Clinical picture and treatment of 2212 patients with common variable immunodeficiency

Gastrointestinal Manifestations and Complications of Primary Immunodeficiency Disorders

Gastrointestinal (GI) involvement can be the presenting disease manifestation in patients with primary immunodeficiency disorders (PIDs). Infections and noninfectious diarrhea are frequent manifestations; however, malignancy and inflammatory and autoimmune-related GI diseases are also described. GI symptoms and disease seen in association with PIDs can mimic other diseases but are often resistant to conventional treatments owing to alternate disease mechanisms. Despite the advances in treatments for these conditions, therapy for immunodeficiency-related GI disease is often empiric.

Failure of B Cell Tolerance in CVID

Common variable immunodeficiency (CVID) comprises a group of related disorders defined by defects in B cell function and antibody production. Concurrent autoimmune features are common, but the underlying pathogenic mechanisms of autoimmunity in CVID are poorly understood. Overlap in some clinical and laboratory features suggests a shared pathogenesis, at least in part, with systemic lupus erythematosus (SLE). One important part of SLE pathogenesis is loss of B cell tolerance, an aspect that warrants further study in CVID. The study of inherently autoreactive 9G4⁺ B cells has led to a greater understanding of B cell tolerance defects in lupus. Study of these B cells in CVID has yielded conflicting results, largely due to differences in methodological approaches. In this study, we take a comprehensive look at 9G4⁺ B cells throughout B cell development in CVID patients and compare patients both with and without autoimmune features. Using flow cytometry to examine B cell subpopulations in detail, we show that only those CVID patients with autoimmune features demonstrate significant expansion of 9G4⁺ B cells, both in naïve and multiple memory populations. Examination of two autoreactive B cell subsets recently characterized in SLE, the activated naïve (aNAV) and double negative 2 (DN2) B cells, reveals an expanded 9G4⁺ DN2 population to be common among CVID patients. These results reveal that both multiple central and peripheral B cell tolerance defects are related to autoimmunity in CVID. Furthermore, these data suggest that the autoreactive DN2 B cell population, which has not previously been examined in CVID, may play an important role in the development of autoimmunity in patients with CVID.

Current Understanding and Recent Developments in Common Variable Immunodeficiency Associated Autoimmunity

Common variable immunodeficiency (CVID) is the most prevalent symptomatic primary immunodeficiency and comprises a group of disorders with similar antibody deficiency but a myriad of different etiologies, most of which remain undefined. The variable aspect of CVID refers to the approximately half of patients who develop non-infectious complications in addition to heightened susceptibility to infection. The pathogenesis of these complications is poorly understood and somewhat counterintuitive because these patients that are defined by their immune futility simultaneously have elevated propensity for autoimmune disease. There are numerous aspects of immune dysregulation associated with autoimmunity in CVID that have only begun to be studied. These findings include elevations of T helper type 1 and follicular helper T cells and B cells expressing low levels of CD21 as well as reciprocal decreases in regulatory T cells and isotype-switched memory B cells. Recently, advances in genomics have furthered our understanding of the fundamental biology underlying autoimmunity in CVID and led to precision therapeutic approaches. However, these genetic etiologies are also associated with clinical heterogeneity and incomplete penetrance, highlighting the fact that continued research efforts remain necessary to optimize treatment. Additional factors, such as commensal microbial dysbiosis, remain to be better elucidated. Thus, while recent advances in our understanding of CVID-associated autoimmunity have been exciting and substantial, these current scientific advances must now serve as building blocks for the next stages of discovery.

Common variable immune deficiency: case studies

Common variable immune deficiency (CVID) is one of the most common congenital immune defects encountered in clinical practice. The condition occurs equally in males and females, and most commonly in the 20- to 40-year-old age group. The diagnosis is made by documenting reduced serum concentrations of immunoglobulin G (IgG), IgA, and usually IgM, together with loss of protective antibodies. The genetics of this syndrome are complex and are still being unraveled, but the hallmarks for most patients, as with other immune defects, include acute and chronic infections of the sinopulmonary tract. However, other noninfectious autoimmune or inflammatory conditions may also occur in CVID, and indeed these may be the first and only sign that a significant immune defect is present. These manifestations include episodes of immune thrombocytopenia, autoimmune hemolytic anemia, or neutropenia, in addition to splenomegaly, generalized or worrisome lymphadenopathy, and malignancy, especially lymphoma. These issues commonly bring the patient to the attention of hematologists for both evaluation and treatment. This article discusses 3 cases in which patients with CVID had some of these presenting issues and what hematology input was required.

Primary immunodeficiency-related bronchiectasis in adults: comparison with bronchiectasis of other etiologies in a French reference center

BACKGROUND

Bronchiectasis is a heterogeneous disease depending on etiology. It represents the most frequent non-infectious pulmonary complication of primary immunodeficiencies (PID). We investigated whether bronchiectasis associated with PID had a distinct course in comparison to bronchiectasis of other causes.

METHODS

Retrospective single-center study of adult patients diagnosed with non-cystic fibrosis bronchiectasis with more than 5 years of follow-up and at least 4 pulmonary functional tests available at one year apart. They were divided into three groups: PID- related bronchiectasis, idiopathic/post infectious-related bronchiectasis and other causes of bronchiectasis. Respiratory functional data and clinical outcomes were compared.

RESULTS

Of 329 patients with bronchiectasis diagnosed in Foch Hospital (Suresnes, France), 98 patients fulfilled the selected criteria (20 PID-related cases, 39 idiopathic or post-infectious cases, and 39 cases with other causes). Median time of follow-up was 9.5 years. Groups were similar concerning initial characteristics (female 70.4%, never smokers 59.2%, mild severity bronchiectasis according to the FACED score and median FEV1 at diagnosis 73.5% predicted values [Q1-Q3: 53.75-90.5]), except PID patients who were younger (median age of 51.5 vs 62 years, p = 0.02). Eighty-five percent of PID patients received immunoglobulin substitution (median trough level was measured at 10.5 g/dl [10;10.92]). Global median FEV1 annual decline was 25.03 ml/year [8.16;43.9] and 19.82 ml/year [16.08;48.02] in the PID patients group. Forty-five percent of patients had bacterial colonization, pneumoniae occurred in 56% of patients and median exacerbation annual rate was 0.8 [0.3-1.4]. Hemoptysis occurred in 31.6% of patients. Global mortality rate was 11.2%. We did not record any significant difference for all clinical and functional outcomes between patients with PID and other etiologies. The median decline in FEV1 was similar in the three groups.

CONCLUSIONS

The course of PID-related bronchiectasis was similar to bronchiectasis of other causes. Provided that patients receive immunoglobulin replacement, the course of PID-related bronchiectasis seems to be independent of the underlying immune disorder.

Common variable immune deficiency: case studies

Common variable immune deficiency (CVID) is one of the most common congenital immune defects encountered in clinical practice. The condition occurs equally in males and females, and most commonly in the 20- to 40-year-old age group. The diagnosis is made by documenting reduced serum concentrations of immunoglobulin G (IgG), IgA, and usually IgM, together with loss of protective antibodies. The genetics of this syndrome are complex and are still being unraveled, but the hallmarks for most patients, as with other immune defects, include acute and chronic infections of the sinopulmonary tract. However, other noninfectious autoimmune or inflammatory conditions may also occur in CVID, and indeed these may be the first and only sign that a significant immune defect is present. These manifestations include episodes of immune thrombocytopenia, autoimmune hemolytic anemia, or neutropenia, in addition to splenomegaly, generalized or worrisome lymphadenopathy, and malignancy, especially lymphoma. These issues commonly bring the patient to the attention of hematologists for both evaluation and treatment. This article discusses 3 cases in which patients with CVID had some of these presenting issues and what hematology input was required.

