Association of SARS-COV-2 viral RNAemia, IL- 6 gene polymorphism, serum IL-6 and peripheral blood lymphocytes and monocytes with disease severity in COVID-19 patients

Coronavirus disease 2019 (COVID-19) is a fatal pandemic viral disease caused by the severe acute respiratory syndrome corona virus type-2 (SARS-CoV-2). The aim of this study is to observe the associations of IL-6, SARS-COV-2 viral load (RNAemia), IL- 6 gene polymorphism and lymphocytes and monocytes in peripheral blood with disease severity in COVID-19 patients. This study was carried out from March 2021 to January 2022. RT-PCR positive 84 COVID-19 patients and 28 healthy subjects were enrolled. Blood was collected to detect SARS-COV-2 viral RNA (RNAemia) by rRT-PCR, serum IL-6 level by chemiluminescence method, SNPs of IL-6 by SSP-PCR, immunophenotyping of lymphocytes and monocyte by flow cytometry. Serum IL-6 level (pg/ml) was considerably high among critical patients (102.02 +/- 149.7) compared to severe (67.20 +/- 129.5) and moderate patients (47.04 +/- 106.5) and healthy controls (3.5 +/- 1.8). Serum SARS-CoV-2 nucleic acid positive cases detected mostly in critical patients (39.28%) and was correlated with extremely high IL-6 level and high mortality (R =.912, P < 0.001). Correlation between IL-6 and monocyte was statistically significant with disease severity (severe group, p < 0.001, and 0.867*** and critical group p < 0.001 and 0.887***). In healthy controls, moderate, severe and critically ill COVID-19 patients, IL-6 174G/C (rs 1800795) GG genotype was 82.14%, 89.20%, 67.85% and 53.57% respectively. CC and GC genotype had strong association with severity of COVID-19 when compared with GG genotype. Significant statistical difference found in genotypes between critical and moderate groups (p < 0.001, OR-10.316, CI-3.22-23.86), where CC genotype was associated with COVID-19 severity and mortality. The absolute count of T cell, B cell, NK cell, CD4+ T cells and CD8+ T cells were significantly decreased in critical group compared to healthy, moderate and severe group (P < 0.001). Exhaustion marker CD94/NKG2A was increased on NK cells and CD8+ cytotoxic T cell among critical and severe group. Absolute count of monocyte was significantly increased in critical group (P < 0.001). Serum IL-6, IL-6 174 G/C gene and SARS-CoV-2 RNAaemia can be used in clinical practice for risk assessment;T cell subsets and monocyte as biomarkers for monitoring COVID-19 severity. Monoclonal antibody targeting IL-6 receptor and NKG2A for therapeutics may prevent disease progression and decrease morbidity and mortality.Copyright © 2023 Elsevier Inc.

COVID-19-Related Encephalitis in a Child with PIK3CD Defect

Introduction: COVID-19 related encephalitis has been reported in pediatric patients;however, there are no reports in patients with inborn errors of immunity (IEI). Activated PI3K Delta Syndrome (APDS) is a disease of immune dysregulation with immunodeficiency, autoimmunity, and abnormal lymphoproliferation resulting from autosomal dominant gain-offunction variants in PIK3CD or PIK3R1 genes. We investigate a family with APDS, one mother and three children, one of whom developed COVID-19 related encephalitis. Method(s): Patients were consented to an IRB-approved protocol at our institution. Medical records and detailed immunophenotyping were reviewed. Family members were sequenced for IEI with a targeted gene panel. Result(s): The index case is a 10-year-old female with a known pathogenic variant in PIK3CD (c.3061 G > A, p.Glu1021Lys), who contracted SARS-COV-2 despite one COVID-19 vaccination in the series. Her disease course included COVID-related encephalitis with cerebellitis and compression of the pons, resulting in lasting truncal ataxia and cerebellar mutism. At that time, the patient was not on immunoglobulin replacement therapy (IgRT), but was receiving Sirolimus. Besides the index case, 3 family members (2 brothers, 1 mother) also share the same PIK3CD variant with variable clinical and immunological phenotypes. All children exhibited high transitional B-cells, consistent with developmental block to follicular B cell stage. Increased non-class switched IgM+ memory B cells and skewing towards CD21lo B cell subset, which is considered autoreactive-like, was observed in all patients. Of note, the patient had low plasmablasts, but normal immunoglobulins. Of her family members, only one was receiving both sirolimus and IgRT. Conclusion(s): We describe a rare case of COVID-19-related encephalitis in a patient with inborn error of immunity while not on IgRT. This may indicate infection susceptibility because of a lack of sufficient immunity to SARS-CoV-2, unlike the rest of her family with the same PIK3CD variant.Copyright © 2023 Elsevier Inc.

