Severe Enteropathy and Hypogammaglobulinemia Complicating Refractory Mycobacterium tuberculosis Complex Disseminated Disease in a Child with IL-12Rβ1 Deficiency

Abstract

Purpose: Mendelian susceptibility to mycobacterial disease is a rare clinical condition characterized by a predisposition to infectious diseases caused by poorly virulent mycobacteria. Other infections such as salmonellosis and candidiasis are also reported. The purpose of this article is to describe a young boy affected with various infectious diseases caused by Mycobacterium tuberculosis complex, Salmonella sp, Klebsiella pneumonie, Citrobacter sp., and Candida sp, complicated with severe enteropathy and transient hypogammaglobulinemia.

Methods: We reviewed medical records and performed flow cytometry staining for lymphocyte populations, lymphocyte proliferation in response to PHA, and intracellular IFN-γ production in T cell PHA blasts in the patient and a healthy control. Sanger sequencing was used to confirm the genetic variants in the patient and relatives.

Results: Genetic analysis revealed a bi-allelic mutation in IL12RB1 (C291Y) resulting in complete IL-12Rβ1 deficiency. Functional analysis demonstrated the lack of intracellular production of IFN-γ in CD3+ T lymphocytes from the patient in response to rhIL-12p70.

Conclusions: To our knowledge, this is the third patient with MSMD due to IL-12Rβ1 deficiency complicated with enteropathy and hypogammaglobulinemia and the first case of this disease to be described in Colombia.

Keywords: IL-12Rβ1 deficiency; Mycobacteria; enteropathy; hypogammaglobulinemia.