Bq. Goka et al., Complement binding to erythrocytes is associated with macrophage activation and reduced haemoglobin in Plasmodium falciparum malaria, T RS TROP M, 95(5), 2001, pp. 545-549
Citations number
34
Categorie Soggetti
Envirnomentale Medicine & Public Health","Medical Research General Topics
Journal title
TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICAL MEDICINE AND HYGIENE
We have examined IgG and complement factor C3d deposition on erythrocytes b
y means of the direct Coombs' test (DAT) and looked for an association with
the anaemia seen in falciparum malaria in children living in an area of hy
perendemic malaria transmission (in Ghana). In one study (in 1997), 53 out
of 199 patients had a positive DAT. Of these, 45 samples reacted with anti-
C3d antibodies, 2 with anti-IgG and 6 with both reagents. There were signif
icantly lower haemoglobin (Hb)-levels and higher prevalence of spleen enlar
gement in DAT-positive than in DAT-negative patients. Hb-levels were indepe
ndently associated with DAT and age. This initial study was designed to inv
estigate the role of intravascular haemolysis (IVH), but we found no associ
ation between IVH and either DAT result or anaemia. Because of the risk of
selection bias we repeated the study using consecutive enrolment of malaria
patients and were able to confirm the results in a total of 49 DAT-positiv
e and 183 DAT-negative patients. This second study (in 1998) was designed t
o look at the importance of erythrophagocytosis through measurement of plas
ma neopterin levels and total nitrite and nitrate as markers of NO-release.
Both parameters were significantly higher in DAT-positive than in DAT-nega
tive patients (P < 0.001), indicating that complement binding to erythrocyt
es was associated with macrophage activation. Plasma levels of haptoglobin,
interleukin-10 and tumour necrosis factor-alpha did not vary between the g
roups. The studies support the role of complement activation and erythropha
gocytosis in the pathogenesis of anaemia in falciparum malaria in African c
hildren.