SAFETY AND PHARMACOKINETICS OF IGPRO20 (SUBCUTANEOUS IMMUNOGLOBULIN) AND IGPRO10 (INTRAVENOUS IMMUNOGLOBULIN) IN ADULTS WITH SYSTEMIC SCLEROSIS (SSC) – RESULTS FROM A PHASE 2 TRIAL

BackgroundSystemic sclerosis (SSc) is a severe, progressive multisystem rheumatic disease with high mortality, but without approved disease-modifying treatment to stop or reverse course of disease. Intravenous immunoglobulin G (IgG) may have a positive impact on SSc based upon available literature reports. However, to date, there have been no clinical trials evaluating subcutaneous IgG (SCIG) in SSc. In particular, the impact of pathologically altered skin in SSc on local safety and pharmacokinetics (PK) of SCIG has not been explored yet.ObjectivesThe primary and secondary objectives of this trial (NCT04137224) included safety, including local infusion safety, and bioavailability of subcutaneous IgG (IgPro20) in adults with diffuse cutaneous SSc (dcSSc).MethodsThis was a randomized, open-label, crossover study. Adult subjects with dcSSc diagnosis within 5 years from first non-Raynaud's phenomenon and modified Rodnan Skin Score of 15-45 at screening were randomized 1:1 to sequence A (IgPro20, 20% normal human subcutaneous immunoglobulin followed by IgPro10, 10% normal human intravenous immunoglobulin) or sequence B (IgPro10 followed by IgPro20). Each subject was to complete two treatment periods (16 weeks each), with up to 40 weeks (including screening) study duration for an individual subject. Doses received were 0.5g/kg/week split over two sessions for IgPro20, and 2g/kg/4 weeks split over 2-5 days for IgPro10. The primary endpoint was safety of IgPro20, described as treatment-emergent adverse events (TEAEs) and changes in clinical observations.Results27 subjects were randomized, with 13 subjects to sequence A and 14 subjects to sequence B. In total, 25 subjects completed the study. Of 27 treated subjects, 107 TEAEs occurred in 22 subjects (81.5%) over the 36-week study period, the majority of which were mild or moderate. The most common TEAEs (>10% of subjects) by preferred term (PT) were headache (12 events occurring in 6 subjects [22.2%]), COVID-19 (3 events occurring in 3 subjects [11.1%]), diarrhoea (3 events occurring in 3 subjects [11.1%]), and vomiting (3 events occurring in 3 subjects [11.1%]).A total of 10 serious AEs (SAEs) were reported in 6 subjects (Viral infection, Chronic gastritis, Vomiting, Dehydration, Upper gastrointestinal haemorrhage, Chest pain, Myocardial infarction, Myocardial ischemia, Breast cancer, Interstitial lung disease). Among these, one subject experienced 2 SAEs (myocardial ischemia & myocardial infarction) and was discontinued from study treatment. None of the SAEs were considered related to study treatment by the investigator, and no deaths were reported.For IgPro20, 14 infusion site reactions (ISRs) occurred in 5 subjects (19.2%), all were mild or moderate in severity. The most common ISRs were infusion site pain and infusion site swelling (3 events in 2 subjects each, 7.7%). In total, 686 IgPro20 infusions were performed, resulting in an overall ISR rate per infusion of 0.02, ie 2 ISRs per 100 infusions. No ISRs were reported for IgPro10.No clinically relevant trends in vital signs, body weight, clinical laboratory tests, electrocardiograms, or pulmonary function tests were observed.PK profiles and bioavailability in dcSSc subjects were similar to those observed in other approved indications such as Primary Immunodeficiency. Population relative bioavailability of IgPro20, based on dose-normalized, baseline-corrected AUC0-tau was 0.761 (90% CI: 0.7033, 0.8232), ie 76.1% compared to IgPro10 (intravenous IgG).ConclusionThe overall safety profiles of IgPro20 and IgPro10 in subjects with dcSSc were consistent with that in approved indications such as CIDP, including a relatively low ISR rate for IgPro20. PK profiles and bioavailability were also similar to other indications. This study indicates that subcutaneous administration of IgPro20 has acceptable safety, bioavailability and PK profiles in patients with dcSSc. AcknowledgementsEditorial assistance was provided by Meridian HealthComms Ltd., funded by CSL Behring.Disclosure of InterestsChristopher P Denton Speakers bureau: Ja ssen, Boehringer Ingelheim, Consultant of: GSK, CSL Behring, Boehringer Ingelheim, Merck, Roche, Sanofi, Grant/research support from: GSK, CSL Behring, Inventiva, Horizon, Otylia Kowal-Bielecka Speakers bureau: Abbvie, Janssen-Cilag, Boehringer Ingelheim, Medac, MSD, Novartis, Pfizer, Sandoz, Consultant of: Boehringer Ingelheim and Novartis, Grant/research support from: Received congress support from Abbvie, Boehringer Ingelheim, and Medac, Susanna Proudman Speakers bureau: Boehringer Ingelheim, Grant/research support from: Janssen, Marzena Olesińska Consultant of: AstraZeneca, Margitta Worm Consultant of: Novartis Pharma GmbH, Sanofi-Aventis Deutschland GmbH, DBV Technologies S.A, Aimmune Therapeutics UK Limited, Regeneron Pharmaceuticals, Inc, Leo Pharma GmbH, Boehringer Ingelheim Pharma GmbH &Co.KG, ALK-Abelló Arzneimittel GmbH, Kymab Limited, Amgen GmbH, Abbvie Deutschland GmbH & Co. KG, Pfizer Pharma GmbH, Mylan Germany GmbH (A Viatris Company), AstraZeneca GmbH, Lilly Deutschland GmbH and GlaxoSmithKline GmbH & Co. KG., Nicoletta Del Papa Speakers bureau: Janssen Cilag, Boehringer Ingelheim., Marco Matucci-Cerinic Speakers bureau: Biogen, Sandoz, Boehringer Ingelheim, Consultant of: CSL Behring, Boehringer Ingelheim, Grant/research support from: MSD, Chemomab, Jana Radewonuk Shareholder of: CSL Behring, Employee of: CSL Behring, Jeanine Jochems Shareholder of: CSL Behring, Employee of: CSL Behring, Amgad Shebl Shareholder of: CSL Behring, Employee of: CSL Behring, Anna Krupa Shareholder of: CSL Behring, Employee of: CSL Behring, Jutta Hofmann Shareholder of: CSL Behring, Employee of: CSL Behring, Maria Gasior Shareholder of: CSL Behring, Employee of: CSL Behring.