Predominantly Antibody-Deficient Patients With Non-infectious Complications Have Reduced Naive B, Treg, Th17, and Tfh17 Cells

Background: Patients with predominantly antibody deficiency (PAD) suffer from severe and recurrent infections that require lifelong immunoglobulin replacement and prophylactic antibiotic treatment. Disease incidence is estimated to be 1:25,000 worldwide, and up to 68% of patients develop non-infectious complications (NIC) including autoimmunity, which are difficult to treat, causing high morbidity, and early mortality. Currently, the etiology of NIC is unknown, and there are no diagnostic and prognostic markers to identify patients at risk.

Objectives: To identify immune cell markers that associate with NIC in PAD patients.

Methods: We developed a standardized 11-color flow cytometry panel that was utilized for in-depth analysis of B and T cells in 62 adult PAD patients and 59 age-matched controls.

Results: Nine males had mutations in Bruton's tyrosine kinase (BTK) and were defined as having X-linked agammaglobulinemia. The remaining 53 patients were not genetically defined and were clinically diagnosed with agammaglobulinemia (n = 1), common variable immunodeficiency (CVID) (n = 32), hypogammaglobulinemia (n = 13), IgG subclass deficiency (n = 1), and specific polysaccharide antibody deficiency (n = 6). Of the 53, 30 (57%) had one or more NICs, 24 patients had reduced B-cell numbers, and 17 had reduced T-cell numbers. Both PAD–NIC and PAD+NIC groups had significantly reduced Ig class-switched memory B cells and naive CD4 and CD8 T-cell numbers. Naive and IgM memory B cells, Treg, Th17, and Tfh17 cells were specifically reduced in the PAD+NIC group. CD21^lo B cells and Tfh cells were increased in frequencies, but not in absolute numbers in PAD+NIC.

Conclusion: The previously reported increased frequencies of CD21^lo B cells and Tfh cells are the indirect result of reduced naive B-cell and T-cell numbers. Hence, correct interpretation of immunophenotyping of immunodeficiencies is critically dependent on absolute cell counts. Finally, the defects in naive B- and T-cell numbers suggest a mild combined immunodeficiency in PAD patients with NIC. Together with the reductions in Th17, Treg, and Tfh17 numbers, these key differences could be utilized as biomarkers to support definitive diagnosis and to predict for disease progression.

Liver stiffness assessment by transient elastography suggests high prevalence of liver involvement in common variable immunodeficiency

BACKGROUND

Up to 50% of patients with common variable immunodeficiency (CVID) present persistently increased serum levels of liver enzymes and/or mild hepatomegaly. Ultrasound-based transient elastography (TE) is largely used for early detection of the progression of chronic liver diseases, but has never been employed in CVID. We performed a cross-sectional study to evaluate TE values in a cohort of adult CVID-patients.

METHODS

Full blood count, liver function test, liver and spleen sonogram and ultrasound-based TE were performed in 77 adult CVID patients. Demographic and clinical data were retrospectively collected from medical files.

RESULTS

33.8% (26/77) patients presented increased TE values ranging from moderate fibrosis to cirrhosis. TE values were positively correlated with ALP, γGT, spleen longitudinal diameter and peripheral blood counts (no significant correlation with BMI, AST, ALT, total proteins, albumin, bilirubin and hemoglobin). Moreover, liver stiffness was higher in patients with the clinical phenotypes polyclonal lymphoproliferation and enteropathy, and patients with both these complications had an increased risk (OR: 7.14) of presenting pathologic TE values compared with those without anyone of these.

CONCLUSIONS

Transient elastography is a useful tool to be used alongside clinical and laboratory data to assess liver involvement in CVID.

[Immunodeficiency in chronic rhinosinusitis : An important and often underestimated cause]

BACKGROUND

Chronic rhinosinusitis (CRS) is one of the most frequent chronic diseases. Among these patients the prevalence of immune defects is higher than in the healthy general population.

METHODS

A selective review of the literature was carried out in PubMed and Medline covering the period between 2008 and 2019. Additionally, recent German publications in journals not listed in the abovementioned databases were analyzed.

RESULTS

The diagnostic workflow with respect to the immunodeficiency consists of a detailed anamnesis and physical examination, laboratory tests and the antibody reaction to polysaccharide vaccines and antigens. Beside antibiotic treatment, vaccinations and immunoglobulin replacement are available. Notwithstanding the above, functional endoscopic surgery of the paranasal sinuses should be performed according to guideline recommendations.

CONCLUSION

Patients with CRS who do not sufficiently respond to conservative and surgical treatment should be checked for underlying immunodeficiencies.

Updated modelling of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters

Conditions and evidence continue to evolve related to the prediction of the prevalence of immunodeficiency-associated long-term vaccine-derived poliovirus (iVDPV) excreters, which affect assumptions related to forecasting risks and evaluating potential risk management options. Multiple recent reviews provided information about individual iVDPV excreters, but inconsistencies among the reviews raise some challenges. This analysis revisits the available evidence related to iVDPV excreters and provides updated model estimates that can support future risk management decisions. The results suggest that the prevalence of iVDPV excreters remains highly uncertain and variable, but generally confirms the importance of managing the risks associated with iVDPV excreters throughout the polio endgame in the context of successful cessation of all oral poliovirus vaccine use.

An updated review on activated PI3 kinase delta syndrome (APDS)

Activated Phosphoinositide 3-kinase δ syndrome (APDS) is a newly recognised primary immunodeficiency disease. It has currently been a hot topic of clinical research and new data are emerging regarding its pathogenesis, clinical manifestations and treatment. Patients with APDS syndrome have significant autoimmune manifestations and lymphoproliferation. It is important to differentiate APDS from the usual polygenic CVID in view of the availability of targeted therapy like mTOR inhibitors such as Rapamycin and selective PI3Kδ inhibitors. We provide a comprehensive review on this interesting disorder focusing light on its etiology, genetic research and emerging therapy.

Common pre-diagnostic features in individuals with different rare diseases represent a key for diagnostic support with computerized pattern recognition?

BACKGROUND

Rare diseases (RD) result in a wide variety of clinical presentations, and this creates a significant diagnostic challenge for health care professionals. We hypothesized that there exist a set of consistent and shared phenomena among all individuals affected by (different) RD during the time before diagnosis is established.

OBJECTIVE

We aimed to identify commonalities between different RD and developed a machine learning diagnostic support tool for RD.

METHODS

20 interviews with affected individuals with different RD, focusing on the time period before their diagnosis, were performed and qualitatively analyzed. Out of these pre-diagnostic experiences, we distilled key phenomena and created a questionnaire which was then distributed among individuals with the established diagnosis of i.) RD, ii.) other common non-rare diseases (NRO) iii.) common chronic diseases (CD), iv.), or psychosomatic/somatoform disorders (PSY). Finally, four combined single machine learning methods and a fusion algorithm were used to distinguish the different answer patterns of the questionnaires.

