Sarcoidosis-Associated Immune Thrombocytopenic Purpura and Focal Segmental Glomerulosclerosis

Purpose of study A 32-years old male with known multi-system sarcoidosis in remission for 5 years off treatment presented to the emergency room with complaints of generalized weakness, hematemesis, epistaxis, and bruises. Physical examination was notable for petechiae, ecchymosis along with papules and plaques suggestive of active sarcoid skin lesions on his extremities. Laboratory workup was significant for thrombocytopenia 3000/uL, acute kidney injury with sub-nephrotic proteinuria. Peripheral blood smear did not show evidence of hemolysis and direct Coombs test was negative. Infectious workup including COVID-19, HIV, and hepatitis serologies were negative. Computed Tomography (CT) of chest, abdomen, and pelvis showed mild splenomegaly and an increased number of sub-centimeter hilar and mediastinal lymph nodes. The patient was treated with dexamethasone 40 mg daily for 4 days and intravenousimmunoglobulins (IVIG-2 gm/kg) for possible Immune Thrombocytopenic Purpura (ITP) with improvement in platelet count to 42000/uL by day 3. His workup for AKI and sub-nephrotic proteinuria was negative apart from a positive ANA (1: 160) with low complements. The anti-phospholipid antibody panel was negative. The ACE level was markedly elevated (>80U/L). The patient could not get a renal biopsy due to severe thrombocytopenia. He was discharged but was re-admitted in 15 days for severe thrombocytopenia of 1000/uL, epistaxis, and bruising. We continued high dose steroids along with IVIG 1 gm/kg for refractory ITP with minimal response and started anti-CD20 agent (Rituximab) 375 mg/m2 weekly with thrombopoietin-receptor agonist (Eltrombopag). His platelets count improved in response to treatment and subsequent renal biopsy showed focal and segmental glomerulosclerosis along with mild interstitial fibrosis, tubular atrophy thought to be from long standing sarcoidosis. There was also evidence of focal arteriosclerosis with no evidence of granulomas, immune complex, complement, or IgG4 deposition. Given skin lesions, thrombocytopenia, extensive lymphadenopathy, and renal involvement with markedly elevated ACE levels the overall picture was consistent with active multi-system sarcoidosis. His platelet count increased to 177,000/uL at the time of discharge. Currently, the patient is on slow steroid taper along with Eltrombopag 25 mg every other day without any recurrence of his symptoms so far. Methods used We described one case of sarcoidosis with hematologic and renal involvement. Summary of results Our patient developed hematologic and renal complications approximately 6 years after being diagnosed with sarcoidosis. Initially, he did not demonstrate sufficient clinical response to IVIG and high dose steroids. However, after a course of anti-CD20 agent (Rituximab) and with the addition of thrombopoietin-receptor agonist (Eltrombopag) he showed improvement of platelet count and stabilization of the renal function. Currently, the patient is receiving maintenance therapy with Prednisone 7.5 mg daily along with Eltrombopag 25 mg twice weekly with no recurrence of ITP and stable renal function. A further decision on whether the patient needs another cycle of Rituximab will be determined by the patient's clinical course. Conclusions Highly variable manifestations of Sarcoidosis can pose a significant diagnostic and therapeutic challenge as can be seen from our case. ITP is a rare hematological manifestation of sarcoidosis and addition of anti-CD20 agents should be considered in refractory cases.

SARS-CoV-2 antibody avidity responses in natural infection and vaccination

Background: In ongoing SARS CoV-2 pandemic, understanding antibody responses have played a key role in measuring extent of exposure, protection from reinfection, vaccine efficacy and serodiagnosis. Antibody avidity is total binding strength of immunoglobulin G (IgG) toward its target epitope. High antibody avidity has been correlated with effective neutralization of the SARSCoV-2 virus. However, the data on avidity responses against COVID-19 infection and vaccination are limited. Objective(s): To understand the avidity responses among sera of naturally infected, recovered COVID-19 patients;naive Covaxin, Covishield vaccinees and breakthrough infections. Material(s) and Method(s): In this study, we utilized an in-house developed SARS-CoV-2 anti-spike receptor binding domain (SRBD) IgG ELISA to optimize the avidity assay. A panel of anti-SARS-CoV- 2 SRBD IgG positive serum samples were treated with known concentration of a chaotropic agent (urea) for disruption of the noncovalent interactions of the antigen-antibody complex. This disruption causes low avidity antibodies to dissociate which gives the percentage of high avidity antibodies present in a serum sample. Additionally, the optimized assay was used to understand the avidity responses among sera belonging to individuals naturally infected and recovered after COVID-19, naive Covaxin and Covishield vaccinees;followed by breakthrough infections. Result(s) and Conclusion(s): The anti-SRBD avidity progressively elevated over a period of twelve months. Moreover, overall antibody avidity responses were similar in the case of natural infection and naive two doses of Covaxin and Covishield vaccinated individuals. However, avidity responses were high among individuals with a breakthrough infection as compared to naive vaccinees.

