TNFR2 expression is a hallmark of human memory B cells with suppressive function.

Tumor Necrosis Factor Receptor 2 (TNFR2) expression is increasingly being linked to tolerogenic immune reactions and cells with suppressor function including a subset of T-regulatory cells. B-regulatory cells play an important role in control of T-cell responses and inflammation. Recently, we described TNFR2 as a marker for IL-10-producing B cells, a hallmark of this cell subset. Here, we demonstrate that proliferation of T cells is reduced in the presence of TNFR2 positive human memory B cells generated with TLR9 ligand, while TNFR2- and TNFR2+CD27- B cells display costimulatory activity. Our data further reveal that IL-10 secretion is characteristic of IgM+ naïve and memory B cells but suppressive activity is not restricted to IL-10: (i) the inhibitory effect of TNFR2+ switched memory B cells was comparable to that exerted by TNFR2+ IgM+ memory B cells although IL-10 secretion levels in the cocultures were lower; (ii) supernatants from TNFR2+ memory B cells failed to suppress T-cell proliferation. Based on our findings, we propose that formation of Breg is a specific characteristic of human memory B cells undergoing terminal differentiation. Our data further corroborate that TNFR2 represents a viable marker for identification of memory B cells with regulatory function.

Nonpermissive bone marrow environment impairs early B-cell development in common variable immunodeficiency.

Common variable immunodeficiency (CVID) is a disease characterized by increased susceptibility to infections, hypogammaglobulinemia, and immune dysregulation. Although CVID is thought to be a disorder of the peripheral B-cell compartment, in 25% of patients, early B-cell development in the bone marrow is impaired. Because poor B-cell reconstitution after hematopoietic stem cell transplantation has been observed, we hypothesized that in some patients the bone marrow environment is not permissive to B-cell development. Studying the differentiation dynamics of bone marrow-derived CD34+ cells into immature B cells in vitro allowed us to distinguish patients with B-cell intrinsic defects and patients with a nonpermissive bone marrow environment. In the former, immature B cells did not develop and in the latter CD34+ cells differentiated into immature cells in vitro, but less efficiently in vivo. In a further group of patients, the uncommitted precursors were unable to support the constant development of B cells in vitro, indicating a possible low frequency or exhaustion of the precursor population. Hematopoietic stem cell transplantation would result in normal B-cell repopulation in case of intrinsic B-cell defect, but in defective B-cell repopulation in a nonpermissive environment. Our study points to the importance of the bone marrow niche in the pathogenesis of CVID.

Severe Fatigue Is Common Among Pediatric Patients with Primary Immunodeficiency and Is Not Related to Disease Activity.

PURPOSE: Fatigue is a distressing symptom commonly reported among pediatric patients with primary immunodeficiency (PID). However, the relationship between fatigue and disease activity is currently unknown. METHODS: In this cross-sectional study, we examined the prevalence of severe fatigue, the effect of fatigue on health-related quality of life (HRQoL), and the effects of disease activity and comorbidity on fatigue severity among pediatric patients 2-18 years of age with PID. Fatigue and HRQoL were assessed using the pediatric quality of life inventory multidimensional fatigue scale (PedsQL MFS) and generic core scales (PedsQL GCS), respectively. Linear regression analyses and an analysis of covariance were used to compare the fatigue scores with the scores obtained from a healthy control group. Data were adjusted for age and sex. RESULTS: Of the 91 eligible patients, 79 were assessed (87% participation rate), with a mean age of 10.4 ± 4.4 years. Pediatric patients with PID reported significantly higher fatigue levels compared to healthy peers, with an 18.9% prevalence of severe fatigue. Moreover, higher fatigue levels were inversely associated with HRQoL in all domains and directly associated with school absences. We found that severe fatigue was comparable between common variable immunodeficiency (CVID), combined immunodeficiency (CID), and selective immunoglobulin A deficiency (SIgAD) patients, but was not reported in the X-linked agammaglobulinemia (XLA) patients studied. Finally, fatigue severity was not significantly associated with disease activity or comorbidity. CONCLUSIONS: Nearly 20% of pediatric patients with PID reported experiencing severe fatigue, and fatigue was reported among a wide range of PID subcategories. In addition, severe fatigue negatively affected the patient's quality of life and daily functioning, but was not associated with disease activity or comorbidity. Thus, targeting severe fatigue might be a promising strategy for improving the overall well-being and quality of life of pediatric patients with PID.

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.

A Spectrum of Clinical Findings from ALPS to CVID: Several Novel LRBA Defects.