RESULTS

The questionnaire contained 53 questions. A total sum of 1763 questionnaires (758 RD, 149 CD, 48 PSY, 200 NRO, 34 healthy individuals and 574 not evaluable questionnaires) were collected. Based on 3 independent data sets the 10-fold stratified cross-validation method for the answer-pattern recognition resulted in sensitivity values of 88.9% to detect the answer pattern of a RD, 86.6% for NRO, 87.7% for CD and 84.2% for PSY.

CONCLUSION

Despite the great diversity in presentation and pathogenesis of each RD, patients with RD share surprisingly similar pre-diagnosis experiences. Our questionnaire and data-mining based approach successfully detected unique patterns in groups of individuals affected by a broad range of different rare diseases. Therefore, these results indicate distinct patterns that may be used for diagnostic support in RD.

Hypogammaglobulinemia: a diagnosis that must not be overlooked

Humoral immunological defects are frequent and important causes of hypogammaglobulinemia, leading to recurrent infections, autoimmunity, allergies, and neoplasias. Usually, its onset occurs in childhood or during the second and third decades of life; however, the diagnosis is made, on average, 6 to 7 years afterwards. As a consequence, antibody defects can lead to sequelae. Here we describe the clinical-laboratory characteristics, treatment, and prognoses of patients with hypogammaglobulinemia. An observational, cross-sectional, and retrospective study of patients attending the recently established outpatient group of Clinical Immunology between 2013 and 2018 was carried out. Patients with IgG levels below 2 standard deviations from the mean values for the age and/or impaired antibody response were included. Eight patients (3 F and 5 M; median age=41 years (16–65), average symptom onset at 25 years (1–59), and time to diagnosis of 10 years were included. The main infections were: sinusitis in 7/8, pneumonia in 6/8, otitis in 2/8, tonsillitis and diarrhea in 2/8, and diarrhea in 2/8 patients. Hypothyroidism was identified in 4/8 (50%) patients. Rhinitis was found in 7/8 (87.5%) and asthma in 3/8 (37.5%) patients. The tomographic findings were consolidations, atelectasis, emphysema, ground glass opacity, budding tree, bronchial thickening, and bronchiectasis. Immunoglobulin reposition was used between 466 and 600 mg/kg monthly (514.3 mg·kg^-1·dose^-1). Prophylactic antibiotic therapy was included in 7/8 (87.5%) patients. Airway manifestations prevailed in patients with hypogammaglobulinemia. There is a need for educational work to reduce the time of diagnosis and initiation of treatment, avoiding sequelae.

Focus on Chronic Variable Immunodeficiency for Primary Care Practitioners, the Gatekeepers to Optimal Health Outcomes for Primary Immunodeficiency Syndromes

Purpose of Review

This review sought to assess the extent and causes of suboptimal healthcare outcomes for chronic variable immunodeficiency (CVID).

Recent Findings

Significant improvements in diagnostic technology and treatment protocols over time were found, leading to reduced morbidity and mortality for those accessing therapies. Treatments continue to be largely non-curative with financing (mainly insurance coverage) an obstacle. Symptom recognition by primary care practitioners (PCP) remains a gating factor to treatment and a widespread and persistent barrier to optimal health outcomes.

Summary

CVID is a subtype of primary immunodeficiency (PIDD) associated with under-diagnosis. It has emerged as a health issue more prevalent than historically known. No symptom-recognition framework for early detection of CVID has been generally accepted; those proposed for primary immunodeficiencies have shown low sensitivity, low specificity or both. Positive trends in cases diagnosed have been aided by awareness campaigns and international collaborations. However, treatments for CVID will not realize full potential without effective, accepted frameworks for timely identification in the clinic.

Congenital sideroblastic anemia associated with B cell immunodeficiency, periodic fevers, and developmental delay: A case report and review of mucocutaneous features

This is a 40-year-old woman with sideroblastic anemia with B cell immunodeficiency, periodic fevers, and developmental delay syndrome, who has genital and extragenital lichen sclerosus on the abdomen and the upper back that have become erythematous and painful during febrile episodes. This report summarizes the published cases of sideroblastic anemia with B cell immunodeficiency, periodic fevers, and developmental delay and highlights associated mucocutaneous features.

Low percentages of regulatory T cells in common variable immunodeficiency (CVID) patients with autoimmune diseases and its association with increased numbers of CD4+CD45RO+ T and CD21low B cells

BACKGROUND

Common variable immunodeficiency (CVID) is a heterogeneous group of primary antibody deficiencies defined by marked reductions in serum IgG, IgA and/or IgM levels and recurrent bacterial infections. Some patients are associated with defects in T cells and regulatory T cells (Tregs), resulting in recurrent viral infections and early-onset autoimmune disease.

METHODS

We analyzed whether there is an association between Tregs cells (CD4+CD25+CD127^low and CD4+CD25+FoxP3+); memory T cells (CD4+CD45RO+); memory B cells (CD19+CD27-IgD-); and CD21^low B cells (CD19+CD38^lowCD21^low); as well as autoimmune manifestations in 36 patients with CVID (25 women and 11 men, mean age 24 years), all by flow cytometry.

RESULTS

Fourteen patients presented with autoimmune diseases (AI) (39%), including 11 with autoimmune thrombocytopenia (ITP) (31%); two with vitiligo (6%); one with systemic lupus erythematosus (LES) (3%); and one with multiple sclerosis (MS) (3%). CVID patients with AI had a reduced proportion of Tregs (both CD4+CD25+CD127^low and FoxP3+ cells) compared with healthy controls. CVID patients with AI had expanded CD21^low B cell populations compared with patients who did not have AI. A correlation between increased CD4+CD45RO T cell populations and reduced Tregs was also observed.

CONCLUSIONS

Our results showed that 39% of patients with CVID had AI and reduced Tregs populations. Research in this area might provide noteworthy data to better understand immune dysfunction and dysregulation related to CVID.

A Computational Pipeline for the Diagnosis of CVID Patients

Common variable immunodeficiency (CVID) is one of the most frequently diagnosed primary antibody deficiencies (PADs), a group of disorders characterized by a decrease in one or more immunoglobulin (sub)classes and/or impaired antibody responses caused by inborn defects in B cells in the absence of other major immune defects. CVID patients suffer from recurrent infections and disease-related, non-infectious, complications such as autoimmune manifestations, lymphoproliferation, and malignancies. A timely diagnosis is essential for optimal follow-up and treatment. However, CVID is by definition a diagnosis of exclusion, thereby covering a heterogeneous patient population and making it difficult to establish a definite diagnosis. To aid the diagnosis of CVID patients, and distinguish them from other PADs, we developed an automated machine learning pipeline which performs automated diagnosis based on flow cytometric immunophenotyping. Using this pipeline, we analyzed the immunophenotypic profile in a pediatric and adult cohort of 28 patients with CVID, 23 patients with idiopathic primary hypogammaglobulinemia, 21 patients with IgG subclass deficiency, six patients with isolated IgA deficiency, one patient with isolated IgM deficiency, and 100 unrelated healthy controls. Flow cytometry analysis is traditionally done by manual identification of the cell populations of interest. Yet, this approach has severe limitations including subjectivity of the manual gating and bias toward known populations. To overcome these limitations, we here propose an automated computational flow cytometry pipeline that successfully distinguishes CVID phenotypes from other PADs and healthy controls. Compared to the traditional, manual analysis, our pipeline is fully automated, performing automated quality control and data pre-processing, automated population identification (gating) and deriving features from these populations to build a machine learning classifier to distinguish CVID from other PADs and healthy controls. This results in a more reproducible flow cytometry analysis, and improves the diagnosis compared to manual analysis: our pipelines achieve on average a balanced accuracy score of 0.93 (±0.07), whereas using the manually extracted populations, an averaged balanced accuracy score of 0.72 (±0.23) is achieved.

