples through a 0.45 mum filter to remove large particles, then passed the material through 100kDa cut-off ultrafiltration membrane (PierceTM) columns, and finally used protein A/G Magnetic Beads (Life Technologies) to specifically deplete Ig, removing >99.99% of Ig as assessed with a human IgG ELISA Kit (Abcam). Result(s): ACE2 is a metalloprotease that requires Zn2+ for activity. However, we found that the plasma of 11 of the 67 patients could cleave a synthetic ACE2 peptide substrate, even though the plasma samples were collected using EDTA anticoagulant. When we spiked plasma with synthetic ACE2, no ACE2 substrate cleavage activity was observed unless Zn2+ was added, or the plasma was diluted to decrease EDTA concentration. After processing samples by size exclusion and protein A/G adsorption, the plasma samples did not cleave the ACE2 substrate peptide. Conclusion(s): The data suggest that some patients with COVID-19 develop Igs with activity capable of cleaving synthetic ACE2 substrate. Since abzymes can exhibit promiscuous substrate specificities compared to the enzyme whose active site image they resemble, and since proteolytic cascades regulate physiologic processes, anti-RBD abzymes may contribute to some otherwise obscure features of COVID-19 pathogenesis. (Figure Presented).

Impact of Gut Microbiota on Immunogenicity to Covid-19 Vaccines in Plwh

Background: Immune responses to SARS-CoV-2 vaccines in people living with HIV (PLWH) have been the focus of several recent studies. As the gut microbiome can influence vaccine immunogenicity, in this study we are the first to investigate whether the baseline gut microbiota can predict immune responses to the BNT162b2 SARS-CoV-2 vaccine in people living with HIV (PLWH) and healthy controls (HC). Method(s): Fecal samples were collected from PLWH (n=68) and HC (n=75) at baseline, prior to the first vaccine dose, to extract DNA for 16S rRNA sequencing. The individuals were part of the COVAXID Clinical trial, where humoral and cellular responses to SARS-CoV-2 vaccine were evaluated on day 35 after the first dose. Comprehensive bioinformatic tools were used for bacterial identification to further reveal the associations between gut microbiota and SARS-CoV-2 antibody, spike CD4+ T cell responses, and clinical parameters such as age, gender, CD4/CD8 ratio, and length of antiretroviral (ART) treatment. Result(s): At day 35 post vaccination, HC showed significantly higher spike IgG titers than PLWH (p=0.0001). Interestingly, both phylogenetic and alpha-diversity were negatively correlated with antibody titers, in the whole cohort and within groups. Similarly, individuals with low alpha-diversity had higher levels of spike specific CD4+T-cell responses. Agathobacter, Lactobacillus, Bacteroides, and Lachnospira were positively correlated with both antibody levels and spike-specific CD4+ T-cell responses while Methanobrevibacter, Marvinbryantia, Cloacibacillus, and Succinivibrio have a negative one. Within the PLWH group, the gut microbiota taxa associated with CD4+ counts, such as Lachnospira (p=0.002), Oscillibacter (p=0.019) and Flavonifractor (p=0.017), were found to be positively correlated with spike IgG levels. Additionally, the length of ART treatment and CD4/CD8 ratio displayed a positive association with bacterial diversity. Notably, different microbiome profiles and immune status in PLWH, affect their immune responses to vaccination. Conclusion(s): Our results show potential associations between gut microbiota diversity and spike IgG responses after COVID-19 vaccination. These findings were consistent in the whole cohort, albeit group differences between the microbiome compositions in PLWH and HC were observed. Based on our findings, we propose that microbiome modulation could optimize immunogenicity to SARS-Cov-2 vaccines.

Antibody Subclass Responses to SARS-CoV-2 in severe and nonsevere COVID-19 Patients

Background: SARS-CoV-2 is a highly contagious respiratory virus responsible for COVID-19 pandemic. To understand the role of antibodies in neutralization, our study quantified circulating levels of IgA/IgG and IgG subtypes induced at different days post onset of symptoms, in severe and non severe patients. Objective(s): To quantify circulating levels of IgA, IgG and IgG subclass in severe and non severe patients induced at different days post onset of symptoms. Material(s) and Method(s): Serum or plasma samples collected from 79 COVID-19 patients were used. Indirect SARS-CoV-2 specific IgA, IgG, and IgG subclass specific ELISAs were performed. Antibody titers between severe and non severe patients were compared at different times post onset of clinical symptoms. Titers in ELISA were correlated to neutralizing antibody titers. Results and Conclusion(s): Over 75% patients were positive for IgA and IgG antibodies in the first week. The ELISA titers did not differ during the first week of infection. However, patients with severe disease exhibited raised titers. Neutralizing antibody titers correlated with the ELISA titers in mild presentation but not in severe disease. IgA and IgG1 antibodies correlated stronger with neutralizing antibodies. The findings highlighted that IgA together with IgG play an important in SARS-CoV-2 neutralization.