Distinct patterns of microvasculature in the cutaneous lesions of leprosy

This work is an investigation on the microvasculature of the cutaneous infi ltrates of leprosy with the immunohistochemical. staining of endothelial ce lls in cutaneous biopsies. Anti-Factor VIII-related antigen antibody (anti- FVIII-ra) and Ulex Europaeus-1 lectin (UEA-1) binding were utilized as endo thelial cell markers. Thirty-nine patients grouped according to the Ridley- Jopling classification (14 borderline tuberculoid, 18 borderline lepromatou s, 6 lepromatous, and 1 indeterminate leprosy) were selected for this study . Two microvascular architectural patterns could be clearly distinguished: lepromatous lesions presented a dense and tortuous mesh of microvessels amo ng the Mycobacterium leprae-glutted macrophages; whereas the microvessels i n the tuberculoid lesions were restricted to the periphery of the granuloma s and were not seen among the central epithelioid cells. We were able to di stinguish three basic morphological kinds of infiltrate distribution relate d to the microvessels: micronodules, cords and macronodules. intensificatio ns of the FVIII-ra immunoreactivity and UEA-1 binding capacity were observe d in the endothelial cells of microvessels involved by the inflammatory inf iltrate. A distinct cytokine expression profile at the leprosy poles and th e role of mast cells in angiogenesis were speculated as factors contributin g to these distinct patterns. Growth of the lesion and systemic disseminati on of M. leprae in the bipolar spectrum of leprosy may hypothetically be in fluenced by the vascular-infiltrate relationship. The detection of angiogen esis in the cutaneous lesions of leprosy may bring about alternate and/or a dditional strategies for leprosy treatment.