02875nas a2200349   4500000000100000008004100001260001300042653002400055653002300079653001100102653001900113653001100132653001200143653002500155653003000180653003200210653000900242653001900251100001600270700001300286700001200299700001400311700001300325700001200338700001300350245017900363856007300542300001100615490000700626520187800633022001402511       2006                            d  c2006 Sep10aAntigens, Bacterial10aBacterial Proteins10aBiopsy10aDNA, Bacterial10aHumans10aleprosy10aMycobacterium leprae10apolymerase chain reaction10aSensitivity and Specificity10aSkin10aTaq Polymerase1 aMartinez AN1 aBritto C1 aNery JA1 aSampaio E1 aJardim M1 aSarno E1 aMoraes M00aEvaluation of real-time and conventional PCR targeting complex 85 genes for detection of Mycobacterium leprae DNA in skin biopsy samples from patients diagnosed with leprosy.  uhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC1594745/pdf/2250-05.pdf  a3154-90 v443 a<p>In spite of the decrease in the number of registered leprosy patients, the number of new cases diagnosed each year (400,000) has remained essentially unchanged. Leprosy diagnosis is difficult due to the low sensitivity of current methodologies to identify new cases. In this study, conventional and TaqMan real-time PCR assays for detection of Mycobacterium leprae DNA were compared to current classification based on clinical, bacteriological, and histological evaluation. M. leprae DNA was extracted from frozen skin biopsy specimens from 69 leprosy patients enrolled in the study and was amplified using specific primers for either the antigen 85B-coding gene or the 85A-C intergenic region by using conventional and real-time PCR. The detection rate was 100% among multibacillary (MB) patients and ranged from 62.5% to 79.2% among paucibacillary (PB) patients according to the assay used. The TaqMan system for 85B gene amplification showed the highest sensitivity, although conventional PCR using the 85A-C gene as a target was also efficient. The cycle threshold (C(T)) values obtained using the TaqMan system were able to statistically (P < 0.0001) differentiate MB (mean C(T), 28.06; standard deviation [SD], 4.51) from PB (mean C(T), 33.06; SD, 2.24) patients. Also, there was a correlation between C(T) values and the bacteriological index for MB patients (Pearson's r, -0.444; P = 0.008). Within the PB patients' group, we tested normal skin from six patients exhibiting the pure neuritic form of leprosy (PNL). Five out of six PNL patients were positive for the presence of M. leprae DNA, even in the absence of skin lesions. In conclusion, the TaqMan real-time PCR developed here seems to be a useful tool for rapidly detecting and quantifying M. leprae DNA in clinical specimens in which bacilli were undetectable by conventional histological staining.</p>  a0095-1137