[Genetic component of the immune response to Mycobacterium leprae in healthy subjects].
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
One hundred two armadillos captured from the wild were lepomin tested. Nine of them (8.8%) showed a positive Mitsuda reaction. The histopathological appearance of the reaction had a spectrum showing tuberculoid, borderline tuberculoid, borderline lepromatous, and lepromatous histology. It is possible that armadillos can develop all the different types of leprosy seen in humans. The armadillo is a good animal model to test protective vaccines against leprosy.
Existence of subpolar tuberculoid leprosy was postulated by a few leprologists to explain clinical variations near the tuberculoid pole but failed to precisely identify the same. An attempt has been made to describe the clinical and histological features of subpolar tuberculoid leprosy. 76 cases of the TT-BT range according to Ridley-Jopling classification were examined by detailed clinical, histological and immunological methods. Definite clinical and histological discrepancies from either BT or TTp were seen in 30 (39.4%) cases, confirming the existence of subpolar tuberculoid leprosy (TTs) and thus clarifying the immunological spectrum of leprosy.
Reversal reactions (RR) or acute neuritis episodes are frequently observed in borderline tuberculoid (BT) leprosy patients during the first year of treatment, and are associated with a rapid increase in cell-mediated immunity. Because HLA-linked genes have been shown to be an important factor in determining the type of leprosy that develops in susceptible individuals and because HLA molecules regulate cellular interactions in the immune system, we have investigated whether RR are associated with HLA antigens in Ethiopian patients. The data reported here indicate that this is not the case: no significant differences in the distribution of HLA class I and class II antigens were observed among three groups: 28 BT patients with a history of RR, 27 BT patients with no history of RR, and 33 healthy individuals. In contrast to these negative results, we observed that HLA-DR3 was associated with high skin-test responsiveness against Mycobacterium leprae antigens among RR patients. Since DR3 was not associated with RR per se, the observed DR3-associated high responsiveness to M. leprae may not be primarily related to the development of RR.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The Hansen-Anergic Fringe ("HAF") of the population is the minority genetically incapable of developing that variety of specific immunity to Myco. hansenii which leads to the positivity of the Mitsuda reaction. In spite of the fact that the HAF was identified as early as 1937, its real proportion in the human species is still not exactly known. Considering that Myco. tuberculosis has been proved to induce Mitsuda-positivity in the genetically capable majority, studies with the tuberculin reactions and cross-stimulation with BCG should be instrumental for the determination of the width of the HAF in various races and different endemic and non-endemic areas. In Brazil it stands around 20-25%, but more accurate studies are necessary. Between the HAF and the Mitsuda-positive or potentially positive majority there is a zone of "intermediate reactivity" which also needs quantification. The specific HAF reacts normergically to all other tests so far investigated and has not yet been associated with any other kind of immuno-deficiency. Also, it has not been associated with any of the known genetical markers, although HLA studies seem promising. If its postulated genetical nature is confirmed, the possibility of effective vaccination will be doubtful.
Explore the source record for details and available documents.
Hanseniasis patients and contacts of Virchowian patients, totaling 467 persons have been submitted to Mitsuda's reaction. These individuals have been divided into five groups: group 1 compounded of 59 persons, relatives of Virchowian patients; group 2 - 171 persons, employees of the Hospital Lauro de Souza Lima working there for more than one year; group 3 - 127 hanseniasis patients in activity, Mitsuda negative; group 4 - 63 hanseniasis patients in activity, Mitsuda positive; group 5 - 47 Virchowian patients, inactive, Mitsuda negative. The analysis of the data showed that: a) hanseniasis patients, both Mitsuda positive and negative, do not present positivity to Fernandez's reaction; b) early reaction can be observed more frequently in individuals of group 1 than in those of group 2. Mitsuda's antigen causes the reversal of Fernandez's reaction in about 30% of indirect contacts; c) the percentage of negative Mitsuda's reactions (without induration) does not differ between groups 1 and 2, though indurations smaller than 5 mm have been as many as 10 times more frequent in individuals of group 1. A second application of the antigen in Mitsuda negative persons showed the reversal of the test in 100% of the tested subjects.
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.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
From the field of view of own observative and experiences was tried to outline the present situation in leprosy. It is referred to the results of the modern epidemiological, bacteriological, immunological and medicamentous leprosy research which was particularly stimulated under the impression of the increasing DDS-resistance of the leprosy bacteria. At present ambulatory polychemotherapy, sometimes combined with a vaccination technique, is in the centre of the world-wide combat programme against leprosy. In no other infectious disease, however, social-economical points of view are so important as in leprosy and in the opinion of the author they are finally also decisive for an actually successful and permanent combat.
This study examined the risk of relapse in 421 paucibacillary patients who had defaulted after varying periods of dapsone monotherapy; short of the recommended course. The 421 patients contributed a total of 2,162 person years of risk; 10 patients relapsed, giving a relapse rate of 4.6 per 1000 persons years of risk, or a crude relapse rate (RR) of 2.4%. This paper discusses the issue of defaulters with paucibacillary leprosy and the findings of the study suggest that defaulters with paucibacillary leprosy are not a serious problem in terms of leprosy control.
Explore the source record for details and available documents.