Long-Term Immunological Memory of SARS-CoV-2 Is Present in Patients with Primary Antibody Deficiencies for up to a Year after Vaccination.

Some studies have found increased coronavirus disease-19 (COVID-19)-related morbidity and mortality in patients with primary antibody deficiencies. Immunization against COVID-19 may, therefore, be particularly important in these patients. However, the durability of the immune response remains unclear in such patients. In this study, we evaluated the cellular and humoral response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigens in a cross-sectional study of 32 patients with primary antibody deficiency (n = 17 with common variable immunodeficiency (CVID) and n = 15 with selective IgA deficiency) and 15 healthy controls. Serological and cellular responses were determined using enzyme-linked immunosorbent assay and interferon-gamma release assays. The subsets of B and T lymphocytes were measured using flow cytometry. Of the 32 patients, 28 had completed the vaccination regimen with a median time after vaccination of 173 days (IQR = 142): 27 patients showed a positive spike-peptide-specific antibody response, and 26 patients showed a positive spike-peptide-specific T-cell response. The median level of antibody response in CVID patients (5.47 ratio (IQR = 4.08)) was lower compared to healthy controls (9.43 ratio (IQR = 2.13)). No difference in anti-spike T-cell response was found between the groups. The results of this study indicate that markers of the sustained SARS-CoV-2 spike-specific immune response are detectable several months after vaccination in patients with primary antibody deficiencies comparable to controls.

Advances and Challenges of the Decade: The Ever-Changing Clinical and Genetic Landscape of Immunodeficiency.

In the past 10 years, we have witnessed major advances in clinical immunology. Newborn screening for severe combined immunodeficiency has become universal in the United States and screening programs are being extended to severe combined immunodeficiency and other inborn errors of immunity globally. Early genetic testing is becoming the norm for many of our patients and allows for informed selection of targeted therapies including biologics repurposed from other specialties. During the COVID-19 pandemic, our understanding of essential immune responses expanded and the discovery of immune gene defects continued. Immunoglobulin products, the backbone of protection for antibody deficiency syndromes, came into use to minimize side effects. New polyclonal and monoclonal antibody products emerged with increasing options to manage respiratory viral agents such as SARS-CoV-2 and respiratory syncytial virus. Against these advances, we still face major challenges. Atypical is becoming typical as phenotypes of distinct genetic disease overlap whereas the clinical spectrum of the same genetic defect widens. Therefore, clinical judgment needs to be paired with repeated deep immune phenotyping and upfront genetic testing, as technologies rapidly evolve, and clinical disease often progresses with age. Managing patients with organ damage resulting from immune dysregulation poses a special major clinical challenge and management often lacks standardization, from autoimmune cytopenias, granulomatous interstitial lung disease, enteropathy, and liver disease to endocrine, rheumatologic, and neurologic complications. Clinical, translational, and basic science networks will continue to advance the field; however, cross-talk and education with practicing allergists/immunologists are essential to keep up with the ever-changing clinical and genetic landscape of inborn errors of immunity.

Case report: Evolution of pulmonary manifestations and virological markers in critical COVID-19 infection in Bruton's agammaglobulinemia.

Despite several reports and small case series on the disease course of SARS-CoV-2 infection in patients with inborn errors of immunity (IEI), including X-linked agammaglobulinemia (XLA), this topic remains incompletely described. Here we present the case of a 38-year-old unvaccinated man with XLA, who acquired SARS-CoV-2 infection and experienced a protracted disease course with 47 days of SARS-CoV-2 positivity, critical COVID-19 with respiratory insufficiency necessitating intensive care and ventilatory support, and prompting repeated intensified treatments with remdesivir, dexamethasone, and monoclonal antibodies to eventually control infection. We describe the disease course and treatment and review the current literature on COVID-19 susceptibility and evidence for vaccine efficacy in patients with XLA.

Human genetics of SARS-CoV-2 infection and critical COVID-19.

BACKGROUND: During the past 2 years, studies on patients with SARS-CoV-2 infection have revealed rare inborn errors of immunity (IEIs) in type interferon (IFN) pathways underlying critical COVID-19 pneumonia. This has provided insights into pathophysiological mechanisms and immune signaling circuits regulating antiviral responses to SARS-CoV-2 and governing the susceptibility to and outcome of SARS-CoV-2 infection in humans. OBJECTIVES: In this review, the current knowledge on IEIs underlying critical COVID-19 is presented, and the clinical implications of these findings for individualized prophylaxis and treatment are outlined. SOURCES: The review is based on a broad literature search, including primarily studies on whole-exome sequencing, and to a lesser extent genome-wide association studies, of patients with critical COVID-19, as well as retrospective descriptive studies of the SARS-CoV-2 disease course in individuals with known IEIs. CONTENT: The review describes the discovery of monogenic IEI in 9 genetic loci related to the production or responses to type I IFN in patients with critical COVID-19 pneumonia and the surprising finding of phenocopies of these, represented by neutralizing autoantibodies to type IFN in a significant proportion of patients with critical pneumonia, particularly in elderly men, and further enriched in patients with lethal disease course. Moreover insights gained from studies on SARS-CoV-2 infection, disease course, and outcome in patients with known IEI is presented. Finally, some hypotheses for a possible genetic basis of autoimmune, inflammatory, and long-term complications of SARS-CoV-2 infection are presented and discussed. IMPLICATIONS: Uncovering IEIs underlying critical COVID-19 or other severe SARS-CoV-2 disease manifestations provides valuable insights into the basic principles of antiviral immune responses and pathophysiology related to SARS-CoV-2 infection. Such knowledge has important clinical implications for identification of susceptible individuals and for diagnosis, prophylaxis, and treatment of patients to reduce disease burden and improve preparedness against viral pandemics with known or emerging viruses in the future.

