Histological and immunological correlates of suspected leprosy lesions.

Thirty-two subjects with suspected leprosy lesions were investigated to assess various modalities of sensibility and sweat function and these were correlated with immunological and histological parameters. It was found that pain and temperature, mediated by small unmyelinated fibres were impaired in the early lesions. Impairment of sweat function was seen only when one of the modalities of sensibility was also affected. Antibodies specific to a protein (35 kDa) antigen and phenolic glycolipid 1 of Mycobacterium leprae were positive in nine and 12 cases respectively, while 15 of the 31 biopsies revealed the presence of mycobacterial antigens in these lesions. The implications of these findings are discussed.

Post-vaccination sensitization with ICRC vaccine.

ICRC vaccine is one of the candidate anti-leprosy vaccines under test in a large scale comparative vaccine in trial. The objectives of the present study was to study the sensitization potential, as measured by Rees' MLSA and lepromin, and reactogenicity of this vaccine preparation in the local population. The study included 368 'healthy' individuals aged 1-70 years. Each individual received either ICRC vaccine or normal saline (control) by random allocation. They were also tested with Rees' MLSA and lepromin-A, 12 weeks after vaccination. Reactions to Rees' MLSA were measured after 48 hours and those to lepromin-A after 48 hours and three weeks. Character and size of local response, at the vaccination site, were recorded at 3rd, 8th and 15th week after vaccination. The results of the study showed that healing of vaccination lesion was uneventful, the mean size of the lesion being 10.3 mm. The mean sizes of post-vaccination reactions, to Rees' MLSA and lepromin (both early and late reactions), were significantly higher in the vaccine group compared to that in the normal saline group; the sensitizing effect attributable to the vaccine was of the order of 3.5 mm, 1.7 mm and 2.2 mm respectively. In conclusion, the study has demonstrated that ICRC vaccine was 'safe' and produced significant sensitizing effect as measured by post-vaccination sensitization to Rees' MLSA and lepromin, in the local population.

Nine-banded armadillo (Dasypus novemcinctus) as an animal model for leprosy.

Dr. Dharmendra was one of the most distinguished leprologists of our time. He loved India so much that he offered his entire life to fight leprosy, a major health problem in India. He realized the great need in this much neglected field of medicine and willingly gave his utmost, whatever be the cost. He served in the field of leprosy with great distinction and he earned the respect of his fellow workers from all over the world. He made outstanding contributions to the study of leprosy, the identification and isolation of the active principle in the lepromin reagent, the use of lepromin test for identifying persons susceptible to leprosy, the use of an antileprosy drug as a means of chemoprophylaxis, the nurturing of the Indian Journal of Leprosy and developing it as one of the foremost leprosy journals, are a few of his major contributions. He received many well deserved national and international honours and awards. I first met Dr. Dharmendra in 1956 and feel privileged to have known him and to be associated with him all these years. I am honored to be asked to contribute this paper for a publication meant to pay tribute to his memory.

Hypopigmented lesions in early leprosy--a clinical and histological study.

26 Patients of leprosy presenting with hypopigmented lesions were divided on morphological grounds into 3 Sub groups, Group I (9 patients) with well-defined single patch with moderate to complete sensory loss; Group II (8 patients) with single ill-defined lesion having partial sensory loss; and Group III (9 patients) having multiple hypo-pigmented patches with mild to moderate sensory loss. Epidermal atrophy was a conspicuous histological finding in all groups. Only patients in Group I showed epitheloid cells in dermal infiltrate with erosion of epidermis in one case. This group may be labelled as maculoanesthetic leprosy. Patients in Group II and III showed mononuclear cell infiltrate in dermis, around neurovascular bundles and appendages. They were histologically consistent with indeterminate leprosy. Follow-up biopsy after six to eight months of treatment showed healing of the lesion of reduction in the infiltrate in most cases.

Sub-clinical infection with Mycobacterium leprae in household contacts of leprosy.

870 household contacts of leprosy patients were examined for sub-clinical infection with M. leprae by smear (skin and nasal), lepromin and FLA-ABS tests. 0.6%, 3.3%, 71.5% and 14.4% of the contacts were found to be positive for skin smear, nasal smear, lepromin and FLA-ABS tests respectively. An analysis of the results revealed that 4% of the lepromin positive contacts and 3.6% of the lepromin negative contacts were positive to both FLA-ABS and skin or nasal smear.

Studies on healthy contacts of leprosy patients--a preliminary report.

91 healthy contacts of leprosy patients were studied for subclinical infection and possibly the pre-clinical stage of the disease using a battery of tests. It was observed that the test based on competitive inhibition of monoclonal antibody binding to the MY2 a determinant of M. leprae identifies a preclinical stage of the disease.

Effect of repeated lepromin testing on experimental nine-banded armadillo leprosy.

Twenty-eight armadillos were lepromin tested and infected with M. leprae; 18 intravenously and 10 intradermally. The lepromin test was repeated after 3 months and at intervals of 6 months thereafter until their death or sacrifice up to 30 months. The one animal with tuberculoid lepromin was resistant and 14 of the 16 with lepromatous lepromin developed generalized disease. Of the 11 with borderline lepromin, 6 developed disseminated disease and 5 were resistant. There is a definite relationship between resistance and tuberculoid lepromin in the armadillo. Repeated lepromin testing had no effect in the rate of infection and the course of the disease in animals infected intravenously. In the intradermally infected animals the results were inconclusive. Whereas all the 20 animals with disseminated disease showed lesions in the liver, spleen and lymph nodes, only 4 animals had sciatic nerve involvement. Peripheral nerve trunk is not necessarily the preferred site in the armadillo. Lung lesions were an important cause of death in lepromatous armadillos.