Immunoepidemiology of Wuchereria bancrofti infection in two East African communities: antibodies to the microfilarial sheath and their role in regulating host microfilaraemia.
The response pattern of specific antibodies to the microfilarial sheath (sheath-Ab) of the mosquito-borne filarial parasite Wuchereria bancrofti was investigated in individuals from two East African communities with different levels of endemicity. Individuals from both communities presented a strong inverse relationship between positivity for sheath-Ab and being positive for microfilariae (mf) and circulating filarial antigens (CFA). The prevalence of sheath-Ab positivity was highest in young individuals, but peaked at a younger age in the high (1-14 years) than the low (15-19 years) endemicity community. IgG1, IgG2, IgG3 and IgE intensities to a crude adult filarial worm antigen were higher, and IgG4 intensities were lower, in sheath-Ab positive than in sheath-Ab negative individuals, probably reflecting the infection status of individuals. From the study it appears that individuals become sheath-Ab positive before mf and/or CFA can be detected in the peripheral blood, and only after later disappearance of sheath-Ab from the circulation can CFA and mf be diagnosed. In light of the findings, possible roles of the distinct sheath-Ab in the host-parasite relationship are discussed, and a hypothesis is proposed which suggests that sheath-Ab play an important role in the regulation of host microfilaraemia.
Simonsen
Paul E
PE
DBL - Centre for Health Research and Development, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 57, 1871 Frederiksberg C, Denmark. pesi@life.ku.dk
Meyrowitsch
Dan W
DW
Jaoko
Walter G
WG
Malecela
Mwele N
MN
Michael
Edwin
E
D000293:Adolescent; D000328:Adult; D000351:Africa, Eastern; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D000947:Antigens, Helminth / Q000097:blood* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D019353:Endemic Diseases; D005260:Female; D005368:Filariasis / Q000453:epidemiology* / Q000276:immunology*; D006790:Host-Parasite Interactions; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D008875:Middle Aged; D018512:Parasitemia / Q000276:immunology*; D016036:Seroepidemiologic Studies; D014958:Wuchereria bancrofti / Q000276:immunology*
D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007074:Immunoglobulin G; D007073:Immunoglobulin E