Diagnosis of a case of X-linked agammaglobulinemia with juvenile idiopathic arthritis and recurrent pneumonia in Bangladesh

Abstract

X-linked agammaglobulinemia (XLA) is a rare hereditary primary immunodeficiency disorder caused by mutation in the Bruton's tyrosine kinase (BTK) gene located in the Xq22 region of the X chromosome. It is characterized by absolute or marked deficiency of matured B-cells in circulation as well as decreased in all immunoglobulin (Ig) classes. We have reported one case who is a 48-month-old boy and suffering from recurrent pneumonia, skin abscess, otitis media, and swelling of the left knee joint. His serum Ig levels showed an IgM level of <0.169 g/l, IgG 2.43 g/l, and IgA <0.256 g/l. Immunophenotyping of lymphocyte subsets showed an absence of B-cells. Intracellular BTK protein expression in monocytes by flow cytometry showed a markedly reduced mean fluorescence index which confirmed the diagnosis of XLA. Antibiotics with intravenous Ig therapy were started.

Keywords

• bangladesh
• bruton's tyrosine kinase
• flow cytometry
• x-linked agammaglobulinemia