[Pre-exposure prophylaxis of new COVID-19 coronavirus infection with tixagevimab/cilgavimab in adult Moscow patients with primary immunodeficiencies].

BACKGROUND: Primary immunodeficiencies (PIDs), now known as inborn errors of immunity, are a group of inherited diseases caused by defects in the genes that control the immune response. Patients with PIDs have risks of developing a severe course and/or death in COVID-19. Passive immunization with long-acting monoclonal antibodies (MABs) to SARS-CoV-2 should be considered as pre-exposure prophylaxis in patients with PIDs. Tixagevimab/cilgavimab is a combination of MABs that bind to the SARS-CoV-2 spike protein. AIM: To evaluate the efficacy and safety of pre-exposure prophylaxis of new SARS-CoV-2 infection in PIDs with the combination of tixagevimab/cilgavimab. MATERIALS AND METHODS: Forty eight patients diagnosed with PIDs were included in the study. Median follow-up after drug administration was 174 days. The total number of confirmed coronavirus infections in patients with PIDs as well as 6 months before and after administration of MAT were assessed. RESULTS: In the analyzed cohort, the overall incidence of COVID-19 from pandemic onset to MABs administration was 75% (36/48), with 31% (11/36) of over-infected patients having had the infection more than once. The incidence of COVID-19 immediately 6 months before the introduction of tixagevimab/cilgavimab was 40%. All patients who had COVID-19 after pre-exposure prophylaxis had a mild infection. The incidence of COVID-19 6 months after tixagevimab/cilgavimab administration significantly decreased compared to the incidence 6 months before administration (7 and 40%, respectively; p<0.001). CONCLUSION: The use of tixagevimab/cilgavimab in patients with PIDs is effective as pre-exposure prophylaxis and reduces the risk of severe COVID-19.

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.