COVID-19: Impact, Diagnosis, Management and Phytoremediation

COVID-19, or SARS-CoV-2, is an extremely deadly virus that is responsible for over half a million deaths of people in the world. This virus originated in China in December 2019 and rapidly spread worldwide in 2-3 months, and affected every part of the world. Its life-threatening nature forced governments in all countries to take emergency steps of lockdown that affected the entire world's education, health, social and economic aspects. Due to the implementation of these emergencies, the population is facing psychological, social and financial problems. Additionally, this pandemic has significantly influenced the health care systems as all the resources from governments of all countries were directed to invest funds to discover new diagnostic tests and manage COVID-19 infection. The impact of the COVID-19 pandemic on the education and social life of the population is described in this article. Additionally, the diagnosis, management, and phytoremedia-tion to control the spread of COVID-19 and traditional medicinal plants' role in managing its mild symptoms have been discussed.Copyright © 2023 Bentham Science Publishers.

Influenza A and influenza B antibody determination in an Austrian cohort

Influenza is an infectious respiratory disease caused by influenza A and B, which is a virus characterized by a high mutation rate with new strains appearing regularly, making regular booster vaccinations necessary. In this study, we evaluated the immune status of Influenza A and B by using ELISA. A questionnaire was utilized to appraise the immunization anamnesis and the stance on vaccination. In total, 202 probands participated in this study. 35.6% of the probands were vaccinated, 10.9% indicated a confirmed influenza infection. 88.1% had a positive influenza A titer, whereas a positive influenza B titer was determined in only 38.6%. Additionally, a correlation between vaccination and titer could be observed. In this study, we were able to show a higher vaccination rate in our cohort than the Austrian average. Additionally, a higher percentage showed a positive influenza A titer compared to influenza B titer.Copyright © 2022

A Case of Iga Vasculitis That Developed Gross Hematuria and Lower-Limb Purpura Following Covid-19 Vaccines

Introduction: There have been some reports on flare-ups of kidney diseases following COVID-19 vaccines such as IgA nephropathy and minimal change disease. However, there have been few reports on those of IgA vasculitis following the vaccines yet. We report a case of IgA vasculitis with a flare-up of gross hematuria and lower-limb purpura following Moderna COVID-19 vaccines. Method(s): The patient is a 16-year-old female with no previous history of abnormal results of urinalyses before April in 2021. She had developed microscopic hematuria, proteinuria and purpura on both of her lower limbs that emerged and then disappeared repeatedly since then. She received Moderna COVID-19 vaccines in August and September in 2021, both of which were followed by gross hematuria lasting for around 10 days. The lower-limb purpura reemerged at the same time as the hematuria. Microscopic hematuria of around 30-49 RBC/HPF, glomerular hematuria of moderate degree and urine protein-to-creatinine ratio (UPCR) of around 0.8 g/gCr had continuously been detected. Skin and kidney biopsies were performed in December in 2021 and in February in 2022 respectively. Result(s): The skin tissue showed formation of leukocytoclastic vasculitis, and the kidney tissue showed that of cellular and fibrocellular crescents and endocapillary hypercellularity. Immunofluorescence staining of both tissues showed deposition of galactose-deficient IgA1(Gd-IgA1) and C3, and she was diagnosed as IgA vasculitis. She received steroid pulse therapy followed by tonsillectomy. The lower-limb purpura has disappeared after she received three courses of the steroid pulse therapy, but microscopic hematuria and UPCR of around 0.8 g/gCr have still continued. Conclusion(s): IgA vasculitis is leukocytoclastic vasculitis characterized by deposition of Gd-IgA1 on microvessel walls in skin and on glomerular capillaries in kidneys. The detailed mechanism of IgA vasculitis has not been fully elucidated yet. Gross hematuria following an upper respiratory infection is considered as a characteristic clinical symptom of IgA vasculitis as well as IgA nephropathy. Post-vaccination gross hematuria of patients with IgA nephropathy has been reported, and it is believed that innate immunity is related to its mechanism. Moderna COVID-19 vaccines, which the patient received, are mRNA vaccines. We estimate that exposure to the mRNA vaccine triggered excess glomerular deposition of Gd-IgA1-containing immune complexes and subsequent gross hematuria by overactivation of innate immunity such as Toll-like receptors that detect RNA. This case suggests that such immune activation by a mRNA vaccine might be related not only to the mechanism of IgA nephropathy but also to that of IgA vasculitis. No conflict of interestCopyright © 2023

Relapses or de-novo IgA nephropathy following COVID-19 vaccination, a narrative review