INTRODUCTION: Autosomal recessively inherited lipopolysaccharide-responsive beige-like anchor (LRBA) protein deficiency was shown to be responsible for different types of inborn errors of immunity, such as common variable immunodeficiency (CVID) and autoimmune lymphoproliferative syndrome (ALPS). The aim of this study was to compare patients with LRBA-related ALPS and LRBA-related CVID, to describe their clinical and laboratory phenotypes, and to prepare an algorithm for their diagnosis and management. METHODS: Fifteen LRBA-deficient patients were identified among 31 CVID and 14 possible ALPS patients with Western blotting (WB), primary immunodeficiency disease (PIDD) gene, next-generation panel screening (NGS), and whole exome sequencing (WES). RESULTS: The median age on admission and age of diagnosis were 7 years (0.3-16.5) and 11 years (5-44), respectively. Splenomegaly was seen in 93.3% (14/15) of the patients on admission. Splenectomy was performed to 1/5. Recurrent upper respiratory tract infections (93.3% (14/15)), autoimmune cytopenia (80% (12/15)), chronic diarrhea (53.3% (8/15)), lower respiratory tract infections (53.3% (8/15)), lymphoma (26.6% (4/15)), Evans syndrome (26.6% (4/15)), and autoimmune thyroiditis (20% (3/15)) were common clinical findings and diseases. Lymphopenia (5/15), intermittant neutropenia (4/15), eosinophilia (4/15), and progressive hypogammaglobulinemia are recorded in given number of patients. Double negative T cells (TCRαß+CD4-CD8-) were increased in 80% (8/10) of the patients. B cell percentage/numbers were low in 60% (9/15) of the patients on admission. Decreased switched memory B cells, decreased naive and recent thymic emigrant (RTE) Thelper (Th) cells, markedly increased effector memory/effector memory RA+ (TEMRA) Th were documented. Large PD1+ population, increased memory, and enlarged follicular helper T cell population in the CD4+ T cell compartment was seen in one of the patients. Most of the deleterious missense mutations were located in the DUF1088 and BEACH domains. Interestingly, one of the two siblings with the same homozygous LRBA defect did not have any clinical symptom. Hematopoietic stem cell transplantation (HSCT) was performed to 7/15 (46.6%) of the patients. Transplanted patients are alive and well after a median of 2 years (1-3). In total, one patient died from sepsis during adulthood before HSCT. CONCLUSION: Patients with LRBA deficiency may initially be diagnosed as CVID or ALPS in the clinical practice. Progressive decrease in B cells as well as IgG in ALPS-like patients and addition of IBD symptoms in the follow-up should raise the suspicion for LRBA deficiency. Decreased switched memory B cells, decreased naive and recent thymic emigrant (RTE) Th cells, and markedly increased effector memory/effector memory RA+ Th cells (TEMRA Th) cells are important for the diagnosis of the patients in addition to clinical features. Analysis of protein by either WB or flow cytometry is required when the clinicians come across especially with missense LRBA variants of uncertain significance. High rate of malignancy shows the regulatory T cell's important role of immune surveillance. HSCT is curative and succesful in patients with HLA-matched family donor.

Gastric Cancer Screening in Common Variable Immunodeficiency.

Individuals with common variable immunodeficiency (CVID) have an increased risk of gastric cancer, and gastrointestinal lymphoma, yet screening for premalignant gastric lesions is rarely offered routinely to these patients. Proposed screening protocols are not widely accepted and are based on gastric cancer risk factors that are not applicable to all CVID patients. Fifty-two CVID patients were recruited for screening gastroscopy irrespective of symptoms or blood results and were compared to 40 controls presenting for gastroscopy for other clinical indications. Overall, 34% of CVID patients had intestinal metaplasia (IM), atrophic gastritis or moderate to severe non-atrophic gastritis, which can increase the risk of gastric cancer, compared to 7.5% of controls (p < 0.01). Focal nodular lymphoid hyperplasia, a precursor lesion for gastrointestinal lymphoma, was seen in eight CVID patients (16%), one of whom was diagnosed with gastrointestinal lymphoma on the same endoscopy. High-risk gastric pathology was associated with increased time since diagnosis of CVID, smoking, Helicobacter pylori, a low-serum pepsinogen I concentration, and diarrhea, but not pepsinogen I/II ratio, iron studies, vitamin B12 levels or upper gastrointestinal symptoms. There was a lower rate of detection of IM when fewer biopsies were taken, and IM and gastric atrophy were rarely predicted by the endoscopist macroscopically, highlighting the need for standardized biopsy protocols. The prevalence of premalignant gastric lesions in patients with CVID highlights the need for routine gastric screening. We propose a novel gastric screening protocol to detect early premalignant lesions and reduce the risk of gastric cancer and gastric lymphoma in these patients.

Significant differences in B-cell subpopulations characterize patients with chronic graft-versus-host disease-associated dysgammaglobulinemia.

