Polymorphonuclear leucocyte elastase in plasmodium falciparum malaria

Abstract

Sixty-one patients with falciparum malaria were studied prospectively to determine the plasma concentrations of the lysosomal proteinase, polymorphonuclear leucocyte elastase (PMN-elastase) and their relationship to disease severity. The patients were divided into 3 groups; severe (parasitaemia >5%) or vital organ dysfunction (n=23), moderate (parasitaemia l%-5% without complications) (n= 15), and mild (parasitaemia <l%)(n=23). The mean plasma PMN-elastase level in 10 healthy Thai volunteers was 49�5 (SD=21�6) ng/ml (range 33-65 ng/ml). Plasma PMN-elastase concentrations on admission were elevated (>2�SD above normal) in all patients with severe malaria and were above 100 ng/ml in 86-6% and 65% of the moderately severe and mild patients respectively. PMN-elastase levels during the first 3 hospital days were significantly higher in severe malaria compared with the other 2 groups (P=<0�001-0 013). The levels decreased as the patients became afebrile and aparasitaemic. Admission plasma concentrations of PMN-elastase correlated directly with bilirubin (rs=0�50, P<0�001), serum glutamic oxalacetic transaminase (rs=0�54, P0�001), parasite count (rs=0�62, P<0�001), blood urea nitrogen (rs=0�54, P<0�001) and inversely with antithrombin III activity (rs=0�54, PcO-OOl) and the platelet count (rs=0�58, P<0�001). Polymorphonuclear leucocyte activation may contribute to the pathogenesis of severe malaria. � 1992, SPIE. © 1992, Oxford University Press. All rights reserved.