Update in understanding common variable immunodeficiency disorders (CVIDs) and the management of patients with these conditions

Screening for primary immune deficiency among patients with bronchiectasis

INTRODUCTION

To assess frequency and methods of PID (primary immune deficiency) screening among patients with bronchiectasis by pneumologists in clinical practice.

METHODS

All the patients hospitalized in the department of pneumology of the Poitiers University Hospital between April 2013 and April 2020 with a diagnosis of bronchiectasis on chest computerized tomography were included. Patients aged 70 and over and those with already known PID were excluded. Primary endpoint was the proportion of patients having had serum immunoglobulin (Ig) assay and serum protein electrophoresis (SPE) analysis. Secondary endpoints were factors associated with prescription of SPE and/or Ig assay, proportion of patients with newly diagnosed PID and their characteristics and factors associated with repeated courses of antibiotics.

RESULTS

Among the 133 patients included, 43% had SPE+Ig assay, 34% SPE only and 23% neither. The proportion of patients with asthma was higher in the "SPE+Ig assay" group (33.3%) compared to the "SPE only" (11.1%) and the "Neither SPE nor Ig assay" groups (6.4%) (P=0.002). Four patients were newly diagnosed for PID of whom 3 had subclass IgG deficiency. Factors associated with repeated courses of antibiotics were generalized bronchiectasis (P=0.02) and asthma (P=0.04).

CONCLUSION

PID is underscreened by pneumologists among patients with bronchiectasis. Association of SPE+Ig assay+IgG subclass assay appears as the most accurate combination.

Limitations in the clinical utility of vaccine challenge responses in the evaluation of primary antibody deficiency including Common Variable Immunodeficiency Disorders

Vaccine challenge responses are an integral component in the diagnostic evaluation of patients with primary antibody deficiency, including Common Variable Immunodeficiency Disorders (CVID). There are no studies of vaccine challenge responses in primary hypogammaglobulinemia patients not accepted for subcutaneous/intravenous immunoglobulin (SCIG/IVIG) replacement compared to those accepted for such treatment. Vaccine challenge responses in patients enrolled in two long-term prospective cohorts, the New Zealand Hypogammaglobulinemia Study (NZHS) and the New Zealand CVID study (NZCS), were compared in this analysis. Almost all patients in the more severely affected SCIG/IVIG treatment group achieved protective antibody levels to tetanus toxoid and H. influenzae type B (HIB). Although there was a highly significant statistical difference in vaccine responses to HIB, tetanus and diphtheria toxoids, there was substantial overlap in both groups. In contrast, there was no significant difference in Pneumococcal Polysaccharide antibody responses to Pneumovax® (PPV23). This analysis illustrates the limitations of evaluating vaccine challenge responses in patients with primary hypogammaglobulinemia to establish the diagnosis of CVID and in making decisions to treat with SCIG/IVIG. The conclusion from this study is that patients with symptoms attributable to primary hypogammaglobulinemia with reduced IgG should not be denied SCIG/IVIG if they have normal vaccine responses.

ICOS agonist vopratelimab modulates follicular helper T cells and improves B cell function in common variable immunodeficiency

Common variable immunodeficiency (CVID) is an immune defect characterized by hypogammaglobulinemia and impaired development of B cells into plasma cells. As follicular helper T cells (TFH) play a central role in humoral immunity, we examined TFH cells in CVID, and investigated whether an inducible T cell co-stimulator (ICOS) agonist, vopratelimab, could modulate TFH, B cell interactions and enhance immunoglobulin production. CVID subjects had decreased TFH17 and increased TFH1 subsets; this was associated with increased transitional B cells and decreased IgG+ B and IgD-IgM-CD27+ memory B cells. ICOS expression on CVID CD4+ T cells was also decreased. However, ICOS activation of CD4+ T cells by vopratelimab significantly increased total CVID TFH, TFH2, cell numbers, as well as IL-4, IL-10 and IL-21 secretion in vitro. Vopratelimab treatment also increased plasma cells, IgG+ B cells, reduced naïve & transitional B cells and significantly increased IgG1 secretion by CVID B cells. Interestingly, vopratelimab treatment also restored IgA secretion in PBMCs from several CVID patients who had a complete lack of endogenous serum IgA. Our data demonstrate the potential of TFH modulation in restoring TFH and enhancing B cell maturation in CVID. The effects of an ICOS agonist in antibody defects warrants further investigation. This biologic may also be of therapeutic interest in other clinical settings of antibody deficiency.

Oropharyngeal microbial ecosystem perturbations influence the risk for acute respiratory infections in common variable immunodeficiency

Background

The respiratory tract microbiome is essential for human health and well-being and is determined by genetic, lifestyle, and environmental factors. Patients with Common Variable Immunodeficiency (CVID) suffer from respiratory and intestinal tract infections, leading to chronic diseases and increased mortality rates. While CVID patients' gut microbiota have been analyzed, data on the respiratory microbiome ecosystem are limited.

Objective

This study aims to analyze the bacterial composition of the oropharynx of adults with CVID and its link with clinical and immunological features and risk for respiratory acute infections.

Methods

Oropharyngeal samples from 72 CVID adults and 26 controls were collected in a 12-month prospective study. The samples were analyzed by metagenomic bacterial 16S ribosomal RNA sequencing and processed using the Quantitative Insights Into Microbial Ecology (QIME) pipeline. Differentially abundant species were identified and used to build a dysbiosis index. A machine learning model trained on microbial abundance data was used to test the power of microbiome alterations to distinguish between healthy individuals and CVID patients.

Results

Compared to controls, the oropharyngeal microbiome of CVID patients showed lower alpha- and beta-diversity, with a relatively increased abundance of the order Lactobacillales, including the family Streptococcaceae. Intra-CVID analysis identified age >45 years, COPD, lack of IgA, and low residual IgM as associated with a reduced alpha diversity. Expansion of Haemophilus and Streptococcus genera was observed in patients with undetectable IgA and COPD, independent from recent antibiotic use. Patients receiving azithromycin as antibiotic prophylaxis had a higher dysbiosis score. Expansion of Haemophilus and Anoxybacillus was associated with acute respiratory infections within six months.

Conclusions

CVID patients showed a perturbed oropharynx microbiota enriched with potentially pathogenic bacteria and decreased protective species. Low residual levels of IgA/IgM, chronic lung damage, anti antibiotic prophylaxis contributed to respiratory dysbiosis.

Phenotype and oxidative burst of low-density neutrophil subpopulations are altered in common variable immunodeficiency patients

Common variable immunodeficiency disorder (CVID) is the most common form of primary antibody immunodeficiency. Due to low antibody levels, CVID patients receive intravenous or subcutaneous immunoglobulin replacement therapy as treatment. CVID is associated with the chronic activation of granulocytes, including an increased percentage of low-density neutrophils (LDNs). In this study, we examined changes in the percentage of LDNs and the expression of their surface markers in 25 patients with CVID and 27 healthy donors (HD) after in vitro stimulation of whole blood using IVIg. An oxidative burst assay was used to assess the functionality of LDNs. CVID patients had increased both relative and absolute LDN counts with a higher proportion of mLDNs compared to iLDNs, distinguished based on the expression of CD10 and CD16. Immature LDNs in the CVID and HD groups had significantly reduced oxidative burst capacity compared to mature LDNs. Interestingly we observed reduced oxidative burst capacity, reduced expression of CD10 after stimulation of WB, and higher expression of PD-L1 in mature LDNs in CVID patients compared to HD cells. Our data indicate that that the functional characteristics of LDNs are closely linked to their developmental stage. The observed reduction in oxidative burst capacity in mLDNs in CVID patients could contribute to an increased susceptibility to recurrent bacterial infections among CVID patients.

Common variable immunodeficiency, cross currents, and prevailing winds

Common variable immunodeficiency (CVID) is a heterogenous disease category created to distinguish late-onset antibody deficiencies from early-onset diseases like agammaglobulinemia or more expansively dysfunctional combined immunodeficiencies. Opinions vary on which affected patients should receive a CVID diagnosis which confuses clinicians and erects reproducibility barriers for researchers. Most experts agree that CVID's most indeliable feature is defective germinal center (GC) production of isotype-switched, affinity-maturated antibodies. Here, we review the biological factors contributing to CVID-associated GC dysfunction including genetic, epigenetic, tolerogenic, microbiome, and regulatory abnormalities. We also discuss the consequences of these biological phenomena to the development of non-infectious disease complications. Finally, we opine on topics and lines of investigation we think hold promise for expanding our mechanistic understanding of this protean condition and for improving the lives of affected patients.

