02201nas a2200301   4500000000100000008004100001260001300042653001400055653002000069653003000089653001100119653002500130653003000155653002500185653002500210653002500235653003600260653000900296100001500305700001700320700001500337700001400352245007400366300001000440490000700450520142800457022001401885       2010                            d  c2010 Dec10aApoptosis10aGene Expression10aGene Expression Profiling10aHumans10aImmunohistochemistry10aIn Situ Nick-End Labeling10aLeprosy, lepromatous10aLeprosy, Tuberculoid10aMycobacterium leprae10aProto-Oncogene Proteins c-bcl-210aSkin1 ade Souza V1 aNogueira MES1 aBelone AFF1 aSoares CT00aAnalysis of apoptosis and Bcl-2 expression in polar forms of leprosy.  a270-40 v603 a<p>Apoptosis eliminates pathogen-infected cells. Its modulation can influence the course of infections, permitting the survival of intracellular pathogens. In leprosy, which presents several clinical manifestations related to bacillary burden and host immune status, the mechanisms responsible for the persistence of the bacillus are unknown. Few studies have focused on apoptosis over the disease spectrum and as a defense mechanism against Mycobacterium leprae. We evaluated apoptosis using terminal transferase dUTP nick end labeling and the expression of Bcl-2 by immunohistochemistry in skin lesions from 11 tuberculoid and 15 lepromatous leprosy patients. Each specimen was evaluated by determining the number of positive cells in 10 fields at × 400 magnification. We observed a higher number of apoptotic cells in tuberculoid lesions in comparison with lepromatous leprosy (42.5 cells per 10 fields vs. 11.5 cells per 10 fields, P<0.0001). Expression of Bcl-2, conversely, was larger in lepromatous than in tuberculoid samples (172.0 cells per 10 fields vs. 17.7 cells per 10 fields, P<0.0001). These observations suggest modulation of apoptosis in leprosy, primarily in lepromatous patients, for which the decrease in cell death could support M. leprae survival and contribute to the success of infection. Conversely, in tuberculoid patients, apoptosis could contribute to reducing propagation of the bacillus.</p>  a1574-695X