Impact of SARS-CoV-2 infection in pregnancy on fetal immune state

SARS-CoV-2 infection during pregnancy is associated with increased risk of adverse maternal and pregnancy outcomes. Maternal COVID- 19 is associated with immune activation and inflammatory response in the pregnant individual and an altered immune repertoire in the placenta. Mother-to-child transmission of infection is reported but uncommon. Still, the potential impact of maternal SARS-CoV-2 infection on the immunologic and inflammatory state of the infant is of interest, both for the acute health of the newborn and longer-term outcomes. In this talk, we will discuss the mixed data from cord blood and infant studies of cytokine profiles, transcriptomics, immunophenotyping, and functional studies. We will address the timing and severity of maternal infection as we explore the potential immunological consequences of in utero exposure to maternal SARS-CoV-2 infection.

Primary immunodeficiency associated with a SAMD9L mutation

Background: SAMD9L is a tumor suppressor involved in regulating the proliferation and maturation of cells, particularly those derived from the bone marrow, and appears to play an important role in cerebellar function. It can be activated in hematopoietic stem cells by type I and type II interferons. It has been hypothesized to act as a critical antiviral gatekeeper regulating interferon dependent demand driven hematopoiesis. Gain of function mutations can present with an immunodeficiency due to transient severe cytopenias during viral infection. Case presentation: We report a 3-year-old boy born full term with a history of severe thrombocytopenia requiring transfusions, developmental delay, ataxia, seizure disorder, and recurrent severe respiratory viral infections. His infectious history was significant for respiratory syncytial virus with shock requiring extracorporeal membrane oxygenation complicated by cerebral infarction and a group A streptococcus empyema, osteomyelitis requiring a left below the knee amputation, and infections with rhinovirus, COVID-19, and parainfluenza requiring hospitalizations for respiratory support. Initial immunologic evaluation was done during his hospitalization for parainfluenza. His full T cell subsets was significant for lymphopenia across all cell lines with CD3 934/microL, CD4 653/microL, CD8 227/microL, CD19 76/microL, and CD1656 61/microL. His mitogen stimulation assay to phytohemagglutinin and pokeweed was normal. Immunoglobulin panel showed a mildly decreased IgM of 25 mg/dL, but normal IgA and IgG. Vaccine titers demonstrated protective titers to 12/22 pneumococcus serotypes, varicella, diphtheria, mumps, rubella, and rubeola. Repeat full T cell subsets 6 weeks later revealed marked improvement in lymphocyte counts with CD3 3083/microL, CD4 2101/microL, CD8 839/microL, CD19 225/microL, and CD1656/microL. A primary immunodeficiency genetic panel was ordered and positive for a heterozygous SAMD9L c.1549T>C (p.Trp517Arg) mutation classified as a variant of unknown significance. Discussion(s): This patient's history of severe viral infections, ataxia, thrombocytopenia, and severe transient lymphopenia during infection is suggestive of a SAM9DL gain of function mutation. Protein modeling done by the laboratory suggests this missense mutation would affect protein structure. The mutation found has been observed in individuals with thrombocytopenia. This case highlights the importance of immunophenotyping both during acute illness and once recovered.Copyright © 2023 Elsevier Inc.

Immunotherapy: OFF-THE-SHELF PARTIAL HLA MATCHING SARS-COV-2 ANTIGEN SPECIFIC T CELL THERAPY FOR SEVERE COVID-19 PATIENTS

Background & Aim: Immunological characteristics of COVID-19 show pathological hyperinflammation associated with lymphopenia and dysfunctional T cell responses. These features provide a rationale for restoring functional T cell immunity in COVID-19 patients by adoptive transfer of SARS-CoV-2 specific T cells. Methods, Results & Conclusion(s): To generate SARS-CoV-2 specific T cells, we isolated peripheral blood mononuclear cells from 7 COVID-19 recovered and 13 unexposed donors. Consequently, we stimulated cells with SARS-CoV-2 peptide mixtures covering spike, membrane and nucleocapsid proteins. Then, we culture expanded cells with IL-2 for 21 days. We assessed immunophenotypes, cytokine profiles, antigen specificity of the final cell products. Our results show that SARSCoV- 2 specific T cells could be expanded in both COVID-19 recovered and unexposed groups. Immunophenotypes were similar in both groups showing CD4+ T cell dominance, but CD8+ and CD3+CD56+ T cells were also present. Antigen specificity was determined by ELISPOT, intracellular cytokine assay, and cytotoxicity assays. One out of 14 individuals who were previously unexposed to SARS-CoV-2 failed to show antigen specificity. Moreover, ex-vivo expanded SARS-CoV-2 specific T cells mainly consisted of central and effector memory subsets with reduced alloreactivity against HLA-unmatched cells suggesting the possibility for the development of third-party partial HLA-matching products. In conclusion, our findings show that SARSCoV- 2 specific T cell can be readily expanded from both COVID-19 and unexposed individuals and can therefore be manufactured as a biopharmaceutical product to treat severe COVID-19 patients.Copyright © 2023 International Society for Cell & Gene Therapy

