Evaluation of interleukin-12 receptor ß1 and interferon gamma receptor 1 deficiency in patients with disseminated BCG infection.

INTRODUCTION: Disseminated BCG infections among other complications of Bacillus Calmette-Guérin (BCG) vaccine are rare and have occurred in children with immunodeficiency disorders such as mendelian susceptibility to mycobacterial disease (MSMD) which could be due to defects in some elements of IL-12/IFN-γ axis. MSMD-causing mutations have been identified in 10 genes during the last two decades. Among them, mutations in the IL12Rß1 and IFNγR1 genes constitute about 80% of recorded cases of MSMD syndrome. The aim of this study was to investigate IL-12Rß1 and IFN-γR1 deficiencies in patients with disseminated BCG infection. METHODS: This study was performed on 31 children with disseminated BCG infections who referred to children's medical center. Whole blood cell culture was performed in presence of BCG, IL-12 and IFN-γ stimulators. The supernatants were assayed for IFN-γ and IL-12p70 by ELISA method. In order to evaluate IL12Rß1 and IFN-γR1 receptors expression, flow cytometry staining was performed on the patients' T-cells stimulated with PHA. RESULTS: Flow cytometry staining of 31 Iranian patients with disseminated BCG infections with the average age of 43 months showed lack of the expression of IL-12Rß1 and IFN-γR1 genes in PHA-T-cells of the nine and one patients, respectively in whom the incomplete production of IFN-γ and IL-12 was reported by ELISA. Among these 10 patients, eight cases had related parents (80%). CONCLUSION: It is recommended that to avoid BCG complications, screening be performed for MSMD before BCG inoculation in individuals with positive family history of primary immunodeficiency diseases and inhabitants of areas with high frequency of consanguinity.