Genetics and clinical phenotypes in common variable immunodeficiency

Common variable immunodeficiency (CVID) is one of the most common symptomatic groups of inborn errors of immunity. In addition to infections resulting from insufficient levels of immune globulins and antibodies, many patients develop inflammatory or autoimmune conditions, which are associated with increased mortality. This aspect of CVID has been the focus of many studies, and dissecting the clinical phenotypes of CVID, has had the goal of providing biomarkers to identify these subjects, potentially at the time of diagnosis. With the application of whole exome (WES) and whole genome analyses, an increasing number of monogenic causes of CVID have been elucidated. From the standpoint of the practicing physician, an important question is whether the clinical phenotype, particularly the occurrence of autoinflammation of autoimmunity, might suggest the likelihood of identifying a causative mutation, and if possible the gene most likely to underlie CVID. We addressed this question in a patient group of 405 subjects diagnosed with CVID from one medical center.

Understanding the Spectrum of Immune Dysregulation Manifestations in Autoimmune Lymphoproliferative Syndrome and Autoimmune Lymphoproliferative Syndrome-like Disorders

As a disorder of immune dysregulation, autoimmune lymphoproliferative syndrome (ALPS) stems from pathogenic variants in the first apoptosis signal-mediated apoptosis (Fas) and Fas-ligand pathway that result in elevations of CD3+ TCRαβ+ CD4- CD8- T cells along with chronic lymphoproliferation, a heightened risk for malignancy, and importantly for the rheumatologist, increased risk of autoimmunity. While immune cytopenias are the most encountered autoimmune phenomena, there is increasing appreciation for ocular, musculoskeletal, pulmonary and renal inflammatory manifestations similar to more common rheumatology diseases. Additionally, ALPS-like conditions that share similar clinical features and opportunities for targeted therapy are increasingly recognized via genetic testing, highlighting the need for rheumatologists to be facile in the recognition and diagnosis of this spectrum of disorders. This review will focus on clinical and laboratory features of both ALPS and ALPS-like disorders with the intent to provide a framework for rheumatologists to understand the pathophysiologic drivers and discriminate between diagnoses.

Interplay between epigenetic and genetic alterations in inborn errors of immunity

Inborn errors of immunity (IEIs) comprise a variety of immune conditions leading to infections, autoimmunity, allergy, and cancer. Some IEIs have no identified mutation(s), while others with identical mutations can display heterogeneous presentations. These observations suggest the involvement of epigenetic mechanisms. Epigenetic alterations can arise from downstream activation of cellular pathways through both extracellular stimulation and genetic-associated changes, impacting epigenetic enzymes or their interactors. Therefore, we posit that epigenetic alterations and genetic defects do not exclude each other as a disease-causing etiology. In this opinion, encompassing both basic and clinical viewpoints, we focus on selected IEIs with mutations in transcription factors that interact with epigenetic enzymes. The intricate interplay between these factors offers insights into genetic and epigenetic mechanisms in IEIs.

Immune Checkpoint Pathway Expression in Lymphocyte Subpopulations in Patients with Common Variable Immunodeficiency and Chronic Lymphocytic Leukemia

This study aims to gain a deeper understanding of chronic lymphocytic leukemia (CLL) and common variable immunodeficiency (CVID) by studying immune cells and specific immune checkpoint signaling pathways. The analysis of the percentage of selected immune points and their ligands (PD-1/PD-L1, CTLA-4/CD86, and CD200R/CD200) on peripheral blood lymphocyte subpopulations was performed using flow cytometry, and additional analyses determining the serum concentration of the above-mentioned molecules were performed using enzyme immunoassay tests. The obtained results indicate several significant changes in the percentage of almost all tested molecules on selected subpopulations of T and B lymphocytes in both CVID and CLL patients in relation to healthy volunteers and between the disease subunits themselves. The results obtained were also supported by the analysis of the serum concentration of soluble molecules tested. By uncovering valuable insights, we hope to enhance our comprehension and management of these conditions, considering both immunodeficiencies and hematological malignancies. Understanding the role of these signaling pathways in disease development and progression may lead to the development of modern, personalized diagnostic and therapeutic strategies. Ultimately, this knowledge may enable the monitoring of the immune system in patients with CVID and CLL, paving the way for improved patient care in the future.

TRIM55 promotes noncanonical NF-κB signaling and B cell-mediated immune responses by coordinating p100 ubiquitination and processing

The ubiquitination-dependent processing of NF-κB2 (also known as p100) is a critical step in the activation of the noncanonical NF-κB pathway. We investigated the molecular mechanisms regulating this process and showed that TRIM55 was the E3 ubiquitin ligase that mediated the ubiquitination of p100 and coordinated its processing. TRIM55 deficiency impaired noncanonical NF-κB activation and B cell function. Mice with a B cell-specific Trim55 deficiency exhibited reduced germinal center formation and antibody production. These mice showed less severe symptoms than those of control mice upon the induction of a systemic lupus-like disease, suggesting B cell-intrinsic functions of TRIM55 in humoral immune responses and autoimmunity. Mechanistically, the ubiquitination of p100 mediated by TRIM55 was crucial for p100 processing by VCP, an ATPase that mediates ubiquitin-dependent protein degradation by the proteasome. Furthermore, we found that TRIM55 facilitated the interaction between TRIM21 and VCP as well as TRIM21-mediated K63-ubiquitination of VCP, both of which were indispensable for the formation of the VCP-UFD1-NPL4 complex and p100 processing. Together, our results reveal a mechanism by which TRIM55 fine-tunes p100 processing and regulates B cell-dependent immune responses in vivo, highlighting TRIM55 as a potential therapeutic target for lupus-like disease.

Case Report: Mycosis fungoides as an exclusive manifestation of common variable immunodeficiency in a family with a NFKB2 gene mutation

Background

Common variable immunodeficiency disorders (CVIDs), which are primary immunodeficiencies characterized by the failure of primary antibody production, typically present with recurrent bacterial infections, decreased antibody levels, autoimmune features, and rare atypical manifestations that can complicate diagnosis and management. Although most cases are sporadic, approximately 10% of the patients may have a family history of immunodeficiency. Genetic causes involving genes related to B-cell development and survival have been identified in only a small percentage of cases.

Case presentation

We present the case of a family with two brothers who presented with mycosis fungoides as an exclusive symptom of a common variable immunodeficiency disorder (CVID). Whole-exome sequencing of the index patient revealed a pathogenic variant of the NFKB2 gene. Based on this diagnosis and re-evaluation of other family members, the father and brother were diagnosed with this rare immune and preneoplastic syndrome. All CVID-affected family members presented with mycosis fungoides as their only symptom, which is, to the best of our knowledge, the first case to be reported.

Conclusion

This case highlights the importance of high-throughput sequencing techniques for the proper diagnosis and treatment of hereditary hematological disorders.

Interleukin-9 rescues class switching of Memory B cells derived from Common variable immunodeficiency patients

Impaired class switch memory (CSM) B cell formation is the hallmark of common variable immunodeficiency (CVID). Various T cell abnormalities have been observed in CVID patients indicating inadequate T-cell help to B cells. A major setback in understanding its pathogenesis is due to diverse clinical presentation. Therefore, we performed extensive immunological investigation in a cohort of CVID patients with similar clinical findings in order to unravel the T cell dysfunction and its influence on the defective humoral immune response. All recruited CVID patients exhibited B cells in the normal range, but reduced CSM B cells. However, patients showed reduced T cell proliferation, reduced level of serum Interleukin-9 (IL-9) and frequency of IL-9 expressing CD4 (Th-9) cells. IL-9 supplementation along with CD40 engagement was effective in inducing in vitro CSM B cells formation in CVID patients. Thus, IL-9 supplementation has the potential to restore impaired CSM B cell formation in CVID.