Improving laboratory haematology training: Developing an educational resource for haematology trainees in the west midlands

Introduction: Laboratory training is an integral part of haematology specialty training. Trainees at ST3 usually have limited experience of laboratory functions and find approaching this daunting. Sound grounding in laboratory processes and techniques and rapport with the biomedical scientists is important in the first year. In the West Midlands, specialty trainees have dedicated ST3 laboratory induction time. Local discussions suggest variation in experiences and that training has been negatively impacted by the COVID-19 pandemic. Method(s): To assess baseline laboratory induction, an electronic survey was sent to registrars who commenced ST3 haematology training in the West Midlands during the pandemic (February 2020 to February 2022). Questions assessed time spent in the laboratory, activities undertaken and self-reported confidence understanding tests and techniques before and after their placement. A range of strategies to improve and standardise laboratory training were proposed. The Laboratory Induction Workbook was designed and written by senior registrars in the West Midlands Deanery to complement existing training as part of a quality improvement project. Result(s): 7/8 (88%) trainees completed the survey. All trainees reported minimal prior experience of a haematology laboratory;during laboratory induction 3/7 (43%) were not provided with a local checklist or framework. Trainees spent most time on blood film morphology, with an increase in confidence reported by 7/7 (100%) trainees. Conversely, only 4/7 (57%) trainees visited blood bank, 2/7 (29%) learned about immunophenotyping, and 0/7 (0%) trainees explored genetic testing during this training period. A Laboratory Induction Workbook in three sections was developed: (1) An introduction to blood film and bone marrow morphology, (2) 22 cases covering the breadth of the curriculum and highlighting important topics and (3) signposting to key resources/contacts. The workbook focussed on linking clinical aspects with laboratory tests, encouraging self-directed study and empowering registrars to seek out learning opportunities in their local laboratory and within the region. The workbook was distributed to all new starting haematology trainees in the West Midlands in August 2022. Conclusion(s): Initial feedback has been positive, formal feedback is awaited. Future work includes the addition of extra cases to the workbook, transferring it into an interactive electronic format with use of QR coding, and regular review to ensure content is up to date. We also plan to extend the scope of the workbook for more senior trainees as an exam revision resource.

Pandemic stress induces systemic immune changes and placental inflammation independently of SARS-CoV-2 infection in pregnancies

Problem: Environmental stress during pregnancy has known impacts on both maternal and fetal health. In terms of theCOVID-19 pandemic, the majority of published work has focused on the impact of the infection itself, without considering the potential immune impact of pandemic related-stress.We, therefore, assessed the impact of pandemic stress, independently of SARS-CoV-2 infection, on the circulating and placental immune profiles of pregnant individuals. Method(s): Placentas from 239 patients were collected at the Sainte- Justine Hospital, Montreal, Canada. Of these, 199 patients delivered during the pandemic and were exposed to pandemic stress with (+: 79) or without (-: 120) SARS-CoV-2 infection, the latter exposed to pandemic stress only. Pre-pandemic historic controls (uncomplicated pregnancies, Ctrl: 40), were also included. Placental biopsies were collected to assess cytokine levels by ELISAs and histopathological lesions. A sub-study with 35 pre-pandemic pregnancies (unexposed) and 20 who delivered during the pandemic (exposed) was also conducted. The latter (exposed/unexposed) were all uncomplicated pregnancies. We collected maternal blood prior to delivery for immunophenotyping, and plasma/peripheral blood mononuclear cells (PBMCs) were isolated. Inflammatory mediators in the plasma were quantified by ELISAs. Co-culture assays with PBMCs and human umbilical vein endothelial cells (HUVECs) were performed to assess endothelial activation. Demographical/obstetrical data were obtained through chart review. Result(s): SARS-CoV-2+ patients were multiethnic (63.4%), had higher pre-pregnancyBMI (28.9 vs. 24.8 inCtrl, P<.05), and elevated preterm birth rate (16.5% vs. 5.8% in SARS-CoV-2-, P < .05 and 0.0% in Ctrl, P < .01). In the placentas, we observed an increase in the levels of IL- 1Ra (P < .05) and CRP (P < .05) in both SARS-CoV-2 groups, while IL-6 (P = .0790) and MCP-1 (P < .001) were elevated solely in SARS-CoV- 2-. These changes were predominant in placentas with inflammatory lesions on histopathological analysis. Moreover, we observed elevated CD45+ cells (P < .001) in the placentas from both SARS-CoV-2 groups versus Ctrl. Considering that the differences we observed were important in the SARS-CoV-2- group, we performed a study solely on uncomplicated pregnancies, either exposed or unexposed to pandemic stress. At the systemic level, we observed a decrease in the percentage of Th2 cells (P < .001), leading to a pro-inflammatory Th1/Th2 imbalance in exposed individuals. Decreased Treg (P < .05) and Th17 (P < .05) versus unexposed was also observed. Surprisingly, decreased levels of circulating IL-6 (P < .05), MCP-1 (P < .01), and CRP (P<.05) were seen in exposed versus unexposed individuals. Finally,we observed increased secretion of ICAM, a marker of endothelial activation, solely in endothelial cells co-cultured with PBMCs from exposed individuals. Conclusion(s): Overall, placental inflammatory profiles differed between pregnant individuals exposed to pandemic stress with or without SARS-CoV-2 infection. Moreover, we observed that the pandemic stress exposed group presented a systemic pro-inflammatory bias. This highlights the need to understand the differences between the effects of pandemic-related stress and the added burden of SARS-CoV-2 infection itself on maternal and fetal health. Our work also supports an association between an increased risk of hypertension/ preeclampsia and SARS-CoV-2 infection that might be driven in part by pandemic-related stress.

