Fifty-three children with tuberculous meningitis (TBM) were studied in parallel with 37 children with
primary pulmonary complex (PPC), 32 tuberculin skin positive controls, and 38 skin negative controls for
immunological evaluation. Proportions of peripheral blood total T and T helper lymphocytes (TH) were
significantly reduced in TBM (TSS, TH32) as compared to PPC (T70, TH40) and Controls (T74, TH43),
but response to mitogens phytohaemagglutinin (PHA) and poke weed mitogen (Pwm) were comparable in
all the groups. Response of peripheral blood lymphocytes to tubercular protein (PPD) was significantly
greater in the tuberculin skin positive group, but comparable between the TBM and PPC groups. There
was no significant difference in the proportion of B lymphocytes, antibody levels to PPD and monocyte
capacity to release hydrogen peroxide in the four groups. These findings suggest that there is no definite
immunological spectrum in childhood tuberculosis