Eight years of follow-up experience in children with mendelian susceptibility to mycobacterial disease and review of the literature

Background: Mendelian susceptibility to mycobacterial disease (MSMD) is a rare primary immunodeficiency, caused by non-tuberculous mycobacteria or Bacillus Calmette-Guerin (BCG) vaccine and characterized by severe diseases in childhood. Objective: In this study, we examined eight years followed-up 12 Turkish children with genetically proven MSMD and we tried to evaluate the survival rate with succesfull disease management, rate of consanguinity, molecular, cellular and clinical features of patients. In addition, we wanted to emphasize the importance of early diagnosis before administration of BCG vaccine in countries where this vaccine is routinely used. Methods: Twelve patients diagnosed with molecular studies [IFNγR1 complete (n = 1), IFNγR2 partial (n = 3), IL12Rβ1 (n = 6), NEMO (n = 1), STAT1 mutation (n = 1)] were included. Results: Ten patients (83%) were born from consanguineous parents and frequency of family history for the primary immunodeficiency was 58% (n = 7). All the cases had been immunized with BCG vaccine (Mycobacterium bovis) due to lack of early diagnosis. Two patients had BCG-itis and four patients had “BCG-osis”. Survival rate was 75% after successful disease management with antibiotics, anti-tuberculous agents and recombinant IFN-γ. Conclusion: It was concluded that MSMD must be differentiated from different forms of primary immunodeficiencies, so clinicians should be aware of MSMD especially in patients with BCG vaccine complications and non-tuberculous mycobacterial infection. © 2023, Allergy and Immunology Society of Thailand. All rights reserved. ; Jeffrey Modell Foundation, JMF