02258nas a2200337   4500000000100000008004100001260001600042653002700058653004400085653002200129653002100151653001100172653002300183653002800206653001800234653001300252653001200265653002600277653003000303653005700333100001500390700001200405700001300417700001400430700001200444245010400456300001000560490000800570520132800578022001401906       1986                            d  c1986 Feb 0110aAntibodies, Monoclonal10aAntigens, Differentiation, T-Lymphocyte10aAntigens, Surface10aErythema Nodosum10aHumans10aImmunity, Cellular10aImmunoenzyme Techniques10aInterleukin-210aLepromin10aleprosy10aStaining and Labeling10aT-Lymphocytes, Regulatory10aTumor Necrosis Factor Receptor Superfamily, Member 71 aModlin R L1 aMehra V1 aJordan R1 aBloom B R1 aRea T H00aIn situ and in vitro characterization of the cellular immune response in erythema nodosum leprosum.  a883-60 v1363 a<p>We sought to evaluate cell-mediated immune responses in erythema nodosum leprosum (ENL), a reactional state occurring in lepromatous leprosy. Skin biopsies from patients with leprosy were studied with monoclonal antibodies against T lymphocyte antigenic determinants, interleukin 2 (IL 2), and IL 2 receptors (Tac) by using immunoperoxidase staining of frozen sections. Peripheral blood lymphocytes from 18 ENL patients were tested in vitro for lepromin-induced suppression of Con A stimulation. Serial studies of seven lepromatous patients who developed ENL during the course of the study showed increases in both the Leu-3a:Leu-2a ratio and the number of IL 2-positive cells. IL 2-positive cells comprised 0.3% of the cells in all of the ENL lesions studied as compared with the 0.03% found in nonreactional lepromatous lesions (P less than 0.001). Lepromin-induced suppression of the Con A response, present in nonreactional lepromatous patients, significantly decreased in patients developing the ENL reaction, but returned after recovery from ENL. These changes in tissues and peripheral blood suggest that the pathogenesis of ENL is related to cell-mediated immune processes. Despite these immunologic changes, however, ENL patients do not recover antigen-specific skin tests or eliminate Mycobacterium leprae.</p>  a0022-1767