A New Registry for Genetic Diagnosis of Inborn Errors of Immunity within the Military Health System

Genotypic definition of monogenic inborn errors of immunity (IEIs) continues to accelerate with broader access to next generation sequencing, underscoring this aggregated group of disorders as a major health burden impacting both civilian and military populations. At an estimated prevalence of 1 in 1200 individuals, IEIs affect ~8,000 patients within the Military Health System (MHS). Despite access to targeted gene/exome panels at military treatment facilities, most affected patients never receive a definitive genetic diagnosis that would significantly improve clinical care. To address this gap, we established the first registry of IEI patients within the MHS with the goal of identifying known and novel pathogenic genetic defects to increase diagnosis rates and enhance clinical care. Using the registry, a research protocol was opened in July 2022. Since July we have enrolled 75 IEI patients encompassing a breadth of phenotypes including severe and recurrent infections, bone marrow failure, autoimmunity/autoinflammation, atopic disease, and malignancy. Enrolled patients provide blood and bone marrow samples for whole genome, ultra-deep targeted panel and comprehensive transcriptome sequencing, plus cryopreservation of peripheral blood mononuclear cells for future functional studies. We are also implementing and developing analytical methods for identifying and interrogating non-coding and structural variants. Suspected pathogenic variants are adjudicated by a clinical molecular geneticist using state-of-the-art analysis pipelines. These analyses subsequently inform in vitro experiments to validate causative mutations using cell reporter systems and primary patient cells. Clinical variant validation and return of genetic results are planned with genetic counseling provided. As a proof of principle, this integrated genetic evaluation pipeline revealed a novel, candidate TLR7 nonsense variant in two adolescent brothers who both endured critical COVID-19 pneumonia, requiring mechanical ventilation and extracorporeal membrane oxygenation. Our protocol is therefore poised to greatly enrich clinical genetics resources available in the MHS for IEI patients, contributing to better diagnosis rates, informed family counseling, and targeted treatments that collectively improve the health and readiness of the military community. Moreover, our efforts should yield new mechanistic insights on immune pathogenesis for a broad variety of known and novel IEIs.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.

Mild COVID-19 outcomes in adults with inborn errors of immunity: a single-center experience

Currently, 640 million cases of coronavirus disease 2019 (COVID-19) and 6.6 million deaths have been reported world-wide. Risk factors for severe COVID-19 are known, including those with compromised immunity. Among patients with inborn errors of immunity (IEI), early reports of severe outcomes lead to strict masking and social distancing measures. While this resulted in relatively low infection rates among those with IEI, real-world data describing the clinical course of COVID-19 in this patient population have remained limited. We performed a retrospective study of adult IEI patients followed by our center in which a positive test (rapid antigen or PCR) for COVID-19 was determined between November 2021-November 2022. Medical charts were reviewed, and patient interviews conducted. All patients provided informed consent. Twenty-nine patients were enrolled (22 females, 7 males), aged between 18-69 years (median: 20-29 years). The cohort included those with antibody deficiencies (41.37%), combined immunodeficiencies (34.48%;HIES, CARD11, STAT1-GOF), immune dysregulation disorders (20.69%;LRBA deficiency, AIRE deficiency) and phagocyte defect (3.45%;CGD). The duration of symptoms ranged between 3 days-4 weeks (median: < 1 week). Upper respiratory symptoms (including sore throat, congestion) were reported in 97% while fever was present in 41% of patients. Prior to infection, 14 (48%) patients had underlying asthma or bronchiectasis - 2 subsequently experienced shortness of breath and were treated with inhalers or Sotrovimab, respectively. No treatment was required in 65.5% of cases. The remaining received Paxlovid (10.3%), Sotrovimab (13.79%), or antibiotics (10.3%). Of the 2 patients with STAT1-GOF, one tested positive during a repeat episode of febrile neutropenia which required hospitalization. No other patients were hospitalized or needed ICU admission. No deaths were recorded. In light of these favourable outcomes, patients with IEI can gradually and safely return to normal activities.Copyright © 2023 Elsevier Inc.

