Genetic evaluation in the children with BCG or severe mycobacterial infection

Bacillus Calmette-Guérin (BCG) is an attenuated vaccine and is only vaccine approved in clinical to against Mycobacterium Tuberculosis (TB). BCG has used more than 40 years in world-wide with very good safety record. Large scale clinical studying had shown that BCG is efficient to prevent the severe TB infection in children; however, it has little or no effect to prevent the pulmonary TB infection in adult, which is the most common TB infection in human. Even low pathogenic ability, BCG infection was observed in young children; the prevalence was around 1 in 10 thousand newborns vaccinated. In Taiwan, there were at least 14 cased with BCG infection had been record from 2005 to 2008. Recent studying suggested the non-pathogenic BCG infection in children might reflect the immuno-compromised due to the inborn genetic defects. Even without BCG vaccination, those children might still suffer from other infection due to their genetic immunodeficiency. Current clinical diagnosis is not able to identify the possible genetic disorders. ”Vaccine Safety” is a very important society and health issue; the BCG infection due to the vaccine became a critical debate in public health. The aim of this studying is to identify the relation the host genetic factor and BCG infection. The severe combined immunodeficiency (SCID) was known to an etiology of BCG infection. Nevertheless, there are more than 10 mono-genetic disorders associated BCG or mycobacterial infections in otherwise health patients. We will collaborate with Taiwan CDC (Center of disease control), to identify the possible immunogenetic defect by the molecular diagnosis in the children with BCG infection or severe TB infection in Taiwan. This proposal will perform the genetic diagnosis in the patients with BCG or severe TB; the diagnosis will be very helpful for the clinical treatment and further care. In other hand, this systematic studying in BCG infection children will provide more evidence about the safe of BCG vaccine for the public health. Finally, in long term, we plan to use this cohort to identify the novel genetic disorder to explain the susceptibility to the mycobacterial infection and understand the human immune system against mycobacterial infection.

Project ID:PG10304-0122
External Project ID:CDC103-101