ACTIVATION OF ALTERNATIVE PATHWAY OF COMPLEMENT BY ENTAMOEBA-HISTOLYTICA

  • 1 January 1978
    • journal article
    • research article
    • Vol. 34  (1) , 10-18
Abstract
A cytopathogenic effect was observed when E. histolytica was exposed to human sera from individuals with no clinical history or laboratory evidence of amoebiasis. Absorption studies showed that the effect was not due to natural antibodies. Studies performed using EDTA, cobra venom factor (CoF) and heat-inactivation at 56.degree. C indicated that the cytopathogenic effect was complement [C] dependent. Using ethylene glycol tetracetic acid and Mg2+, zymosan, heat-inactivation at 50.degree. C to destroy the activity of factor B of the alternative pathway and electrophoretic studies with anti-human factor B showed that E. histolytica activated the properdin pathway. C determinations indicated that incubation of E. histolytica with normal human serum consumed C. The diminution in CH50 correlated with a consumption of C3 but not of C1, C4 and C2. E. histolytica trophozoites apparently activate the alternative pathway of the human C system.