02604nas a2200361   4500000000100000008004100001260001300042653001500055653001000070653000900080653002700089653001900116653001100135653001100146653002200157653001200179653002000191653002600211653000900237653001600246653001800262653003000280100001300310700001600323700001400339700002000353700001500373245005600388300001200444490000700456520176500463022001402228       1981                            d  c1981 Jun10aAdolescent10aAdult10aAged10aAntibodies, Monoclonal10aConcanavalin A10aFemale10aHumans10aIntradermal Tests10aleprosy10aLeukocyte Count10aLymphocyte Activation10aMale10aMiddle Aged10aT-Lymphocytes10aT-Lymphocytes, Regulatory1 aBach M A1 aChatenoud L1 aWallach D1 aPhan Dinh Tuy F1 aCottenot F00aStudies on T cell subsets and functions in leprosy.  a491-5000 v443 a<p>T cell subsets and T cell functions were explored in 31 leprosy patients with the following methods: determination of the percentages of the different T cell subpopulations defined by monoclonal antibodies directed at total T cells, helper T cells and suppressor/cytotoxic T cells; measurement of the in vitro proliferative responses to mitogens; study of the concanavalin A-induced suppressive activity, assessed on MLC; measurement of delayed-type hypersensitivity by skin testing. The confrontation between immunological lepromatous patients without type-2 reaction (erythema nodosum leprosum), (2) lepromatous patients without ENL (erythema nodosum leprosum), (2) lepromatous patients was recent ENL and (3) tuberculoid patients. Unexpectedly, groups 1 and 3, although differing strongly in their clinical status and their sensitivity to lepromin (absent in group 1 and strong in group 3), showed a similar immunological profile with a normal percentage of T cells and a normal distribution of T cells among the major T cell subset contrasting with a moderate decrease of proliferative responses to mitogens and impaired delayed-type hypersensitivity reactions. Concanavalin A-induced suppressive activity was type-2 reaction) strongly differed from both other groups, showing striking abnormalities other groups, showing striking abnormalities of the repartition of the T cell subsets, with increased percentages of helper T cells and decreased percentages of suppressor T cells, and elevated proliferative responses to mitogens. Concanavalin A-induced suppressive activity was reduced in most patients of this group. It is suggested that this imbalance between T cell subsets contributes to the occurrence of ENL reactions in lepromatous patients.</p>  a0009-9104