COVID-associated pernio: Mechanistic insights to an abortive, seronegative SARS-CoV-2 infection

Introduction: SARS-CoV-2 replicates primarily in the airways but generates a systemic immune response mediated by Type I interferons (IFN-I). Pernio is a rare skin manifestation of disorders characterized by excessive IFN-I signalling. Although pernio increased in incidence during the pandemic, the relationship to SARS-CoV-2 remains controversial. Because of the pivotal nature of interferons in COVID-19 outcomes, pernio offers a window to investigate the biology underlying host resiliency to SARS-CoV-2 infection. Method(s): To further assess COVID-associated pernio, we characterized clinical samples from affected patients across 4 waves of the pandemic and investigated mechanistic feasibility in a rodent model. Patients were followed longitudinally with banking of blood and tissue. Golden hamsters were mock-treated or intra-nasally infected with SARS-CoV-2 and harvested at 3-and 30-days post-infection. Result(s): In affected tissue, immunophenotyping utilizing multiplex immunohistochemistry profiled a robust IFN-1 signature characterized by plasmacytoid dendritic cell activation. Viral RNA was detectable in a subset of cases using in situ hybridization for the SARS-CoV-2 S gene transcript. Profiling of the systemic immune response did not reveal a durable type 1 interferon signature. Consistent with previous literature, antibody and T-cell specific responses to SARS-CoV-2 were not detected. Nasopharyngeal SARS-CoV-2 inoculation in hamsters resulted in rapid dissemination of viral RNA and the generation of an IFN-I response that were both detectable in the paws of infected animals. Conclusion(s): Our data support a durable local IFN signature, with direct evidence of viral SARS-CoV-2 RNA in acral skin and suggest that COVID-associated pernio results from an abortive, seronegative SARS-CoV-2 infection.

Multi-omic longitudinal study reveals immune correlates of clinical course among hospitalized COVID-19 patients.

The IMPACC cohort, composed of >1,000 hospitalized COVID-19 participants, contains five illness trajectory groups (TGs) during acute infection (first 28 days), ranging from milder (TG1-3) to more severe disease course (TG4) and death (TG5). Here, we report deep immunophenotyping, profiling of >15,000 longitudinal blood and nasal samples from 540 participants of the IMPACC cohort, using 14 distinct assays. These unbiased analyses identify cellular and molecular signatures present within 72 h of hospital admission that distinguish moderate from severe and fatal COVID-19 disease. Importantly, cellular and molecular states also distinguish participants with more severe disease that recover or stabilize within 28 days from those that progress to fatal outcomes (TG4 vs. TG5). Furthermore, our longitudinal design reveals that these biologic states display distinct temporal patterns associated with clinical outcomes. Characterizing host immune responses in relation to heterogeneity in disease course may inform clinical prognosis and opportunities for intervention.