Manifestations of chronic graft-versus-host disease (cGVHD) can resemble those seen in immunodeficiency states and autoimmune disorders. Reports by us and others suggest an involvement of B cells in the pathogenesis of cGVHD. We investigated B-lymphocyte subpopulations in cGVHD cohorts defined by serum immunoglobulin G (IgG) levels to characterize novel biomarkers for impairment of humoral immunity after allogeneic hematopoietic stem cell transplantation. Seventy-six patients were enrolled a median of 46 months after hematopoietic stem cell transplantation. The hypogammaglobulinemia group had significantly diminished CD19(+) B cells (165 vs 454 vs 417 × 106L) with elevated CD19(+)CD21(low) immature (16.5%, 7.7%, and 9.1%) and CD19(+)CD21(int-high)CD38(high)IgM(high) transitional (10.5% vs 4.2% vs 6.3%) B-cell proportions compared with the normogammaglobulinemia and hypergammaglobulinemia groups. CD19(+)CD10(-)CD27(-)CD21(high) naive B cells were highly elevated in all patients with cGVHD. CD19(+)CD27(+)IgD(+) non-class-switched (4 vs 12 vs 11 × 106/L) and class-switched (7 vs 35 vs 42 × 106/L) memory B cells were significantly lower in the hypogammaglobulinemia group compared with the others. Besides significantly higher B-cell activation factor/B-cell ratios, significantly more cGVHD patients with hypergammaglobulinemia had autoantibodies compared with the hypogammaglobulinemia subgroup (68% vs 24%, P = .024). In conclusion, B-cell subpopulations can serve as novel cellular biomarkers for immunodeficiency and autoimmunity indicating different pathogenetic mechanisms of cGVHD and encouraging future prospective longitudinal studies.

Common variable immunodeficiency - new insight into the pathogenesis and the quest for a workable classification.

In this editorial we argue that more and more complex classifications for patients with common variable immunodeficiency (CVID) fail to identify those patients at high risk of developing infections. We propose that the minimal requirement to identify such patients is the absolute numbers of total and memory B cells and the IgM response to immunization with polysaccharides. If these data should be confirmed, they will provide the basis for a good classification of a heterogeneous group of patients. This simple, workable classification may result in a clinically useful identification of patients prone to more aggressive infections.

Is there a role for microbiome-based approach in common variable immunodeficiency?

Common variable immunodeficiency (CVID) is a primary immunodeficiency characterized by low levels of serum immunoglobulins and increased susceptibility to infections, autoimmune disorders and cancer. CVID embraces a plethora of heterogeneous manifestations linked to complex immune dysregulation. While CVID is thought to be due to genetic defects, the exact cause of this immune disorder is unknown in the large majority of cases. Compelling evidences support a linkage between the gut microbiome and the CVID pathogenesis, therefore a potential for microbiome-based treatments to be a therapeutic pathway for this disorder. Here we discuss the potential of treating CVID patients by developing a gut microbiome-based personalized approach, including diet, prebiotics, probiotics, postbiotics and fecal microbiota transplantation. We also highlight the need for a better understanding of microbiota-host interactions in CVID patients to prime the development of improved preventive strategies and specific therapeutic targets.

Telomere-dependent replicative senescence of B and T cells from patients with type 1a common variable immunodeficiency.

A subset of patients with common variable immunodeficiency (CVID), group 1a of the Freiburg classification, is characterized by increased B cells expressing low levels of CD21 (CD21(low) ), lymphoproliferation and autoimmunity. The CD21(low) B cells have been shown to be profoundly anergic, and defects of BCR-mediated calcium signaling and of T cells have been described in CVID 1a. We found that also the classical naïve B cells from CVID 1a patients, but not from CVID non-1a patients, proliferated poorly. The B cells of CVID 1a patients had a reduced capacity to divide reminiscent of the proliferative arrest associated with replicative senescence. Thus, we investigated whether lymphocyte dysfunction in CVID 1a was related to telomere-dependent replicative senescence, and found that both the B and the T cells from CVID 1a patients had significantly shorter telomeres compared with B and T cells from CVID non-1a patients. Telomere lengths in B and T cells were significantly correlated, indicating that the rate of telomere attrition in lymphocytes is an individual characteristic of CVID patients. Our findings suggest that telomere-dependent replicative senescence contributes to the immune dysfunction of CVID 1a patients, and may provide an important clue for a better understanding of the pathogenesis of CVID.

Utility of peripheral blood B cell subsets analysis in common variable immunodeficiency.