Impacts of the COVID-19 response on populations with chronic conditions and developmental disabilities

People with chronic conditions faced a type of double jeopardy during the COVID-19 pandemic. Their pre-existing health conditions made them more likely to become severely ill-and more likely to be admitted to intensive care, intubated, and die-if infected with SARS-CoV-2, the virus that causes COVID-19. At the same time, access to needed screening, testing, and treatment was often limited due to the cancelation of primary care services by healthcare providers and systems overwhelmed by the need to treat patients with COVID-19. Patients with chronic conditions feared being exposed to COVID-19 while receiving care. The resulting stress, fear, and anxiety made the management of chronic diseases even more difficult. Several subsets of patients with certain medical conditions, including immunodeficiencies and disabilities, were particularly impacted. The COVID-19 pandemic, and the response to it, also impacted support and services available to caregivers and heightened stress, particularly among parents and caregivers. © 2023 The authors.

Cellular and humoral immunogenicity of the COVID-19 vaccine and COVID-19 disease severity in individuals with immunodeficiency.

Background: A well-coordinated adaptive immune response is crucial for limiting COVID-19 disease. Some individuals with immunodeficiency are at a high risk of developing severe COVID-19. Therefore, the development of standardized methods for measuring different arms of the vaccine response in the setting of immunodeficiency is of particular interest. In this study, we compared the vaccine response of individuals living with immunodeficiency with healthy controls in terms of interferon gamma (IFN-γ) production and spike protein-specific antibody level post primary COVID-19 vaccination and booster vaccines. Additionally, the disease severity of those individuals who contracted COVID-19 was assessed. Methods: Whole blood was stimulated overnight from 71 participants and 99 healthy controls. Commercially available PepTivator® peptide pool and trimeric spike protein stimulation were used. ELISA was used to analyze IFN-γ levels. The total SARS-CoV-2 spike protein antibody titre was measured using a Roche Elecsys® S total antibody assay. Patient characteristics, COVID-19 infection status and IDDA 2.1 'Kaleidoscope' scores were recorded. Vaccine responses were scored from zero to three. Results: 99% of healthy controls, 89% of individuals with IEI and 76% with secondary immunodeficiency (SID) had an IFN-γ level above the validated reference range after peptide mix stimulation following primary vaccination. There was an increase in IFN-γ levels in patients with inborn errors of immunity (IEI) following the booster vaccine (p = 0.0156). 100% of healthy controls, 70% of individuals living with IEI and 64% of individuals living with SID had detectable spike protein-specific antibody levels following the primary vaccination. 55% of immunodeficiency patients who had mild COVID-19 and 10% with moderate/severe COVID-19 had detectable antibody and IFN-γ levels post vaccine. The mean pre-infection IDDA 2.1 scores were higher in individuals who developed moderate/severe COVID-19 (25.2 compared to 9.41). Conclusions: Covid whole-blood IGRA is a highly accurate, straightforward and robust assay and can be easily adapted to measure cellular response to COVID-19. A complete evaluation of the vaccine response may be particularly important for individuals living with immunodeficiency. A clinical immunodeficiency score and a validated vaccine response score may be valuable tools in estimating COVID-19 disease risk and identifying individuals living with immunodeficiency who may benefit from enhanced vaccination schedules.

Specific Cellular and Humoral Immune Responses to the Neoantigen RBD of SARS-CoV-2 in Patients with Primary and Secondary Immunodeficiency and Healthy Donors.

Patients with antibody deficiency disorders, such as primary immunodeficiency (PID) or secondary immunodeficiency (SID) to B-cell lymphoproliferative disorder (B-CLPD), are two groups vulnerable to developing the severe or chronic form of coronavirus disease caused by SARS-CoV-2 (COVID-19). The data on adaptive immune responses against SARS-CoV-2 are well described in healthy donors, but still limited in patients with antibody deficiency of a different cause. Herein, we analyzed spike-specific IFN-γ and anti-spike IgG antibody responses at 3 to 6 months after exposure to SARS-CoV-2 derived from vaccination and/or infection in two cohorts of immunodeficient patients (PID vs. SID) compared to healthy controls (HCs). Pre-vaccine anti-SARS-CoV-2 cellular responses before vaccine administration were measured in 10 PID patients. Baseline cellular responses were detectable in 4 out of 10 PID patients who had COVID-19 prior to vaccination, perceiving an increase in cellular responses after two-dose vaccination (p < 0.001). Adequate specific cellular responses were observed in 18 out of 20 (90%) PID patients, in 14 out of 20 (70%) SID patients and in 74 out of 81 (96%) HCs after vaccination (and natural infection in some cases). Specific IFN-γ response was significantly higher in HC with respect to PID (1908.5 mUI/mL vs. 1694.1 mUI/mL; p = 0.005). Whereas all SID and HC patients mounted a specific humoral immune response, only 80% of PID patients showed positive anti-SARS-CoV-2 IgG. The titer of anti-SARS-CoV-2 IgG was significantly lower in SID compared with HC patients (p = 0.040), without significant differences between PID and HC patients (p = 0.123) and between PID and SID patients (p =0.683). High proportions of PID and SID patients showed adequate specific cellular responses to receptor binding domain (RBD) neoantigen, with a divergence between the two arms of the adaptive immune response in PID and SID patients. We also focused on the correlation of protection of positive SARS-CoV-2 cellular response to omicron exposure: 27 out of 81 (33.3%) HCs referred COVID-19 detected by PCR or antigen test, 24 with a mild course, 1 with moderate symptoms and the remaining 2 with bilateral pneumonia that were treated in an outpatient basis. Our results might support the relevance of these immunological studies to determine the correlation of protection with severe disease and for deciding the need for additional boosters on a personalized basis. Follow-up studies are required to evaluate the duration and variability in the immune response to COVID-19 vaccination or infection.

