Skin biopsies from 100 patients with untreated lepromatous leprosy from Malaysia, India, Africa, and South America were examined with particular regard to pathological changes in intima, media, or adventitia of blood vessels and to the presence of leprosy bacilli in these layers. Bacilli were found in capillaries, venules, or arterioles in all cases, and in many instances they were present in endothelial lining cells or smooth muscle in large masses (globi). In several cases, solid-staining bacilli in endothelial lining cells were especially prominent. The findings are discussed in relation to a) the continuous bacteremia of lepromatous leprosy, b) the role of endothelial cells in phagocytosis, c) smooth muscle cells of the media as a site in which bacilli may persist, and d) the transmission of human leprosy by biting arthropods.
Fifteen patients with pure lepromatous leprosy were treated for 12 months with DDS at 50 mgm. twice weekly. The drug was fully effective in this dose, and the incidence and severity of ENL were not less than on larger doses
An account is given of the first hundred consecutive proven cases of sulphone resistance in leprosy, detected in Malaysia between 1963 and 1974. Proof of resistance was clinical in eighty patients and was obtained by drug-sensitivity testing in mice in ninety-six patients; 76 cases were proved both clinically and experimentally, and there was no discrepancy between the two methods. Sulphone resistance was confined to patients with lepromatous-type leprosy--i.e., patients with a large bacterial population. Clinical evidence of relapse due to drug resistance appeared 5-24 years after the start of sulphone treatment. Low dosage favoured the appearance of resistance; therefore regular treatment of lepromatous leprosy with dapsone in full dosage is recommended. The attainment of "skin smears negative for leprosy bacilli" is no test of cure of lepromatous leprosy.
To differentiate the leprosy agents Mycobacterium leprae and Mycobacterium lepromatosis and correlate them with geographic distribution and clinicopathologic features.