[Participation of platelets in the process of fibrosis in patients with mansonic schistosomiasis].

The aim of this study was to evaluate platelet activation through P-selectin, and PDGF-AB and TGF beta 1 content, in schistosomiasis patients who developed fibrosis (F3) and who did not present this (F0), and in a control group (C). The results showed that the percentage of P-selectin in platelets without agonist stimulation was 10.6% in F3, 11.1% in F0 and 6.3% in C. After the addition of ADP/adrenaline, the percentages were 44%, 25.3% and 42%, respectively. The PDGF-AB and TGF beta 1 contents per platelet were 11,016 ng/dl (F3), 3,172 ng/dl (F0) and 5.01 ng/dl (C) and 0,012 ng/dl (F3), 5.27 ng/dl (F0) and 4.66 ng/dl (C), respectively. Concerning the P-selectin, we can conclude that platelets from patients with schistosomiasis continued to be responsive to agonists, despite being pre-activated. There were no differences in TGF beta 1 between the groups, but the PDGF-AB content was significantly higher in F3. This suggests that PDGF-AB may have some participation in the development of fibrosis.