Reduction in CD1 positive epidermal Langerhans cell numbers in leprosy lesions following epicutaneous application of 2:4 dinitrochlorobenzene.

A study was made on Langerhans cells (LC) in the dermal lesions of leprosy after epicutaneous application of 2:4 dinitrochlorobenzene (DNCB) to the lesion. LC were quantitated with OKT6 monoclonal antibody and indirect immunofluorescence. A depletion or reduction in the numbers of CD1+ epidermal LC was observed at both 4 and 24 hours after the application of DNCB in the lesions of both tuberculoid and lepromatous leprosy, compared to untreated lesions.

Group specific component (Gc) in erythema nodosum leprosum (ENL).

The distribution of phenotypes of group specific component (Gc) was examined in 71 lepromatous leprosy (LL) patients without any history of ENL reaction and 65 LL patients with history of frequent episodes of ENL reaction. The distribution of none of the phenotypes of Gc (Gc 1-1, Gc 2-1, Gc 2-2) was statistically significant among these groups.

Analysis of circulating immune complexes from leprosy patients for Mycobacterium leprae antigens.

Circulating immune complexes (CICs) from 31 leprosy patients (16 tuberculoid, 15 lepromatous) and 12 healthy volunteers, precipitated by 3.5% polyethylene glycol, were individually subjected to SDS-PAGE and immunoblotting using a variety of monoclonal and polyclonal antibodies against Mycobacterium leprae. A common mycobacterial antigen of an apparent molecular size of 65 kDa was identified in CICs from about 40% of the patients.

Correlation between inhibitory effect of quinolones and mycolic acid metabolism in mycobacteria.

Mycolic acids are important components having a significant role in maintaining the rigidity of mycobacterial cell wall. They could also be the barrier for penetration of certain drugs into the bacterial cell. A novel in vitro model system was established for assessing the effect of Ciproflaxacin on mycolic acid metabolism in pathogenic mycobacteria M.

Treatment of paucibacillary leprosy with a regimen containing rifampicin, dapsone and prothionamide.

Ninety paucibacillary leprosy patients having indeterminate (I), tuberculoid (TT) and borderline tuberculoid (BT) type of leprosy with bacterial index (BI) of less than two on the Ridley scale were treated with rifampicin (RFM) 600 mg once a month, dapsone (DDS) 100 mg daily and prothionamide (PTH) 250 mg daily. Treatment was stopped at the end of six months. The patients tolerated the drugs fairly well and in only two patients the drugs had to be stopped (in one due to jaundice and in the other due to gastric intolerance).

A preliminary study of correlation of immuno-histological and ultrastructural characteristics of neural granuloma in leprosy patients.

With an aim to better understand the pathogenesis of nerve damage in leprosy, peripheral nerve biopsies from six untreated leprosy cases (3 BT/TT and 3 BL/LL) were studied by electronmicroscopy and immuno-histology. In addition to routine histopathology for diagnosis, infiltrating cells of granuloma were characterized after preparation of single cell suspension. The lymphocytes in the lesion were characterized by E and EAC rosetting and macrophage phagocytic system (MPS) cells were studied using histochemical markers like esterase and peroxidase.

Histological changes with combined chemotherapy and immunotherapy in highly bacillated lepromatous leprosy.

Highly bacillated untreated lepromatous cases with an initial BI 4+ of to 6+ were treated with combined multidrug treatment (MDT) and immunotherapy with heat killed Mycobacterium w or BCG. The vaccines were administered intradermally every six months. It was observed that majority of cases on immunotherapy showed increased lymphocytic infiltration (both at local and distant sites) and some cases showed epithelioid cells as well.

Clinical and bacteriological progress of highly bacillated BL-LL patients discontinuing treatment after different periods of MDT.

Highly bacillated lepromatous patients (BL/LL) with an initial bacterial index (BI) of 4 to 6+ are being treated with a modified World Health Organization-recommended multiple-drug therapy (WHO/MDT) regimen consisting of rifampin 600 mg once a month, clofazimine 100 mg on alternate days, and dapsone 100 mg daily. The clinical and bacteriological profiles of the patients who had discontinued treatment at different durations have been compared with patients who took the same treatment until attainment of smear negativity. All six of the patients who had discontinued treatment at 12-18 months had worsened clinically and bacteriologically, and viable bacilli could be demonstrated in those tested for ATP.

On the value of sequential serology with a Mycobacterium leprae-specific antibody competition ELISA in monitoring leprosy chemotherapy.

The Mycobacterium leprae-specific antibody assays--a serum antibody competition test (SACT-ELISA) for the epitope on the 35-kDa protein, and an enzyme immunoassay for the disaccharide epitope of phenolic glycolipid-I (PGDS-ELISA)--were evaluated as tools for the serological monitoring of chemotherapy in 20 lepromatous and 6 tuberculoid leprosy patients. In addition to estimates for M. leprae-specific antibodies, assessments of the bacterial index (BI) and clinical activity of the disease were also carried out prospectively in these patients on two to four occasions over a period of 19 months.

Rapid characterization of Mycobacterium fortuitum-chelonei complex by restriction fragment length polymorphism of ribosomal RNA genes.

