title: Evidence for protective immunity to bancroftian filariasis in the Cook Islands.
abstract: To challenge the concept of protective immunity in lymphatic filariasis, 19 adult residents of a Wuchereria bancrofti-endemic island who had been diagnosed 17 years earlier as putatively immune endemic normals (PI/EN) were reexamined. Even with continued exposure to infection, all 19 had maintained their apparent infection-free status. Studies to define the mechanisms underlying this putative immunity revealed that cellular immune responses (including proliferation; generation of interleukin [IL]-2, IL-5, IL-10, interferon-gamma, and granulocyte-macrophage colony-stimulating factor) to adult- and microfilarial-stage antigens, but not antibody responses, were markedly greater than those of 20 age-matched, infected patients. Furthermore, the PI/EN group was comprised of high- and low-responding persons who were clinically indistinguishable. These findings provide evidence that protective immunity to lymphatic filariasis does occur and that it is probably T cell-mediated.
authors.affiliation: Laboratory of Parasitic Diseases, National Institutes of Health, Bethesda, Maryland 20892-0425, USA.
authors.forename: C
authors.initials: C
authors.lastname: Steel
authors.forename: A
authors.initials: A
authors.lastname: Guinea
authors.forename: E A
authors.initials: EA
authors.lastname: Ottesen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000909:Antibodies, Helminth / Q000032:analysis; D000947:Antigens, Helminth / Q000276:immunology; D017178:Brugia malayi / Q000737:chemistry; D002648:Child; D004605:Elephantiasis, Filarial / Q000175:diagnosis / Q000453:epidemiology / Q000276:immunology*; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis; D006801:Humans; D007111:Immunity, Cellular; D007073:Immunoglobulin E / Q000032:analysis / Q000097:blood; D007074:Immunoglobulin G / Q000032:analysis / Q000097:blood; D007371:Interferon-gamma / Q000032:analysis; D016753:Interleukin-10 / Q000032:analysis; D007376:Interleukin-2 / Q000032:analysis; D015848:Interleukin-5 / Q000032:analysis; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D011114:Polynesia; D013997:Time Factors; D014958:Wuchereria bancrofti / Q000276:immunology*
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D007074:Immunoglobulin G; D007376:Interleukin-2; D015848:Interleukin-5; D016753:Interleukin-10; D007073:Immunoglobulin E; D007371:Interferon-gamma; D016178:Granulocyte-Macrophage Colony-Stimulating Factor