Immunoglobulin A (IgA) nephropathy is the most common type of glomerulonephritis worldwide characterized by excessive serum levels of glycosylated which triggers the generation of glycan-specific IgG and IgA autoantibodies. This pathological condition results in the formation of circulatory IgA immune complexes, which are essential for the development of glomerular inflammation, especially IgA nephropathy. The serum galactosylated IgA1, IgG, and IgA autoantibodies are suggested as the biomarkers of IgA nephropathy since IgA antibodies are early markers for disease activity too. Serum IgA antibodies emerged as the early COVID-19-specific antibody response about two days after initial symptoms of COVID-19 in comparison with IgG and IgM antibody concentrations, which appeared after five days. IgA nephropathy is frequently presented as microscopic or macroscopic hematuria and proteinuria with a male predominance. COVID-19 infection can include several organs aside from the lungs, such as kidneys through different mechanisms. It is demonstrated in most cases that short-lasting symptoms such as gross hematuria resolve either spontaneously or following a short course of steroids. This review summarized the reported cases of relapses or denovo reported cases of relapses or de-novo IgA nephropathy and IgA vasculitis following COVID-19 vaccination.Copyright © 2023 The Author(s);Published by Society of Diabetic Nephropathy Prevention. This is an open-access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Seroconversion in COVID-19 Infection and Comparison of Antibody Responses in Symptomatic Versus Asymptomatic Individuals

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. Following infection, antibodies are formed against the spike (S) and nucleocapsid (N) proteins, which are the primary viral antigens of SARS-CoV-2. This study aims to determine the antibody response three weeks post-infection and its persistence. To study antibody responses in COVID-19-positive individuals and to compare the degree of antibody response in symptomatic and asymptomatic individuals. The persistence of the antibody response was also assessed. Adult patients (> 15 years of age) who were diagnosed as COVID-19-positive by RT-PCR, three weeks after swab positivity were tested for total antibody levels against COVID-19 antigens by electrochemiluminescence assay. Out of 226 individuals, 129 were symptomatic and 97 were asymptomatic. Among the 129 symptomatic individuals, 74 exhibited an antibody response, whereas in the asymptomatic individuals, only 10 exhibited an antibody response. The antibody response was found to be significant in symptomatic individuals compared to that in asymptomatic individuals (p < 0.05). All follow-up individuals were seropositive at the end of both 6 and 8 months. Antibodies against SARS-CoV-2 persist for 8 months following infection. Despite the waning of antibodies against the nucleocapsid antigen, there was no complete disappearance of antibodies.Copyright © 2023 The Author(s).

Immunopathogenetic Aspects and Effectiveness of Combination Therapy for Influenza A (H1N1)pdm2009 in Children.

Introduction. The continuing circulation of influenza A (H1N1)pdm2009 virus poses a threat of a new epidemic rise. It is known that influenza A (H1N1)pdm2009 is characterized by a severe course, development of life-threatening complications, and high mortality, which is associated not only with the biological features of the pathogen, but also with the induction of deep immunosuppression, especially the interferon system and the cellular-type immune response. The role of influenza in the development of severe forms of the new coronavirus infection COVID-19 has been revealed. The increase of the number of virus strains resistant to various classes of antiviral drugs is of unfavorable importance. This requires the development of new approaches to the treatment of influenza A (H1N1)pdm2009 with the combined use of drugs with complex antiviral and immunocorrective activity. Purpose. To substantiate the combination therapy of influenza A (H1N1)pdm2009 in children using oseltamivir (Tamiflu) and recombinant interferon-alpha2b (Viferon). Materials and methods. Clinical and laboratory examination of 85 children aged from 3 to 5 years with moderate (43) and severe forms (42) of influenza A (H1N1)pdm2009 was carried out. Results and discussion. In patients with severe forms of A(H1N1)pdm2009 influenza, a higher frequency of anamnestic risk groups (85.7%), frequent development of febrile fever (100%), severe intoxication symptoms (100%), symptoms of laryngitis (28.6%), tracheitis (57.1%), bronchitis (76.2%), dyspeptic (42.9%) and cerebral syndromes (62.9%), other complications (80.9%) were revealed. In these patients, more significant changes of the indicators of the cellular type of the immune response were found - the decrease of CD3, CD4, CD8, the humoral type of immune response - the increase of CD20, IgM, circulating immune complexes, the decrease of IgA and IgG, innate immunity factors - the decrease of the metabolic activity of neutrophils, moderate increase of CD16. The combined administration of recombinant interferon-alpha2b (Viferon) and oseltamivir (tamiflu) compared with oseltamivir (tamiflu) monotherapy reduced the duration of fever (Me 2, IQI 1-4 days and Me 3, IQI 2-4 days), intoxication (Me 3, IQI 2-4.5 days and Me 4.5, IQI 3-7 days), symptoms of rhinitis (Me 5, IQI 4-7 days and Me 6.5, IQI 4.5-7.5 days), pharyngitis (Me 5, IQI 4-7 days and Me 6.5, IQI 4.5-7.5 days), tracheitis (Me 2, IQI 1-3 days and Me 3.5, IQI 2-4 days), bronchitis (Me 3, IQI 2-5 days and Me 5, IQI 4-6 days). In this group, the complications developed less frequently (4.5% and 33.3%);there was the decrease of hospitalization time (Me 5, IQI 4-7 days and Me 6.5, IQI 5-7 days). There was the increase of the number of children, who (after 10 days from the start of therapy) had sanitation of the nasopharynx from the virus (90.9% and 61.9%). Conclusion. The high frequency of anamnestic risk groups and the induction of deep immunosuppression, especially the cellular component of immunity, are the cause of the formation of severe forms of influenza A (H1N1)pdm2009. This justified the appointment of combination therapy using the neuraminidase inhibitor oseltamivir (Tamiflu) and recombinant interferon-alpha2b (Viferon), which not only inhibits virus replication, but also has immunocorrective activity against the interferon system and cellular immunity. The high efficiency of the combined administration of recombinant interferon-alpha2b (Viferon) and oseltamivir (Tamiflu) lets to recommend the inclusion of these drugs in the treatment of severe forms of influenza A(H1N1)pdm2009 in children.Copyright © 2020, Professionalnye Izdaniya. All rights reserved.