Using labelled, gamma-32P rRNA of mycobacteria as a probe restriction fragment length polymorphism (RFLP) of rRNA genes of strains belonging to the Mycobacterium fortuitum-chelonei complex was analysed. Each DNA sample was cleaved with EcoRI restriction endonuclease, the fragments were separated by agarose gel electrophoresis and transferred to nitrocellulose membrane. Fragments of DNA containing rRNA genes were identified by hybridization with gamma-32P-labelled rRNA.

In situ demonstration of Mycobacterium leprae antigens in leprosy lesions using monoclonal antibodies.

Cryostat sections of skin and nerve lesions of leprosy were stained with monoclonal antibodies recognising Mycobacterium leprae antigens and indirect immunofluorescence. In both the tuberculoid and lepromatous lesions, PGL1, 55-65-kDa, 17-kDa protein antigens and cross-reactive non-protein antigens were present. 65-kDa antigens were seen mainly in the skin lesions of lepromatous leprosy.

Immunohistological analysis of nerve granulomas in neuritic leprosy.

Immunohistological analysis of infiltrates of nerves in patients with neuritic leprosy was carried out using monoclonal antibodies defining T cell subsets, Langerhans cells, HLA DR antigens, and indirect immunofluorescence. In all, eight nerves were analyzed. 2 of the 8 nerves showed epithelioid cell granulomas surrounded by large numbers of lymphocytes.

CD1-positive epidermal Langerhans cells in regressed tuberculoid and lepromatous leprosy lesions.

A comparison was made of the numbers of epidermal Langerhans cells in active and regressed lesions of tuberculoid and lepromatous leprosy using the OKT6 and OKIa monoclonal antibodies. A reduction in the numbers of CD1+ epidermal Langerhans cells was noticed in the regressed lesions of both the tuberculoid and lepromatous leprosy lesions unlike the active lesions. The majority of infiltrates in both types of regressed lesions were HLA-DR+ and CD1-.

Detection of subclinical infection in leprosy: an 8 years follow-up study.

A follow-up study has been carried out using Fluorescent Leprosy Antibody Absorption (FLA-ABS) test in 1069 healthy contacts of multi and pauci-bacillary leprosy patients. Simultaneously lepromin testing with Dharmendra antigen has also been done to determine their delayed type hypersensitivity. In nearly 8 years of follow-up, 46 contacts have developed disease and of these 41 contacts were FLA-ABS positive and lepromin negative.

Effect of chemotherapy on viability of Mycobacterium leprae as determined by ATP content, morphological index and FDA-EB fluorescent staining.

Viable bacterial populations were estimated in bacilli purified from 105 biopsies from 40 untreated and 65 multibacillary leprosy patients treated with multidrug therapy (MDT) for varying periods. The bacilli were purified and viability was determined by ATP content, morphological index (MI), and fluorescein diacetate-ethidium bromide (FDA-EB) staining. Viable populations were calculated, taking 3.

Application of ATP assay for in vitro drug screening testing against human derived M. leprae.

In this study, the ATP content of M. leprae exposed to various antimicrobial agents has been measured to evaluate its usefulness in drug sensitivity screening. Purified M.

Relapses in paucibacillary patients after treatment with three short-term regimens containing rifampin.

Three multidrug regimens all containing rifampin and dapsone have been tried for the treatment of 278 cases of paucibacillary leprosy. Regimen I was the one recommended by the WHO Study Group. Regimen II was the same as Regimen I with depsone alone continued for a further 6 months.

Results of a modified WHO regimen in highly bacilliferous BL/LL patients.

A regimen consisting of 600 mg of rifampin once a month, 100 mg of clofazimine on alternate days, and 100 mg of dapsone daily was used in 56 untreated, highly bacillated borderline lepromatous/lepromatous (BL/LL) patients with an average bacterial index (BI) of 4.45. Treatment was continued until skin-smear negativity.

Appraisal of two Mycobacterium leprae-specific serological assays for monitoring chemotherapy in lepromatous (LL/BL) leprosy patients.

Two of the Mycobacterium leprae-specific assays--a serum antibody competition (for an epitope on 35-kDa protein) test (SACT) and an enzyme-linked immunosorbent assay (ELISA) for the disaccharide epitope of phenolic glycolipid-I (PGDS)--were comparatively evaluated as tools for monitoring chemotherapy in 125 lepromatous leprosy (LL/BL) patients. An adaptation of the SACT from a radioimmunoassay (RIA) to an ELISA procedure is also described. A moderate but statistically significant correlation was observed between the assays, although SACT appeared to be the more sensitive of the two.

In vitro studies on dermal leprosy granulomas: assessment of division and protein synthesis of cells.

Single cell suspension from dermal leprosy granulomas (10 tuberculoid and 10 lepromatous) was prepared and an assessment of the division and protein synthesis by the cells was made. The cells of tuberculoid granulomas showed a high incorporation of 3H-thymidine and 14C-leucine. On the contrary, the cells of the lepromatous granulomas exhibited poor division but their protein synthesis remained unimpaired.