A retrospective review of immunology patients with primary and/or secondary immunodeficiency, demonstrating the benefits of the rapid transitioning from intravenous immunoglobulin to subcutaneous immunoglobulin at the onset of the COVID-19 pandemic.

Forty-four of 50 immunology patients with primary or secondary immunodeficiency receiving intravenous immunoglobulin at a hospital in New South Wales, Australia, were rapidly enrolled in the subcutaneous immunoglobulin (SCIg) programme at the onset of the 2020 COVID-19 pandemic. Health and economic outcomes demonstrated that SCIg provides clinical efficacy as evidenced by the number of infections and maintenance of IgG levels, and also facilitates cost reduction in immunoglobulin maintenance programmes.

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.

Allergic diseases and immunodeficiencies in children, lessons learnt from COVID-19 pandemic by 2022: A statement from the EAACI-section on pediatrics.

By the April 12, 2022, the COVID-19 pandemic had resulted in over half a billion people being infected worldwide. There have been 6.1 million deaths directly due to the infection, but the pandemic has had many more short- and long-term pervasive effects on the physical and mental health of the population. Allergic diseases are among the most prevalent noncommunicable chronic diseases in the pediatric population, and health-care professionals and researchers were seeking answers since the beginning of pandemic. Children are at lower risk of developing severe COVID-19 or dying from infection. Allergic diseases are not associated with a higher COVID-19 severity and mortality, apart from severe/poorly controlled asthma. The pandemic disrupted routine health care, but many mitigation strategies, including but not limited to telemedicine, were successfully implemented to continue delivery of high-standard care. Although children faced a multitude of pandemic-related issues, allergic conditions were effectively treated remotely while reduction in air pollution and lack of contact with outdoor allergens resulted in improvement, particularly respiratory allergies. There is no evidence to recommend substantial changes to usual management modalities of allergic conditions in children, including allergen immunotherapy and use of biologicals. Allergic children are not at greater risk of multisystem inflammatory syndrome development, but some associations with Long COVID were reported, although the data are limited, and further research is needed. This statement of the EAACI Section on Pediatrics provides recommendations based on the lessons learnt from the pandemic, as available evidence.

Correlation between Clinical and Immunological Variables and Humoral Response to SARS-CoV-2 Vaccination in Adult Patients with Antibody Deficiency Disorders.

BACKGROUND: Prophylactic vaccination has proven to be the most effective strategy to fight the COVID-19 pandemic. METHODS: This was a prospective observational cohort study involving 30 predominantly antibody deficiency disorders (ADD)-afflicted adult patients on immunoglobulin replacement therapy vaccinated with three doses of the mRNA-1273 COVID-19 vaccine, and 10 healthy controls. Anti-RBD IgG antibodies were determined in plasma samples collected just before the first dose of mRNA-based COVID-19 vaccine and on weeks 4, 8, 24, and 28 following the first vaccination. Patients were categorized based on the levels of anti-RBD antibodies determined on w8 as non-, low-, and responders. Chi-square and Kruskal-Wallis tests were used to see if any variables correlated with humoral response levels. Any adverse effects of the mRNA-based vaccine were also noted. RESULTS: The COVID-19 vaccine was safe and well-tolerated. The humoral response elicited at w8 after vaccination depended on the type of ADD, the type of immunoglobulin deficiency, the presence of granulomatous lymphocytic interstitial lung disease, recent use of immunosuppressive drugs, and the switched memory B cells counts. The third vaccine dose boosted humoral response in previous responders to second dose but seldom in non-responders. CONCLUSIONS: The humoral response of patients with predominant ADD depends mostly on the type of immunodeficiency and on the frequency of B and T cell populations.

