Dichotomy of protective cellular immune responses to human visceral leishmaniasis. Clin Exp Immunol
| dc.Faculty | Endemic Diseases | en_US |
| dc.contributor.author | Khalil, Eltahir Awad G. | |
| dc.contributor.author | Ibrahim, Muntaser E. | |
| dc.contributor.author | Elhassan, Ibrahim M. | |
| dc.contributor.editor | . | en_US |
| dc.date | 2005 | |
| dc.date.accessioned | 2015-11-12T10:04:23Z | |
| dc.date.available | 2015-11-12T10:04:23Z | |
| dc.date.issued | 2015-11-12 | |
| dc.date.submitted | 2015 | |
| dc.description | 6 Pages | |
| dc.description.abstract | Healing/protective responses in human visceral leishmaniasis (VL) are associated with stimulation/production of Th1 cytokines, such as interferon IFN-g , and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non-endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non-reactivity following injection with one of four doses of Alum-precipitated autoclaved Leishmania major (Alum/ALM) ± bacille Calmette–Guérin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side-effects and without an increase in antileishmanial antibodies or interleukin (IL)-5. Five volunteers (5/44; 11·4%) had significant IFN-g production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples ( P = 0·001) but were LST non-reactive. On day 45, more than half the volunteers (26/44; 59·0%) had significantly high LST indurations (mean 9·2 ± 2·7 mm) and high IFN-g levels (mean 1008 ± 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen-induced IFN-g production (mean 873 ± 290; median 902; P = 0·001), but were non-reactive in LST. An additional five volunteers (5/44; 11·4%) had low IFN-g levels (mean 110 ± 124 pg/ml; median 80) and were non-reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN-g levels, but significant LST induration (mean 10 ± 2·9 mm; median 11). By day 90 the majority of volunteers (27/44; 61·4%) had significant LST induration (mean 10·8 ± 9·9 mm; P < 0·001), but low levels of L. donovani antigeninduced IFN-g (mean 66·0 ± 62 pg/ml; P > 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN-g and LST induration, while five volunteers had low levels of IFN-g (< 100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow-up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN-g production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN-g response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy. | en_US |
| dc.identifier.uri | http://khartoumspace.uofk.edu/123456789/17022 | |
| dc.publisher | university of khartoum | en_US |
| dc.subject | dichotomy, human visceral leishmaniasis, immune responses | en_US |
| dc.title | Dichotomy of protective cellular immune responses to human visceral leishmaniasis. Clin Exp Immunol | en_US |
| dc.type | Publication | en_US |