Abstract
Background: Selective IgA deficiency (SIgAD) is the most prevalent
primary immunodeficiency with almost unknown etiology. This study aimed
to investigate the clinical diagnostic and prognostic values of
lymphocytes subsets and function in symptomatic SIgAD patients. Methods:
A total of 30 available SIgAD patients from the Iranian registry and 30
age-sex-matched healthy controls were included in the present study. We
analyzed B and T cell peripheral subsets and T cell proliferation assay
by flow cytometry in SIgAD patients with mild and severe clinical
phenotypes. Results: Our results indicated a significant increase in
naïve and transitional B cells and a strong decrease in marginal
zone-like and switched memory B-cells in SIgAD patients. We found that
naïve and central memory CD4+ T cell subsets, as well as Th1, Th2 and
regulatory T cells have significantly decreased. On the other hand,
there was a significant reduction in central and effector memory CD8+ T
cell subsets, whereas proportions of both (CD4+ and CD8+) terminally
differentiated effector memory T cells (TEMRA) were significantly
elevated in our patients. Although some of T cell subsets in severe
SIgAD were similar, decrease in marginal-zone and switched memory B
cells and increase in CD21low B cell of severe SIgAD patients were
slightly prominent. Moreover, the proliferation activity of CD4+ T cells
was strongly impaired in SIgAD patients with a severe phenotype.
Conclusion: SIgAD patients have varied cellular and humoral
deficiencies. Therefore, T cell and B cell assessment might help in
better understanding the heterogeneous pathogenesis and prognosis
estimation of the disease. Keywords: Primary immunodeficiency, Selective
IgA deficiency, B cell subsets, T cell subsets, flow cytometry,
proliferation assay