Dapsone hypersensitivity syndrome with circulating 190-kDa and 230-kDa autoantibodies.

Dapsone has potent anti-inflammatory effects, and is used in the treatment of leprosy, cutaneous vasculitis, neutrophilic dermatoses, and dermatitis herpetiformis and other blistering disorders. However, it may cause severe adverse reactions such as hypersensitivity syndrome, which is characterized by fever, skin rash, hepatitis and lymphadenopathy. We report a 44-year-old female Korean patient with dapsone hypersensitivity syndrome (DHS) that presented as a bullous skin eruption. The patient had a 1-year history of urticarial vasculitis, treated with antihistamines, prednisolone and dapsone. Although the skin lesions improved, she reported fever, nausea, abdominal pain, jaundice, fatigue and skin rashes. On physical examination, there were generalized erythematous macules and purpura with facial oedema that developed into vesicles on the upper limbs. Histological examination of a skin biopsy of a vesicular lesion found subepidermal oedema with a mixed inflammatory cell infiltrate, including eosinophils in the dermis. Indirect immunofluorescence testing using normal foreskin as substrate revealed IgG deposits in the basement membrane zone. Circulating autoantibodies against antigens of 190 and 230 kDa were found by immunoblotting analysis using epidermal extracts. This case illustrates DHS with the formation of circulating autoantibodies.

In vitro effect of interleukin-2 on proliferative responses of peripheral blood T cells from leprosy patients.

Because of the important role played by interleukin-2(IL-2) in T cell growth and differentiation, we investigated the effect of exogenous IL-2 on the proliferative response of peripheral blood mononuclear cells(PBMCs) from 77 leprosy patients. The proliferative responses of PBMCs from lepromatous leprosy(LL) or borderline lepromatous leprosy(BL) patients to M. leprae were significantly lower(cpm 6,051 +/- 803 for LL type; 4,951 +/- 2,529 for BL type) than those from tuberculoid leprosy(TT) or borderline tuberculoid leprosy(BT) patients (28,853 +/- 28,916 for TT type; 15,884 +/- 334 for BT type). To investigate the effect of exogenous IL-2, purified IL-2 was added at the start of culture at 100 unit/ml. There was an apparent increase in 3H-thymidine incorporation of M. leprae-stimulated PBMCs(18,723 +/- 6,503) in the presence of IL-2 compared to the results without IL-2(6,051 +/- 803) in LL patients. Twenty nine out of 33 LL patients belonged to the responders to IL-2 and four patients were nonresponders. Therefore we conclude that the defective cell mediated immune response in LL patients may result from diminished production of IL-2, but we can not exclude the possibility of diminished expression of the IL-2 receptor. And we suggest that the immunologic heterogeneous response of an individual to M. leprae is important to the pathogenesis of clinical disease in the same LL patients.

Interleukin-1 beta production by monocytes from leprosy patients.

The cause responsible for the lack of an efficient cell-mediated immunity or a delayed type hypersensitivity to M. leprae in lepromatous patients is poorly understood. But the resistance to M. leprae infection in humans is likely mediated by the activated macrophages to present M. leprae antigen to T cells for cell-mediated immunity. Phenolic glycolipid-I (PGL-I) is a M. leprae-specific antigen and is supposed to play a significant role in the long lasting unresponsiveness in lepromatous leprosy. In this study, IL-1 activities were tested among leprosy patients to evaluate monocyte function and the role of IL-1 in the immunosuppression in leprosy. We found that peripheral blood mononuclear cells (PBMCs) from tuberculoid patients were strongly reactive to M. leprae (mean cpm; 28,853 +/- 28,916), but the proliferative responses of PBMCs from lepromatous patients (mean cpm; 6,051 +/- 803) were significantly lower. IL-1 concentration in culture supernatant of monocytes from lepromatous patients was similar to that from tuberculoid patients with stimulation of M. leprae (lepromatous: 1,014 +/- 637 pg/ml, tuberculoid: 1,012 +/- 167 pg/ml) or lipopolysaccharides (IPS) (lepromatous: 3,479 +/- 2,188 pg/ml, tuberculoid: 4,246 +/- 2,432 pg/ml). The IL-1 concentration is sera from lepromatous patients (42 +/- 30 pg/ml) tended to be higher than those from tuberculoid patients (28 +/- 69 pg/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

HLA and leprosy in Koreans.

