Gamma interferon production by lymphocytes from children infected with L. chagasi
Bacellar, O.; Barral-Netto, M.; Badaró, R.; Carvalho, E.M.
Brazilian Journal of Medical and Biological Research 24(8): 791-795
1991
ISSN/ISBN: 0100-879X PMID: 1797267 Document Number: 372842
The present study was performed to evaluate the ability of lymphocytes from 18 children living in Jacobina, Bahia, Brazil, an endemic area of visceral leishmaniasis (VL), to produce gamma-interferon. These children had no previous history of VL and were considered to be infected with Leishmania chagasi [L. infantum chagasi] based on leishmanial seroconversion. The gamma IFN levels were determined by radioimmunoassay on supernatants of lymphocyte cultures (3 x 106/ml) stimulated with PHA (final dilution 1:10) and L. chagasi antigen (10 micro g/ml). The gamma-IFN production by lymphocytes from seroconverting children stimulated with PHA (178 +or- 151 U/ml) and L. chagasi (47 +or- 77 U/ml) was significantly higher than that observed in visceral leishmaniasis. For clinical follow-up, these 18 seroconverting children were divided into 3 groups: asymptomatic infection (N = 4); self-healing subclinical illness (N = 9), and subclinical infection progressing to VL (N = 5). Gamma IFN levels in children with either asymptomatic or subclinical infection (65 +or- 85 U/ml) were significantly higher than those observed in children progressing to VL (9 +or- 6 U/ml). The data demonstrate that there is an association between gamma-IFN levels and the clinical course of Leishmania infection.