Anti-interferon-alpha autoantibodies in patients with inborn errors of Immunity and rheumatic diseases before and during the COVID-19 pandemic

Introduction: Type 1 interferon (IFN) autoantibodies, such as anti-IFNalpha, have pathogenic significance in life-threatening COVID-19 pneumonia. Ten to twenty percent of severe COVID cases are associated with type I IFN autoantibodies. These autoantibodies likely pre-exist while others arise de novo relative to SARS-CoV-2 infection. It is unclear to what extent type I anti-IFN autoantibodies are induced by SARS-CoV-2 infection and contribute to COVID-19 severity. We investigated these phenomena in those with inborn errors of immunity (IEI) and rheumatic disease (RHE). Aim(s): We aim to compare the prevalence and neutralization ability of anti-IFNalpha autoantibodies in IEI and RHE patients using archived blood samples before and after the COVID-19 pandemic began. Method(s): We determined the presence of autoantibodies against IFNalpha in plasma samples by enzyme linked immunosorbent assay in 453 patients with IEI or RHE who were testing either before or after the COVID-19 pandemic began in March 2020. Using flow cytometry, we determined the function of IFNalpha autoantibodies in plasma to block CD4T cell activation by inhibiting STAT-1 phosphorylation. Result(s): We found that 25 patients with IEI or RHE were positive for anti-IFNalpha autoantibodies. 10 out of 229 patient samples collected before the pandemic (4.2%) tested positive whereas 15 out of 224 patient samples collected after the pandemic began (7.0%) were positive. Seven of the 25 patients (28%) who tested positive had neutralizing antibodies in plasma, which prevented STAT-1 phosphorylation in CD4T cells;all of these patients had partial recombination activating gene deficiency (pRD) except for one patient with autoimmunity, leukemia and selective IgA deficiency. One pRD patient had anti-IFNalpha autoantibodies with neutralization capacity before the pandemic, which persisted after hematopoietic stem cell transplantation (HSCT) with full immune reconstitution. The patient was immunized for SARS-CoV-2 before and after HSCT and acquired COVID-19 infection a year after HSCT. The patient was symptomatic but never hospitalized and fully recovered despite having anti-IFNalpha autoantibodies. Conclusion(s): Anti-IFNalpha autoantibody levels were comparable before and after the start of the COVID-19 pandemic in IEI and RHE patients but only 28% of cases were neutralizing. The clinical implications of these autoantibodies are yet to be determined.Copyright © 2023 Elsevier Inc.

Severity Outcomes among Adult Patients with Primary Immunodeficiency and COVID-19 Seen in Emergency Departments, United States, April 2020-August 2021.

Primary immunodeficiencies (PIs) are a group of diseases that increase susceptibility to infectious diseases. Few studies have examined the relationship between PI and COVID-19 outcomes. In this study, we used Premier Healthcare Database, which contains information on inpatient discharges, to analyze COVID-19 outcomes among 853 adult PI and 1,197,430 non-PI patients who visited the emergency department. Hospitalization, intensive care unit (ICU) admission, invasive mechanical ventilation (IMV), and death had higher odds in PI patients than in non-PI patients (hospitalization aOR: 2.36, 95% CI: 1.87-2.98; ICU admission aOR: 1.53, 95% CI: 1.19-1.96; IMV aOR: 1.41, 95% CI: 1.15-1.72; death aOR: 1.37, 95% CI: 1.08-1.74), and PI patients spent on average 1.91 more days in the hospital than non-PI patients when adjusted for age, sex, race/ethnicity, and chronic conditions associated with severe COVID-19. Of the largest four PI groups, selective deficiency of the immunoglobulin G subclass had the highest hospitalization frequency (75.2%). This large study of United States PI patients provides real-world evidence that PI is a risk factor for adverse COVID-19 outcomes.

Immune Responses 6 Months After mRNA-1273 COVID-19 Vaccination and the Effect of a Third Vaccination in Patients with Inborn Errors of Immunity.

