Pediatric Common Variable Immunodeficiency Research Articles

84 Rituximab Responsive Immune Dysregulation in Pediatric Common Variable Immunodeficiency

84 Rituximab Responsive Immune Dysregulation in Pediatric Common Variable Immunodeficiency

Immune Dysregulation in Pediatric Common Variable Immunodeficiency: Implications for the Diagnostic Approach

Infections and infectious complications are hallmarks of common variable immunodeficiency (CVID) and the leading cause of morbidity and mortality in affected patients at any age. However, the pediatric CVID is no longer perceived as a primary immunodeficiency associated solely with infectious manifestations; autoimmune, allergic, lymphoproliferative, and malignant disorders and organ-specific immunopathology also characterize the spectrum of non-infectious complications. In this study, we sought to determine the role of immune dysregulation and frequency of non-infectious sequelae in children affected with CVID. We also aimed at providing an insight into the pathogenesis of non-infectious complications and at delineating the diagnostic approach to pediatric CVID with immune dysregulation. An in-depth retrospective analysis of clinical manifestations and their correlations with selected immune parameters was performed in a group of 39 CVID children, followed by our pediatric immunology department. Whereas recurrent sinopulmonary infections were present in all (100%) of the children studied, an unexpectedly high rate of non-infectious disorders and immune dysregulation phenotypes were observed in as many as 32 (82.05%) patients, compared with infection-only phenotypes limited to 7 (17.95%) male patients. The most common inflammatory comorbidity was asthma, diagnosed in 21 (53.85%) patients. The second most frequent immune dysregulation group was autoimmune disorders, present in 18 (46.15%) of the children studied with a high rate of autoimmune thyroiditis in as many as 10 (25.64%) of the CVID-affected children. Lymphoproliferation was seen in 14 children (35.90%), and, among them, lymphadenopathy occurred in nine (23.08%) cases and granulomatous lymphocytic interstitial lung disease in seven (17.95%) cases. Finally, malignancies occurred in two female patients (5.13%), papillary thyroid cancer in the first one and T-cell lymphoblastic leukemia in the other one. The most prominent abnormalities in the B- and T-cell compartment contributing to complex immune deficiency and immune dysregulation phenotypes were seen in the autoimmunity group, showing significant reductions in the switched memory B cell, naive T helper cell, and regulatory T-cell subsets. Herein, we document the previously unreported high rate of immune dysregulation in pediatric CVID as a clinical and diagnostic challenge with the variability of defects in the humoral and cellular immune responses.

Rituximab as a single agent for successful treatment of granulomatous and lymphocytic interstitial lung disease in a pediatric patient with common variable immunodeficiency

Granulomatous and lymphocytic interstitial lung disease (GLILD) occurs in 10% to 20 % of adult patients with common variable immunodeficiency (CVID).1 The frequency of GLILD in pediatric CVID is not well established, but various forms of interstitial lung disease were reported in 15% of children.2 There is a lack of robust scientific evidence on how to treat and when to start treatment of GLILD, but most regiments aim at T and B lymphocytes. Experience with the effectiveness of systemic steroids has been diverse.

Functions of NK and iNKT cells in pediatric and adult CVID, ataxia telangiectasia and agammaglobulinemia patients

Primary immune deficiencies (PID) are known to be more than 400 genetic defects caused by the impairment in development and/or functions of the immune system. Common Variable Immunodeficiency (CVID), Ataxia Telangiectasia (AT) and Agammaglobulinemia (AG) are examples of the most common immunodeficiency syndrome. Natural killer (NK) cells are a component of innate immune system and play a major role in the host-rejection of both tumors and virally infected cells. iNKT cells have a role in autoimmune and infectious diseases and controlling of tumor rejection. In this study, NK and iNKT cells and their functions, and intracellular cytokine amount are aimed to determine in patients that suffer CVID, AT and AG. NKp30, NKp46, NKG2D, perforin and granzyme mRNA expression levels were analyzed using RT-PCR. Receptors, cytokine amount of NK cell subset and iNKT were analyzed by flow cytometry. Decreased CD3+ T and elevated NK cell subset in pediatric AT were found. Expression of NKp44 was decreased in adult AG, but not in pediatric patients. Low NKp44 expression in CD3−CD16+CD56dim NK cell subset was found in pediatric AT patients. High HLA-DR, perforin and granzyme expression were found in CD3−CD16+CD56dim NK cell subset of pediatric CVID and AT patients. Alteration of the number of NK subsets, NK receptor expression and cytokine production were observed in pediatric patients compared to healthy subjects.

