T CELL
SUBPOPULATIONS IN TUBERCULOSIS AND INFLUENCE OF ANTITUBERCULOSIS THERAPY
Kumar L, Ray M, Vohra H
Advanced
Pediatric Centre, P.G.I.M.E.R., Chandigarh, India
Objective: Tuberculosis (TB) is
associated with both qualitative and quantitative defects in cell mediated
immune responses. Limited information is available on the lymphocyte
subpopulations in different forms of TB in children. We studied the
differences in the lymphocyte subpopulations in pulmonary TB (PTB), central
nervous system TB (CNSTB), lymph nodal TB (LNTB) and disseminated TB (DTB)
both during active disease and in response to antituberculosis therapy
(ATT).
Methods: A prospective study on
50 children, age less than12 years (PTB = 20, CNSTB=10, LNTB=10, DTB=10)
and thirty age-matched controls was done. Lymphocyte subpopulations were
determined by flowcytometry on day 0 and 1,2,3,6 months of ATT and only
once in control subjects.
Results: On day 0, T cells were
significantly reduced when compared to controls in all forms of tuberculosis.
(p<0.05). The counts increased and normalized by 6 months of ATT, but
the rise was least in children with DTB. There was no significant
difference in the B cell profile in children with PTB, CNSTB and LNTB
compared to controls on day 0, whereas in DTB the numbers were
significantly high (p<0.05)
which normalized by 6months. CD4 cells were reduced in comparison to normal
children. (p<0.01) at day 0 which was maximum in children with DTB. On
ATT these normalized by 3 months although difference continued to exist
between DTB and other groups. (p<0.05) CD8 cells were increased at day 0
(p<0.05), maximum in DTB. These normalized by 6 months of ATT. The NK
cells were low on day 0 in children with TB and corrected by 3 months.
Levels of activated T cells remained unchanged during the period of study.
Conclusions: Significant CD4
lymphopenia and reduction of CD4: CD8 ratio was present in all forms of TB,
most in DTB. The abnormalities corrected by 3-6 month of ATT, the progress
being slow in DTB.