PURPOSE: Patients with inborn errors of immunity (IEI) are at increased risk of severe coronavirus disease-2019 (COVID-19). Effective long-term protection against COVID-19 is therefore of great importance in these patients, but little is known about the decay of the immune response after primary vaccination. We studied the immune responses 6 months after two mRNA-1273 COVID-19 vaccines in 473 IEI patients and subsequently the response to a third mRNA COVID-19 vaccine in 50 patients with common variable immunodeficiency (CVID). METHODS: In a prospective multicenter study, 473 IEI patients (including X-linked agammaglobulinemia (XLA) (N = 18), combined immunodeficiency (CID) (N = 22), CVID (N = 203), isolated or undefined antibody deficiencies (N = 204), and phagocyte defects (N = 16)), and 179 controls were included and followed up to 6 months after two doses of the mRNA-1273 COVID-19 vaccine. Additionally, samples were collected from 50 CVID patients who received a third vaccine 6 months after primary vaccination through the national vaccination program. SARS-CoV-2-specific IgG titers, neutralizing antibodies, and T cell responses were assessed. RESULTS: At 6 months after vaccination, the geometric mean antibody titers (GMT) declined in both IEI patients and healthy controls, when compared to GMT 28 days after vaccination. The trajectory of this decline did not differ between controls and most IEI cohorts; however, antibody titers in CID, CVID, and isolated antibody deficiency patients more often dropped to below the responder cut-off compared to controls. Specific T cell responses were still detectable in 77% of controls and 68% of IEI patients at 6 months post vaccination. A third mRNA vaccine resulted in an antibody response in only two out of 30 CVID patients that did not seroconvert after two mRNA vaccines. CONCLUSION: A similar decline in IgG titers and T cell responses was observed in patients with IEI when compared to healthy controls 6 months after mRNA-1273 COVID-19 vaccination. The limited beneficial benefit of a third mRNA COVID-19 vaccine in previous non-responder CVID patients implicates that other protective strategies are needed for these vulnerable patients.

Detection of specific RBD+ IgG+ memory B cells by flow cytometry in healthcare workers and patients with inborn errors of immunity after BNT162b2 m RNA COVID-19 vaccination.

Introduction: Inborn errors of immunity (IEI) are a heterogeneous group of diseases caused by intrinsic defects of the immune system. Estimating the immune competence of immunocompromised patients for an infection risk assessment or after SARS-CoV-2 vaccination constituted a challenge. Methods: The aim of this study was to determine the humoral responses of patients with IEI through a comprehensive analysis of specific receptor-binding domain-positive (RBD+) IgG+ memory B cells (MBCs) by flow cytometry, together with routine S-specific IgG antibodies and QuantiFERON SARS-CoV-2 (T-cell response), before the vaccine and 3 weeks after a second dose. Results and discussion: We first analyzed the percentage of specific RBD+ IgG+ MBCs in healthy healthcare workers. Within the control group, there was an increase in the percentage of specific IgG+ RBD+ MBCs 21 days after the second dose, which was consistent with S-specific IgG antibodies.Thirty-one patients with IEI were included for the pre- and post-vaccination study; IgG+ RBD+ MBCs were not evaluated in 6 patients due to an absence of B cells in peripheral blood. We detected various patterns among the patients with IEI with circulating B cells (25, 81%): an adequate humoral response was observed in 12/25, consider by the detection of positive S-specific IgG antibodies and the presence of specific IgG+ RBD+ MBCs, presenting a positive T-cell response; in 4/25, very low S-specific IgG antibody counts correlated with undetectable events in the IgG+ RBD+ MBC compartment but with positive cellular response. Despite the presence of S-specific IgG antibodies, we were unable to detect a relevant percentage of IgG+ RBD+ MBCs in 5/25; however, all presented positive T-cell response. Lastly, we observed a profound failure of B and T-cell response in 3 (10%) patients with IEI, with no assessment of S-specific IgG antibodies, IgG+ RBD+ MBCs, and negative cellular response. The identification of specific IgG+ RBD+ MBCs by flow cytometry provides information on different humoral immune response outcomes in patients with IEI and aids the assessment of immune competence status after SARS-CoV-2 mRNA vaccine (BNT162b2), together with S-specific IgG antibodies and T-cell responses.

COVID-19 vaccination in patients with primary immunodeficiencies: an international survey on patient vaccine hesitancy and self-reported adverse events.