Adaptive Immunity Dysregulation Is Associated to the Development of Long Covid

Background: The pathogenetic mechanisms behind the development of long- COVID (LC) are largely unknown. Because both plasma SARS-CoV-2 RNAemia and dysregulated immunity have been correlated with COVID-19 severity, we evaluated whether they are associated with LC. Method(s): We consecutively enrolled unvaccinated hospitalized COVID-19 patients during acute-COVID-19 (T0) in March-October 2020 who either developed LC at a follow-up visit 2-3 months from virologic clearance (T1) or did not. LC was defined as persistence >=2 months after recovery of >=1 symptom: anosmia, dysgeusia, fever, gastrointestinal symptoms, dyspnoea, fatigue, musculoskeletal pain, muscle weakness, brain fog. We measured: SARS-CoV-2 RNAemia (RT-qPCR, log10(copies/mL)), magnitude (ELISA, AUC) and functionality (pseudovirus neutralization, ID50;Fc-mediated functions, %ADCC) of SARS-CoV-2-specific antibodies, SARS-CoV-2-specific B and CD4-T-cells (Immunophenotype, AIM and ICS assays). Result(s): We enrolled 48 COVID-19 individuals, 38/48 (79.2%) developed LC (LC+) and 10 did not (LC-). LC+ and LC- had similar co-morbidities and symptoms in the acute phase (Fig.1A), and the majority showed a radiologically documented SARS-CoV-2 pneumonia. The SARS-CoV-2 RNAemia did not differ between groups at both time points. The levels of RBD-specific Abs, as well as their functionality, appeared to increase over time in the LC- group but not in the LC+ (Fig.1B-D). Similarly, a trend towards increased RBD-specific B-cells was observed over time in the LC- group but not in LC+ (Fig.1E). B-cell immunophenotyping showed a significant increase over time of classical memory B cells (MBCs) at the expenses of activated MBCs (Fig.1F-G) as well as an IgA class-switching in the LC- group compared to LC+ (Fig.1H-I). Furthermore, LC+ showed a faster decline of SARS-CoV-2-specific (CD69+CD137+) CD4- TEMRA and CD4-TEM (Fig.1L-M). Finally, IFN-gamma-producing TREG of LC- individuals increased over time (Fig.1N). Conclusion(s): Acutely ill, hospitalized COVID-19 patients developing LC feature a dysregulated SARS-CoV-2-specific humoral as well as B- and T-cell response, in both magnitude and functionality, suggesting a link between dysregulated SARS-CoV-2-specific adaptive immunity and LC development. The fine understanding of the factors contributing to such dysregulation in LC patients is strongly needed, that might further inform targeted therapeutic interventions. (Figure Presented).

Differential Association of Cytomegalovirus with Acute and Post-Acute Covid-19

Background: Asymptomatic Cytomegalovirus (CMV) infection reshapes systemic immune responses and its replication can be both a consequence and cause of inflammation. As CMV resides in the same tissues affected by SARSCoV- 2, we hypothesized that asymptomatic CMV co-infection might modify the pathogenesis of both acute and post-acute COVID-19. Method(s): Participants had current or prior nucleic acid-confirmed SARS-CoV-2 infection in the COVID-19 Multi-Phenotyping for Effective Therapies (COMET, n=219), Immunophenotyping Assessment in a COVID-19 Cohort (IMPACC, n=244) or the Long-term Impact of Infection with Novel Coronavirus (LIINC, n=327) cohorts. We assessed the relationship between CMV serostatus and odds of hospitalization and plasma SARS-CoV-2 N antigen levels during acute COVID-19 as well as post-acute "Long COVID" symptoms, defined as >=1 of 32 COVID-19-attributed symptoms present at least 60 days following initial symptom onset. Result(s): Among 758 participants, 518 were hospitalized for their acute COVID-19 episode. CMV seropositivity was independently associated with a 1.9-fold increased odds of hospitalization for acute COVID-19, after adjustment for age, sex, race, ethnicity, HIV status, prior autoimmune disease, diabetes, and obesity (p=0.01, A). Among those hospitalized, CMV seropositivity was also associated with higher plasma SARS-CoV-2 N antigen levels (median 936 vs. 323 pg/ml, P=0.03, B), which remained significant after adjustment for potential confounders, but not with ICU admission (n=209), death (n=58), or thrombotic events (n=31). In contrast to its relationship to acute COVID-19 disease severity, CMV seropositivity was independently associated with a 48% decreased odds of having neurocognitive Long COVID symptoms such has headache and brain fog 4 months after initial COVID-19 diagnosis (P=0.036). Conversely, serologic evidence of Epstein-Barr Virus (EBV) reactivation and HIV both increased the odds of these symptoms (C). Conclusion(s): CMV seropositivity is associated with a 1.9-fold higher odds of hospitalization in people with acute COVID-19 and a nearly 3-fold higher SARS-CoV-2 antigen burden in hospitalized patients. In contrast, CMV seropositivity is associated with a decreased odds of neurocognitive Long COVID symptoms, while other chronic viral co-infections like EBV reactivation and HIV are associated with an increased odds of this complication. The biologic mechanisms mediating these relationships are unknown, but warrant further investigation. (Figure Presented).

Pbmc Immunophenotyping and Plasma Inflammatory Profile of Children with Long Covid