In Vivo Antiviral Efficacy of LCTG-002, a Pooled, Purified Human Milk Secretory IgA product, Against SARS-CoV-2 in a Murine Model of COVID-19

Immunoglobulin A (IgA) is the most abundant antibody (Ab) in human mucosal compartments including the respiratory tract, with the secretory form of IgA (sIgA) being dominant and uniquely stable in these environments. sIgA is naturally found in human milk, which could be considered a global resource for this biologic, justifying the development of human milk sIgA as a dedicated airway therapeutic for respiratory infections such as SARS-CoV-2. In the present study, methods were therefore developed to efficiently extract human milk sIgA from donors who were either immunologically naïve to SARS-CoV-2 (pooled as a control IgA) or had recovered from a PCR-confirmed SARS-CoV-2 infection that elicited high-titer anti-SARS-CoV-2 Spike sIgA Abs in their milk (pooled together to make LCTG-002). Mass spectrometry determined that proteins with a relative abundance of 1.0% or greater were all associated with sIgA. None of the proteins exhibited statistically significant differences between batches. Western blot demonstrated all batches consisted predominantly of sIgA. Compared to control IgA, LCTG-002 demonstrated significantly higher binding to Spike, and was also capable of blocking the Spike - ACE2 interaction in vitro with 6.3x greater potency compared to control IgA (58% inhibition at ∼240ug/mL). LCTG-002 was then tested in vivo for its capacity to reduce viral burden in the lungs of K18+hACE2 transgenic mice inoculated with SARS-CoV-2. LCTG-002 was demonstrated to significantly reduce SARS-CoV-2 titers in the lungs compared to control IgA when administered at either 250ug/day or 1 mg/day, as measured by TCID50, plaque forming units (PFU), and qRT-PCR, with a maximum reduction of 4.9 logs. This innovative study demonstrates that LCTG-002 is highly pure, efficacious, and well tolerated in vivo, supporting further development of milk-derived, polyclonal sIgA therapeutics against SARS-CoV-2 and other mucosal infections.

Extended List of Warning Signs in Qualification to Diagnosis and Treatment of Inborn Errors of Immunity in Children and Young Adults

BACKGROUND AND OBJECTIVES

Inborn errors of immunity (IEI) refer to genetically determined disorders presenting with recurrent infections, autoimmunity, allergies, and malignancies. IEI is now commonly used, replacing the previously used term primary immunodeficiencies (PID). The 10 warning signs of IEI are widely used in the identification patients with IEI. The aim of the study was to determine and compare the utility of the 10 and 14 warning signs in IEI diagnosing.

METHODS

A retrospective analysis of 2851 patients was performed (98.17% were subjects under 18 years old and 1.83% were adults). All patients were questioned about the 10 warning signs and four additional signs: severe eczema, allergies, hemato-oncologic disorders and autoimmunity. Sensitivity, specificity, positive and negative predictive values, and odds ratio were calculated for the 10 and 14 warning signs.

RESULTS

IEI were diagnosed in a total of 896 (31.4%) patients and excluded in 1955 (68.6%). The strongest predictors of IEI were hemato-oncologic disorders (OR = 11.25; p < 0.001) and autoimmunity (OR = 7.74; p < 0.001). The strongest predictors of severe IEI were hemato-oncologic disorders (OR = 89.26; p < 0.001), positive family history (OR = 25.23; p < 0.001), and autoimmunity (OR = 16.89; p < 0.001). There were 20.4% and 14% of IEI patients without any signs from the 10 and 14 warnings signs, respectively (p < 0.001). 20.3% and 6.8% of patients with severe PIDs had no presence of any signs from 10 and 14 signs, respectively (p = 0.012).

CONCLUSIONS

The 10 warning signs have limited usefulness in identifying IEI. The modified list of 14 warning signs seems to represent an effective diagnostic method for the detection of IEI patients, especially those with severe PIDs.

Long-term follow-up in common variable immunodeficiency: the pediatric-onset and adult-onset landscape

Introduction

The primary aim of this study is to investigate the evolution of the clinical and laboratory characteristics during the time in a longitudinal cohort of pediatric-onset and adult-onset Common Variable Immunodeficiency (CVID) patients in order to identify early predictive features of the disease and immune dysregulation complications.

Methods

This is a retrospective-prospective monocentric longitudinal study spanning from 1984 to the end of 2021. The data of pediatric-onset vs. adult-onset patients have been compared for immunological features and for infectious and non-infectious complications assessed at diagnosis and follow-up.

Results

Seventy-three CVID patients have been enrolled, with a mean of 10.0 years (SD ± 8.17) of prospective follow-up. At diagnosis, infections were observed in 89.0% of patients and immune dysregulation in 42.5% of patients. At diagnosis, 38.6% of pediatric-onset and 20.7% of adult-onset patients presented with only infections. Polyclonal lymphoid proliferation (62.1%) and autoimmunity (51.7%) were more prevalent in the adult-onset than in the pediatric-onset group (polyclonal lymphoid proliferation 52.3% and autoimmunity 31.8%, respectively). Enteropathy was present in 9.1% of pediatric-onset and 17.2% of adult-onset patients. The prevalence of polyclonal lymphoid proliferation increased during follow-up more in pediatric-onset patients (diagnosis 52.3%-follow-up 72.7%) than in adult-onset patients (diagnosis 62.1%-follow-up 72.7%). The cumulative risk to develop immune dysregulation increases according to the time of disease and the time of diagnostic delay. At the same age, pediatric-onset patients have roughly double the risk of having a complication due to immune dysregulation than adult-onset patients, and it increases with diagnostic delay. The analysis of lymphocyte subsets in the pediatric-onset group showed that CD21 low B cells at diagnosis may be a reliable prognostic marker for the development of immune dysregulation during follow-up, as the ROC curve analysis showed (AUC = 0.796). In the adult-onset group, the percentage of transitional B cells measured at diagnosis showed a significant accuracy (ROC AUC = 0.625) in identifying patients at risk of developing immune dysregulation.

Discussion

The longitudinal evaluation of lymphocyte subsets combined with clinical phenotype can improve the prediction of lymphoid proliferation and allow experts to achieve early detection and better management of such complex disorder.

Common Variable Immunodeficiency Patient Fecal Microbiota Transplant Recapitulates Gut Dysbiosis

Purpose

Patients with non-infectious complications have worse clinical outcomes in common variable immunodeficiency (CVID) than those with infections-only. Non-infectious complications are associated with gut microbiome aberrations, but there are no reductionist animal models that emulate CVID. Our aim in this study was to uncover potential microbiome roles in the development of non-infectious complications in CVID.

Methods

We examined fecal whole genome shotgun sequencing from patients CVID, and non-infectious complications, infections-only, and their household controls. We also performed Fecal Microbiota transplant from CVID patients to Germ-Free Mice.

Results

We found potentially pathogenic microbes Streptococcus parasanguinis and Erysipelatoclostridium ramosum were enriched in gut microbiomes of CVID patients with non-infectious complications. In contrast, Fusicatenibacter saccharivorans and Anaerostipes hadrus, known to suppress inflammation and promote healthy metabolism, were enriched in gut microbiomes of infections-only CVID patients. Fecal microbiota transplant from non-infectious complications, infections-only, and their household controls into germ-free mice revealed gut dysbiosis patterns in recipients from CVID patients with non-infectious complications, but not infections-only CVID, or household controls recipients.

Conclusion

Our findings provide a proof of concept that fecal microbiota transplant from CVID patients with non-infectious complications to Germ-Free mice recapitulates microbiome alterations observed in the donors.

Identification of novel NFKB1 and ICOS frameshift variants in patients with CVID

Common variable immunodeficiency (CVID) is a 'late-onset' primary immunodeficiency characterized by variable manifestations and genetic heterogeneity. A monogenic cause of CVID has been reported in 10% of patients. In this study, we identified two novel pathogenic variants implicated in monogenic CVID by whole exome sequencing (WES) analysis: a heterozygous nuclear factor κB subunit 1 (NFKB1) p.G686fs mutation and a homozygous inducible T-cell co-stimulator (ICOS) p.L96Sfs mutation. The predicted crystal models indicated premature truncation of the two mutated proteins. Both variants were demonstrated as loss-of-function mutations and were associated with overlapped manifestations of respiratory fungal infection and splenomegaly. We further performed a detailed assessment of immunologic phenotypes and impaired lymphocyte functions in patients. Moreover, we discovered an association between monoclonal T-large granular lymphocyte proliferation and ICOS-deficient CVID for the first time. These observations lead to a new perspective on the underlying genetic heterogeneity of CVID.

Neurologic Manifestations of Common Variable Immunodeficiency: Impact on Quality of Life

BACKGROUND AND OBJECTIVES

Common variable immunodeficiency is a systemic disease and not solely a disease of humoral immunity. Neurologic symptoms associated with common variable immunodeficiency are underrecognized and warrant further study. This work aimed to characterize the neurologic symptoms reported by people living with common variable immunodeficiency.

METHODS

We conducted a single academic medical center study of neurologic symptoms reported by adults previously diagnosed with common variable immunodeficiency. We used a survey of common neurologic symptoms to determine the prevalence of these symptoms in a population with common variable immunodeficiency and further assessed these patient-reported symptoms with validated questionnaires and compared symptom burden with other neurologic conditions.