SIGNIFICANCE OF CONGENITAL IMMUNITY DEFECTS IN THE STUDY OF EPIDEMIOLOGY OF HUMAN INFECTIOUS AND NON-INFECTIOUS DISEASES

Primary immunodeficiencies (PID) are conditions caused by genetic defects in the immune system. Their main manifestation is an infectious syndrome (recurrent severe infections caused by common pathogens, with gross defects in immunity). However, as the PID study progressed, descriptions of patients with hypersensitivity to rare and opportunistic infections, mycobacterioses, including BCG infection, with severe/atypical course of common viral infections, including COVID-19, emerged. Due to the inability of the immune system of patients to control the oncogenic potential of various viruses, with defects in some immune mechanisms, these patients develop various tumors (Kaposi’s sarcoma, EBV-associated smooth muscle tumor) or an increase in the frequency of, for example, EBV-associated lymphomas. The creation of the Russian register of PIDs makes it possible to predict the development of certain rare/opportunistic infectious and infectious diseases in the Russian Federation. The most important is the prevention of the development of rare/opportunistic infections by early detection of patients with PID and their pathogenetic treatment, including immunomodulatory, replacement therapy with human normal immunoglobulin preparations, as well as radical therapy – hematopoietic stem cell transplantation. In addition, an important epidemiological aspect of the study of PID is that patients are often unable to eliminate infectious pathogens for a long time and serve as a reservoir of various infections (vaccinal and wild strains of poliomyelitis, COVID-19). © 2022, Pediatria Ltd. All rights reserved.

Case Report: X-Linked SASH3 Deficiency Presenting as a Common Variable Immunodeficiency.

SASH3 is a lymphoid-specific adaptor protein. In a recent study, SASH3 deficiency was described as a novel X-linked combined immunodeficiency with immune dysregulation, associated with impaired TCR signaling and thymocyte survival in humans. The small number of patients reported to date showed recurrent sinopulmonary, cutaneous and mucosal infections, and autoimmune cytopenia. Here we describe an adult patient previously diagnosed with common variable immunodeficiency (CVID) due to low IgG and IgM levels and recurrent upper tract infections. Two separate, severe viral infections drew our attention and pointed to an underlying T cell defect: severe varicella zoster virus (VZV) infection at the age of 4 years and bilateral pneumonia due type A influenza infection at the age of 38. Genetic testing using an NGS-based custom-targeted gene panel revealed a novel hemizygous loss-of-function variant in the SASH3 gene (c.505C>T/p.Gln169*). The patient's immunological phenotype included marked B cell lymphopenia with reduced pre-switch and switch memory B cells, decreased CD4+ and CD8+ naïve T cells, elevated CD4+ and CD8+ TEMRA cells, and abnormal T cell activation and proliferation. The patient showed a suboptimal response to Streptococcus pneumoniae (polysaccharide) vaccine, and a normal response to Haemophilus influenzae type B (conjugate) vaccine and SARS-CoV-2 (RNA) vaccine. In summary, our patient has a combined immunodeficiency, although he presented with a phenotype resembling CVID. Two severe episodes of viral infection alerted us to a possible T-cell defect, and genetic testing led to SASH3 deficiency. Our patient displays a milder phenotype than has been reported previously in these patients, thus expanding the clinical spectrum of this recently identified inborn error of immunity.

SARS-CoV-2 T Cell Response in Severe and Fatal COVID-19 in Primary Antibody Deficiency Patients Without Specific Humoral Immunity.