Lymphocyte Subset Abnormalities in Pediatric-Onset Common Variable Immunodeficiency

Introduction: Common variable immunodeficiency (CVID) is characterized by recurrent infections, autoimmunity, lymphoproliferation, hypogammaglobulinemia, and defective antibody production. In CVID, B-cell abnormalities were described to predict end organ involvement and prognosis. Pediatric-onset CVID is much rarer than adult CVID, and lymphocyte subset abnormalities have not been thoroughly evaluated. Objective: We sought to determine lymphocyte subset abnormalities and their association with end organ involvement in pediatric-onset CVID patients. Methods: The clinical manifestations and laboratory findings including absolute numbers and percentages of B-, T-, and NK cell populations were assessed in pediatric-onset CVID patients and compared to age-matched healthy controls. The patients were divided into 2 groups according to age at assessment (pediatric CVID patients: 10–16 years, n = 9; and adult CVID patients: >16 years, n = 13). The comparisons between lymphocyte subsets and organ involvement were also evaluated. Results: Mean age at symptom onset was 18 (3–204) months. All CVID patients with pediatric onset had decreased levels of total and memory B cells, CD4⁺ T cells, CD4⁺CD45RA⁺ naive T cells, and recent thymic emigrant (RTE) cells. On the other hand, they had increases in CD8⁺CD45RO⁺ memory T cells. Interestingly, adult CVID patients demonstrated high frequencies of activated and double-negative T cells, which were unique only for this group of patients. Specific cellular abnormalities associated with the reduction in B and NK cells and increase in CD8⁺ T cells were found in patients with bronchiectasis. Moreover, in pediatric CVID patients, low serum IgA levels and decreased numbers of naive T and RTE cells were determined as risk factors for chronic diarrhea. Conclusions: Specific abnormalities in B- and T-lymphocyte compartments were identified in pediatric-onset CVID patients and appear to be associated with end organ manifestations.

Hypogammaglobulinemia in children: a warning sign to look deeply?

This study investigated phenotypic and functional characteristics of lymphocytes in children with common variable immunodeficiency (CVID) and unclassified hypogammaglobulinemia (UH), as well as B-cell subsets in non-consanguineous parents. Blood samples of 30 children, CVID (n = 9), UH (n = 9), healthy donors HD (n = 12), and 19 adults (parents and controls) were labeled by a combination of surface markers to identify CD4, CD8 T-cell and B-cell subpopulations. T-cell cytokine production in children was analyzed in vitro after stimulation with phytohemagglutinin (PHA) and tetanus toxoid. We observed low percentages of switched memory B cells in children with CVID, increase in total CD4+ T-cell counts, and high percentages of transitional B cells only in UH group. Analysis of T-cell immunity showed that CVID children had decreased percentages of CD8+ IFN-γ-producing cells after stimulation with PHA and tetanus toxoid. Parent of children with CVID had low percentages of naive B cell and increased percentages of memory B cells in comparison with controls. These results suggest that (i) early combined immune defect in children with CVID and (ii) a possible familial B-cell disturbance in pediatric CVID.

A Clinical and Laboratory Approach to the Evaluation of Innate Immunity in Pediatric CVID Patients.

Defective adaptive immune responses are well studied in common variable immunodeficiency (CVID) patients; however, more focus is needed on innate immune system defects to explain CVID’s clinical and laboratory heterogeneity. This is the first study comparing migratory function of granulocytes, oxidative burst activity of phagocytic cells, surface integrin expressions on neutrophils and lymphocytes, natural killer (NK) cell numbers and cytotoxic activity, natural killer T cells, lymphocyte subsets such as CD8+CD28+, CD4+CTLA-4+ cells in CVID patients (n: 20) and healthy controls (n: 26). The relationship between laboratory findings and some clinical was also investigated. CD3+CD8+ T cytotoxic cells were found to be elevated in CVID patients, but CD3+CD8+CD28+ or CD3+CD8+CD28− cells did not show any significant difference. CD4+CTLA-4+ cell percentages were significantly lower in CVID patients compared to healthy controls. Severe CVID patients had decreased percentages of NK cells with increased NK cell cytotoxicity suggesting possibly increased activation. Furthermore, CD3−CD16+CD56+CD28+ cells of CVID patients were elevated while percentage of CD28− NK cells was decreased. Neutrophil migration percentages were lower but and oxidative burst activity was not affected. CD11a expressions on these cells were depressed in contrast to increased expression of CD18. Innate immunity defects may affect the extent of recurrence and severity of infections in CVID. Our observations highlight some of these associations and indicate the need for further similar studies for improving better innate system evaluation batteries for these patients. Further phenotypic correlations of these analyses will help clinicians reach a more definitive target for the molecular genetic diagnostic of pediatric CVID patients.

Treatment of comorbid selective mutism and procedural anxiety in a child with pediatric common variable immunodeficiency disease: A case study.