RESULTS

A volunteer sample of adults (aged 18 years or older) previously diagnosed with common variable immunodeficiency at the University of Utah Clinical Immunology/Immune Deficiency Clinic who were able to read and comprehend English and willing and able to answer survey-based questions were recruited. Of 148 eligible participants identified, 80 responded and 78 completed the surveys. The mean age of respondents was 51.3 years (range 20-78 years); 73.1% female and 94.8% White. Patients with common variable immunodeficiency reported many common neurologic symptoms (mean 14.6, SD 5.9, range 1-25), with sleep issues, fatigue, and headache reported by more than 85%. Validated questionnaires addressing specific neurologic symptoms supported these results. T-scores on Neuro QoL questionnaires for sleep (mean 56.4, SD 10.4) and fatigue (mean 54.1, SD 11) were higher, indicating more dysfunction, than in the reference clinical population (p < 0.005). The Neuro QoL questionnaire for cognitive function showed a lower T-score (mean 44.8, SD 11.1) than that in the reference general population (p < 0.005), indicating worse function in this domain.

DISCUSSION

Among survey respondents, there is a marked burden of neurologic symptoms. Given the impact of neurologic symptoms on health-related quality-of-life measures, clinicians should screen patients with common variable immunodeficiency for the presence of these symptoms and offer referral to neurologists and/or symptomatic treatment when indicated. Frequently prescribed neurologic medications may also affect the immune system, and neurologists should consider screening patients for immune deficiency before prescribing them.

Primary antibody deficiency-associated arthritis shares features with spondyloarthritis and enteropathic arthritis

OBJECTIVE

The clinical spectrum of primary antibody deficiencies (PADs) and especially common variable immunodeficiency (CVID) includes various autoimmune disorders. We studied the prevalence and the features of articular rheumatic disease in a cohort of patient with PADs.

METHODS

In this retrospective cohort study, complete clinical data of 268 patients with PADs, mainly consisting of patients with CVID, visiting the immunology outpatient clinic of a German tertiary hospital between 2018 and 2021 were collected. Those included case history, physical examination, laboratory as well as radiological findings.

RESULTS

Inflammatory arthritis was diagnosed in 16.4% of studied patients and was significantly more common among patients with PAD-associated enteropathy (OR 13.39, p=0.0001), splenomegaly (OR 6.09, p=0.0001) or atopic diseases (OR 3.31, p=0.021). Given HLA-B27 status, the involvement of the axial skeleton and the presence of features, such as anterior uveitis, inflammatory bowel disease, psoriasis and/or dactylitis, 75% of studied patients fulfilled the Assessment of Spondyloarthritis International Society classification criteria.

CONCLUSION

PAD-associated arthritis frequently shares features with spondyloarthritis (SpA) and enteropathic arthritis. The latter may suggest the interconnected pathomechanisms of inflammatory arthritis in SpA and PADs.

Hypogammaglobulinemia: A contributing factor to multiple sclerosis fatigue?

OBJECTIVE

Fatigue is one of the most disabling and difficult to treat symptoms of autoimmune diseases and frequently presents in people with multiple sclerosis (PwMS). Hypogammaglobulinemia for immunoglobulin G (IgG) affects approximately 8-25% of PwMS. We performed a retrospective analysis to investigate the association of MS-fatigue and IgG hypogammaglobulinemia.

METHODS

PwMS, treated at Eginition University Hospital Athens or at the University Hospital Bern, were included (n = 134 patients (Bern n = 99; Athens n = 35)). Mann Whitney U-test (MWT), ANOVA test, Chi² test and multivariable linear regression models were run.

RESULTS

97/134 (72.4%) PwMS reported fatigue. In the multivariable linear regression analysis, IgG serum concentration (-1.6, 95%CI -2.7 - -0.5, p = 0.006), daytime sleepiness (0.8, 95%CI 0.2-1.4, p = 0.009), and a depressive mood (1.1, 95%CI 0.8-1.4, p < 0.001) were significantly associated with fatigue. The impact of IgG serum concentration (-2.9 95%CI -4.7 - -1.1, p = 0.002) remained significant also in the subcohort of PwMS without depressive symptoms or daytime sleepiness.

CONCLUSIONS

We found an association between IgG hypogammaglobulinemia and fatigue in PwMS (Level of Evidence IV), which might be translated to other autoimmune diseases. It bears a potential therapeutic consequence considering IgG supplementation strategies, if our finding can be validated prospectively.

An Expert Opinion/Approach: Clinical Presentations, Diagnostic Considerations, and Therapeutic Options for Gastrointestinal Manifestations of Common Variable Immune Deficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency. It is characterized by impaired B-cell differentiation. Although patients can be diagnosed with CVID anytime during their lifetime, most patients have symptoms for 5-9 years before their diagnosis. The diagnosis of CVID starts with a detailed history focusing on the infectious and noninfectious manifestations of the disease. In patients who are suspected to experience CVID, quantitative immunoglobulins (Ig) should be checked to confirm the diagnosis. IgG should be at least 2 times less than the age-specific SD along with either a low IgA or IgM and with evidence of impaired vaccine response. CVID is usually associated with infectious and/or noninfectious conditions, the latter of which can be inflammatory, autoimmune, lymphoproliferative, or malignant, among other manifestations. Ig therapy has positively affected the disease course of patients with infectious complications but has limited effect on the noninfectious manifestations because the noninfectious complications are related to immune dysregulation involving B cells and T cells rather than primarily due to antibody deficiency. When the gastrointestinal (GI) system is involved, patients with CVID may display signs and symptoms that mimic several GI conditions such as celiac disease, pernicious anemia, or inflammatory bowel diseases. The inflammatory bowel disease-like condition is usually treated with steroids, 5-aminosalicylates, thiopurines, or biologic agents to control the inflammation. In this review, the clinical presentations, diagnostic considerations, and therapeutic options for GI manifestations of CVID will be discussed to facilitate the individualized management of these often-complex patients.

Hepatitis E infection in adults with primary immunodeficiency with or without immunoglobulin replacement therapy

BACKGROUND

In a context of secondary immunodeficiency, hepatitis E virus (HEV) infection can be responsible for chronic liver disease.

MATERIALS AND METHODS

We investigated HEV infection in patients with primary immunodeficiency treated (or not) with immunoglobulin (Ig) replacement therapy (IgRT) in France, a country with a high seroprevalence of HEV. In a nationwide study of individuals with primary immunodeficiency, 533 patients (349 and 184 receiving IgRT or not, respectively) were tested for HEV RNA and anti-HEV antibodies. In addition, 23 batches of five different commercially available immunoglobulin preparations were screened for anti-HEV IgG.

RESULTS

Three of the 533 patients displayed markers of a recent HEV infection (HEV RNA in one case, and anti-HEV IgG and IgM in two) but no evidence of chronic liver disease. The overall seroprevalence of HEV was 50% (266 out of 533), with values of 68% and 16% in patients receiving IgRT or not, respectively (p<0.001). Anti-HEV IgG were detected in all batches of immunoglobulin preparations, although the titer varied from 3 to 127 IU/g IgG. Seroconversion was observed in 15 of the 22 (68%) patients tested before and after IgRT.

DISCUSSION

No cases of chronic HEV-related disease were detected among patients with primary immunodeficiency and hypogammaglobulinemia, whether they received IgRT or not. This confirms that patients with primary immunodeficiency have a low risk of chronic infection despite a seroprevalence close to that observed in the French general population and that IgRT, which confers a high HEV seroprevalence, might play a key role in protection against chronic infection.

Genomic crossroads between non-Hodgkin's lymphoma and common variable immunodeficiency

Common variable immunodeficiency (CVID) represents the largest group of primary immunodeficiencies that may manifest with infections, inflammation, autoimmunity, and cancer, mainly B-cell non-Hodgkin's lymphoma (NHL). Indeed, NHL may result from chronic or recurrent infections and has, therefore, been recognized as a clinical phenotype of CVID, although rare. The more one delves into the mechanisms involved in CVID and cancer, the stronger the idea that both pathologies can be a reflection of the same primer events observed from different angles. The potential effects of germline variants on specific somatic modifications in malignancies suggest that it might be possible to anticipate critical events during tumor development. In the same way, a somatic alteration in NHL could be conditioning a similar response at the transcriptional level in the shared signaling pathways with genetic germline alterations in CVID. We aimed to explore the genomic substrate shared between these entities to better characterize the CVID phenotype immunodeficiency in NHL. By means of an in-silico approach, we interrogated the large, publicly available datasets contained in cBioPortal for the presence of genes associated with genetic pathogenic variants in a panel of 50 genes recurrently altered in CVID and previously described as causative or disease-modifying. We found that 323 (25%) of the 1,309 NHL samples available for analysis harbored variants of the CVID spectrum, with the most recurrent alteration presented in NHL occurring in PIK3CD (6%) and STAT3 (4%). Pathway analysis of common gene alterations showed enrichment in inflammatory, immune surveillance, and defective DNA repair mechanisms similar to those affected in CVID, with PIK3R1 appearing as a central node in the protein interaction network. The co-occurrence of gene alterations was a frequent phenomenon. This study represents an attempt to identify common genomic grounds between CVID and NHL. Further prospective studies are required to better know the role of genetic variants associated with CVID and their reflection on the somatic pathogenic variants responsible for cancer, as well as to characterize the CVID-like phenotype in NHL, with the potential to influence early CVID detection and therapeutic management.