Introduction: The Sars-CoV-2 pandemic caused great concern for this novel virus among patients with primary immunodeficiency (PID) or inborn errors of immunity (IEI) and their families. When COVID-19 vaccination program started, no data existed on adverse events (AEs) in this particular patient population, nor if patients felt hesitancy being vaccinated. Objectives: To explore i) reasons for COVID-19 vaccination hesitancy, ii) the number and symptoms of AEs and their severity, durability and management. Method: The organisations International Patient Organisation for Primary Immunodeficiencies (IPOPI), European Society for Immunodeficiencies (ESID) and International Nursing Group for Immunodeficiencies (INGID) distributed a global self-administered online survey. Results: The survey was completed by 1317 patients (mean 47, range 12-100, years) from 40 countries. 41.7% of the patients denoted some hesitancy to COVID-19 vaccination, mainly having doubts about postvaccination protection related to their underlying PID and concerns about negative long-term effects. More women (22.6%) reported "very" or "pretty much" hesitancy compared to men (16.4%) (P<0.05). The most common systemic AEs were fatigue, muscle/body pain and headache, usually the same day or the day after the vaccination and lasting for 1-2 days. 27.8% of the respondents reported severe systemic AEs after any dose of COVID-19 vaccine. Only a minority (7.8%) of these patients visited a health-care professional and 20 patients (1.5%) were hospitalized or seen at emergency room without specifying subsequent admission at the hospital. Significantly more local and systemic AEs were reported after the second dose. No differences regarding AEs were observed across different PID subgroups or vaccine types. Conclusion: At the time of the survey, almost half of the patients reported having felt hesitancy to COVID-19 vaccination highlighting the importance and need of developing joint international guidelines and education programs about COVID-19 vaccination. The types of AEs were comparable to healthy controls, but more frequent AEs were reported. Clinical studies and prospective, detailed registration of AEs related to COVID-19 vaccines in this patient population is of great importance. It is crucial to elucidate whether there is a coincidental or causal association between COVID-19 vaccine and some severe systemic AEs. Our data do not contradict that patients with PID can be advised to be vaccinated against COVID-19, in accordance with applicable national guidelines.

Impact of SARS-CoV-2 infection and COVID-19 on patients with inborn errors of immunity.

Since the arrival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019, its characterization as a novel human pathogen, and the resulting coronavirus disease 2019 (COVID-19) pandemic, over 6.5 million people have died worldwide-a stark and sobering reminder of the fundamental and nonredundant roles of the innate and adaptive immune systems in host defense against emerging pathogens. Inborn errors of immunity (IEI) are caused by germline variants, typically in single genes. IEI are characterized by defects in development and/or function of cells involved in immunity and host defense, rendering individuals highly susceptible to severe, recurrent, and sometimes fatal infections, as well as immune dysregulatory conditions such as autoinflammation, autoimmunity, and allergy. The study of IEI has revealed key insights into the molecular and cellular requirements for immune-mediated protection against infectious diseases. Indeed, this has been exemplified by assessing the impact of SARS-CoV-2 infection in individuals with previously diagnosed IEI, as well as analyzing rare cases of severe COVID-19 in otherwise healthy individuals. This approach has defined fundamental aspects of mechanisms of disease pathogenesis, immunopathology in the context of infection with a novel pathogen, and therapeutic options to mitigate severe disease. This review summarizes these findings and illustrates how the study of these rare experiments of nature can inform key features of human immunology, which can then be leveraged to improve therapies for treating emerging and established infectious diseases.

Cellular mechanisms and clinical applications for phenocopies of inborn errors of immunity: infectious susceptibility due to cytokine autoantibodies.

INTRODUCTION: With a growing knowledge of Inborn errors immunity (IEI), immunological profiling and genetic predisposition to IEI phenocopies have been developed in recent years. AREAS COVERED: Here we summarized the correlation between various pathogen invasions, autoantibody profiles, and corresponding clinical features in the context of patients with IEI phenocopies. It has been extensively evident that patients with anti-cytokine autoantibodies underly impaired anti-pathogen immune responses and lead to broad unregulated inflammation and tissue damage. Several hypotheses of anti-cytokine autoantibodies production are summarized here, including a defective negative selection of autoreactive T cells, abnormal germinal center formation, molecular mimicry, HLA class II allele region, lack of auto-reactive lymphocyte apoptosis, and other possible hypotheses. EXPERT OPINION: Phenocopies of IEI associated with anti-cytokine autoantibodies are increasingly recognized as one of the causes of acquired immunodeficiency and susceptibility to certain pathogen infections, especially facing the current challenge of the COVID-19 pandemic. By investigating clinical, genetic, and pathogenesis autoantibodies profiles associated with various pathogens' susceptibilities, we could better understand the IEI phenocopies with anti-cytokine autoantibodies, especially for those that underlie life-threatening SARS-CoV-2.