Background: Long COVID can be developed by individuals after an infection with SARS-CoV-2 as described by the WHO. Although this condition is more commonly described in adults, it can occur in children and adolescents with a wide range of estimated prevalence of 1-25%. Little is known about the role of the immune system in long COVID. However, one of the main hypotheses about the underlying mechanism in long COVID is that there is an immune and inflammatory dysregulation that persists after the acute infection. The objective of this study is to compare immune cells populations, and inflammatory biomarkers in paediatric populations with and without long COVID. Method(s): We analyzed 55 blood samples from the pediaCOVID cohort (Hospital Germans Trias i Pujol), which includes more than 130 children diagnosed with long COVID and 23 controls. We measured different immune cell populations using spectral cytometry with a panel of 37 cellular markers, and 42 inflammatory markers using Luminex or ELISA. EdgeR was used for statistical analysis of the spectral data;p-values of inflammatory markers were calculated using the likelihood ratio test and they were corrected for multiple comparisons. Result(s): The study cohort had a median age of 14.3 (IQR, 12.5-15.2) and 69.1% female. Patients had at least 3 symptoms associated with long COVID (median [IQR];10 [7-16]). The most common symptom was asthenia/fatigue (98.2%). Compared to the control cohort, children with long COVID had increased numbers of CD4+CD8+ T cells, IgA+CD21+CD27+ memory B cells, and IgA+CD21-CD27- memory B cells, while CD4+ TEMRA cells (CD45RA+, CCR7-), intermediate monocytes (CD14+, CD16+) and classical monocytes (CD14+, CD16-) were decreased (all p< 0.05;q=n.s.). None of the 42 inflammatory biomarkers showed significant differences between children with and without long COVID. Conclusion(s): The results of this study suggest that specific populations of peripheral blood immune cells might be involved in the mechanisms underlying prolonged COVID in children and adolescents. The increase in both IgA+CD21-CD27- and IgA+CD21+CD27+ memory B cells could be associated with the persistence of viral antigen in the gut and/or gut dysbiosis. Moreover, the decrease in CD4+ TEMRA cells could be related to autoantibodies against G-protein coupled receptors (GPCRs), since this cell population can express GPR56, and autoantibodies against GPCRs were previously reported to be elevated in adults with long COVID.

Evaluation of T and B cell immunophenotyping and antibody response post Covid-19 vaccination.

PURPOSE: To evaluate T and B cell subsets and IgG antibodies in response to SARS-CoV-2 post COVID-19 vaccination. METHODS: A total of 50 healthy adults (18-60 years) receiving anti-SARS-CoV-2 vaccination (COVISHIELD) were recruited for the study. Blood samples were collected from participants at 3 time points; just before vaccination (Visit 0, V0), just before booster dose (Visit 1, V1) and 6th month after 1st dose (Visit 2, V2). Peripheral blood mononuclear cell isolation was done and evaluated for T and B cell subsets by Flow cytometry. Quantitative determination of IgG antibodies to SARS-CoV-2 was done by Chemiluminescence immunoassay in all samples. Final data for all three visits was available for 37 participants who remained healthy. Ethics approval was obtained from Medanta Institution of Ethics Committee vide MICR No. 1290/2021 dated 24th May 2021. RESULTS: Mean age of the participants was 34.6 â€‹± â€‹5.7 years (Range: 24-45 years). Highly significant improvement in SARS-CoV-2 IgG levels was observed after each visit {Mean IgG: (V0 v/s. V1: 133.8 â€‹± â€‹339.2AU/ml v/s. 434.5 â€‹± â€‹519.2AU/ml; p-value â€‹= â€‹0.003) and V0 v/s. V2: 133.8 â€‹± â€‹339.2AU/ml v/s. 420.9 â€‹± â€‹394.2AU/ml; p-value â€‹= â€‹0.002) Between visits 0 and 1, the mean value for CD4 Naïve T cells showed significant increase, while CD4 central memory (CM) T cells showed significant decrease. Between visits 0 and 2 the mean values for CD4 Naïve T cells, CD8 Naïve T cells and Pre germinal centre (Pre GC) B cells showed significant increase. During the same period the mean values for CD4CM, CD8 effector memory (EM) and CD8 CM T cells showed significant decrease. CONCLUSION: It is concluded that both, humoral and cellular immunity, play an important role in maintaining immunity against COVID-19 infection, following COVISHIELD vaccination. Moreover, in subjects with normalisation of antibody levels post vaccination, persistence of T cell subsets may still offer some immunity.

The informative value of CD3+CD4+ and CD3+CD8+ T-cell count and cHIS scale as predictors of severe COVID-19 when using interleukin-6 receptor blockers in the in-hospital setting.

