[Immunology of leprosy. Review of data from the 1980-1990 time period]. / Immunologie der Lepra. Ubersicht zu Daten des Zeitraumes 1980-1990.

The classification used for leprosy so far distinguishes between two polar forms (pauci-bacillary and multi-bacillary), with different influences on the immune cells. The identification of specific antigens of the germ surface with monoclonal antibodies allows finer differentiation in classification, which now extends to transitional forms of clinical relevance. The current status of knowledge about immunological phenomena triggered by Mycobacterium leprae is complex, and controversy is rife at present. The bacillus is comparable to other mycobacteria in antigenicity. Owing to the complicated composition of the cellular envelope, few epitopes are accessible for immunological reactions. Investigation on the behaviour of T-lymphocytes in combination with analysis of the bacterial surface structures led to the development of a new pathogenetic concept. In spite of different immunological and inflammatory reactions in patients (reflecting the individual pathology), the discrimination between a partial and a total immunological defect is made. So far, no histocompatibility-antigen type has been found that allows recognition of the predisposition to infection. Immunity against the bacteria is achieved after BCG in some cases. All this suggests that the development of a vaccine via biotechnical synthesis of idiotypes and anti-idiotypes may be possible.

Evidence for an HLA-DR4-associated immune-response gene for Mycobacterium tuberculosis. A clue to the pathogenesis of rheumatoid arthritis?

Antigens of Mycobacterium tuberculosis, M leprae, M scrofulaceum, and M vaccae were injected intradermally in 86 caucasoid leprosy patients, and skin responses (measured in mm of induration at 72 h) were analysed in relation to HLA class II phenotypes. HLA-DR4 was associated with high responsiveness to antigens specific to M tuberculosis but not to antigens shared with other mycobacteria (p = 0.0005). Because DR4 is associated with rheumatoid arthritis (RA) and because a role for M tuberculosis antigens has been suggested both in experimentally induced autoimmune arthritis in rats and in RA, the DR4 associated regulation of the immune response to M tuberculosis may be relevant to the pathogenesis of RA.

[New drugs in the treatment of leprosy]. / Nuevas medicaciones en el tratamiento de la lepra

Two groups of patients were chosen for this treatment; the first group of 14 patients was treated with a daily dose of 600 mg. of Rifampicine and the second group with Rifampicine associated with Isoprodian (1-2 tablets). In the first group clinical and bacteriological improvement was apparent. This was parallel in bacteriological and morphological index. Two patients became negative in nasal mucous. Tolerance was good and number of leprosy reactions 65%. In the second group clinical improvement was good in general but one case that presented a continuous polyneuritis and hepatic intolerance. Bacteriological results were lightly lower than the first group and the number of leprosy reactions 85%. This treatment is considered inferior to the sulfons, which is very expensive. A longer period of time will be needed to appriase results.

WHO co-ordinated short-term double-blind trial with thalidomide in the treatment of acute lepra reactions in male lepromatous patients.

The treatment of lepra reactions constitutes one of the most serious problems in leprosy. For this reason, the first reports in 1965 of the favourable results obtained with thalidomide aroused considerable interest and led WHO, in 1967, to carry out a trial with the co-operation of four centres. A short-term double-blind trial was designed to study the effect of thalidomide, in comparison with acetylsalicylic acid, in the treatment of acute lepra reactions in male lepromatous patients. Acetylsalicylic acid was used instead of a placebo because of its antipyretic and analgesic activity. Because of the severe adverse reactions that may be caused by thalidomide, mainly the teratogenic effects, only males were included in the trial.The results of this short-term study seem to confirm previous reports of the efficacy of thalidomide and indicate that acetylsalicylic acid also seems to be helpful in the management of certain symptoms of lepra reactions.