30-Year Review of Pediatric- and Adult-Onset CVID: Clinical Correlates and Prognostic Indicators

PURPOSE

To evaluate mortality risk factors in pediatric-onset common variable immunodeficiency disorders (CVID), we evaluated the largest single-institution cohort of pediatric-onset CVID patients. Previous publications on CVID have provided valuable descriptive data, but lack risk stratification to guide physicians in management of these patients.

METHODS

Retrospective chart review of 198 subjects with CVID at a single institution, of whom 91 had disease onset at a pediatric age. Clinical and laboratory data were collected at diagnosis and in follow-up. Odds ratios and Fisher tests were utilized to examine trends. This study was approved by an institutional review board.

RESULTS

Clinical features and laboratory results for subjects diagnosed with CVID at a pediatric age are similar to those who had adult-onset CVID. However, majority of the deceased subjects (13/18) were at a pediatric age at CVID symptom onset. These subjects had a lower age at mortality, multiple comorbidities, and often depression. The most common cause of death was infection. Lung disease (OR 5, p < 0.05) and infection with severe/opportunistic organisms (OR 9, p < 0.05) are directly related to increased mortality. Delay in diagnosis of CVID is also correlated with mortality. Intermediary markers correlating with mortality include anemia, GERD, and depression.

CONCLUSIONS

There are many similarities between patients with pediatric- and adult-onset CVID; however, the mortality of pediatric CVID in our cohort is striking. This is the first study to identify specific factors correlated with mortality in pediatric-onset CVID to guide pediatricians and subspecialists in managing these immunodeficient patients.

Birds of a feather: Common variable immune deficiencies

OBJECTIVE

To update the reader on recently proposed common variable immune deficiency (CVID) diagnostic criteria, newly uncovered CVID pathobiology, freshly identified CVID-related genes, and novel CVID therapies.

DATA SOURCES

PubMed Central.

STUDY SELECTIONS

We selected 60 clinical and translational research articles that have shaped CVID diagnostic criteria, introduced personalized therapies, and advanced our understanding of CVID biology and genetics. We have incorporated recent articles and older published work that are foundational to the modern understanding of this protean disease.

RESULTS

CVID has proven to be a heterogenous group of antibody deficiency diseases driven by defects in diverse biologic processes, including B-cell development, activation, tolerance, class-switch recombination, somatic hypermutation, and lymphoproliferation. Recent genetic advances have enabled identification of several CVID-related gene defects that may contribute to patients' infectious and noninfectious symptoms.

CONCLUSION

Improved understanding of the aberrant biologic processes that drive CVID and the disease's genetic basis may be useful in directing therapeutic decisions, especially in cases complicated by autoimmune, lymphoproliferative, and inflammatory features.

How to Identify Common Variable Immunodeficiency Patients Earlier: General Practice Patterns

PURPOSE

Diagnostic delay is a major problem concerning common variable immunodeficiency (CVID). We aimed to determine the pattern of general practitioner (GP) consultations in individuals diagnosed with CVID within 3 years before the diagnosis and whether the risk of diagnosis was associated with the frequency of consultations or character of examinations.

METHODS

We conducted a nested case-control study, identifying 132 adult CVID patients and 5940 age- and gender-matched controls from national registers during 1997-2013. We used conditional logistic regression to calculate the odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

The median number of consultations among individuals with CVID was more than twice that of the controls in all 3 years (3rd, 10; 2nd, 11.5; and 1st, 15.4 vs. 4). We found a statistically significant association between the number of consultations and the risk of a subsequent CVID diagnosis, independent of age and gender, but strongest in the individuals < 40 years. In the 3rd year before diagnosis, having 9-15 consultations compared with 1-4 was associated with an OR (95%CI) of 5.0 (2.3-10.9), 2.4 (1.1-5.4), and 1.3 (0.3-5.3) for those aged 18-40, 41-60, and > 60, respectively. Several examinations (i.e., blood tests for inflammation/infection and pulmonary function test) were associated with increased odds of a subsequent CVID diagnosis.

CONCLUSION

The risk of a CVID diagnosis was highly related to both the number of consultations and the character of examinations performed by the GP. CVID should be a differential diagnosis among patients with multiple consultations, especially in patients < 40 years old.

Common variable immunodeficiency patients display elevated plasma levels of granulocyte activation markers elastase and myeloperoxidase

Common variable immunodeficiency disorders (CVIDs) represent a group of primary immunodeficiency diseases characterized by hypogammaglobulinemia and dysfunctional immune response to invading pathogens. Previous studies have indicated that CVID is associated with microbial translocation and systemic myeloid cell activation.

The goal of this study was to determine whether patients with CVID display elevated systemic levels of markers of granulocyte activation and whether the levels are further influenced by intravenous immunoglobulin (IVIg) infusions. The plasma levels of granulocyte activation markers elastase and myeloperoxidase were determined using enzyme-linked immunosorbent assay (ELISA) in 46 CVID patients and 44 healthy controls. All CVID patients were in a stable state with no apparent acute infection. In addition, granulocyte activation markers’ plasma levels in 24 CVID patients were determined prior to and 1 h following IVIg administration. Neutrophil elastase and myeloperoxidase plasma levels were significantly higher in CVID patients than in healthy controls. Systemic elastase levels were further increased following IVIg administration. In vitro stimulation of 13 CVID patients’ whole blood using IVIg in a therapeutically relevant dose for 2 h resulted in a significant increase in plasma elastase levels compared to unstimulated blood. The data presented here indicate that CVID is associated with chronic granulocytic activation which is further exacerbated by administering IVIg. Increased myeloperoxidase and elastase levels may contribute to associated comorbidities in CVID patients.

Aberrant X chromosome skewing and acquired clonal hematopoiesis in adult-onset common variable immunodeficiency

Advances in genomic medicine have elucidated an increasing number of genetic etiologies for patients with common variable immunodeficiency (CVID). However, there is heterogeneity in clinical and immunophenotypic presentations and a limited understanding of the underlying pathophysiology of many cases. The primary defects in CVID may extend beyond the adaptive immune system, and the combined defect in both the myeloid and lymphoid compartments suggests the mechanism may involve bone marrow output and earlier progenitors. Using the methylation profile of the human androgen receptor (AR) gene as a surrogate epigenetic marker for bone marrow clonality, we examined the hematopoietic compartments of patients with CVID. Our data show that clonal hematopoiesis is common among patients with adult-onset CVID who do not have associated noninfectious complications. Nonblood tissues did not show a skewed AR methylation status, supporting a model of an acquired clonal hematopoietic event. Attenuation of memory B cell differentiation into long-lived plasma cells (CD20^–CD27⁺CD38⁺CD138⁺) was associated with marked changes in the postdifferentiation methylation profile, demonstrating the functional consequence of clonal hematopoiesis on humoral immunity in these patients. This study sheds light on a potential etiology of a subset of patients with CVID, and the findings suggest that it is a stage of an acquired lymphocyte maturation disorder.