Long term longitudinal follow-up of an AD-HIES cohort: the impact of early diagnosis and enrollment to IPINet centers on the natural history of Job's syndrome.

Job's syndrome, or autosomal dominant hyperimmunoglobulin E syndrome (AD-HIES, STAT3-Dominant Negative), is a rare inborn error of immunity (IEI) with multi-organ involvement and long-life post-infective damage. Longitudinal registries are of primary importance in improving our knowledge of the natural history and management of these rare disorders. This study aimed to describe the natural history of 30 Italian patients with AD-HIES recorded in the Italian network for primary immunodeficiency (IPINet) registry. This study shows the incidence of manifestations present at the time of diagnosis versus those that arose during follow up at a referral center for IEI. The mean time of diagnostic delay was 13.7 years, while the age of disease onset was < 12 months in 66.7% of patients. Respiratory complications, namely bronchiectasis and pneumatoceles, were present at diagnosis in 46.7% and 43.3% of patients, respectively. Antimicrobial prophylaxis resulted in a decrease in the incidence of pneumonia from 76.7% to 46.7%. At the time of diagnosis, skin involvement was present in 93.3% of the patients, including eczema (80.8%) and abscesses (66.7%). At the time of follow-up, under therapy, the prevalence of complications decreased: eczema and skin abscesses reduced to 63.3% and 56.7%, respectively. Antifungal prophylaxis decreased the incidence of mucocutaneous candidiasis from 70% to 56.7%. During the SARS-CoV-2 pandemic, seven patients developed COVID-19. Survival analyses showed that 27 out of 30 patients survived, while three patients died at ages of 28, 39, and 46 years as a consequence of lung bleeding, lymphoma, and sepsis, respectively. Analysis of a cumulative follow-up period of 278.7 patient-years showed that early diagnosis, adequate management at expertise centers for IEI, prophylactic antibiotics, and antifungal therapy improve outcomes and can positively influence the life expectancy of patients.

NFKB2 haploinsufficiency identified via screening for IFN-α2 autoantibodies in children and adolescents hospitalized with SARS-CoV-2-related complications.

BACKGROUND: Autoantibodies against type I IFNs occur in approximately 10% of adults with life-threatening coronavirus disease 2019 (COVID-19). The frequency of anti-IFN autoantibodies in children with severe sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is unknown. OBJECTIVE: We quantified anti-type I IFN autoantibodies in a multicenter cohort of children with severe COVID-19, multisystem inflammatory syndrome in children (MIS-C), and mild SARS-CoV-2 infections. METHODS: Circulating anti-IFN-α2 antibodies were measured by a radioligand binding assay. Whole-exome sequencing, RNA sequencing, and functional studies of peripheral blood mononuclear cells were used to study any patients with levels of anti-IFN-α2 autoantibodies exceeding the assay's positive control. RESULTS: Among 168 patients with severe COVID-19, 199 with MIS-C, and 45 with mild SARS-CoV-2 infections, only 1 had high levels of anti-IFN-α2 antibodies. Anti-IFN-α2 autoantibodies were not detected in patients treated with intravenous immunoglobulin before sample collection. Whole-exome sequencing identified a missense variant in the ankyrin domain of NFKB2, encoding the p100 subunit of nuclear factor kappa-light-chain enhancer of activated B cells, aka NF-κB, essential for noncanonical NF-κB signaling. The patient's peripheral blood mononuclear cells exhibited impaired cleavage of p100 characteristic of NFKB2 haploinsufficiency, an inborn error of immunity with a high prevalence of autoimmunity. CONCLUSIONS: High levels of anti-IFN-α2 autoantibodies in children and adolescents with MIS-C, severe COVID-19, and mild SARS-CoV-2 infections are rare but can occur in patients with inborn errors of immunity.

