OBJECTIVETo find out the mechanism of drug resistance by detecting the mutations of HIV RNA in patients who failed in the anti-HIV therapy, to direct the clinical use of anti-HIV drugs and to complement the existing drug resistant database.

METHODSHIV RNA and DNA were extracted from the plasma of 10 HIV-infected patients who developed drug resistance in the Clinic of AIDS, Ruhr University, Bochum, Germany. Then HIV-RNA was amplified in the reverse transcriptase (RT) and protease regions by polymerase chain reaction (PCR). After purified, the PCR products was sequenced. The acquired sequences were compared with the international standard strain HXB2CG and the resistant database of Stanford University.

RESULTSSome mutations were found to cause the corresponding resistance to certain drugs and were consistent with the clinical results. Some mutations existed in some patients, such as V179I in RT and K20T, K20I in protease, which hadn't been reported in the resistant database of Stanford University yet.

CONCLUSIONPatients who fail in HAART have different mutations in RT and protease regions. Mutations such as V179I in RT and K20T, K20I etc in protease may be related to drug resistance.