Clonal hematopoiesis is common among a subset of patients with common variable immunodeficiency (CVID), suggesting that CVID may be a stage of lymphoid dysplasia.

Autoimmunity in common variable immunodeficiency

OBJECTIVE

Common variable immunodeficiency (CVID) is a primary immunodeficiency that is clinically heterogeneous, characterized by both infectious and noninfectious complications. Although the hallmark of disease presentation is commonly a history of recurrent sinopulmonary infections, autoimmunity and noninfectious inflammatory conditions are increasingly associated with CVID.

DATA SOURCES

A comprehensive literature search using PubMed of basic science and clinical articles was performed.

STUDY SELECTIONS

Articles discussing the association of autoimmunity with primary immunodeficiency, specifically CVID, were selected.

RESULTS

The most common autoimmune conditions are cytopenias, including immune thrombocytopenia purpura and hemolytic anemia, but organ-specific autoimmune/inflammatory complications involving the gastrointestinal, skin, joints, connective tissue, and respiratory tract. In most cases, immunoglobulin replacement therapy does not ameliorate or treat these inflammatory complications, and additional immunomodulatory treatments are needed.

CONCLUSION

Mechanisms producing these conditions are poorly understood but include cytokine and cellular inflammatory pathways, and loss of tolerance to self-antigens through the multiple signaling molecules and pathways common to tolerance and immune deficiency.

Impaired HDL Function Amplifies Systemic Inflammation in Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency, characterized by inadequate antibody responses and recurrent bacterial infections. Paradoxically, a majority of CVID patients have non-infectious inflammatory and autoimmune complications, associated with systemic immune activation. Our aim was to explore if HDL, known to have anti-inflammatory properties, had impaired function in CVID patients and thereby contributed to their inflammatory phenotype. We found reduced HDL cholesterol levels in plasma of CVID patients compared to healthy controls, particularly in patients with inflammatory and autoimmune complications, correlating negatively with inflammatory markers CRP and sCD25. Reverse cholesterol transport capacity testing showed reduced serum acceptance capacity for cholesterol in CVID patients with inflammatory and autoimmune complications. They also had reduced cholesterol efflux capacity from macrophages to serum and decreased expression of ATP-binding cassette transporter ABCA1. Human HDL suppressed TLR2-induced TNF release less in blood mononuclear cells from CVID patients, associated with decreased expression of transcriptional factor ATF3. Our data suggest a link between impaired HDL function and systemic inflammation in CVID patients, particularly in those with autoimmune and inflammatory complications. This identifies HDL as a novel therapeutic target in CVID as well as other more common conditions characterized by sterile inflammation or autoimmunity.

Primary Immunodeficiency and the Gut

This article presents the most common gastrointestinal, hepatic, and pancreatic manifestations of the primary immunodeficiency diseases, including the appropriate laboratory testing, endoscopic evaluation, and recommendations for further management.

Common Variable Immune Deficiency and Associated Complications

Common variable immunodeficiency disorders refer to a relatively common primary immune deficiency group of diseases that present with infectious and inflammatory complications secondary to defects in antibody production and sometimes in cellular immunity. The disorder often presents in middle age or later with recurrent sinopulmonary infections, bronchiectasis, or a plethora of noninfectious complications such as autoimmune disorders, granulomatous interstitial lung disease, GI diseases, malignancies (including lymphoma), and multisystem granulomatous disease resembling sarcoidosis. Infusion of immunoglobulin by IV or subcutaneous is the mainstay of therapy. Management of complications is often difficult as immune suppression may be necessary in these conditions and entails the use of medications and biologicals which may further increase the risk for infections. Specifically, bronchiectasis, granulomatous lymphocytic interstitial lung disease, repeated sinopulmonary infections, and malignancies are sequelae of antibody deficiency that may present to the pulmonologist. This review will provide an updated understanding of the molecular aspects, differential diagnosis, presentations, and the management of common variable immunodeficiency disorders.

Factors Beyond Lack of Antibody Govern Pulmonary Complications in Primary Antibody Deficiency

PURPOSE

Pulmonary complications occur frequently in primary antibody deficiency (PAD). While the impact of antibody deficiency may appear implicit for certain respiratory infections, immunoglobulin replacement therapy does not completely ameliorate pulmonary complications in PAD. Thus, there may be antibody-independent factors influencing susceptibility to respiratory disease in PAD, but these remain incompletely defined.

METHODS

We harnessed the multicenter US Immunodeficiency Network primary immunodeficiency registry to compare prevalence of asthma, bronchiectasis, interstitial lung disease (ILD), and respiratory infections between two forms of PAD: common variable immunodeficiency (CVID) and x-linked agammaglobulinemia (XLA). We also defined the clinical and immunological characteristics associated with ILD and asthma in CVID.

RESULTS

Asthma, bronchiectasis, ILD, pneumonia, and upper respiratory infections were more prevalent in CVID than XLA. ILD was associated with autoimmunity, bronchiectasis, and pneumonia as well as fewer B and T cells in CVID. Asthma was the most common chronic pulmonary complication and associated with lower IgA and IgM in CVID. Age of symptom onset or CVID diagnosis was unrelated with ILD or asthma.

CONCLUSION

Despite having less severe immunoglobulin deficiency than XLA, respiratory infections, ILD, and asthma were more common in CVID. Among CVID patients, ILD was associated with autoimmunity and reduced lymphocytes and asthma with lower immunoglobulins. Though our results are tempered by registry limitations, they provide evidence that factors beyond lack of antibody promote pulmonary complications in PAD. Efforts to understand how genetic etiology, nature of concurrent T cell deficiency, and propensity for autoimmunity shape pulmonary disease may improve treatment of PAD.

Idiopathic, Refractory Sweet's Syndrome Associated with Common Variable Immunodeficiency: a Case Report and Literature Review

PURPOSE OF REVIEW

Sweet's syndrome (SS) is classically considered a hypersensitivity reaction often associated with autoimmune disorders and malignancy. SS has also been increasingly reported to occur with immunodeficiencies. We present a case of treatment-refractory, systemic SS as the initial manifestation in a young child with common variable immunodeficiency (CVID). We also review current literature about SS and concurrent immunodeficiencies and autoimmunity in CVID patients.

RECENT FINDINGS

Few case reports exist regarding the co-occurrence of Sweet's syndrome and primary immunodeficiencies. SS is characterized by a pro-inflammatory state with a neutrophil predominance resulting in a spectrum of clinical manifestations. CVID is a multifactorial antibody deficiency that can be associated with autoimmunity, which some studies have proposed to be secondary to altered CD21 expression. SS occurring in patients with CVID has been infrequently reported, and one case study demonstrated improvement of Sweet's associated skin lesions with immunoglobulin replacement. In our case, the patient had multi-system SS refractory to multiple immunomodulatory therapies. To our knowledge, this is the first report of the effective and safe use of intravenous tocilizumab and oral lenalidomide to treat SS in a child with CVID. Immunoglobulin replacement reduced the frequency of infections and may have contributed to the opportunity to wean the immunosuppressive therapies for Sweet's syndrome. Sweet's syndrome as an initial manifestation of co-occurring immunodeficiencies is rare, and providers need a high index of suspicion. In addition, treatment of SS associated with an immunodeficiency can be a challenge. Treatment with immunoglobulin replacement reduces the frequency of infections, and in some patients with concurrent SS may improve skin lesions and reduce the need for immunomodulator therapy. Further study is necessary to better understand the pathogenesis of CVID in patients with SS and to identify possible biomarkers that predict who with SS are at risk for developing hypogammaglobulinemia.