HLA antigens in 157 unrelated Koreans with leprosy have been identified and compared with 162 healthy Korean controls. The patient group consisted of 124 with lepromatous leprosy and 33 with tuberculoid leprosy. Although no significant differences were detected between the two patient groups, several antigens were found to be increased in the combined patient group compared to healthy controls. Two Class I antigens were increased: HLA-A11 (22% vs 12%) and Aw33 (27% vs 14%). Four Class II antigens were increased: HLA-DR1 (16% vs 7%), DR2 (39% vs 21%), DRw9 (14% vs 6%) and DQw1 (74% vs 55%). HLA-DR4 (28% vs 48%), DRw53 (46% vs 69%) and DQw3 (50% vs 75%) in contrast were significantly decreased in patients. Interaction of DR1, DR2, DRw9 and DQw1 as risk factors was analyzed. HLA-DR2 appeared to be the strongest risk factor. No evidence for synergy between DR1, DR2 and DRw9 was detected. DQw1 was not significantly increased in patients in the absence of DR1 and DR2, and thus it was not apparent in this study that DQw1 was an independent risk factor.

Oxidation of formate by mycobacteria of the scrofulaceum group.

Intact cells obtained from Mycobacterium scrofulaceum as well as from mycobacterial strains M.A6 and M.R56 isolated respectively from leprous tissues of armadillo and rat leproma and grown with glycerol as the oxidizable substrate catalyzed complete oxidation of formate. The stoichiometry of formate oxidase system yielded a value of 2 mol of CO2 produced per mole of O2 or per 2 moles of formate consumed. Cell-free preparations from these three strains of mycobacteria contained formate dehydrogenase which was associated exclusively in the particulate fraction. Formate oxidation was markedly stimulated by small amounts of selenite and molybdate added together. Formate-reduced minus oxidized difference spectra disclosed cytochromes of the b type while spectral evidence did not suggest the existence of cytochromes a or c components. The effect of 2-N-heptyl-4-hydroxyquinoline-N-oxide on the redox state of cytochromes indicated that formate oxidation was mediated by cytochrome b with absorption maximum of 556 nm and not of 562 nm.

In vitro cultivation of mycobacteria in cholesterol lecithin media from lepromas of rats infected with Mycobacterium lepraemurium.

In vivo grown M. lepraemurium suspensions were inoculated into a basal medium containing cholesterol and lecithin. Slow growing strains of mycobacteria were cultured regularly in these media. The presence of free cholesterol or cholesterol in serum or cholesterol in trypsin-digested egg yolk was essential for growth. The primary cultures were difficult to obtain, but the strains were easily subcultured. A heavy inoculum was necessary to obtain primary cultures in the liquid media, no growth occurred on semisolid agar slants. Similarly slow-growing primary cultures were obtained on Ogawa egg yolk media. Growth developed in a considerably shorter time if Ogawa's medium was enriched with 0.4% yeast extract (Difco). The cultures obtained on Ogawa egg yolk media were successfully subcultered in liquid cholesterol-lecithin media. The relation of the cultured strains of mycobacteria to the pathology of murine leprosy is not yet clear. The dynamics of cholesterol metabolism in the macrophages related to murine leprosy is discussed.

Mycobacterium leprae and phenoloxidase activity.

Our earlier studies indicated that the enzyme o-diphenoloxidase was absent in Mycobacterium leprae separated from depromatous human tissues. At that time the bacilli were not available from any other source. The existence or absence of this enzyme in M. leprae recovered from infected armadillo tissues were reinvestigated. The intact cells which were metabolically active, failed to oxidize DOPA. Likewise, DOPA and its derivatives were not oxidized by the enzymatically active cell-free preparations from M. leprae. Upon incubation of DOPA for more than 2 h with whole cell suspensions or particulate fractions, there was no development of colour with an absorption maximum of 540 nm as has been reported for an intermediate of DOPA oxidation. However, DOPA and several phenolic compounds were very actively oxidized by mushroom tyrosinase. The results suggested that M. leprae is deficient in o-diphenoloxidase, and this enzyme is not an intrinsic characteristic of this mycobacterium.