Visceral leishmaniosis in HIV-positive patients: primary infection, reactivation and latent infection. Impact of the CD4+ T-lymphocyte counts.
OBJECTIVE
To discriminate cases of visceral leishmaniosis (VL) following a primary infection from cases originating in a reactivation of a latent Leishmania infection and to assess the impact of CD4+ T-cell counts on the occurrence of VL in patients with HIV disease.


METHODS
We searched by Western blotting for the presence of Leishmania infantum-specific antibodies in the sera of 236 HIV-positive patients. We performed a follow-up of antileishmanial serology and analysed the evolution of the CD4+ T-cell counts for 14 HIV-positive VL patients and for 18 HIV-positive Leishmania-seropositive patients without VL.


RESULTS
This study (1) showed that the VL disease/Leishmania infection ratio in HIV-positive individuals is high (1 : 10); (2) discriminated between a primary Leishmania infection (five patients who converted from Leishmania-seronegative to Leishmania-seropositive) and a reactivation of a latent infection (seven patients); (3) showed that HIV-positive individuals with dramatically low CD4+ T-cell counts maintained or generated a specific antileishmanial antibody production; (4) demonstrated that the primary-VL appeared at significantly higher (P = 0.028) CD4+ T-cell levels than the reactivation-VL; (5) documented the existence of HIV-positive Leishmania-seropositive individuals who despite a severe and prolonged immunosuppression did not develop VL (eight of 18).


CONCLUSIONS
Our data stress the utility of the follow-up by Western blotting for an early diagnosis of VL, and therefore an early treatment, for HIV-positive patients living in endemic areas. They suggest that in a latent Leishmania infection supplementary control mechanism(s) might operate in addition to the T-cell-mediated response, and provide a further example of non-appearance of an opportunistic infection despite a severe reduction in CD4+ T cells.
Kubar
J
J
Groupe de Recherche en Immunopathologie de la Leishmaniose, Laboratoire de Parasitologie, Faculté de Médecine de Nice, France. kubar@unice.fr
Marty
P
P
Lelièvre
A
A
Quaranta
J F
JF
Staccini
P
P
Caroli-Bosc
C
C
Le Fichoux
Y
Y
D017088:AIDS-Related Opportunistic Infections / Q000276:immunology* / Q000469:parasitology; D000208:Acute Disease; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000918:Antibody Specificity; D015153:Blotting, Western; D018791:CD4 Lymphocyte Count; D005260:Female; D005500:Follow-Up Studies; D015658:HIV Infections / Q000276:immunology* / Q000469:parasitology; D006801:Humans; D016867:Immunocompromised Host; D018314:Leishmania infantum / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000276:immunology*; D008297:Male; D008875:Middle Aged
D000913:Antibodies, Protozoan