Common Variable Immune Deficiency: An Outpatient Experience

OBJECTIVES

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiencies encountered by physicians, yet it is still poorly described and vastly underdiagnosed and underreported. It is characterized by low levels of immunoglobulins IgG, IgM, and IgA, recurrent infections, and an increased incidence of autoimmune conditions and malignancies. Diverse clinical presentation, poor understanding of its true prevalence, and the daunting, rarely ordered, diagnostic testing make this disease incredibly difficult to diagnose in a primary care setting. Our objectives in this study were to establish a simple marker that can be used in a primary care setting to raise suspicion of CVID and prompt further diagnostic testing and to demonstrate that the true prevalence of CVID is much higher than previously reported.

METHODS

Data on 441 patients who underwent Ig electrophoresis testing during a 4-year period were analyzed retrospectively for the presence of hypogammaglobulinemia and number of clinic visits for infectious processes.

RESULTS

The average number of clinic visits before testing in patients with no identified antibody deficiency was 1.89 and in patients with any deficiency 2.22. The odds ratio for each additional visit was 1.089, which was not statistically significant (P = 0.103). When the data were recoded to be capped at 6 clinic visits, the odds ratio for each visit up to 6 was 1.119, which was marginally significant (P = 0.058).

CONCLUSIONS

Patients with Ig deficiencies tend to have a higher number of office visits related to infectious processes. This difference, however, was not statistically significant in our study, likely because of the small number of participants. Our study also demonstrated that the prevalence of CVID is likely much higher than currently reported, and it highlights the difficulties related to the convoluted diagnostic process of this disease.

A Novel Targeted Amplicon Next-Generation Sequencing Gene Panel for the Diagnosis of Common Variable Immunodeficiency Has a High Diagnostic Yield: Results from the Perth CVID Cohort Study

With the advent of next-generation sequencing (NGS), monogenic forms of common variable immunodeficiency (CVID) have been increasingly described. Our study aimed to identify disease-causing variants in a Western Australian CVID cohort using a novel targeted NGS panel. Targeted amplicon NGS was performed on 22 unrelated subjects who met the formal European Society for Immunodeficiencies-Pan-American Group for Immunodeficiency diagnostic criteria for CVID and had at least one of the following additional criteria: disease onset at age <18 years, autoimmunity, low memory B lymphocytes, family history, and/or history of lymphoproliferation. Candidate variants were assessed by in silico predictions of deleteriousness, comparison to the literature, and classified according to the American College of Medical Genetics and Genomics-Association for Molecular Pathology criteria. All detected genetic variants were verified independently by an external laboratory, and additional functional studies were performed if required. Pathogenic or likely pathogenic variants were detected in 6 of 22 (27%) patients. Monoallelic variants of uncertain significance were also identified in a further 4 of 22 patients (18%). Pathogenic variants, likely pathogenic variants, or variants of uncertain significance were found in TNFRSF13B, TNFRSF13C, ICOS, AICDA, IL21R, NFKB2, and CD40LG, including novel variants and variants with unexpected inheritance pattern. Targeted amplicon NGS is an effective tool to identify monogenic disease-causing variants in CVID, and is comparable or superior to other NGS methods. Moreover, targeted amplicon NGS identified patients who may benefit from targeted therapeutic strategies and had important implications for family members.

Autoimmunity in Primary Immunodeficiencies (PID)

Primary immunodeficiency (PID) may impact any component of the immune system. The number of PID and immune dysregulation disorders is growing steadily with advancing genetic detection methods. These expansive recognition methods have changed the way we characterize PID. While PID were once characterized by their susceptibility to infection, the increase in genetic analysis has elucidated the intertwined relationship between PID and non-infectious manifestations including autoimmunity. The defects permitting opportunistic infections to take hold may also lead the way to the development of autoimmune disease. In some cases, it is the non-infectious complications that may be the presenting sign of PID autoimmune diseases, such as autoimmune cytopenia, enteropathy, endocrinopathies, and arthritis among others, have been reported in PID. While autoimmunity may occur with any PID, this review will look at certain immunodeficiencies most often associated with autoimmunity, as well as their diagnosis and management strategies.

Intravenous Immunoglobulins Promote an Expansion of Monocytic Myeloid-Derived Suppressor Cells (MDSC) in CVID Patients

Common variable immunodeficiency disorders (CVID), the most common primary immune deficiency, includes heterogeneous syndromes characterized by hypogammaglobulinemia and impaired antibody responses. CVID patients frequently suffer from recurrent infections and inflammatory conditions. Currently, immunoglobulin replacement therapy (IgRT) is the first-line treatment to prevent infections and aminorate immune alterations in CVID patients. Intravenous Immunoglobulin (IVIg), a preparation of highly purified poly-specific IgG, is used for treatment of immunodeficiencies as well as for autoimmune and inflammatory disorders, as IVIg exerts immunoregulatory and anti-inflammatory actions on innate and adaptive immune cells. To determine the mechanism of action of IVIg in CVID in vivo, we determined the effect of IVIg infusion on the transcriptome of peripheral blood mononuclear cells from CVID patients, and found that peripheral blood monocytes are primary targets of IVIg in vivo, and that IVIg triggers the acquisition of an anti-inflammatory gene profile in human monocytes. Moreover, IVIg altered the relative proportions of peripheral blood monocyte subsets and enhanced the proportion of CD14⁺ cells with a transcriptional, phenotypic, and functional profile that resembles that of monocytic myeloid-derived suppressor cells (MDSC). Therefore, our results indicate that CD14 + MDSC-like cells might contribute to the immunoregulatory effects of IVIg in CVID and other inflammatory disorders.

Pulmonary Manifestations of Primary Humoral Deficiencies

Primary immunodeficiencies are a group of conditions characterized by developmental or functional alterations in the immune system caused by hereditary genetic defects. Primary immunodeficiencies may affect either the innate or the adaptive (humoral and cellular) immune system. Pulmonary complications in primary humoral deficiencies are frequent and varied and are associated with high morbidity and mortality rates. The types of complications include bronchiectasis secondary to recurrent respiratory infections and interstitial pulmonary involvement, which can be associated with autoimmune cytopenias, lymphoproliferation, and a range of immunological manifestations. Early detection is key to timely management. Immunoglobulin replacement therapy reduces the severity of disease, the frequency of exacerbations, and hospital admissions in some primary humoral deficiencies. Therefore, the presence of pulmonary disease with concomitant infectious and/or autoimmune complications should raise suspicion of primary humoral deficiencies and warrants a request for immunoglobulin determination in blood. Once diagnosis is confirmed; early immunoglobulin replacement therapy will improve the course of the disease. Further studies are needed to better understand the pathogenesis of pulmonary disease related to primary humoral deficiencies and favor the development of targeted therapies that improve the prognosis of patients.

Protocol for the unclassified primary antibody deficiency (unPAD) study: Characterization and classification of patients using the ESID online Registry

Background

Primary antibody deficiencies (PADs) without an identified monogenetic origin form the largest and most heterogeneous group of primary immunodeficiencies. These patients often remain undiagnosed for years and many present to medical attention in adulthood after several infections risking structural complications. Not much is known about their treatment, comorbidities, or prognosis, nor whether the various immunological forms (decreased total IgG, IgG subclass(es), IgM, IgA, specific antibody responses, alone or in combination(s)) should be considered as separate, clearly definable subgroups. The unclassified primary antibody deficiency (unPAD) study aims to describe in detail all PAD patients without an identified specific monogenetic defect regarding their demographical, clinical, and immunological characteristics at presentation and during follow-up. In constructing these patterns, the unPAD study aims to reduce the number of missed and unidentified PAD patients in the future. In addition, this study will focus on subclassifying unPAD to support the identification of patients at higher risk for infection or immune dysregulation related complications, enabling the development of personalized follow-up and treatment plans.

