| Abstract: | The levels of Factor B (B), properdin (P)
and the third complement component (C3) in
serial serum samples obtained from 36 hospitali-
zed patients with epidemic hemorrhagic fever
(EHF) were measured by single radial immuno-
diffusion. These proteins of the alterna.tive
activating pathway of C were activated and their
circulating levels reduced. Good correlations
were observed between the B, P a.nd C3 levels
in patient sera The alternative C pathway was
activated in these patients. The num.ber of the
positive cases and positive sera was increa.sed
with severity of illness, strongly suggesting the
correlation of activatio,n of this pathway with the
disease condition. In addition, activat.ion of the
classical C pathway in the same patients was
again observed through determination of activa-
tion of the first complement component (CI) by
assessing the ratio of the subunit Clr to subunit
Cls (the Clr:Cls ratio) according to a method
previously described. Some discrepancies were
found in activation between the 2 pathways.
A variety of biologically act.ive peptides
produced during enormous activation of the C
system via the alternative and classical pathwaysmay co-ntribute to a number of serious conse-
quences in EHF, including increased vascular
permeability9 hypotension, shock, hemorrhage
and renal damage. |