Immunopathogenetic Aspects and Effectiveness of Combination Therapy for Influenza A (H1N1)pdm2009 in Children.

Introduction. The continuing circulation of influenza A (H1N1)pdm2009 virus poses a threat of a new epidemic rise. It is known that influenza A (H1N1)pdm2009 is characterized by a severe course, development of life-threatening complications, and high mortality, which is associated not only with the biological features of the pathogen, but also with the induction of deep immunosuppression, especially the interferon system and the cellular-type immune response. The role of influenza in the development of severe forms of the new coronavirus infection COVID-19 has been revealed. The increase of the number of virus strains resistant to various classes of antiviral drugs is of unfavorable importance. This requires the development of new approaches to the treatment of influenza A (H1N1)pdm2009 with the combined use of drugs with complex antiviral and immunocorrective activity. Purpose. To substantiate the combination therapy of influenza A (H1N1)pdm2009 in children using oseltamivir (Tamiflu) and recombinant interferon-alpha2b (Viferon). Materials and methods. Clinical and laboratory examination of 85 children aged from 3 to 5 years with moderate (43) and severe forms (42) of influenza A (H1N1)pdm2009 was carried out. Results and discussion. In patients with severe forms of A(H1N1)pdm2009 influenza, a higher frequency of anamnestic risk groups (85.7%), frequent development of febrile fever (100%), severe intoxication symptoms (100%), symptoms of laryngitis (28.6%), tracheitis (57.1%), bronchitis (76.2%), dyspeptic (42.9%) and cerebral syndromes (62.9%), other complications (80.9%) were revealed. In these patients, more significant changes of the indicators of the cellular type of the immune response were found - the decrease of CD3, CD4, CD8, the humoral type of immune response - the increase of CD20, IgM, circulating immune complexes, the decrease of IgA and IgG, innate immunity factors - the decrease of the metabolic activity of neutrophils, moderate increase of CD16. The combined administration of recombinant interferon-alpha2b (Viferon) and oseltamivir (tamiflu) compared with oseltamivir (tamiflu) monotherapy reduced the duration of fever (Me 2, IQI 1-4 days and Me 3, IQI 2-4 days), intoxication (Me 3, IQI 2-4.5 days and Me 4.5, IQI 3-7 days), symptoms of rhinitis (Me 5, IQI 4-7 days and Me 6.5, IQI 4.5-7.5 days), pharyngitis (Me 5, IQI 4-7 days and Me 6.5, IQI 4.5-7.5 days), tracheitis (Me 2, IQI 1-3 days and Me 3.5, IQI 2-4 days), bronchitis (Me 3, IQI 2-5 days and Me 5, IQI 4-6 days). In this group, the complications developed less frequently (4.5% and 33.3%);there was the decrease of hospitalization time (Me 5, IQI 4-7 days and Me 6.5, IQI 5-7 days). There was the increase of the number of children, who (after 10 days from the start of therapy) had sanitation of the nasopharynx from the virus (90.9% and 61.9%). Conclusion. The high frequency of anamnestic risk groups and the induction of deep immunosuppression, especially the cellular component of immunity, are the cause of the formation of severe forms of influenza A (H1N1)pdm2009. This justified the appointment of combination therapy using the neuraminidase inhibitor oseltamivir (Tamiflu) and recombinant interferon-alpha2b (Viferon), which not only inhibits virus replication, but also has immunocorrective activity against the interferon system and cellular immunity. The high efficiency of the combined administration of recombinant interferon-alpha2b (Viferon) and oseltamivir (Tamiflu) lets to recommend the inclusion of these drugs in the treatment of severe forms of influenza A(H1N1)pdm2009 in children.Copyright © 2020, Professionalnye Izdaniya. All rights reserved.