Methods and analysis

We present a protocol for a multicenter observational cohort study using the ESID online Registry. Patients of all ages who have given informed consent for participation in the ESID online Registry and fulfill the ESID Clinical Working Definitions for ‘unclassified antibody deficiency’, ‘deficiency of specific IgG’, ‘IgA with IgG subclass deficiency’, ‘isolated IgG subclass deficiency’, ‘selective IgM deficiency’, ‘selective IgA deficiency’ or ‘common variable immunodeficiency’ will be included. For all patients, basic characteristics can be registered at first registration and yearly thereafter in level 1 forms. Detailed characteristics of the patients can be registered in level 2 forms. Consecutive follow-up forms can be added indefinitely. To ensure the quality of the collected data, all data will be fully monitored before they are exported from the ESID online Registry for analysis. Outcomes will be the clinical and immunological characteristics of unPAD at presentation and during follow-up. Subgroup analyses will be made based on demographical, clinical and immunological characteristics.

Growth in diagnosis and treatment of primary immunodeficiency within the global Jeffrey Modell Centers Network

BACKGROUND

Primary immunodeficiencies (PI), which include more than 450 single-gene inborn errors of immunity and may affect up to 1% of the population, are genetic disorders that impair the immune system. If not properly identified and treated, individuals with PI are subject to serious, prolonged, and sometimes life-threatening infections or autoimmunity. Despite advancements, awareness of PI remains a critical issue for physicians and the public alike, as this leads to the enhanced and expedited management of these conditions. To address this critical issue, the Jeffrey Modell Foundation (JMF) formed a global network of specialized centers. The goal of this endeavor was to raise awareness of PI to better identify, diagnose, and treat patients, reducing associated mortality and morbidity and improving quality of life (QOL). For more than two decades, the Jeffrey Modell Centers Network (JMCN) has served as the foundation upon which these goals have been pursued. The JMCN currently includes 909 Expert Physicians at 400 institutions, in 316 cities, and 86 countries spanning six continents.

METHODS

A survey was developed by JMF for members of the JMCN, following the most recent Classification of PI from the IUIS Expert Committee, to periodically describe the patient population, including treatment modalities and demographics. Physician-reported data from 2021 was compared to that from 2018 and 2013. Physicians in the JMCN also reported on select outcomes of their PI patients one year prior to and one year following diagnosis.

RESULTS

A total of 300 JMF Physician Surveys from 681 physicians were included in this analysis. This is a 75% physician response rate. From 2013 to 2021, there was a 96.3% increase in patients followed in the US and an 86.1% increase globally. During the same period, patients identified with a specific PI defect increased by 46.6% in the US and 47.9% globally. Patients receiving IgG and HSCT increased by 110% and 201% respectfully since 2013. Early diagnosis led to reported decreased morbidity and mortality and reduced calculated healthcare costs.

CONCLUSIONS

This global analysis of physician-reported data on patients with PI demonstrates an increase in both diagnosed and treated patients. This substantial increase from within the JMCN is a testament to its impact. In addition to building an extensive global patient database, the expanding JMCN serves as a unique and critical resource, providing the infrastructure for earliest diagnosis, optimized treatments, and implementation of standard-of-care and best practices. The JMCN provides a critical platform that facilitates the education of physicians and patients, awareness initiatives, and research advances, through collaboration and connectivity, ultimately resulting in improved outcomes and QOL for patients with PI. The JMCN has steadily and substantially grown for more than two decades and continues to substantively impact the field of Immunology globally.

Fatigue Is Common in Immunoglobulin G Subclass Deficiency and Correlates With Inflammatory Response and Need for Immunoglobulin Replacement Therapy

Purpose

Individuals with immunoglobulin G deficiency (IgGsd) often complain of fatigue. The correlation between systemic inflammation and fatigue is unknown. In this study perceived quality of life (QoL) and fatigue in individuals with IgGsd, on and off immunoglobulin replacement therapy (IgRT) were correlated to inflammatory markers in plasma to identify the subgroup that benefits from IgRT.

Method

Thirty-five IgGsd-patients were sampled on three occasions: at baseline, after being on IgRT for at least 18 months, and 18 months after discontinuation of IgRT. Short form 36, EQ-5D-5L visual analogue scale and fatigue impact scale questionnaires were used for evaluation of QoL and fatigue. Furthermore, a panel of 92 inflammatory markers were analysed in plasma. Thirty-two gender- and age-matched healthy individuals were included as controls and sampled on one occasion.

Results

QoL was lower and perceived fatigue higher in IgGsd compared to the controls. Severe fatigue and low QoL were associated with the need to restart IgRT (which is considered in IgGsd-individuals with a high burden of infections in Sweden). Twenty-five inflammatory factors were dysregulated in IgGsd and the plasma protein patterns were similar regardless of whether IgRT was ongoing or not. Enrichment analysis indicated IL-10 signalling as the most affected pathway. Severe fatigue was associated with decreased levels of the neurotrophic factors VEGFA and CSF-1.

Conclusion

Fatigue is a major contributory factor to impaired health-related QoL in IgGsd and is related to the need for IgRT. Low-grade systemic inflammation is a potential driver of fatigue. In addition to the burden of infections, we suggest the degree of fatigue should be considered when the decision to introduce IgRT is made.

Fatal epistaxis in a case of common variable immunodeficiency: A case report and review of the literature

Common variable immunodeficiency (CVID) is a primary immunodeficiency disease. We present a case of a patient with CVID complicated by rhinosinusitis with granulomatous inflammation. Treatment for this patient was challenging with regards recognition of the granulomatous manifestation as well as treatment in the setting immunodeficiency and was ultimately unsuccessful.

Good's Syndrome: Time to Move on From Reviewing the Past

For seven decades, the pathophysiology of Good’s syndrome (GS) has remained a mystery, with few attempts to solve it. Initially described as an association between hypogammaglobulinemia and thymoma, controversy exists whether this is a unique disease, or a subgroup of Common Variable Immune Deficiency (CVID). Recently, some distinguishing aspects of both syndromes have come to light reflecting fundamental differences in their underlying pathophysiology. GS and CVID differ in demographic features and immune phenotype. GS is found almost exclusively in adults and is characterized by a significantly reduced or absence of peripheral B cells. In CVID, which also occurs in children, most patients have normal or slightly reduced peripheral B cells, with a distinguishing feature of low memory B cells. Similarly, differences in T cell dysregulation and manifestations of hematologic cytopenias may further distinguish GS from CVID. Knowledge of the clinical phenotype of this rare adult immune deficiency stems from individual case reports, retrospective, and cross-sectional data on a few cohorts with a limited number of well characterized patients. The understanding of pathophysiology in GS is hampered by the incomplete and inconsistent reporting of clinical and laboratory data, with a limited knowledge of its natural history. In this mini review, we discuss current state of the art data and identify research gaps. In order to resolve controversies and fill in knowledge gaps, we propose a coordinated paradigm shift from incidence reporting to robust investigative studies, addressing mechanisms of disease. We hope this novel approach sets a clear direction to solve the current controversies.

Establishing the Molecular Diagnoses in a Cohort of 291 Patients With Predominantly Antibody Deficiency by Targeted Next-Generation Sequencing: Experience From a Monocentric Study

Predominantly antibody deficiencies (PAD) are a heterogeneous group of disorders characterized by dysfunctional antibody production, low immunoglobulin levels in serum and impaired vaccine responses. The clinical picture is variable, ranging from mild symptoms to severe complications, which may include autoimmunity, gastrointestinal disease, allergy, and malignancies. If left untreated, PAD patients are at risk of enduring disease progression, irreversible organ damage, and reduced life expectancy. A timely diagnosis has been shown to significantly improve disease prognosis. Here, we report on our experience using targeted gene panel sequencing by employing Agilent's HaloPlex or SureSelect and Illumina's MiSeq technologies in a cohort of 291 individuals who presented with low or absent immunoglobulin levels in combination with or without other clinical features. In total, we have detected over 57 novel or previously reported relevant mutations in ADA, ADA2, BTK, CTLA4, LRBA, NFKB1, NFKB2, PIK3CD, STAT3, and TNFRSF13B. Overall, a genetic diagnosis could be made in 24.7% of the investigated patients. The percentage of coverage for the targeted regions ranged from 90% to 98% in this study. Moreover, functional assays were performed on a defined group of the patients carrying candidate variants in CTLA4, LRBA, NFKB1 and BTK, which confirmed their deleterious effect on protein expression and/or function. This study reiterates that the immunological heterogeneity of predominantly antibody deficiencies may have a diverse genetic origin, although certain clinical features may hint towards a specific group of defects. Employing targeted sequencing panels proves to be a very time- and cost-efficient, yet reliable, method for the establishment of a genetic diagnosis in individuals with PAD. However, in case of negative panel results, or if functional testing reveals inconspicuous observations in patients with a clear indication for genetic testing, further work-up including whole exome or whole genome sequencing should be considered.

