Parasitology


Research Article

The influence of sex and age on antibody isotype responses to Schistosoma mansoni and Schistosoma japonicum in human populations in Kenya and the Philippines


M. WEBSTER a1 , B. D. L. LIBRANDA-RAMIREZ a2 , G. D. ALIGUI a3 , R. M. OLVEDA a2 , J. H. OUMA a4 , H. C. KARIUKI a4 , G. KIMANI a5 , G. R. OLDS a6 , A. J. C. FULFORD a1 , A. E. BUTTERWORTH a1 and D. W. DUNNE a1
a1 Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP
a2 Research Institute for Tropical Medicine, Alabang, Muntinlupa, Metro Manila 1770, Philippines
a3 International Health Institute, Brown University, Providence, Rhode Island 02912, USA
a4 Division of Vector Borne Disease, P.O. Box 20750, Nairobi, Kenya
a5 Kenya Medical Research Institute, P.O. Box 54840, Nairobi, Kenya
a6 MetroGeneral Health Medical Centre, 2500 MetroHealth Drive, Cleveland, 44109–1998, USA

Abstract

We have investigated the effects of host age and sex on human antibody isotype responses to Schistosoma mansoni and Schistosoma japonicum adult worm (AW) and soluble egg (SEA) antigens, using sera from subjects in Kenya and the Philippines. Similar trends with age were observed between the two populations despite host, parasite and environmental differences between the two geographical locations. IgE to AW increased with age, whereas most isotype responses to SEA decreased with age. IgG1, IgG3 and IgG4 subclass responses to adult worm, however, did not show a broadly rising or falling pattern with age. Males were found to have higher IgG1, IgG4 and IgE to AW in both populations. This sex difference remained significant in the Kenyan population even after controlling statistically for confounding factors such as age and differences in intensity of infection. Analysis of S. mansoni and S. japonicum adult worm antigens reactive with IgE revealed a predominant 22 kDa band in both parasites. Only those individuals with relatively high IgE titres specifically reactive with S. mansoni or S. japonicum AW had detectable IgE against Sj22 or Sm22.

(Received June 24 1996)
(Accepted October 2 1996)

Key Words: human antibody isotypes; IgE; Schistosoma mansoni; Schistosoma japonicum.

Correspondence:

Corresponding author: Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP. Tel: +01223 333338. Fax: +01223 333741. E-mail: MW145@mole.bio.cam.ac.uk



Metrics