01944nas a2200289   4500000000100000008004100001260001300042653002600055653002300081653001600104653001100120653001200131653002500143653003000168653003900198653000900237100001300246700001200259700001200271700001300283700001200296245015600308300001000464490000700474520115900481022001401640       2003                            d  c2003 Jul10aAntibodies, Bacterial10aBacterial Proteins10aDNA Primers10aHumans10aleprosy10aMycobacterium leprae10apolymerase chain reaction10aRepetitive Sequences, Nucleic Acid10aSkin1 aKang T-J1 aKim S-K1 aLee S-B1 aChae G-T1 aKim J-P00aComparison of two different PCR amplification products (the 18-kDa protein gene vs. RLEP repetitive sequence) in the diagnosis of Mycobacterium leprae.  a420-40 v283 a<p>To determine the best molecular method for diagnosing leprosy, two sets of Mycobacterium leprae-specific primers were compared. Fresh biopsies and slit skin smear samples were obtained from 67 leprosy patients and examined by touchdown (TD) PCR using primers amplifying either a 129-bp fragment of the RLEP repetitive sequence or a 360-bp fragment of the 18-kDa protein gene of M. leprae. Seventeen of 30 (56.7%) biopsy specimens and four of 37 (10.8%) slit skin smear specimens were positive using the primer for the 18-kDa protein gene, whereas 24 of 30 (80%) biopsy and 27 of 37 (73%) slit skin smear samples showed detectable PCR products in the RLEP repetitive sequence. Twenty-one of 31 cases (67.7%) with a bacterial index of zero were PCR positive for the primer RLEP repetitive sequence. These results demonstrate that detection of M. leprae using PCR with primers to a RLEP sequence is more sensitive and specific than PCR with the 18-kDa protein gene primers and also slit smears with acid fast staining. PCR of RLEP repetitive sequences is therefore a useful means of detecting M. leprae DNA even when it is present at very low levels.</p>  a0307-6938