New approach to investigate Common Variable Immunodeficiency patients using spectrochemical analysis of blood

Common variable immune deficiency (CVID) is a primary immunodeficiency disease, characterized by hypogammaglobulinemia, recurrent infections and various complications. The clinical heterogeneity of CVID has hindered identification of an underlying immune defect; diagnosis relies on clinical judgement, alongside evidence-based criteria. The lack of pathognomonic clinical or laboratory features leads to average diagnostic delays of 5 years or more from the onset. Vibrational spectroscopic techniques such as Fourier-transform infrared (FTIR) spectroscopy have recently gained increasing clinical importance, being rapid-, non-invasive and inexpensive methods to obtain information on the content of biological samples. This has led us to apply FTIR spectroscopy to the investigation of blood samples from a cohort of CVID patients; revealing spectral features capable of stratifying CVID patients from healthy controls with sensitivities and specificities of 97% and 93%, respectively for serum, and 94% and 95%, respectively for plasma. Furthermore we identified several discriminating spectral biomarkers; wavenumbers in regions indicative of nucleic acids (984 cm⁻¹, 1053 cm⁻¹, 1084 cm⁻¹, 1115 cm⁻¹, 1528 cm⁻¹, 1639 cm⁻¹), and a collagen-associated biomarker (1528 cm⁻¹), which may represent future candidate biomarkers and provide new knowledge on the aetiology of CVID. This proof-of-concept study provides a basis for developing a novel diagnostic tool for CVID.

Immunosuppressive therapy with rituximab in common variable immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary antibody deficiency in adulthood and is characterized by the marked reduction of IgG and IgA serum levels. Thanks to the successful use of polyvalent immunoglobulin replacement therapy to treat and prevent recurrent infections, non-infectious complications, including autoimmunity, polyclonal lymphoproliferation and malignancies, have progressively become the major cause of morbidity and mortality in CVID patients. The management of these complications is particularly challenging, often requiring multiple lines of immunosuppressive treatments. Over the last 5–10 years, the anti-CD20 monoclonal antibody (i.e., rituximab) has been increasingly used for the treatment of both autoimmune and non-malignant lymphoproliferative manifestations associated with CVID. This review illustrates the evidence on the use of rituximab in CVID. For this purpose, first we discuss the mechanisms proposed for the rituximab mediated B-cell depletion; then, we analyze the literature data regarding the CVID-related complications for which rituximab has been used, focusing on autoimmune cytopenias, granulomatous lymphocytic interstitial lung disease (GLILD) and non-malignant lymphoproliferative syndromes. The cumulative data suggest that in the vast majority of the studies, rituximab has proven to be an effective and relatively safe therapeutic option. However, there are currently no data on the long-term efficacy and side effects of rituximab and other second-line therapeutic options. Further randomized controlled trials are needed to optimize the management strategies of non-infectious complications of CVID.

A Systematic Review on Predisposition to Lymphoid (B and T cell) Neoplasias in Patients With Primary Immunodeficiencies and Immune Dysregulatory Disorders (Inborn Errors of Immunity)

Primary immunodeficiencies and immune dysregulatory disorders (PIDDs; now referred to as inborn errors in immunity) are rare disorders with a prevalence of 41. 4 or 50.5 per 100,000 persons (1). The incidence of malignancy in PIDD patents is the second-highest cause of death in children as well as adults, after infection, and is higher in certain PIDDs compared to others. We performed a systematic review of the literature to identify reports of B cell and T cell neoplasias in PIDDs and clustered them based on their classification in the IUIS schema. As would be expected, higher susceptibility to malignancies are typically reported in patients with Common Variable Immunodeficiency (CVID), combined immunodeficiencies affecting cellular immunity, in particular, DNA repair defects, or in the context of impaired immune regulatory control. There is not much evidence of increased risk for cancer in patients with innate immune defects, indicating that not all types of infection or genetic susceptibility predispose equally to cancer risk. Viral infections, in particular EBV, HHV and HPV, have been shown to increase susceptibility to developing cancer, but also patients with defects in immune regulation, such as Autoimmune Lymphoproliferative Syndrome (ALPS), activated p110delta syndrome (APDS type 1) and IL-10 receptor deficiency among others have a higher incidence of neoplastic disease, particularly lymphomas. In fact, lymphomas account for two-thirds of all malignancies reported in PIDD patients (2), with either a combined immunodeficiency or DNA repair defect predominating as the underlying immune defect in one registry, or antibody deficiencies in another (3). The vast majority of lymphomas reported in the context of PIDDs are B cell lymphomas, though T cell lymphomas have been reported in a few studies, and tend to largely be associated with chromosomal breakage disorders (4) or Cartilage Hair Hypoplasia (5). There appears to be a much higher prevalence of T cell lymphomas in patients with secondary immunodeficiencies (6), though this could reflect treatment bias. We reviewed the literature and summarized the reports of B and T cell lymphoma in PIDD patients to survey the current state of knowledge in this area.

Assessing the Functional Relevance of Variants in the IKAROS Family Zinc Finger Protein 1 (IKZF1) in a Cohort of Patients With Primary Immunodeficiency

Common variable immunodeficiency (CVID) is the most frequent symptomatic primary immunodeficiency. Patients with CVID are prone to recurrent bacterial infection due to the failure of adequate immunoglobulin production. Monogenetic defects have been identified in ~25% of CVID patients. Recently, mutations in IKZF1, encoding the zinc-finger transcription factor IKAROS which is broadly expressed in hematopoietic cells, have been associated with a CVID-like phenotype. Herein we describe 11 patients with heterozygous IKZF1 variants from eight different families with autosomal dominant CVID and two siblings with an IKZF1 variant presenting with inflammatory bowel disease (IBD). This study shows that mutations affecting the DNA binding domain of IKAROS can impair the interaction with the target DNA sequence thereby preventing heterochromatin and pericentromeric localization (HC-PC) of the protein. Our results also indicate an impairment of pericentromeric localization of IKAROS by overexpression of a truncated variant, caused by an immature stop codon in IKZF1. We also describe an additional variant in TNFSF10, encoding Tumor Necrosis Factor Related Apoptosis Inducing Ligand (TRAIL), additionally presented in individuals of Family A. Our results indicate that this variant may impair the TRAIL-induced apoptosis in target cell lines and prohibit the NFκB activation by TRAIL and may act as a modifier in Family A.

The Clinical Features of Bronchiectasis Associated with Alpha-1 Antitrypsin Deficiency, Common Variable Immunodeficiency and Primary Ciliary Dyskinesia--Results from the U.S. Bronchiectasis Research Registry

Objective

This study compares and contrasts the clinical features of non-cystic fibrosis bronchiectasis with 3 uncommon disorders known to be associated with bronchiectasis but with distinctly different underlying defined pathophysiologic derangements, namely severe alpha-1 antitrypsin deficiency (AATD), common variable immunodeficiency (CVI) and primary ciliary dyskinesia (PCD).