BACKGROUND: Clinical and laboratory signs of hyperinflammatory response in COVID-19 may serve as prognostic markers of the disease scenario. In real-world practice, there is an unmet need to determine the optimal timing of identifying predictors of SARS-CoV-2 adverse outcomes in the context of patient stratification to improve the effectiveness of anti-IL-6R therapy. Lymphopenia has a high informative value for the adverse prognosis of the COVID-19 course; however, the informative value of CD3+CD4+, CD3+CD8+ T-cell count remains questionable. In addition to lymphocyte phenotyping, a six-criterion additive scale (cHIS) was used in the study. AIM: To study the informative value of CD3+CD4+, CD3+CD8+ T-cell phenotyping and cHIS scale as predictors of severe COVID-19 when using IL-6R blockers. MATERIALS AND METHODS: A single-center, bi-directional study included 179 patients with SARS-CoV-2-induced community-acquired pneumonia with severe acute inflammation and progressing respiratory failure. Data were obtained from electronic patient records. Anti-IL-6R was administered in addition to standard therapy in the cohorts. The following disease outcomes were used to determine the informative value of the studied parameters: mortality and hospital discharge. Inflammatory markers were measured before and after administering anti-IL-6R, followed by monitoring. Statistical analysis was performed using SPSS (version 25.0). The quantitative indices were described using the median and interquartile range. Quantitative indices were compared using nonparametric methods: Mann-Whitney U-test, Kruskal-Wallis test. The groups were compared by qualitative characteristics using Pearson's chi-square test. Correlation analysis of quantitative indicators was performed using Spearman rank correlation. For additional analysis of the cHIS scale, odds ratio and decision tree methods were used. Differences were considered statistically significant at р≤0,05. RESULTS: Immunophenotyping of lymphocytes as a predictor of the severe SARS-CoV-2 requires further research. The cHIS scale may be implemented in routine clinical practice due to its high predictive value. A cHIS score of ≥2 on the first day of admission is a critical threshold for intensification and revision of therapy. The prognosis with cHIS is logically relevant in the first three days of hospitalization. CONCLUSION: The main result of the study is the definition of target groups of patients with community-acquired SARS-CoV-2 pneumonia for the IL-6R-blockers, considering the timing of their effective use in real clinical practice.

Hairy Cell Leukemia in a Filipino Male during the COVID-19 Pandemic - Report of a Rare Case

Hairy cell leukemia (HCL) is a rare, chronic, mature B-cell lymphoproliferative disorder accounting for 2% of all leukemias. In this paper, we would like to present our experience in the management of HCL in a financially limited setting where other diagnostic tests and chemotherapy are unavailable. The case report aims to emphasize the recognition of the distinctive morphology of hairy cells in the peripheral blood in the consideration of the initial diagnosis. A 60-year-old Filipino male was incidentally found to have anemia, thrombocytopenia and an absolute neutrophilic count below 1,000 in a pre-operative clearance for elective herniorrhaphy. Blood smear revealed atypical lymphocytes with hair like cytoplasmic projections. CT-scan of the abdomen showed splenomegaly and prominent paraaortic nodes. Flow cytometry of the bone marrow aspirate was consistent with an involvement of a Mature B cell neoplasm markers CD19, CD20, CD22 and surface immunoglobulin lambda and hairy cell leukemia markers CD11c, CD103 and CD25. He responded to six-weekly sessions of Cladribine with remission of the bone marrow and hematologic parameters. HCL is a rare type of a mature B cell neoplasm characterized by pancytopenia, splenomegaly, bone marrow fibrosis and the presence of atypical lymphoid cells with hairy projections in blood, bone marrow and spleen. Immunophenotyping express CD11c, CD103, CD123, and CD25. BRAF V600E mutation is the disease defining genetic event. Cladribine and Pentostatin are the first line of treatment. Cases of leukemia can be easily overlooked because of the mild derangement in the complete blood count. A meticulous differential review of the atypical lymphocyte, is the first step in the diagnosis of this rare disease.Copyright © 2022, Philippine College of Physicians. All rights reserved.

Cellular and Humoral Immune Responses to Vaccination for COVID-19 Are Negatively Impacted by Senescent T Cells: A Case Report.

BACKGROUND: Herein, we aimed to follow up on the cellular and humoral immune responses of a group of individuals who initially received the CoronaVac vaccine, followed by a booster with the Pfizer vaccine. METHODS: Blood samples were collected: before and 30 days after the first CoronaVac dose; 30, 90, and 180 days after the second CoronaVac dose, and also 20 days after the booster with the Pfizer vaccine. RESULTS: Whilst the positivity to gamma interferon-type cellular response increased after the first CoronaVac dose, neutralizing and IgG antibody levels only raised 30 days after the second dose, followed by a drop in these responses after 90 and 180 days. The booster with the Pfizer vaccine elicited a robust cellular and humoral response. A higher number of double-negative and senescent T cells, as well as increased pro-inflammatory cytokines levels were found in the participants with lower humoral immune responses. CONCLUSION: CoronaVac elicited an early cellular response, followed by a humoral response, which dropped 90 days after the second dose. The booster with the Pfizer vaccine significantly enhanced these responses. Furthermore, a pro-inflammatory systemic status was found in volunteers who presented senescent T cells, which could putatively impair the immune response to vaccination.

Pregnancy Outcomes, Immunophenotyping and Immunohistochemical Findings in a Cohort of Pregnant Patients with COVID-19-A Prospective Study.

