Antimycobacterial prophylaxis regarding Bacillus Calmette-Guérin -associated complications in children with primary...

Bacillus Calmette-Guérin (BCG) vaccine derived from Mycobacterium bovis can cause BCG vaccine associated complications (BCG-VAC) especially in patients with primary immunodeficiencies (PID). No consensus exists for antimycobacterial prophylactic therapy for patients with PID who receive the BCG vaccine.

This study aimed to define the risk factors in the development of BCG-VAC and effect of antimycobacterial prophylaxis in PID patients vaccinated with BCG.

This is a retrospective cohort study. 104 patients diagnosed with PID who received the BCG vaccination were referred to pediatric pulmonology in a single center were enrolled. The demographic characteristics, type, dosage and duration of antimycobacterial prophylaxis regimen, treatment modalities for BCG-VAC were documented. Regression analysis was performed to evaluate the effect of covariates for predicting BCG-VAC in patients with PIDs.

Among 104 patients 21 (21.2%) developed BCG-VAC. The frequency of BCG-VAC was highest in patients with Mendelian susceptibility to mycobacterial disease (46.2%) followed by patients with severe combined immunodeficiency (22.4%) and those with chronic granulomatous disease (9.5%). Prophylactic therapy against mycobacterium was initiated for 72 patients (69.2%). Among patients who received the antimycobacterial prophylaxis, BCG-VAC developed in only four patients (5.6%), whereas 17 patients (53.1%) developed BCG-VAC in the non-prophylaxis group and this difference was statistically significant (p < 0.001). Multivariable regression analysis with age at diagnosis, type of PID, receiving antimycobacterial prophylaxis, median T cell number at the time of PID diagnosis and HSCT status showed that not receiving antimycobacterial prophylaxis and lower median T cell number were predictors, with antimycobacterial prophylaxis having the highest odds ratio for BCG-VAC prediction in patients with PIDs (p:<0.001, R²:0.64).

The lower frequency of BCG-VAC in our cohort can be explained by two main reasons; relatively late BCG vaccination schedule and receiving antimycobacterial prophylaxis. It is reasonable to begin antimycobacterial prophylaxis in patients with PIDs who are susceptible to BCG-VAC.