Methods

The Bronchiectasis Research Registry provides a central database for studying patients with non-cystic fibrosis bronchiectasis. This report consists of information from 13 U.S. sites pertaining to the 3 study diagnoses. Patients with AATD (SZ and ZZ phenotypes only), CVI (patients with IgG≤500), PCD (history of physician diagnosed Kartagener's syndrome or PCD), and patients with confirmed absence of the above 3 diagnoses (idiopathic control group) were included in the study. Descriptive statistics were computed for the main demographic and clinical characteristics of the sample stratified by group. Values between the groups were compared using Kruskal-Wallis test, and Chi-squared/ Fisher's exact tests respectively. The significance level was set at 0.05. Software SAS 9.4 was used to perform the statistical analyses.

Results

Of the 2170 participants in the database enrolled as of January 2017, 615 respondents had sufficient data and were included in the analyses. Patients with PCD (n=79, mean age 41.9 years [standard deviation (SD)=14.5]) were significantly younger than patients with AATD (n=58, mean age 66.9 [SD=10.7]), CVI (n=18, mean age 66.7 years [SD=10.5]) or the idiopathic group (n=460, mean age 64.2 [SD=15.9]), p<.0001. Compared to other groups, those with PCD had lower pulmonary function (forced expiratory volume in 1 second [FEV₁] forced vital capacity [FVC] and FEV1/FVC ratio) (p<0.01), and a greater proportion of them reported having exacerbations and/or hospitalizations in the past 2 years (p<0.01). Overall, Pseudomonas aeruginosa and Staphylococcus aureus were the organisms most commonly isolated from sputum. Mycobacterial infection was most commonly reported in those with AATD.

Conclusion

This report from the U.S. Bronchiectasis Research Registry compares and contrasts differences in the clinical features of patients suffering from 3 rare conditions, with different underlying causes, to those without. The group with PCD had more symptoms, greater morbidity, lower lung function and more commonly were infected by Pseudomonas aeruginosa. A greater percentage of those with AATD reported mycobacterial lung involvement.

Pathogenic NFKB2 variant in the ankyrin repeat domain (R635X) causes a variable antibody deficiency

Genetic studies are identifying an increasing number of monogenic causes of Common Variable Immunodeficiency (CVID). Pathogenic variants in the C-terminus of NFKB2 have been identified in the subset of CVID patients whose immunodeficiency is associated with ectodermal dysplasia and central adrenal insufficiency. We describe 2 unrelated CVID pedigrees with 4 cases of pathogenic stop gain variants (c.1903C > T) in the ankyrin repeat domain (ARD) of NF-κB2, leading to a premature truncation of the protein at p.Arg635Term (R635X). By immunophenotyping and functional ex vivo B- and T-cell experiments we characterized the variant by reduced class-switched memory B-cell counts and immature plasmablasts, unable to produce IgG and IgA. Features of a poor proliferative T-cell response and reduced expansion of CD4⁺CXCR5⁺ T cells was only observed in the two clinically affected index cases without any clear clinical correlate. In conclusion, pathogenic stop variants in the ARD of NFKB2 can cause 'infection-only' CVID with an abnormal B-cell phenotype and a variable clinical penetrance.

Clinical and Immunological Phenotype of Patients With Primary Immunodeficiency Due to Damaging Mutations in NFKB2

Non-canonical NF-κB-pathway signaling is integral in immunoregulation. Heterozygous mutations in NFKB2 have recently been established as a molecular cause of common variable immunodeficiency (CVID) and DAVID-syndrome, a rare condition combining deficiency of anterior pituitary hormone with CVID. Here, we investigate 15 previously unreported patients with primary immunodeficiency (PID) from eleven unrelated families with heterozygous NFKB2-mutations including eight patients with the common p.Arg853^* nonsense mutation and five patients harboring unique novel C-terminal truncating mutations. In addition, we describe the clinical phenotype of two patients with proximal truncating mutations. Cohort analysis extended to all 35 previously published NFKB2-cases revealed occurrence of early-onset PID in 46/50 patients (mean age of onset 5.9 years, median 4.0 years). ACTH-deficiency occurred in 44%. Three mutation carriers have deceased, four developed malignancies. Only two mutation carriers were clinically asymptomatic. In contrast to typical CVID, most patients suffered from early-onset and severe disease manifestations, including clinical signs of T cell dysfunction e.g., chronic-viral or opportunistic infections. In addition, 80% of patients suffered from (predominately T cell mediated) autoimmune (AI) phenomena (alopecia > various lymphocytic organ-infiltration > diarrhea > arthritis > AI-cytopenia). Unlike in other forms of CVID, auto-antibodies or lymphoproliferation were not common hallmarks of disease. Immunophenotyping showed largely normal or even increased quantities of naïve and memory CD4⁺ or CD8⁺ T-cells and normal T-cell proliferation. NK-cell number and function were also normal. In contrast, impaired B-cell differentiation and hypogammaglobinemia were consistent features of NFKB2-associated disease. In addition, an array of lymphocyte subpopulations, such as regulatory T cell, Th17-, cTFH-, NKT-, and MAIT-cell numbers were decreased. We conclude that heterozygous damaging mutations in NFKB2 represent a distinct PID entity exceeding the usual clinical spectrum of CVID. Impairment of the non-canonical NF-κB pathways affects function and differentiation of numerous lymphocyte-subpopulations and thus causes a heterogeneous, more severe form of PID phenotype with early-onset. Further characteristic features are multifaceted, primarily T cell-mediated autoimmunity, such as alopecia, lymphocytic organ infiltration, and in addition frequently ACTH-deficiency.

British Society for Immunology/United Kingdom Primary Immunodeficiency Network consensus statement on managing non-infectious complications of common variable immunodeficiency disorders

Common variable immunodeficiency (CVID) represents a heterogeneous group of rare disorders. There is considerable morbidity and mortality as a result of non-infectious complications, and this presents clinicians with management challenges. Clinical guidelines to support the management of CVID are urgently required. The UK Primary Immunodeficiency Network and the British Society for Immunology funded a joint project to address this. A modified Delphi Survey was conducted for the assessment, diagnosis and treatment of the non-infectious blood, respiratory, gut and liver complications of CVID. A steering group of 10 consultant immunologists and one nurse specialist developed and reviewed the survey statements and agreed the final recommendations. In total, 22 recommendations and three areas for research were developed.

Primary Immunodeficiency and Cancer Predisposition Revisited: Embedding Two Closely Related Concepts Into an Integrative Conceptual Framework

Common understanding suggests that the normal function of a "healthy" immune system safe-guards and protects against the development of malignancies, whereas a genetically impaired one might increase the likelihood of their manifestation. This view is primarily based on and apparently supported by an increased incidence of such diseases in patients with specific forms of immunodeficiencies that are caused by high penetrant gene defects. As I will review and discuss herein, such constellations merely represent the tip of an iceberg. The overall situation is by far more varied and complex, especially if one takes into account the growing difficulties to define what actually constitutes an immunodeficiency and what defines a cancer predisposition. The enormous advances in genome sequencing, in bioinformatic analyses and in the functional in vitro and in vivo assessment of novel findings together with the availability of large databases provide us with a wealth of information that steadily increases the number of sequence variants that concur with clinically more or less recognizable immunological problems and their consequences. Since many of the newly identified hard-core defects are exceedingly rare, their tumor predisposing effect is difficult to ascertain. The analyses of large data sets, on the other hand, continuously supply us with low penetrant variants that, at least in statistical terms, are clearly tumor predisposing, although their specific relevance for the respective carriers still needs to be carefully assessed on an individual basis. Finally, defects and variants that affect the same gene families and pathways in both a constitutional and somatic setting underscore the fact that immunodeficiencies and cancer predisposition can be viewed as two closely related errors of development. Depending on the particular genetic and/or environmental context as well as the respective stage of development, the same changes can have either a neutral, predisposing and, in some instances, even a protective effect. To understand the interaction between the immune system, be it "normal" or "deficient" and tumor predisposition and development on a systemic level, one therefore needs to focus on the structure and dynamic functional organization of the entire immune system rather than on its isolated individual components alone.