Antibody-receptor bioengineering and its implications in designing bioelectronic devices.

Antibodies play a crucial role in the defense mechanism countering pathogens or foreign antigens in eukaryotes. Its potential as an analytical and diagnostic tool has been exploited for over a century. It forms immunocomplexes with a specific antigen, which is the basis of immunoassays and aids in developing potent biosensors. Antibody-based sensors allow for the quick and accurate detection of various analytes. Though classical antibodies have prolonged been used as bioreceptors in biosensors fabrication due to their increased fragility, they have been engineered into more stable fragments with increased exposure of their antigen-binding sites in the recent era. In biosensing, the formats constructed by antibody engineering can enhance the signal since the resistance offered by a conventional antibody is much more than these fragments. Hence, signal amplification can be observed when antibody fragments are utilized as bioreceptors instead of full-length antibodies. We present the first systematic review on engineered antibodies as bioreceptors with the description of their engineering methods. The detection of various target analytes, including small molecules, macromolecules, and cells using antibody-based biosensors, has been discussed. A comparison of the classical polyclonal, monoclonal, and engineered antibodies as bioreceptors to construct highly accurate, sensitive, and specific sensors is also discussed.

Immunotherapeutic and immunomodulatory potentials of Antigen-Antibody complex vaccines

Immune system battles with deadly pathogens that mostly deteriorate health and cause morbidity and mortality. Antibodies are considered great players in the elimination of pathogens and hence, provide a shield against the future onset of various diseases. The immune complex, also known as an antigen–antibody (Ag-Ab) complex, exhibits the immunomodulatory potential leading to enhanced vaccine efficacy. A deeper understanding of Fc receptors (FcRs) and the interaction of the Fc part of an antibody with the different immune cells lead to in-depth knowledge of using this strategy for the development of immune complex vaccines. The concept of the Ag-Ab complex has been used in the prevention and therapy of various viral and bacterial diseases. Ag-Ab complex is gaining attention in COVID-19 vaccine development too, due to their greater immunoregulatory potential. The present literature highlights the importance of the Ag-Ab complex, the role of Fc receptors in immunomodulation, and their success as vaccines in viral and bacterial diseases of human and animal origin. Moreover, potential areas and lapses are explored to make better use of this prospect as a vaccine candidate. Studies revealed that the immunogenic and immunomodulatory potential of Ag-Ab complex can lead to greater protection. However, there is a dire need of establishing a link between laboratory and clinical findings to make it effective and safe tool for in vivo treatments. © 2022 Elsevier Ltd

A Computational Framework for Determining the Breadth of Antibodies Against Highly Mutable Pathogens

Highly mutable pathogens pose daunting challenges for antibody design. The usual criteria of high potency and specificity are often insufficient to design antibodies that provide long-lasting protection. This is due, in part, to the ability of the pathogen to rapidly acquire mutations that permit them to evade the designed antibodies. To overcome these limitations, design of antibodies with a larger neutralizing breadth can be pursued. Such broadly neutralizing antibodies (bnAbs) should remain targeted to a specific epitope, yet show robustness against pathogen mutability, thereby neutralizing a higher number of antigens. This is particularly important for highly mutable pathogens, like the influenza virus and the human immunodeficiency virus (HIV). The protocol describes a method for computing the "breadth” of a given antibody, an essential aspect of antibody design. © 2023, Springer Science+Business Media, LLC, part of Springer Nature.

Longitudinal Assessment of Point-of-Care LumiraDx Antigen and Antibody Test Performance During Acute SARS-CoV-2 Infection and Recovery