Rituximab and Abatacept Are Effective in Differential Treatment of Interstitial Lymphocytic Lung Disease in Children With Primary Immunodeficiencies

Background

Interstitial lymphocytic lung disease (ILLD), a recently recognized complication of primary immunodeficiencies (PID), is caused by immune dysregulation, abnormal bronchus-associated lymphoid tissue (BALT) hyperplasia, with subsequent progressive loss of pulmonary function. Various modes of standard immunosuppressive therapy for ILLD have been shown as only partially effective.

Objectives

To retrospectively evaluate the safety and efficacy of abatacept or rituximab in treatment of ILLD in children with PID.

Methods

29 children (median age 11 years) with various forms of PID received one of the two therapy regimens predominantly based on the lesions’ immunohistopathology: children with prevalent B-cell lung infiltration received rituximab (n = 16), and those with predominantly T-cell infiltration received abatacept (n = 17). Clinical and radiological symptoms were assessed using a severity scale developed for the study.

Results

The targeted therapy with abatacept (A) or rituximab (R) enabled long-term control of clinical (A 3.4 ± 1.3 vs. 0.6 ± 0.1; R 2.8 ± 1 vs. 0.7 ± 0.05, p < 0.01) and radiological (A 18.4 ± 3.1 vs. 6.0 ± 2.0; R 30 ± 7.1 vs. 10 ± 1.7, p < 0.01) symptoms of ILLD in both groups and significantly improved patients’ quality of life, as measured by the total scale (TS) score of 57 ± 2.1 in treatment recipients vs. 31.2 ± 1.9 before therapy (p < 0.01).

Conclusions

ILLD histopathology should be considered when selecting treatment. Abatacept and rituximab are effective and safe in differential treatment of ILLD in children.

Challenging Mimickers in the Diagnosis of Sarcoidosis: A Case Study

Sarcoidosis is a systemic granulomatous disease of unknown cause characterized by a wide variety of presentations. Its diagnosis is based on three major criteria: a clinical presentation compatible with sarcoidosis, the presence of non-necrotizing granulomatous inflammation in one or more tissue samples, and the exclusion of alternative causes of granulomatous disease. Many conditions may mimic a sarcoid-like granulomatous reaction. These conditions include infections, neoplasms, immunodeficiencies, and drug-induced diseases. Moreover, patients with sarcoidosis are at risk of developing opportunistic infections or lymphoma. Reliably confirming the diagnosis of sarcoidosis and better identifying new events are major clinical problems in daily practice. To address such issues, we present seven emblematic cases, seen in our department, over a ten-year period along with a literature review about case reports of conditions misdiagnosed as sarcoidosis.

Common Variable Immunodeficiency and Autoimmune Diseases: A Retrospective Study of 95 Adult Patients in a Single Tertiary Care Center

Common variable immunodeficiency (CVID) is the most common clinically significant primary immunodeficiency in adulthood, which presents a broad spectrum of clinical manifestations, often including non-infectious complications in addition to heightened susceptibility to infections. These protean manifestations may significantly complicate the differential diagnosis resulting in diagnostic delay and under-treatment with increased mortality and morbidity. Autoimmunity occurs in up to 30% of CVID patients, and it is an emerging cause of morbidity and mortality in this type of patients. 95 patients (42 males and 53 females) diagnosed with CVID, basing on ESID diagnostic criteria, were enrolled in this retrospective cohort study. Clinical phenotypes were established according to Chapel 2012: i) no other disease-related complications, ii) cytopenias (thrombocytopenia/autoimmune hemolytic anemia/neutropenia), iii) polyclonal lymphoproliferation (granuloma/lymphoid interstitial pneumonitis/persistent unexplained lymphadenopathy), and iv) unexplained persistent enteropathy. Clinical items in the analysis were age, gender, and clinical features. Laboratory data included immunoglobulin (Ig)G, IgM and IgA levels at diagnosis, flow-cytometric analysis of peripheral lymphocytes (CD3+, CD3+CD4+, CD3+CD8+, CD19+, CD4+CD25highCD127low, CD19hiCD21loCD38lo, and follicular T helper cell counts). Comparisons of continuous variables between groups were performed with unpaired t-test, when applicable. 39 patients (41%) showed autoimmune complications. Among them, there were 21 females (53.8%) and 18 males (46.2%). The most prevalent autoimmune manifestations were cytopenias (17.8%), followed by arthritis (11.5%), psoriasis (9.4%), and vitiligo (6.3%). The most common cytopenia was immune thrombocytopenia, reported in 10 out of 95 patients (10.5%), followed by autoimmune hemolytic anemia (n=3, 3.1%) and autoimmune neutropenia (n=3, 3.1%). Other autoimmune complications included thyroiditis, coeliac disease, erythema nodosum, Raynaud’s phenomenon, alopecia, recurring oral ulcers, autoimmune gastritis, and primary biliary cholangitis. There were no statistically significant differences comparing immunoglobulin levels between CVID patients with or without autoimmune manifestations. There was no statistical difference in CD3+, CD8+, CD4+CD25highCD127low T, CD19, CD19hiCD21loCD38lo, and follicular T helper cell counts in CVID patients with or without autoimmune disorders. In conclusion, autoimmune manifestations often affect patients with CVID. Early recognition and tailored treatment of these conditions are pivotal to ensure a better quality of life and the reduction of CVID associated complications.

Oxidative stress in common variable immunodeficiency

Common variable immunodeficiency (CVID) is a heterogenous group of immunologic disorders of unknown etiology. Alterations of the normal cellular balance due to an increase in reactive oxygen species and/or decrease in antioxidant defense may lead to increased oxidative stress. We aimed to evaluate the levels of oxidative stress biomarkers in patients with CVID who had different presentations. We investigated the serum catalase (CAT), erythrocyte superoxide dismutase (SOD), erythrocyte reduced glutathione as antioxidants and serum malondialdehyde levels as lipid peroxidation marker in patients with CVID in Uludag University Hospital Department of Pediatric Allergy and Immunology’s outpatient clinics. In the analysis, there were 21 patients and 27 matched healthy controls. The median levels of CAT in patients with CVID was significantly lower than in healthy controls ( p = 0.04). Among the patients with CVID, 19% had autoimmune disease, one had Sjögren’s syndrome, one had autoimmune alopecia, one had juvenile rheumatoid arthritis, and one had chronic inflammatory demyelinating polyneuropathy. Patients with autoimmune complications had significantly lower CAT levels compared to the ones without autoimmune diseases ( p = 0.03). The patients without non-infectious complications (NICs) had lower SOD levels than the patients with NICs ( p = 0.05). The analysis of oxidative stress markers in the patients with CVID suggested a series of abnormalities in the anti-oxidant system. The clinical syndrome associations may be a useful tool for future studies to set prediction markers for the prognosis of patients with CVID.

State-of-the-art diagnostic evaluation of common variable immunodeficiency

OBJECTIVE

To summarize the current understanding of diagnostic and postdiagnostic evaluation of common variable immunodeficiency (CVID).

DATA SOURCES

PubMed Central database.

STUDY SELECTIONS

Original research articles and review articles from 2015 to 2020 including seminal articles that shaped the diagnostic and postdiagnostic evaluation of CVID were incorporated. This work focuses on initial diagnosis of CVID, genetic evaluations, and postdiagnostic assessment of respiratory, gastrointestinal, and hepatobiliary diseases including spleen and lymph node enlargement.

RESULTS

CVID presents not only with frequent infections but also with noninfectious complications such as autoimmunity, gastrointestinal disease, chronic lung disease, granulomas, liver disease, lymphoid hyperplasia, splenomegaly, or malignancy. The risk of morbidity and mortality is higher in patients with CVID and noninfectious complications. Detailed diagnostic approaches, which may incorporate genetic testing, can aid characterization of individual CVID cases and shape treatment in some instances. Moreover, continued evaluation after CVID diagnosis is key to optimal management of this complex disorder. These postdiagnostic evaluations include pulmonary function testing, radiologic studies, and laboratory evaluations that may be conducted at frequencies determined by disease activity.

CONCLUSION

Although the diagnosis can be achieved similarly in all patients with CVID, those with noninfectious complications have distinct concerns during clinical evaluation. State-of-the-art workup of CVID with noninfectious complications typically includes genetic analysis, which may shape precision therapy, and thoughtful application of postdiagnostic tests that monitor the presence and progression of disease in the myriad of tissues that may be affected. Even with recent advancements, knowledge gaps in diagnosis, prognosis, and treatment of CVID persist, and continued research efforts are needed.