A 51-Year-Old Man With Unresolved Pulmonary Infiltrates Following Streptococcus pneumoniae Pneumonia

CASE PRESENTATION

A 51-year-old man presented to the clinic 8 weeks after a 6-day hospital admission for severe multilobar pneumonia caused by Streptococcus pneumoniae. His productive cough resolved after antibiotics, but he reported persistent dyspnea. He recounted a lifelong history of recurrent sinusitis but no previous episodes of pneumonia. The patient denied fever, weight loss, or tobacco, alcohol, or drug use. He worked as an upholstery craftsman with no work-related exposures. He had no bird or exotic animal exposures, and no history of travel outside Sacramento, California, where he lived. Aside from the recently completed 2-week course of levofloxacin, he was not taking any medications.

CVID-Associated Tumors: Czech Nationwide Study Focused on Epidemiology, Immunology, and Genetic Background in a Cohort of Patients With CVID

Background: Common variable immunodeficiency disorder (CVID) is one of the most frequent inborn errors of immunity, increased occurrence of malignancies, particularly lymphomas, and gastric cancers, has long been noted among CVID patients. Multifactorial etiology, including immune dysregulation, infections, chronic inflammation, or genetic background, is suggested to contribute to tumor development. Here, we present the results of the first Czech nationwide study focused on epidemiology, immunology and genetic background in a cohort of CVID patients who also developed tumors

Methods: The cohort consisted of 295 CVID patients followed for 3,070 patient/years. Standardized incidence ratio (SIR) was calculated to determine the risk of cancer, and Risk ratio (RR) was established to evaluate the significance of comorbidities. Moreover, immunophenotyping, including immunoglobulin levels and lymphocyte populations, was assessed. Finally, Whole exome sequencing (WES) was performed in all patients with lymphoma to investigate the genetic background.

Results: Twenty-five malignancies were diagnosed in 22 patients in a cohort of 295 CVID patients. SIR was more than 6 times greater in comparison to the general population. The most common neoplasias were gastric cancers and lymphomas. History of Immune thrombocytopenic purpura (ITP) was established as a potential risk factor, with over 3 times higher risk of cancer development. The B cell count at diagnosis of lymphoma was reduced in the lymphoma group; moreover, post-treatment B and T cell lymphopenia, associated with poorer outcome, was found in a majority of the patients. Intriguingly, no NK cell depression was observed after the chemotherapy. WES revealed heterogeneous genetic background among CVID patients with tumors, identifying gene variants associated with primary immunodeficiencies (such as CTLA4, PIK3CD, PMS2) and/or increased cancer susceptibility (including BRCA1, RABEP1, EP300, KDM5A).

Conclusions: The incidence of malignancy in our CVID cohort was found to be more than 6 times greater compared to the general population. Gastric cancers and lymphomas were the most frequently diagnosed tumors. ITP was identified as a risk factor for malignancy in CVID patients. WES analysis confirmed a wide genetic heterogeneity among CVID patients. The identified causative or modifying gene variants pointed to errors in mechanisms contributing to both immunodeficiency and malignancy.

Pulmonary Manifestations of Predominantly Antibody Deficiencies

Predominantly antibody deficiencies (PADs) are the most frequent forms of primary immunodeficiency diseases (PIDs). Commonly accompanied with complications involving several body systems, immunoglobulin substitution therapy along with prophylactic antibiotics remained the cornerstone of treatment for PADs and related complications. Patients with respiratory complications should be prescribed an appropriate therapy as soon as possible and have to be adhering to more and longer medical therapies. Recent studies identified a gap for screening protocols to monitor respiratory manifestations in patients with PADs. In the present chapter, the pulmonary manifestations of different PADs for each have been discussed. The chapter is mainly focused on X-linked agammaglobulinemia, common variable immunodeficiency, activated PI3K-δ syndrome, LRBA deficiency, CD19 complex deficiencies, CD20 deficiency, other monogenic defects associated with hypogammaglobulinemia, immunoglobulin class switch recombination deficiencies affecting B-cells, transient hypogammaglobulinemia of infancy, and selective IgA deficiency.

Common variable immune deficiency: Dissection of the variable

Starting about 60 years ago, a number of reports appeared that outlined the severe clinical course of a few adult subjects with profound hypogammaglobinemia. Puzzled by the lack of family history and adult onset of symptoms in most, the name "acquired" hypogammaglobinemia was given, but later altered to the current name common variable immune deficiency. Pathology reports remarked on the loss of lymph node architecture and paucity of plasma cells in lymphoid tissues in these subjects. While characterized by reduced serum IgG and IgA and often IgM, and thus classified among the B-cell defects, an increasing number of cellular defects in these patients have been recognized over time. In the early years, severe respiratory tract infections commonly led to a shortened life span, but the wide spread availability of immune globulin concentrates for the last 25 years has improved survival. However, chronic non-infectious inflammatory and autoimmune conditions have now emerged as challenging clinical problems; these require further immunologic understanding and additional therapeutic measures. Recent study of this phenotypic syndrome have provided an increasingly fertile ground for the identification of autosomal recessive and now more commonly, autosomal dominant gene defects which lead to the loss of B-cell development in this syndrome.

Imaging of Bronchial Pathology in Antibody Deficiency: Data from the European Chest CT Group

Studies of chest computed tomography (CT) in patients with primary antibody deficiency syndromes (ADS) suggest a broad range of bronchial pathology. However, there are as yet no multicentre studies to assess the variety of bronchial pathology in this patient group. One of the underlying reasons is the lack of a consensus methodology, a prerequisite to jointly document chest CT findings. We aimed to establish an international platform for the evaluation of bronchial pathology as assessed by chest CT and to describe the range of bronchial pathologies in patients with antibody deficiency. Ffteen immunodeficiency centres from 9 countries evaluated chest CT scans of patients with ADS using a predefined list of potential findings including an extent score for bronchiectasis. Data of 282 patients with ADS were collected. Patients with common variable immunodeficiency disorders (CVID) comprised the largest subgroup (232 patients, 82.3%). Eighty percent of CVID patients had radiological evidence of bronchial pathology including bronchiectasis in 61%, bronchial wall thickening in 44% and mucus plugging in 29%. Bronchiectasis was detected in 44% of CVID patients aged less than 20 years. Cough was a better predictor for bronchiectasis than spirometry values. Delay of diagnosis as well as duration of disease correlated positively with presence of bronchiectasis. The use of consensus diagnostic criteria and a pre-defined list of bronchial pathologies allows for comparison of chest CT data in multicentre studies. Our data suggest a high prevalence of bronchial pathology in CVID due to late diagnosis or duration of disease.