Background. Rapid COVID-19 tests can offer significant advantages and reduce health disparities. The LumiraDx SARS-CoV-2 platform can perform microfluidic fluorescence assays for the rapid detection of SARS-CoV-2 antigen (Ag) and antibodies (Ab). We evaluated both tests in a longitudinal cohort to evaluate performance during acute SARS-CoV-2 infection and recovery. Methods. We collected nasal samples from 71 unique participants at four clinic visits spanning 0-21 days since symptom onset (DSSO);blood samples were collected from the same participants over six visits spanning 0-87 DSSO. For Ag testing, 232 anterior nasal swabs were assayed by: 1) the LumiraDx Ag test, 2) a laboratory-based electrochemiluminescence immunoassay for N Ag, 3) RT-PCR (Hologic Panther Fusion), and 4) culture (growth in VeroE6AT cells). For Ab testing, 308 serum samples were assayed by: 1) the LumiraDx Ab test and 2) Roche Elecsys Anti-S SARS-CoV-2 total Ab test. Measures of concordance [positive predictive agreement (PPA), negative predictive agreement (NPA), and Cohen's Kappa (K)] were estimated for qualitative results of the LumiraDx tests versus corresponding lab reference tests. Confidence intervals were estimated via bootstrapping. Results. LumiraDx Ag results had strong agreement with lab N-Ag results (K > 0.80) across all samples. Between 0-5 days, agreement was perfect, except for one sample resulting positive by LumiraDx Ag and negative by lab Ag. Agreement with PCR results was moderate overall (K=0.60), though substantial (K > 0.6) for both 0-5 DSSO (PPA=0.96/NPA=0.80) and 6-10 DSSO (PPA=0.96/NPA=0.59). Agreement with culture results was moderate overall (K=0.46): substantial (K=0.6) between 0-5 DSSO (PPA=0.96/NPA=0.60) and fair (K=0.29) between 6-10 DSSO (PPA=1.0/NPA=0.32). LumiraDx Ab results showed almost perfect agreement with lab Ab results across all samples (K=0.88), with substantial agreement (K > 0.7) for samples collected 0-10 DSSO (PPA=0.93/NPA=0.89) and 11-28 DSSO (PPA=0.99/NPA=0.69). Longitudinal agreement of LumiraDx antigen test result and culture positivity, by PCR Ct value. Nasal samples grouped by participant (lines) and agreement of results between LumiraDx antigen test result and culture positivity (proxy for infectiousness). Conclusion. LumiraDx rapid tests perform well compared to more costly and time-consuming lab methods of Ag and Ab detection. The rapid Ag test may be helpful in identifying patients infectious between 0-5 DSSO, given the substantial concordance of the rapid Ag test and culture positivity.

Autoimmune profile evaluation on vaccinated subjects divided in first, second and booster dose

Background: Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rapidly disseminated worldwide. The clinical research for developing vaccines takes several years but considering the state of emergency, all scientific and technological forces have concentrated towards the formulation of vaccines for the disease containment. In less than one year (December 2020) a first messenger RNA vaccine (Comirnaty, BioNTech/ Pfizer) was authorized. However, the vaccines were administered in phase 4 and the scientific community investigated about eventual side effects on the immune system, discussing the vaccination strategy and possible autoimmune implications. Aim(s): Since the vaccines development process has undergone an unprecedented acceleration, to evaluate a relationship between SARSCoV-2 vaccine administration and impact on the autoimmune level, the determination of circulating immune-complexes (CICs) concentrations, the presence of anti-nuclear antibodies (ANA) and second level tests (dsDNA, ENAscreen and ENAprofile), were studied on vaccinated subjects, after first, second and third dose of Pfizer vaccine. Method(s): The recruited subjects were divided according to anti-SARS-CoV-2 IgG RBD antibodies concentrations in: Group I <10 BAU/ml (N=114);Group II >1000 BAU/ml (N=112);Group III >2500 BAU/ml (N=78). CICs were determined by commercial ELISA kit;ANA by indirect immunefluorescence on Hep-2 cells. Result(s): CICs concentration, did not show significant differences, giving the following median values: Group I =5,44 U/ml;Group II =5,49 U/ ml;Group III =4.29 U/ml.Regarding ANA test: 23.7% of samples (27/114) were positive at 1:80 screening dilution and 4.4% (5/114) at 1:160 clinically relevant dilution, in Group I;15.2% of samples (17/112) were positive at 1:80 screening dilution and 2.7% (3/112) at 1:160 dilution, in Group II;finally 10.2% of samples (8/78) were positive at 1:80 screening dilution and 1.2% (1/78) at 1:160 dilution, in Group III. No specific positivity was found in any group. Conclusion(s): our study did not show significant results variations in the different vaccinated populations examined, suggesting the exclusion of a correlation between vaccine administration and the onset of autoimmune disorders.

Vaccine-induced immune thrombotic thrombocytopenia: Updates in pathobiology and diagnosis.

Coronavirus disease 2019 (COVID-19) is a viral respiratory infection caused by the severe acute respiratory syndrome virus (SARS-CoV-2). Vaccines that protect against SARS-CoV-2 infection have been widely employed to reduce the incidence of symptomatic and severe disease. However, adenovirus-based SARS-CoV-2 vaccines can cause a rare, thrombotic disorder termed vaccine-induced immune thrombotic thrombocytopenia (VITT). VITT often develops in the first 5 to 30 days following vaccination and is characterized by thrombocytopenia and thrombosis in unusual locations (e.g., cerebral venous sinus thrombosis). The diagnosis is confirmed by testing for anti-PF4 antibodies, as these antibodies are capable of platelet activation without any cofactor. It can be clinically challenging to differentiate VITT from a similar disorder called heparin-induced thrombocytopenia (HIT), since heparin is commonly used in hospitalized patients. VITT and HIT have similar pathobiology and clinical manifestations but important differences in testing including the need for PF4-enhanced functional assays and the poor reliability of rapid immunoassays for the detection of anti-platelet factor 4 (PF4) antibodies. In this review we summarize the epidemiology of VITT; highlight similarities and differences between HIT and VITT; and provide an update on the clinical diagnosis of VITT.

