B‐Lymphocyte Stimulator and a Proliferation‐Inducing Ligand Serum Levels in IgA‐Deficient Patients With and Without Celiac Disease

Abstract

IgA deficiency (IgAD) is the most common form of immunodeficiency and frequently associates with autoimmunity, especially with celiac disease (CD). The mechanisms underlying IgAD and the development of autoimmunity are still relatively unknown. Elevated B-lymphocyte stimulator (BLyS) and APRIL (a proliferation-inducing ligand) serum levels characterize several autoimmune diseases. We herein investigated BLyS and APRIL serum levels in IgAD patients with and without CD and compared these patients to CD patients with normal IgA and control patients (HBDs). Compared to HBDs, IgAD patients demonstrated a significant increase of BLyS (P < 0.0001) and APRIL (P = 0.003) levels, and no differences were seen between patients with or without CD. While BLyS appeared similarly overexpressed in IgAD and CD patients, APRIL was significantly increased only in IgAD patients. Because APRIL promotes IgA production, its overexpression may represent a physiological mechanism of compensation. BLyS upregulation may be involved in the increased risk of autoimmune disease development characterizing people carrying IgAD.

B-cell activating factor (BAFF) — a new factor linking immunity to diet?

“…BAFF represents a fundamental cytokine of the Tindependent IgA class-switching recombination system through the interaction with the common receptor TACI shared also by other proteins, such as APRIL [21]. In this study, we report elevated BAFF levels among CentralEuropean Caucasian patients with obesity, and we also demonstrate substantial dependence of differences in BAFF plasma levels on gender.…”

Decreased Immunoglobulin A Concentrations in Feces, Duodenum, and Peripheral Blood Mononuclear Cells of Dogs with Inflammatory Bowel Disease

“…In this study, we observed that TGF‐β mRNA expression was significantly decreased in the duodenal mucosa of dogs with IBD, whereas BAFF and APRIL mRNA were increased. Interestingly, serum BAFF and APRIL concentrations are significantly higher in humans with IgA deficiency than in healthy donors . Because BAFF and APRIL promote IgA production, their overexpression may represent a physiologic compensatory mechanism in an attempt to overcome the decrease in IgA concentrations.…”

Autoimmune diseases of gastrointestinal tract in children with humoral immunodeficiency – problems of diagnosis

“…Another hypothesis of association of celiac disease and IgAD proposes an increase of B lymphocyte stimulating factors (B-lymphocyte stimulator (BLyS) and a proliferation inducing ligand -APRIL) noted in IgAD patients as an important factor. A new, large, indepth study did not reveal differences between the level of these factors in IgAD with or without concomitant celiac disease [7]. It seemed, that the possibility of destruction of the mucous membrane and occurrence of clinical symptoms due to disturbed metabolism of gliadin in the case of a lack of secretory IgA is more probable [2].…”