Morbidity and mortality of COVID-19 is increased in patients with inborn errors of immunity (IEI). Age and comorbidities and also impaired type I interferon immunity were identified as relevant risk factors. In patients with primary antibody deficiency (PAD) and lack of specific humoral immune response to SARS-CoV-2, clinical disease outcome is very heterogeneous. Despite extensive clinical reports, underlying immunological mechanisms are poorly characterized and levels of T cellular and innate immunity in severe cases remain to be determined. In the present study, we report clinical and immunological findings of 5 PAD patients with severe and fatal COVID-19 and undetectable specific humoral immune response to SARS-CoV-2. Reactive T cells to SARS-CoV-2 spike (S) and nucleocapsid (NCAP) peptide pools were analyzed comparatively by flow cytometry in PAD patients, convalescents and naïve healthy individuals. All examined PAD patients developed a robust T cell response. The presence of polyfunctional cytokine producing activated CD4+ T cells indicates a memory-like phenotype. An analysis of innate immune response revealed elevated CD169 (SIGLEC1) expression on monocytes, a surrogate marker for type I interferon response, and presence of type I interferon autoantibodies was excluded. SARS-CoV-2 RNA was detectable in peripheral blood in three severe COVID-19 patients with PAD. Viral clearance in blood was observed after treatment with COVID-19 convalescent plasma/monoclonal antibody administration. However, prolonged mucosal viral shedding was observed in all patients (median 67 days) with maximum duration of 127 days. PAD patients without specific humoral SARS-CoV-2 immunity may suffer from severe or fatal COVID-19 despite robust T cell and normal innate immune response. Intensified monitoring for long persistence of SARS-CoV-2 viral shedding and (prophylactic) convalescent plasma/specific IgG as beneficial treatment option in severe cases with RNAemia should be considered in seronegative PAD patients.

Outcomes following SARS-CoV-2 infection in patients with primary and secondary immunodeficiency in the UK.

In March 2020, the United Kingdom Primary Immunodeficiency Network (UKPIN) established a registry of cases to collate the outcomes of individuals with PID and SID following SARS-CoV-2 infection and treatment. A total of 310 cases of SARS-CoV-2 infection in individuals with PID or SID have now been reported in the UK. The overall mortality within the cohort was 17.7% (n = 55/310). Individuals with CVID demonstrated an infection fatality rate (IFR) of 18.3% (n = 17/93), individuals with PID receiving IgRT had an IFR of 16.3% (n = 26/159) and individuals with SID, an IFR of 27.2% (n = 25/92). Individuals with PID and SID had higher inpatient mortality and died at a younger age than the general population. Increasing age, low pre-SARS-CoV-2 infection lymphocyte count and the presence of common co-morbidities increased the risk of mortality in PID. Access to specific COVID-19 treatments in this cohort was limited: only 22.9% (n = 33/144) of patients admitted to the hospital received dexamethasone, remdesivir, an anti-SARS-CoV-2 antibody-based therapeutic (e.g. REGN-COV2 or convalescent plasma) or tocilizumab as a monotherapy or in combination. Dexamethasone, remdesivir, and anti-SARS-CoV-2 antibody-based therapeutics appeared efficacious in PID and SID. Compared to the general population, individuals with PID or SID are at high risk of mortality following SARS-CoV-2 infection. Increasing age, low baseline lymphocyte count, and the presence of co-morbidities are additional risk factors for poor outcome in this cohort.

CD19+IgD+CD27- Naïve B Cells as Predictors of Humoral Response to COVID 19 mRNA Vaccination in Immunocompromised Patients.

Immunocompromised patients are considered high-risk and prioritized for vaccination against COVID-19. We aimed to analyze B-cell subsets in these patients to identify potential predictors of humoral vaccination response. Patients (n=120) suffering from hematologic malignancies or other causes of immunodeficiency and healthy controls (n=79) received a full vaccination series with an mRNA vaccine. B-cell subsets were analyzed prior to vaccination. Two independent anti-SARS-CoV-2 immunoassays targeting the receptor-binding domain (RBD) or trimeric S protein (TSP) were performed three to four weeks after the second vaccination. Seroconversion occurred in 100% of healthy controls, in contrast to 67% (RBD) and 82% (TSP) of immunocompromised patients, while only 32% (RBD) and 22% (TSP) achieved antibody levels comparable to those of healthy controls. The number of circulating CD19+IgD+CD27- naïve B cells was strongly associated with antibody levels (ρ=0.761, P<0.001) and the only independent predictor for achieving antibody levels comparable to healthy controls (OR 1.07 per 10-µL increase, 95%CI 1.02-1.12, P=0.009). Receiver operating characteristic analysis identified a cut-off at ≥61 naïve B cells per µl to discriminate between patients with and without an optimal antibody response. Consequently, measuring of naïve B cells in immunocompromised hematologic patients could be useful in predicting their humoral vaccination response.