Immunotherapeutic and immunomodulatory potentials of Antigen-Antibody complex vaccines

Immune system battles with deadly pathogens that mostly deteriorate health and cause morbidity and mortality. Antibodies are considered great players in the elimination of pathogens and hence, provide a shield against the future onset of various diseases. The immune complex, also known as an antigen-antibody (Ag-Ab) complex, exhibits the immunomodulatory potential leading to enhanced vaccine efficacy. A deeper understanding of Fc receptors (FcRs) and the interaction of the Fc part of an antibody with the different immune cells lead to in-depth knowledge of using this strategy for the development of immune complex vaccines. The concept of the Ag-Ab complex has been used in the prevention and therapy of various viral and bacterial diseases. Ag-Ab complex is gaining attention in COVID-19 vaccine development too, due to their greater immunoregulatory potential. The present literature highlights the importance of the Ag-Ab complex, the role of Fc receptors in immunomodulation, and their success as vaccines in viral and bacterial diseases of human and animal origin. Moreover, potential areas and lapses are explored to make better use of this prospect as a vaccine candidate. Studies revealed that the immunogenic and immunomodulatory potential of Ag-Ab complex can lead to greater protection. However, there is a dire need of establishing a link between laboratory and clinical findings to make it effective and safe tool for in vivo treatments.

Unusual cutaneous leukocytoclastic vasculitis: A case report

Leukocytoclastic vasculitis, also known as cutaneous small vessel vasculitis, embodies a challenging condition for both the physician and the patient. This condition is affecting mainly the small vessels, commonly the post-capillary venules, being characterized by presence of neutrophilic infiltration within and throughout the vessel wall with signs of leukocytoclasia, fibrinoid necrosis and local damage to the vessel wall and the surrounding tissue. Frequently, it is associated with other conditions (cryoglobulinemic vasculitis, IgA vasculitis, ANCA-associated vasculitides), infections, medication, systemic diseases (systemic lupus erythematosus, Sjogren syndrome, rheumatoid arthritis). Cutaneous leukocytoclastic vasculitis is considered a rare condition. We are presenting a 46 year old man, with history of chronic urticaria, presented in our clinic for recurrent intensely pruritic urticarian plaques, disseminated on limbs and trunk, associating bullae with serocitrin content. Petechiae and palpable purpura were observed just in a few places. Bullous lesions occurred after the patient went through COVID-19 and followed a self-treatment with paracetamol. Patch and prick tests were performed on this patient, identifying positive reactions to hydroxyisohexyl-3-cyclohexane-carboxaldehyde, fragrance mix and paracetamol. Histopathological exam evidentiated tipically aspect for leukocytoclastic vasculitis and subepidermal vesicle-bullae lesion. IgM/IgG immune complexes, C3 and fibrinogen were found positive in direct immunofluorescence exam. Through this scientific paper, we are presenting the crucial role of direct immunofluorescence exam in early diagnosis and evolution of this condition, efficacy of oral therapy with dapsone (anti-inflammatory properties, antioxidant scavenger effect, inhibitory effect on chemotaxis and function of neutrophils). Copyright © 2022

In vivo murine studies demonstrate that neutrophil activation by anti-NAP2 antibodies contributes to vaccine-induced immune thrombocytopenia and thrombosis (VITT)

Background: VITT involves thrombocytopenia and thrombosis post-initial anti-SARS-CoV-2 adenoviral vaccination. Most patients are found to have platelet-activating antibodies to the chemokine, platelet factor 4 (PF4) in the absence of heparin. VITT antibodies differ from those in heparin-induced thrombocytopenia (HIT), in which PF4 is bound to heparin. Distinct epitope sites on PF4 for VITT and HIT antibodies were defined (PMID34233346). We noted that the VITT antigenic site is conserved in mouse (m) PF4, and in the platelet-specific chemokine neutrophil-activating peptide 2 (NAP2), both human and mouse. We observed that VITT antibodies bind strongly to NAP2. In an active patient with VITT, we found that VITT antibodies circulate as immune complexes containing either PF4 or NAP2. Importantly, VITT antibodies plus NAP2 activates platelets. Aim(s): We tested in a passive-immunization murine model with VITT antibodies the ability to induce neutrophil-endothelial activation as an indicator of a prothrombotic state and identify the chemokines involved. Method(s): We studied two systems: A femoral vein and a cremaster venule model, using confocal intravital imaging and labeled neutrophils. VITT antibodies were infused into mice transgenic for FcgammaRIIA and lacking PF4 (FcgammaRIIA+/mPF4-/-). Result(s): This led to an immediately reduced neutrophil rolling by ~80% (14-3 m/sec) (Figure 1A,B). Subsequent infusion of PF4 slowed neutrophil rolling by another ~80% (3-0.6 m/sec). In contrast, VITT antibodies did not slow neutrophil speed in FcgammaRIIA+/ mPF4-/-/ mNAP2-/-mice (Figure 1C). Conclusion(s): These data suggest that both NAP2 and PF4 contribute to thrombosis in VITT and may explain the pathogenesis of VITT in patients with no detectable anti-PF4 antibodies. VITT may be prothrombotic because it involves co-activation of neutrophils via NAP2 by way of CXCR2 and FcgammaRIIA. Targeting NAP2 pathobiology may enhance understanding of the pathogenesis of VITT and lead to new therapeutics.