COVID-19 in the context of inborn errors of immunity, autoimmune diseases, and immune suppression

The COVID-19 pandemic reached five waves in three years, with over 6.5 million deaths across the globe. Knowing the differential susceptibility to the novel betacoronavirus has allowed us to better understand the pathophysiology and inflammatory complications and dissect the response against the virus. As in other viral infections, CD8+ T lymphocytes and NK cells stand out as key players, together with viral sensors, type 1 interferons, an exaggerated inflammatory response by NLRP3, and a storm that includes cytokines IL-6 and IL-8. Whole-exome sequencing has identified several genes with pathogenic germline variants in patients with severe COVID-19;said genes would account for around 5% of all severe cases. In addition, up to 20% of hospitalized adults harbor autoantibodies against type-I and III interferons. These findings translate into novel genetic etiologies, whereas autoantibodies explain the worse prognosis of the elderly, linked to the inflammaging phenomenon. In general, patients with known primary immune deficiencies who acquired COVID-19 fared well, with global survival rates over 80% and a predominance of mild courses. The exceptions were patients with severe-combined immune deficiency, and with the autoimmune polyglandular syndrome 1, the latter because they develop autoantibodies against interferon. Neither have there been reports of greater severity in patients with autoimmune or autoinflammatory disorders. However, those receiving immunosuppressant treatments usually have a more protracted course. Patients with NLRP3 or STAT1 gain of function might be especially susceptible to systemic inflammatory complications. In this review, we summarize the global experience in the caretaking of patients with immune alterations who were infected by SARS-CoV-2. © 2022 Instituto Nacional de Pediatria. All rights reserved.

Course of COVID-19 in immunocompromised patients

Purpose - to analyze the currently described variants of the course of COVID-19 in immunocompromised patients in order to inform the medical community and focus on this problem. Two clinical cases of different course of COVID-19 in patients with primary immunodeficiencies, both mild, asymptomatic and severe, with a fatal outcome, are presented. In the first case, in a child with Nijmegen breakage syndrome, despite lymphopenia, the course of SARS-CoV-2 was asymptomatic, which may be due to the regular administration of immunoglobulin for replacement purposes. The peculiarity of the second case was a repeated episode of COVID-19 in an immunocompromised child with APECED. The first episode of COVID-19 in September 2020 had a mild course, but led to the manifestation of immunodeficiency symptoms. The present symptoms (retinopathy, hepatitis), except for mild mucosal candidiasis, are not part of the triad of classic APECED symptoms, although along with the reaction to the live vaccine, they made it possible to suspect immunodeficiency. Immunosuppressive therapy contributed to stabilization of hepatitis, but ocular symptoms were without positive dynamics. The second episode of COVID-19 was observed in January 2022. It proceeded with prolonged fever for 2 weeks, which was resistant to treatment, with progressive cytopenia, hypoproteinemia, hypoalbuminemia, signs of active hepatitis, hyperferritinemia, elevated triglycerides;coagulopathy with low fibrinogen levels. Subsequently, signs of pneumonia were added, confirmed by radiology. Another feature of this case was the presence of a mixed infection - COVID-19 and Epstein-Barr virus infection. The cause of death in this case was not only COVID-19 pneumonia, but also progressive macrophage activation syndrome. Conclusions. Thus, the sequence of COVID-19 in patients with inborn errors of immunity can be either asymptomatic and mild or fatal, depending on the type of immune disorders, the therapy received, and concomitant conditions. SARS-CoV-2 in immunocompromised individuals requires close attention for timely diagnosis of life-threatening conditions. © 2022 Group of Companies Med Expert, LLC. All rights reserved.

Immunoglobulin repertoire restriction characterizes the serological responses of patients with predominantly antibody deficiency.