Treatment of comorbid selective mutism and procedural anxiety in a child with pediatric common variable immunodeficiency disease: A case study.

Immunological Characteristics and Two Novel Mutations in TACI in a Cohort of 28 Pediatric Patients with Common Variable Immunodeficiency

Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by impaired immunoglobulin production. Mutations in the gene encoding TACI (TNFRSF13B) were previously found to be associated with CVID. Previous studies have identified a variety of sequence variants in TACI where A181E and C104R were the most common, with variable frequencies in different ethnic populations. So far, no mutations were identified in the recently reported "TACI highly conserved" (THC) cytoplasmic domain, important for the induction of class switch recombination. Our study evaluated immunological and clinical data on a cohort of 28 Argentinean pediatric CVID patients and allowed the identification of two novel mutations in TNFRSF13B, including one, S231R, affecting the highly conserved THC domain. In contrast, none of the patients presented with A181E and C104R mutations.

High-resolution computed tomography in pediatric common variable immunodeficiency: risks and benefits

High-resolution computed tomography in pediatric common variable immunodeficiency: risks and benefits

Pediatric common variable immunodeficiency: Immunologic and phenotypic associations with switched memory B cells

Recent studies suggest that patients with common variable immunodeficiency (CVID) and low numbers of switched memory B cells have lower IgG levels and higher rates of autoimmune disease, splenomegaly, and granulomatous disease; however, no prior literature has focused exclusively on pediatric cases. We examined the relationship between switched memory B cells and clinical and immunologic manifestations of CVID in a pediatric population. Forty-five patients were evaluated. Patients were categorized as Group I (<5 switched memory B cells/ml, n = 24) or Group II (> or =5 switched memory B cells/mL, n = 21). CD3(+) T-cell counts and CD19(+) B-cell levels were lower among Group I patients. Only those in Group I had meningitis, sepsis, bronchiectasis, granulomatous lung disease, autoimmune cytopenias, or hematologic malignancies. Segregation of pediatric patients into high risk (Group I) and average risk (Group II) may assist in targeting surveillance appropriately.

Inmunodeficiencia común variable: factores pronósticos de lesión pulmonar

Background and objective Lung damage is considered to be key to Common Variable Immunodeficiency (CVID) prognosis. We describe lung damage in pediatric CVID patients and assess its relationship with memory B cells (MB) phenotype, immunoglobulin G (IgG) levels at the time of diagnosis, and diagnostic delay. We also assessed the prevalence of allergy and autoimmune phenomena. Patients and method Cross-sectional study of 17 CVID patients treated at Vall d’Hebron University Hospital. Prevalence ratio and prevalence odds ratio were used to assess the effect of MB cells phenotype, IgG levels and diagnostic delay on lung damage. Results Five of seventeen patients presented bronchiectasis. Diagnostic delay >5 years was significantly associated with more severe lung damage. MBO phenotype and low IgG levels at the time of diagnosis showed a trend to more severe lung damage without reaching statistical signification. A higher prevalence of allergic or autoimmune phenomena was not observed. Conclusions Latter diagnosis is associated with greater lung damage in CVID patients. The study of MB cells should be included in the study of these patients.

Spectrum of illness in pediatric common variable immunodeficiency

Common variable immunodeficiency (CVID) may present at any age but usually presents during adulthood. To study the presentation and associated medical conditions found in pediatric patients with CVID. A medical record review of patients diagnosed as having CVID before the age of 18 years was performed at a tertiary care immunology clinic from 1992 to 2005. Inclusion criteria consisted of presentation with recurrent infections and decrease in 2 of 3 immunoglobulin isotypes (IgG, IgA, IgM) 2 SDs below the age-specific range, with a poor or absent response to immunization. There had to be no other identifiable predisposing cause of the immunodeficiency. A total of 12 patients were identified. The mean age at presentation was 8 years. All patients had low IgG levels with poor functional antibody responses. The most common presenting infections were sinusitis (75%), otitis media (67%), and pneumonia (58%). Bronchiectasis was seen in 3 children. One patient presented with chronic diarrhea due to Giardia. Two patients presented with failure to thrive. Asthma was seen in 10 patients (83%) but was usually diagnosed after the initial presentation. Autoimmune disorders were seen, including 1 patient with idiopathic thrombocytopenia and 2 with neutropenia. Other disorders encountered were growth hormone deficiency, hypothyroidism, end-stage renal disease, and sarcoma. CVID is a difficult diagnosis in the pediatric population because of an unpredictable presentation. Autoimmune disease, growth hormone deficiency, renal disease, and cancer were noted in our population. A high incidence of asthma also may be associated with pediatric CVID.

Spectrum of illness in pediatric common variable immunodeficiency

Spectrum of illness in pediatric common variable immunodeficiency