Post-kala-azar dermal leishmaniasis (PKDL), HIV and pulmonary tuberculosis.

Post-kala-azar dermal leishmaniasis is usually a sequel to visceral leishmaniasis. A 25-year-old woman presented with hypopigmented maculopapular lesions all over the body for the past 4 years without any previous history of visceral leishmaniasis. She was on treatment for leprosy and pulmonary tuberculosis for the past 2 months, but did not show any improvement. Investigations confirmed that she had post-kala-azar dermal leishmaniasis associated with pulmonary tuberculosis and HIV-1 infection. She was started on treatment for the triad of diseases, and showed improvement.

Visceral leishmaniasis and tuberculosis in patients with HIV co-infection.

We describe here two cases, one male and one female, both age 40 years, with visceral leishmaniasis and HIV-1 co-infection. The female patient had features of Koch's abdomen. The male patient had features of tuberculous lymphadenitis and bilateral pleural effusion more marked on the right side. Both were treated with highly active antiretroviral therapy, antituberculous drugs, antibiotics, antifungal medicine (fluconazole) and miltefosine. Both patients showed marked improvement with therapy.

Effect of immunization with lipid associated polysaccharide antigen and anti CD-2 antibodies on class II MHC expression and cellular immune response in BALB/C mice infected with Leishmania donovani.

In a bid to characterize the antigens and immunization mechanisms which may be used to produce a protective response against L. donovani, role of lipid associated polysaccharide (LPS) antigen and whole antigen was evaluated. BALB/C mice were immunized with whole or LPS antigen in combination with one of three putative adjuvents (anti CD-2 antibody/FIA/0.85% Saline). LPS antigen emulsified in anti CD-2 antibody was found to induce significant antibodies in mice on day 28 against challenge with lethal dose of L. donovani. Immunoprophylactic properties of LPS and whole antigen was investigated on day 40 through cytokine elicitation (IL-2), MIF) in culture supernatants of spleen cells, but before that MHC-II expressed on macrophage was studied. The LPS antigen in combination with anti CD-2 antibody was found to be most immuno-reactive inducing higher MHC-II expression on macrophages which was associated with substantial rise in the level of MIF and IL-2. It coincided with decline in antibody titre in 100% mice immunized with LPS antigen while Leishmania injected as whole antigen failed to induce specific macrophage and T-cell response with all the above formulations. We surmise from our data that lipid associated polysaccharide antigen linked to anti CD-2 antibody has potential for eliciting protective immunity against Leishmania.

Relevance of direct agglutination test in seroepidemiological survey of Kala-azar in epidemic foci of Bihar.

The performance of direct agglutination test (DAT) was evaluated under field conditions in three endemic districts of Bihar. In three villages of these districts, 197 households were surveyed with a population of 1167 individuals. Out of 1167 individuals, 603 were clinically examined for VL and blood samples of each examined individual were collected for DAT. The proportion of DAT positivity in both males (32.33%) and females (32.94%) was statistically not significant (p > 0.05). The proportion of DAT positivity in all age groups was observed to be similar (p > 0.05). The GMRT was observed highest in active VL cases. Out of 20 DAT positive individuals having fever, 5 were examined parasitologically (bone marrow aspiration) and in three cases positivity was observed. This showed the relevance of DAT in early diagnosis of visceral leishmaniasis and usefulness of DAT in field conditions.

Reversal of T-cell unresponsiveness through serine-esterase inhibitors mediated enhanced lymphokine induced microbicidal activities in kala-azar.

After presenting processed glycoprotein of Leishmania donovani to T-cell, macrophage seeks the help of a panel of T-cells lymphokines to transform from a state that sustains intra cellular replication of parasite to an effector state for destructing parasites. But esterase and trypsin of macrophage membrane prevent T-cells to release MIF. Role of soya-bean trypsin inhibitor (STI) has been exposed in the present study with a view to alter esterase functional behaviour of macrophage for control of T-cell activation and also, if T-cells once made responsive to antigen by STI do alter macrophage response to T-cells or not. Results establish STI as potent effector molecule, which can serve as an adjuvant to candidate T-cell epitope and synthetic peptide for development of anti-Kala-azar vaccine protocol in future.

Role of HLA-DR antigen on T-cell activation in visceral leishmaniasis.

Ability of peripheral blood monocytes in association with HLA-DR molecules to support T-cell activation in response to soluble Leishmania donovani antigen was investigated. Adherent cells were stained with monoclonal antibodies. The increased number of cells with DR expression was more efficient in presenting L. donovani antigen to sensitized T-cells. The results suggest that quantitative variation in monocytes with expression of DR molecules, correlates with their ability to support T-cell response to L. donovani antigen, in vitro, as assessed by migration inhibition factor (MIF). However, it is not clear whether this is due to only HLA-DR antigen on the surface or whether other factors are involved.