BACKGROUND: Predominantly antibody deficiency (PAD) is the most common category of inborn errors of immunity and is underpinned by impaired generation of appropriate antibody diversity and quantity. In the clinic, responses are interrogated by assessment of vaccination responses, which is central to many PAD diagnoses. However, the composition of the generated antibody repertoire is concealed from traditional quantitative measures of serological responses. Leveraging modern mass spectrometry-based proteomics (MS-proteomics), it is possible to elaborate the molecular features of specific antibody repertoires, which may address current limitations of diagnostic vaccinology. OBJECTIVES: We sought to evaluate serum antibody responses in patients with PAD following vaccination with a neo-antigen (severe acute respiratory syndrome coronavirus-2 vaccination) using MS-proteomics. METHODS: Following severe acute respiratory syndrome coronavirus-2 vaccination, serological responses in individuals with PAD and healthy controls (HCs) were assessed by anti-S1 subunit ELISA and neutralization assays. Purified anti-S1 subunit IgG and IgM was profiled by MS-proteomics for IGHV subfamily usage and somatic hypermutation analysis. RESULTS: Twelve patients with PAD who were vaccine-responsive were recruited with 11 matched vaccinated HCs. Neutralization and end point anti-S1 titers were lower in PAD. All subjects with PAD demonstrated restricted anti-S1 IgG antibody repertoires, with usage of <5 IGHV subfamilies (median: 3; range 2-4), compared to ≥5 for the 11 HC subjects (P < .001). IGHV3-7 utilization was far less common in patients with PAD than in HCs (2 of 12 vs 10 of 11; P = .001). Amino acid substitutions due to somatic hypermutation per subfamily did not differ between groups. Anti-S1 IgM was present in 64% and 50% of HC and PAD cohorts, respectively, and did not differ significantly between HCs and patients with PAD. CONCLUSIONS: This study demonstrates the breadth of anti-S1 antibodies elicited by vaccination at the proteome level and identifies stereotypical restriction of IGHV utilization in the IgG repertoire in patients with PAD compared with HC subjects. Despite uniformly pauci-clonal antibody repertoires some patients with PAD generated potent serological responses, highlighting a possible limitation of traditional serological techniques. These findings suggest that IgG repertoire restriction is a key feature of antibody repertoires in PAD.

Human Inborn Errors of Immunity: 2022 Update on the Classification from the International Union of Immunological Societies Expert Committee.

We report the updated classification of inborn errors of immunity, compiled by the International Union of Immunological Societies Expert Committee. This report documents the key clinical and laboratory features of 55 novel monogenic gene defects, and 1 phenocopy due to autoantibodies, that have either been discovered since the previous update (published January 2020) or were characterized earlier but have since been confirmed or expanded in subsequent studies. While variants in additional genes associated with immune diseases have been reported in the literature, this update includes only those that the committee assessed that reached the necessary threshold to represent novel inborn errors of immunity. There are now a total of 485 inborn errors of immunity. These advances in discovering the genetic causes of human immune diseases continue to significantly further our understanding of molecular, cellular, and immunological mechanisms of disease pathogenesis, thereby simultaneously enhancing immunological knowledge and improving patient diagnosis and management. This report is designed to serve as a resource for immunologists and geneticists pursuing the molecular diagnosis of individuals with heritable immunological disorders and for the scientific dissection of cellular and molecular mechanisms underlying monogenic and related human immune diseases.

COVID-19 Vaccination Responses with Different Vaccine Platforms in Patients with Inborn Errors of Immunity.

Patients with inborn errors of immunity (IEI) in Argentina were encouraged to receive licensed Sputnik, AstraZeneca, Sinopharm, Moderna, and Pfizer vaccines, even though most of the data of humoral and cellular responses combination on available vaccines comes from trials conducted in healthy individuals. We aimed to evaluate the safety and immunogenicity of the different vaccines in IEI patients in Argentina. The study cohort included adults and pediatric IEI patients (n = 118) and age-matched healthy controls (HC) (n = 37). B cell response was evaluated by measuring IgG anti-spike/receptor binding domain (S/RBD) and anti-nucleocapsid(N) antibodies by ELISA. Neutralization antibodies were also assessed with an alpha-S protein-expressing pseudo-virus assay. The T cell response was analyzed by IFN-γ secretion on S- or N-stimulated PBMC by ELISPOT and the frequency of S-specific circulating T follicular-helper cells (TFH) was evaluated by flow cytometry.No moderate/severe vaccine-associated adverse events were observed. Anti-S/RBD titers showed significant differences in both pediatric and adult IEI patients versus the age-matched HC cohort (p < 0.05). Neutralizing antibodies were also significantly lower in the patient cohort than in age-matched HC (p < 0.01). Positive S-specific IFN-γ response was observed in 84.5% of IEI patients and 82.1% presented S-specific TFH cells. Moderna vaccines, which were mainly administered in the pediatric population, elicited a stronger humoral response in IEI patients, both in antibody titer and neutralization capacity, but the cellular immune response was similar between vaccine platforms. No difference in humoral response was observed between vaccinated patients with and without previous SARS-CoV-2 infection.In conclusion, COVID-19 vaccines showed safety in IEI patients and, although immunogenicity was lower than HC, they showed specific anti-S/RBD IgG, neutralizing antibody titers, and T cell-dependent cellular immunity with IFN-γ secreting cells. These findings may guide the recommendation for a vaccination with all the available vaccines in IEI patients to prevent COVID-19 disease.