Case Series: Convalescent Plasma Therapy for Patients with COVID-19 and Primary Antibody Deficiency.

Patients with primary antibody deficiency are at risk for severe and in many cases for prolonged COVID-19. Convalescent plasma treatment of immunocompromised individuals could be an option especially in countries with limited access to monoclonal antibody therapies. While studies in immunocompetent COVID19 patients have demonstrated only a limited benefit, evidence for the safety, timing, and effectiveness of this treatment in antibody-deficient patients is lacking. Here, we describe 16 cases with primary antibody deficiency treated with convalescent plasma in four medical centers. In our cohort, treatment was associated with a reduction in viral load and improvement of clinical symptoms, even when applied over a week after onset of infection. There were no relevant side effects besides a short-term fever reaction in one patient. Longitudinal full-genome sequencing revealed the emergence of mutations in the viral genome, potentially conferring an antibody escape in one patient with persistent viral RNA shedding upon plasma treatment. However, he resolved the infection after a second course of plasma treatment. Thus, our data suggest a therapeutic benefit of convalescent plasma treatment in patients with primary antibody deficiency even months after infection. While it appears to be safe, PCR follow-up for SARS-CoV-2 is advisable and early re-treatment might be considered in patients with persistent viral shedding.

B Cell Response Induced by SARS-CoV-2 Infection Is Boosted by the BNT162b2 Vaccine in Primary Antibody Deficiencies.

BACKGROUND: Patients with primary antibody deficiencies are at risk in the current COVID-19 pandemic due to their impaired response to infection and vaccination. Specifically, patients with common variable immunodeficiency (CVID) generated poor spike-specific antibody and T cell responses after immunization. METHODS: Thirty-four CVID convalescent patients after SARS-CoV-2 infection, 38 CVID patients immunized with two doses of the BNT162b2 vaccine, and 20 SARS-CoV-2 CVID convalescents later and immunized with BNT162b2 were analyzed for the anti-spike IgG production and the generation of spike-specific memory B cells and T cells. RESULTS: Spike-specific IgG was induced more frequently after infection than after vaccination (82% vs. 34%). The antibody response was boosted in convalescents by vaccination. Although immunized patients generated atypical memory B cells possibly by extra-follicular or incomplete germinal center reactions, convalescents responded to infection by generating spike-specific memory B cells that were improved by the subsequent immunization. Poor spike-specific T cell responses were measured independently from the immunological challenge. CONCLUSIONS: SARS-CoV-2 infection primed a more efficient classical memory B cell response, whereas the BNT162b2 vaccine induced non-canonical B cell responses in CVID. Natural infection responses were boosted by subsequent immunization, suggesting the possibility to further stimulate the immune response by additional vaccine doses in CVID.

A multicenter survey on the aspects of everyday life in adult patients with primary antibody deficiencies treated with immunoglobulin G replacement during the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic has changed many aspects of everyday life. Patients with primary immunodeficiency (PID) are in a particularly difficult situation. The purpose of the present study was to contribute to the very limited research on the everyday aspects of functioning in PID patients during the COVID-19 pandemic. METHODS: The survey included 85 adult PID patients treated with immunoglobulin replacement therapy in four reference centers for immunology. Everyday functioning of the patients as well as their opinion concerning new solutions in medical care were analyzed. RESULTS: During the pandemic, the percentage of patients experiencing fear/anxiety has increased from 47% to 70%. The wide dissemination of information about the SARS-CoV-2 in the media has increased anxiety in 40% of the patients. Patients diagnosed with PID were most afraid of the exposure to contact with strangers, especially in public places. As many as 67 respondents (79%) considered the introduction of restrictions concerning social functioning as good. Only every fifth person learned about the pandemic from reliable sources. Eighty three percent of the patients receiving immunoglobulin substitution experienced less fear of SARS-CoV-2 infection. The patients positively evaluated the solutions related to the direct delivery of drugs to the place of residence in order to continue home IgRT therapy. Fifty three respondents (62.5%) believed that the possibility of a remote consultation was a very good solution. CONCLUSION: It is necessary to increase educational activities concerning the pandemic provided by health care professionals, as patients obtain information mainly from the media and the Internet, which adversely affects the feeling of anxiety. The pandemic, in addition to the very negative impact on patients and the deterioration of their daily functioning, has made patients appreciate their life more, devote more time to family and friends, and do things they like.