Abnormalities in peripheral blood B cell subsets have been identified in common variable immunodeficiency (CVID) patients and classification systems based upon their numbers have been proposed to predict the clinical features. We analysed B lymphocyte subsets by multi-colour flow cytometry (MFC) in a cohort of well-characterized CVID patients to look at their clinical relevance and validate the published association of different classification criteria (Freiburg, Paris and Euroclass) with clinical manifestations. CVID patients had a reduced proportion of total and switched memory B cells (MBC, swMBC) compared to normal controls (P < 0·0006). Patients classified in Freiburg Ia had a higher prevalence of granulomatous diseases (P = 0·0034). The previously published associations with autoimmune diseases could not be confirmed. The Euroclass classification was not predictive of clinical phenotypes. The absolute numbers of all B cell subsets were reduced in CVID patients compared to controls. There was a significant linear correlation between low absolute total B cells and MBC with granulomatous disease (P < 0·05) and a trend towards lower B cells in patients with autoimmune diseases (P = 0·07). Absolute number of different B cell subsets may be more meaningful than their relative percentages in assessing the risk of granulomatous diseases and possibly autoimmunity.

Development of common variable immunodeficiency in IgA- and IgG2-deficient patients with systemic lupus erythematosus.

BACKGROUND: There have been few reports on children who developed common variable immunodeficiency (CVID) in association with immunoglobulin A (IgA) and IgG2 deficiencies and systemic lupus erythematosus (SLE). CASE-DIAGNOSIS/TREATMENT: Our patient experienced nephrotic syndrome and acute respiratory distress syndrome (ARDS) caused by influenza A/H1N1 virus infection at 5 years of age. A diagnosis of IgA and IgG2 deficiency and SLE was made on the basis of severe proteinuria, hematuria, hypocomplementemia, high anti-DNA antibody and antinuclear antibody (ANA) titers, and malar rash. However, these clinical signs and symptoms and laboratory features disappeared after the administration of methylprednisolone pulse therapy and prednisolone. For the 5 years following the initial treatment for SLE, the patient experienced a number of infections and had a low serum total IgG level; she was eventually diagnosed with CVID. The administration of intravenous immunoglobulin (IVIG) was required to prevent subsequent infections, and no relapse of SLE was observed. CONCLUSION: We report the development of CVID in an IgA- and IgG2-deficient patient with SLE on the basis of multiple episodes of infection. To prevent the development of CVID in IgA- and IgG2-deficient patients with SLE, it is important to prevent immune dysregulation by the avoidance of infections through the use of IVIG therapy.

Immunodeficiency due to chylous dysplasia: diagnostic and therapeutic considerations.

Among primary immunodeficiencies, common variable immunodeficiency (CVID) is defined by an impaired production of immunoglobulins characterized by low levels of plasma immunoglobulins and an altered antibody response. The case reported here was initially interpreted as a CVID. A 20 year old male suffered from diarrhea, weight loss, and malnutrition. Accurate diagnostic assessment uncovered a protein-losing enteropathy. Conventional oil contrast lymphangiography accurately documented the underlying problem and established the appropriate therapeutic approach. The operation consisted of multiple antigravitational ligatures of dilated and incompetent chylous vessels and chylous vessel-mesenteric vein microanastomoses. Serum albumin and leukocyte counts normalized by 1 week after operation and remained stable with time. There were no more episodes of diarrhea, and the patient regained weight. Accurate diagnostic assessment and particularly lymphangiography may be necessary to properly define difficult cases of immunodeficiency due to intestinal protein loss and to plan a corrective therapeutic functional approach.

[Persistent hypogammaglobulinemia in an ITP patient following treatment with rituximab].

In some cases, immune-mediated thrombocytopenia (ITP) is severe, and requires second-line therapies such as splenectomy and/or Rituximab. In most cases Rituximab is beneficial and safe but in some (though rare) it induces significant hypogammaglobulinemia and persistent decreases in the number of B cells. Patients in whom baseline levels of serum IgM or IgG are low become more prone to develop common variable immune deficiency (CVID) especially when more than one cycle of Rituximab is given. In a few case reports, immune-mediated thrombocytopenia was shown to precede the development of CVID. This could possibly develop following a second bout with Rituximab. The assessment of baseline serum immunoglobulins should be routine in all patients with chronic ITP and those who are candidates for Rituximab therapy.

Neuraxial anesthesia in a parturient with common variable immunodeficiency: a case report.

Choosing whether or not to initiate neuraxial anesthesia in pregnant women with immune system defects may be challenging. Anesthesiologists have the responsibility of making the best decision in terms of anesthesia management for both mother and baby during the labor and delivery process. Whether neuraxial anesthesia is associated with an increased risk of central nervous system infection in immunocompromised compared with healthy patients is unknown. It is also unclear if maternal immune modulation required for fetal tolerance makes pregnant women susceptible to pathogens and causes an altered immune response. Infection-related complications of neuraxial anesthesia are rare but may be severe, especially in immunocompromised parturients. There are no guidelines regarding the indications and limitations of regional anesthesia procedures in these patients. Immunocompromised patients are now seen more commonly, and it is essential to adopt a multidisciplinary approach to their care while tailoring anesthetic plans to the individual. We present the case of a 37-year-old parturient who had a congenital immune deficiency and who developed aseptic meningitis after receiving spinal anesthesia for cesarean delivery.