(1) Background: SARS-CoV-2 infection during pregnancy could determine important maternal and fetal complications. We aimed to prospectively assess placental immunohistochemical changes, immunophenotyping alterations, and pregnancy outcomes in a cohort of patients with COVID-19; (2) Methods: 52 pregnant patients admitted to a tertiary maternity center between October 2020 and November 2021 were segregated into two equal groups, depending on the presence of SARS-CoV-2 infection. Blood samples, fragments of umbilical cord, amniotic membranes, and placental along with clinical data were collected. Descriptive statistics and a conditional logistic regression model were used for data analysis; (3) Results: Adverse pregnancy outcomes such as preterm labor and neonatal intensive care unit admission did not significantly differ between groups. The immunophenotyping analysis indicated that patients with moderate-severe forms of COVID-19 had a significantly reduced population of T lymphocytes, CD4+ T cells, CD8+ T cells (only numeric), CD4+/CD8+ index, B lymphocytes, and natural killer (NK) cells. Our immunohistochemistry analysis of tissue samples failed to demonstrate positivity for CD19, CD3, CD4, CD8, and CD56 markers; (4) Conclusions: Immunophenotyping analysis could be useful for risk stratification of pregnant patients, while further studies are needed to determine the extent of immunological decidual response in patients with various forms of COVID-19.

A comprehensive assessment of four whole blood stabilizers for flow-cytometric analysis of leukocyte populations.

Though cryopreservation of cell fractions is widely used in flow cytometry studies, whole blood cryopreservation is more challenging due to the presence of erythrocytes and effects of fixatives commonly used for preservation. Here, we evaluated and compared head-to-head the performance of four commercial whole blood cryopreservation kits; (1) Cytodelics, (2) Stable-Lyse V2 and Stable-Store V2 (SLSS-V2), (3) Proteomic stabilizer (PROT-1), and (4) Transfix. We found that PROT-1, Transfix, and Cytodelics maintained the distribution of major leukocyte subsets-granulocytes, T cells, natural killer cells, and B cells, on a comparable level to unpreserved samples, despite the attenuation of fluorescence intensities in flow cytometric assays. Moreover, these three stabilizers also maintained the activated phenotypes of neutrophils upon stimulation with N-formylmethionyl-leucyl-phenylalanine and lipopolysaccharides. The upregulation of adhesion molecules (CD11b), Fc receptors (CD16), and granule proteins (CD66b), as well as the shedding of surface L-selectin (CD62L), was conserved most efficiently in PROT-1 and Cytodelics when compared to samples only treated with erythrocyte lysing. However, none of the stabilizers provided a reliable detection of CCR7 for accurate quantification of T cell maturation stages. We also evaluated the performance of Cytodelics in longitudinal clinical samples obtained from acute COVID-19 patients, where it allowed reliable detection of lymphopenia and granulocyte expansion. These results support the feasibility of whole blood cryopreservation for immunophenotyping by flow cytometry, particularly in longitudinal studies. In conclusion, the performance of different stabilizers is variable and therefore the choice of stabilizers should depend on cell type of interest, as well as antibody clones and experimental design of each study.

Immunohistochemical profile of cell cycle control, proliferation and differentiation proteins of the pulmonary atypical alveolar epithelium with COVID-19-induced diffuse alveolar damage as compared to pulmonary [lepidic-growth] adenocarcinoma.

We aim aim to compare immunophenotypic charac-teritics of atypical epithelium (AE) with COVID-19-induced diffuse alveolar damage (DAD) and pulmonary lepidic-growth adenocarcinoma, accounting for cell cycle control, proliferation and differentiation]. Methods. We examined pulmonary tissue specimens from twenty-four fatal cases of CO VID-19-induced acute respiratory damage syndrome confirmed by autopsy (Group 1) and four cases of pulmonary lepidic-growth adenocarcinoma (Group 2). Perpendicular dimensions of 10 nuclei were measured on the H&E slides, means of their sums of products (SPNM) were calculated. We have used p53, Ki67, pi6, p63 antibodies for immunohistochemical staining in each case. We evaluate colour intensity, rate of stained cells of AE and the product of these parameters. We evaluated separately Nuclear and cyto-plasmic staining (couple) and only cytoplasmic staining (cyt) for pi6 expression. We measured proliferative index only at KI-67 stained slides. U-test and Spearman rank correlation test were used for statistical analysis. Results. Expression of p63 was higher in group 1 (p=0.001), while pi6 was more frequently expressed in group 2 (p=0.002). We have found no statistically significant differences (p>0.1) in the p53 and Ki67 expression. Group 1 showed There was negative correlation between the number of days from onset of symptoms and the following variables: Ki67 (r=M).587, p=0.003);SPNM (r 0.406, p=0.049). Conclusion. The present study has shown heterogeneity in levels of cell cycle control expression, proliferation and differentiation of atypical epithelium in the pulmonary lep-idic-growth adenocarcinoma and CO VID-19-induced diffuse alveolar damage.Copyright © 2022 Izdatel'stvo Meditsina. All rights reserved.