Renal Biopsy in Systemic Infections: Expect the Unexpected

Introduction: Infection-related glomerulonephritis is well recognized and often included in the differential diagnosis in patients with ongoing infections. It can be missed, however, if the infection is unusual or undetected. We present three cases where the renal biopsy findings prompted the identification or treatment of systemic infections. Case Description: Case 1: A 84-year-old male presented with acute kidney injury (AKI) and a new purpuric rash. Clinically, IgA nephropathy was suspected. A renal biopsy showed active glomerulonephritis with abundant neutrophils, focal segmental tuft necrosis, and one cellular crescent. Predominantly mesangial immune complex deposits containing IgA and IgG were seen. The findings suggested IgA-rich infection-associated glomerulonephritis. Infectious workup was positive for COVID-19, suggesting exacerbation of IgA nephropathy by recent COVID-19 infection. Case 2: A 31-year-old female status post kidney transplant for granulomatosis with polyangiitis (GPA) had recent pregnancy with preterm delivery, disseminated herpes simplex virus (HSV) infection with HSV hepatitis, and AKI. Urine culture was positive for E. coli. The differential diagnosis included HSV nephritis, drug reaction, rejection, recurrent GPA, thrombotic microangiopathy (TMA), and pyelonephritis. A renal biopsy showed proliferative glomerulonephritis with subendothelial and mesangial immune complex deposits containing IgG and C3. The findings were most consistent with infection-related immune complex glomerulonephritis, most likely related to the HSV infection. Case 3: A 78-year-old female presented with AKI, proteinuria, hematuria, and positive p-ANCA. Clinically, ANCA vasculitis was suspected, and the renal biopsy did show focal, segmental, necrotizing glomerulonephritis. However, immunofluorescence and electron microscopy showed IgM-rich immune complex deposits in the mesangium. The unusual presentation of ANCA glomerulonephritis was suggestive of an underlying infection. Bartonella antibody panel showed very high titers;the patient was treated with antibiotics for Bartonella endocarditis. Discussion(s): Infection-related glomerulonephritis has a wide variety of presentations histologically and clinically. The three cases we present here emphasize the importance of recognizing these entities to help guide treatment and improve patient care.

IgA Nephropathy as a Potential Complication of SARS-CoV-2 Vaccination

Introduction: Vaccination against COVID-19 is essential, however an immunological flare is a potential rare complication resulting in glomerulonephritis with IgA deposits in the mesangium. We present a case of a patient who developed IgA nephropathy postvaccination. Case Description: 48-year-old woman with a past medical history of Leukocytoclastic vasculitis and hypertension presented to the Emergency Department with fatigue, nausea, epigastric pain, foamy urine and a diffuse erythematous purpuric rash within days of receiving the SARS CoV-2 vaccination. Her creatinine was 1.92 mg/dL and urinalysis showed 3+blood and 30 mg/dL of protein. COVID-19 testing was negative. Protein/ creatinine ratio was 2.1 g/g and urine microscopy showed dysmorphic red blood cells. Serologies for HIV, Hepatitis B and C were negative. Further testing revealed negative ANA, normal ASO titer, absent cryoglobulins, rheumatoid factor < 20, C3 158 (nl) and C4 35 (nl). However, IgA level was elevated at 462 mg/dL (reference 70-312 mg/dL). Patient was started on prednisone at a dose of 1mg/kg with a presumptive diagnosis of IgA vasculitis/ HSP. Subsequent skin biopsy was consistent with leukocytoclastic vasculitis while kidney biopsy showed glomerular deposition of IgA and endocapillary hypercellularity. At one month follow-up with nephrology, prednisone taper was started because of good clinical response and partial remission with UPCR reduction to 1 g/g. Prednisone was gradually tapered over the next 2 months. At her 3 month follow-up she was found to be in complete remission with a UPCR 0.2 g/g and her creatinine was 0.83 mg/dL Discussion: We present a case of IgA nephropathy post-SARS CoV-2 mRNA vaccination. It has been speculated that the mRNA lipid nanoparticle-encapsulated platform contained within the mRNA vaccine produces such a robust CD4 and CD8 T-cell response that pro-inflammatory cytokines activate this immune complex associated glomerular disease. In conclusion, SARS CoV-2 vaccination may potentially trigger IgA nephropathy in predisposed patients. Steroid therapy may be efficacious in managing this rare complication.