Hypoparathyroidism-Retardation-Dysmorphism Syndrome due to a Variant in the Tubulin-Specific Chaperone E Gene as a Cause of Combined Immune Deficiency.

BACKGROUND: Hypoparathyroidism-retardation-dysmorphism (HRD) syndrome is a disease composed of hypoparathyroidism, growth retardation, severe developmental delay, and typical dysmorphic features caused by the tubulin-specific chaperone E gene variant. Many patients succumb in infancy to HRD due to overwhelming infections mainly caused by Pneumococcus spp. Knowledge related to the immune system in these patients is scarce. PURPOSE: To define the immune phenotype of a cohort of HRD patients including their cellular, humoral, and neutrophil functions. METHODS: The study included HRD patients followed at Soroka University Medical Center. Clinical and immunological data were obtained, including immunoglobulin concentrations, specific antibody titers, lymphocyte subpopulations, lymphocyte proliferation, and neutrophil functions. RESULTS: Nine patients (5 females and 4 males) were enrolled, aged 6 months to 15 years. All received amoxicillin prophylaxis as part of a routine established previously. Three patients had bacteremia with Klebsiella, Shigella spp., and Candida. Three patients had confirmed coronavirus disease 19 (COVID-19), and two of them died from this infection. All patients had normal blood counts. Patients showed high total IgA and IgE levels, low anti-pneumococcal antibodies in spite of a routine vaccination schedule, and reduced frequency of naive B cells with increased frequency of CD21lowCD27- B cells. All patients had abnormal T-cell population distributions, including reduced terminally differentiated effector memory CD8, inverted CD4/CD8 ratios, and impaired phytohemagglutinin (PHA)-induced lymphocyte proliferation. Neutrophil superoxide production and chemotaxis were normal in all patients tested. CONCLUSION: HRD is a combined immunodeficiency disease with syndromic features, manifesting in severe invasive bacterial and viral infections.

Human IRF1 governs macrophagic IFN-γ immunity to mycobacteria.

Inborn errors of human IFN-γ-dependent macrophagic immunity underlie mycobacterial diseases, whereas inborn errors of IFN-α/ß-dependent intrinsic immunity underlie viral diseases. Both types of IFNs induce the transcription factor IRF1. We describe unrelated children with inherited complete IRF1 deficiency and early-onset, multiple, life-threatening diseases caused by weakly virulent mycobacteria and related intramacrophagic pathogens. These children have no history of severe viral disease, despite exposure to many viruses, including SARS-CoV-2, which is life-threatening in individuals with impaired IFN-α/ß immunity. In leukocytes or fibroblasts stimulated in vitro, IRF1-dependent responses to IFN-γ are, both quantitatively and qualitatively, much stronger than those to IFN-α/ß. Moreover, IRF1-deficient mononuclear phagocytes do not control mycobacteria and related pathogens normally when stimulated with IFN-γ. By contrast, IFN-α/ß-dependent intrinsic immunity to nine viruses, including SARS-CoV-2, is almost normal in IRF1-deficient fibroblasts. Human IRF1 is essential for IFN-γ-dependent macrophagic immunity to mycobacteria, but largely redundant for IFN-α/ß-dependent antiviral immunity.