Interleukin-12 and interferon gamma levels in infants with post BCG lymphadenitis

ABSTRACT

Bacille Calmette Guerin [BCG] is a live bacterial vaccine used in many countries to prevent tuberculosis [TB]. However, because the vaccine consists of live attenuated bacteria, there is still a risk that inoculation with this Mycobacterium bovis strain in immunodeficent infant will cause localized [BCGitis] or disseminated infection, referred to as 'BCG-osis'[1,2] This was prospective hospital based study aiming to determine the serum levels of interleukin-12 and interferon-y among infants with post BCG lymphadenitis. The study included 20 cases [mean +/- SD of age was 4.2 +/- 1.7 months] with newly diagnosed post BCG lymphadenitis group in addition to 20 apparently healthy infants age and sex matched [mean +/- SD of age was 3.9 +/- 1.9 months] as a control group. The study was conducted during the period from March 2008 to November 2010. Both patients and controls were recruited from Paediatric Outpatients Clinics and Paediatric Emergency Department in Assiut University Children Hospital, Egypt. Written informed consents were obtained from the parents of both patients and controls. All cases were subjected to a thorough history, full clinical examinations and investigations which include routine blood tests, immunological studies and serum levels of Interleukin -12 and interferon- gamma. In the post BCG lymphadenitis group, 85% of cases came from rural areas, 45% have positive consanguinity, while 20% of the same group have positive family history of post BCG lymphadenitis. Serum IL-12 and IFN-gamma levels were significantly deceased in cases of post BCG lymphadenitis compared with control group [P< 0.01]. Serum IL-12 and IFN-gamma levels were significantly and positively correlated with age in studied cases. In addition, IL-12 was positively and significantly correlated with IFN-gamma. Serum IL-12 and IFN-gamma levels should be assessed in infants with post BCG lymphadenitis to detect IL-12/ IFN-gamma axis abnormalities. BCG vaccination should be delayed in every newborn and infant with a family history of post BCG lymphadenitis until immunodeficiency diseases and IL-12/IFN-gamma axis abnormalities have been ruled out