THE INFLAMMATORY CYTOKINES IN MEASLES - CORRELATION BETWEEN SERUM INTERFERON-GAMMA LEVELS AND LYMPHOCYTE SUBPOPULATIONS

Interleukin-1 (IL-1-beta), tumour necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) were measured in serum from children with measles using an immunoradiometric assay. The IFN-gamma level was increased in 52 out of 54 patients in the acute phase of measles (< 7 days of illness), and then declined to an undetectable level in the convalescent phase. Neither IL-1 nor TNF could be detected during the course of the illness. The mean serum IFN-gamma level was at its peak on day 4 and could be detected over a 7-day period after the onset of fever, coinciding with the febrile period (6.9 +/- 1.5 days). In the acute phase. the phytohaemagglutinin responses. absolute number of platelets, total lymphocyte counts. CD3+, CD4+, CD8+ cell counts and the CD4/8 ratio were depressed, while stab cell number and lactate dehydrogenase levels were higher than those in the convalescent phase. Using Spearman rank sum test, the IFN-gamma level was correlated negatively with the peripheral lymphocyte (P < 0.05), CD3+ (P < 0.05), CD4+ (P < 0.05) cell counts and the CD4/8 ratio (P < 0.05) and correlated positively with the stab cell count (P < 0.01) but not with any other parameter. When the acute phase findings were compared between 28 complicated and 40 uncomplicated patients, the former were younger (P < 0.01) and had higher maximum body temperature during the illness (P < 0.05) than the latter, there was no difference in their IFN-gamma levels. These results show that endogenous IFN-gamma appears in the circulation during the acute febrile phase of measles, but does not contribute directly to any complication of the disease.