Response to mRNA COVID-19 vaccination in three XLA patients.

X-linked agammaglobulinemia (XLA) is an inborn error of immunity characterized by insufficient production of immunoglobulins and lack of measurable antibody response to vaccines. The rise of novel infections limits the protective effect of immunoglobulin replacement in immunodeficient patients though. While XLA patients are not expected to mount an antibody response to COVID-19 vaccination, it has been demonstrated that XLA patients can mount a T-cell response to COVID-19 vaccines, similar to the influenza vaccine. We present three patients with XLA who received an mRNA COVID-19 vaccine. One patient demonstrated positive antibody response. Many XLA patients do not receive routine vaccinations due to ongoing immunoglobulin replacement therapy and lack of native antibody production, but in addition to T-cell response to vaccination, select XLA patients may mount a positive antibody response. Therefore, COVID-19 vaccination should be encouraged for all XLA patients.

Fatal SARS in X-Linked Lymphoproliferative Disease Type 1: A Case Report.

X-linked lymphoproliferative disease (XLP1) is an inborn error of immunity (IEI) with severe immune dysregulation caused by a mutation in the SH2D1A gene resulting in the absence or dysfunction of signaling lymphocytic activation molecule (SLAM)-associated protein (SAP). The severe acute respiratory syndrome (SARS) caused by SARS-coronavirus (CoV), a highly pathogenic CoV, has been shown to only cause mild diseases in Asian children. We report on a 5-year-old Nepalese boy with agammaglobulinemia and probable SARS who died of diffuse alveolar damage 22 days after admission amid the SARS outbreak. The index patient and his younger brother were genetically confirmed to have XLP1. In the current coronavirus disease 2019 (COVID-19) pandemic, most children also had mild disease only. Children with severe COVID-19 would warrant investigations for underlying IEI, particularly along the pathways leading to immune dysregulation.

Genetic susceptibility to viral disease in humans.

BACKGROUND: During the past decades, studies on patients with severe viral infections have revealed rare inborn errors of immunity (IEIs) underlying these diseases. This has led to important new insights into the molecular genetics and immunological mechanisms governing susceptibility to viral infection in humans. OBJECTIVES: Herein, the current knowledge on major IEIs predisposing to severe or chronic viral infections are described and discussed, and the clinical implications of these findings for individualized prophylaxis and treatment are outlined. SOURCES: The review is based on a broad literature search, including relevant studies primarily based on patients, supported by experimental molecular models in vitro or in mice, to characterize the pathophysiological mechanism governing these disease conditions. CONTENT: Current concepts and principles of genetic predisposition to viral infections in humans are described with a major focus on defects related to innate immune responses and new concepts of constitutive immune mechanisms. The topic therefore spans from seminal studies on the human genetics of herpesvirus infections in the central nervous system, severe influenza, and disease after vaccination with live attenuated viral vaccines, to genetic resistance to viral infection. IMPLICATIONS: Past and present studies of patients with IEIs conferring vulnerability to viral infections have taught us important lessons on protective innate and adaptive antiviral immunity in humans. Such knowledge also has important clinical implications, allowing development of prophylactic and therapeutic solutions to prevent or dampen the clinical consequences of insufficient or dysregulated antiviral immunity in patients. Collectively, such measures are likely to improve patient management at an individualized level and help societies reduce the disease burden from viral infections.

Case Report: BCG-Triggered Hemophagocytic Lymphohistiocytosis in an Infant With X-Linked Recessive Mendelian Susceptibility to Mycobacterial Disease Due to a Variant of Chronic Granulomatous Disease.

In the United Arab Emirates, BCG (Bacillus Calmette-Guérin) is administered to all newborns. We present here a young infant with an inborn error of immunity (IEI) who developed fatal adverse events to this live-attenuated vaccine. This male infant received BCG (Serum Institute of India Pvt., Ltd., India) on Day 11 of life. On Day 25, he developed fever, followed by cervical lymphadenitis and bilateral otitis media with fluid drainage. On Day 118, he was admitted with severe hemophagocytic lymphohistiocytosis (HLH), and passed away on Day 145. The diagnostic exome sequencing test identified a hemizygous nonsense variant, NM_000397.3(CYBB):c.676C>T, p.Arg226* (rs137854592). Pathogenic variants of CYBB [cytochrome b(-245), beta subunit; Mendelian Inheritance in Man [MIM] accession code, 300481] are known to cause "immunodeficiency 34, mycobacteriosis, X-linked" (IMD34, MIM#300645) and "chronic granulomatous disease, X-linked" (CGDX, MIM#306400). The natural history of his illness is consistent with "X-linked recessive Mendelian susceptibility to mycobacterial disease (MSMD)." This entity is responsible for his BCG disease and is a likely trigger of his HLH. This disastrous event underlines the importance of developing worldwide policies that target BCG disease prevention, especially in communities with high prevalence of IEI. Moreover, screening for genetic causes of MSMD in the community could pave the way, at least partially, for scale-up of tuberculosis (TB) prevention.