Interstitial Lung Disease in Common Variable Immunodeficiency

Interstitial lung disease (ILD) is a common complication in patients with common variable immunodeficiency (CVID) and often associated with other features, such as bronchiectasis and autoimmunity. As the ILD term encompasses different acute and chronic pulmonary conditions, the diagnosis is commonly made based on imaging features; histopathology is less frequently available. From a cohort of 637 patients with CVID followed at our center over 4 decades, we reviewed the data for 46 subjects (30 females, 16 males) who had lung biopsies with proven ILD. They had a median age at CVID diagnosis of 26 years old, with a median IgG level at diagnosis of 285.0 mg/dL with average isotype switched memory B cells of 0.5%. Lung biopsy pathology revealed granulomas in 25 patients (54.4%), lymphoid interstitial pneumonia in 13 patients (28.3%), lymphoid hyperplasia not otherwise specified in 7 patients (15.2%), cryptogenic organizing pneumonia in 7 patients (15.2%), follicular bronchitis in 4 patients (8.7%), and predominance of pulmonary fibrosis in 4 patients (8.7%). Autoimmune manifestations were common and were present in 28 (60.9%) patients. Nine patients (19.6%) died, with a median age at death of 49-years-old. Lung transplant was done in 3 of these patients (6.5%) who are no longer alive. These analyses reveal the high burden of this complication, with almost one-fifth of the group deceased in this period. Further understanding of the causes of the development and progression of ILD in CVID patients is required to define the best management for this patient population.

Population pharmacokinetic modelling of intravenous immunoglobulin in patients with predominantly antibody deficiencies

AIMS

There is considerable interpatient variability in the pharmacokinetics (PK) of intravenous immunoglobulin G (IVIG), causing difficulty in optimizing individual dosage regimen. This study aims to estimate the population PK parameters of IVIG and to investigate the impact of genetic polymorphism of the FcRn gene and clinical variability on the PK of IVIG in patients with predominantly antibody deficiencies.

METHODS

Patients were recruited from four hospitals. Clinical data were recorded and blood samples were taken for PK and genetic studies. Population PK parameters were estimated by nonlinear mixed-effects modelling in Monolix®. Models were evaluated using the difference in objective function value, goodness-of-fit plots, visual predictive check and bootstrap analysis. Monte Carlo simulation was conducted to evaluate different dosing regimens for IVIG.

RESULTS

A total of 30 blood samples were analysed from 10 patients. The immunoglobulin G concentration data were best described by a one-compartment model with linear elimination. The final model included both volume of distribution (Vd) and clearance (CL) based on patient's individual weight. Goodness-of-fit plots indicated that the model fit the data adequately, with minor model mis-specification. Genetic polymorphism of the FcRn gene and the presence of bronchiectasis did not affect the PK of IVIG. Simulation showed that 3-4-weekly dosing intervals were sufficient to maintain IgG levels of 5 g L^-1 , with more frequent intervals needed to achieve higher trough levels.

CONCLUSIONS

Body weight significantly affects the PK parameters of IVIG. Genetic and other clinical factors investigated did not affect the disposition of IVIG.

Perspective: Evolving Concepts in the Diagnosis and Understanding of Common Variable Immunodeficiency Disorders (CVID)

Common variable immunodeficiency disorders (CVID) are the most frequent symptomatic primary immune deficiency in adults. At this time, the causes of these conditions are unknown. Patients with CVID experience immune system failure consequent to late onset antibody failure. They have increased susceptibility to infections and are also at risk of severe autoimmune and inflammatory disorders as a result of immune dysregulation. An increasing number of monogenic causes as well as a digenic disorder have been described in patients with a CVID phenotype. If a causative mutation is identified, patients are removed from the umbrella diagnosis of CVID and are reclassified as having a CVID-like disorder, resulting from a specific mutation. In non-consanguineous populations, next-generation sequencing (NGS) identifies a genetic cause in approximately 25% of patients with a CVID phenotype. It is six years since we published our diagnostic criteria for CVID. There is ongoing debate about diagnostic criteria, the role of vaccine responses and genetic analysis in the diagnosis of CVID. There have been several recent studies, which have addressed some of these uncertainties. Here we review this new evidence from the perspective of our CVID diagnostic criteria and speculate on future approaches, which may assist in identifying and assessing this group of enigmatic disorders.

Allergic-like disorders and asthma in patients with common variable immunodeficiency: a multi-center experience

OBJECTIVE

Common variable immune deficiency (CVID) encompasses a variety of diseases characterized by disturbed immunoglobulin (Ig) production and various immune dysregulations. Scarce data are available regarding relationships between CVID and allergic diseases. Here we examined possible associations between allergies and CVID.

METHODS

For this multicenter study, we prospectively enrolled 79 adult CVID patients (≥18 years) who were diagnosed and treated between 2002-2017 at the Hadassah-Hebrew University and Shaare Zedek Medical Centers, Jerusalem, Israel. These patients were examined for allergic manifestations. Patient evaluation comprised medical history, physical examination, skin allergen testing, complete blood count, serum immunoglobulins, IgE levels, and pulmonary function tests.

RESULTS

After implementing exclusion criteria, 29 patients were included in the final analysis. Allergic-like disorders were diagnosed in 65% of CVID patients with non-elevated serum IgE levels. Moreover, allergic CVID patients exhibited a higher prevalence of bronchiectasis on chest CT. Autoimmunity was diagnosed in 41.3% of CVID subjects. The type I allergy detected in our study was non-IgE mediated.

CONCLUSIONS

Timely diagnosis and stratification of allergy in CVID patients is expected to improve their outcome and quality of life, as well as promote appropriate treatment and better management of pulmonary exacerbations.

Primary Immunodeficiency Diseases and Gastrointestinal Distress: Coping Strategies and Dietary Experiences to Relieve Symptoms

In this article, we focus on adults with primary immunodeficiency disease (PID) and their experiences with gastrointestinal (GI) distress with the aim of exploring how they experience living with their condition and the actions they take to relieve GI distress. Twelve adults with PID and GI distress participated in semi-structured, in-depth interviews. The interviews were analyzed following the steps of thematic analysis (TA). The study revealed the complexity of the psychosocial aspects of living with PID and GI distress. Participants experienced GI distress to be highly challenging in daily life and felt they had to cope with the condition alone, without adequate help from the health care service. Participants used a wide and diverse range of coping strategies, and the search for normalcy was evident. Health care professionals should be more proactive in supporting individuals with PID in their struggle to find solutions to problems arising from GI distress.

Histology of Interstitial Lung Disease in Common Variable Immune Deficiency

Interstitial lung disease (ILD) is an important non-infectious complication in several primary immune deficiencies. In common variable immune deficiency (CVID) it is associated with complex clinical phenotypes and adverse outcomes. The histology of ILD in CVID is heterogeneous and mixed patterns are frequently observed within a single biopsy, including non-necrotising granulomatous inflammation, lymphoid interstitial pneumonitis, lymphoid hyperplasia, follicular bronchiolitis, organizing pneumonia, and interstitial fibrosis; ILD has to be differentiated from lymphoma. The term granulomatous-lymphocytic interstitial lung disease (GLILD), coined to describe the histopathological findings within the lungs of patients with CVID with or without multisystem granulomata, is somewhat controversial as pulmonary granulomata are not always present on histology and the nature of infiltrating lymphocytes is variable. In this mini review we summarize the literature on the histology of CVID-related ILD and discuss some of the factors that may contribute to the inter- and intra- patient variability in the histological patterns reported. Finally, we highlight areas for future development. In particular, there is a need for standardization of histological assessments and reporting, together with a better understanding of the immunopathogenesis of CVID-related ILD to resolve the apparent heterogeneity of ILD in this setting and guide the selection of rational targeted therapies in different patients.

Current genetic landscape in common variable immune deficiency

Using whole-exome sequencing to examine the genetic causes of immune deficiency in 235 common variable immunodeficiency (CVID) patients seen in the United States (Mount Sinai, New York), 128 patients from Sweden, and 208 from Iran revealed 68 known disease-causing genes underlying this heterogeneous immune defect. The patients at the time of study ranged from 4 to 90 years of age. Overall, 31%, 36%, and 54% of the patients in the US, Swedish, or Iranian cohorts had mutations. The multiplicity of genes identified in the 571 subjects reflects the complex requirements of B-cell antigen signaling, activation, survival, migration, maturation, and maintenance of antibody-secreting memory B-cell populations to the plasma cell stage. For the US and Swedish cohorts, CVID subjects with noninfectious complications, lymphoid infiltrations, inflamatory conditions, or autoimmunity were somewhat more likely to have an identifiable gene, but in both cohorts, numerous subjects with these medical conditions had no potential gene that could be assigned. Specific clinical patterns of illnesses were also not linked to any given gene defect as there was considerable overlap in clinical presentations. These observations led to a new perspective on the complexity of the immunologic phenotype found in CVID syndrome.