HIV-1 drug resistance patterns among treatment-naïve and therapy-experienced patients in Poland

Abstract

Summary Background HIV-1 drug resistance (DR) is becoming a growing concern. It is estimated that about one out of ten newly HIV-infected persons in Europe acquires HIV-1 drug resistant strain. DR testing is now believed to play a crucial role in proper and successful treatment. The aim of the study was a retrospective analysis of the HIV-1 drug resistance patterns among Polish naive and therapy-experienced patients. Materials and methods In all cases before drug resistance testing viral load was determined as well as CD4/CD8 counts. The sequencing assay was carried out using commercially available assays according to manufacturer's protocol. Electrophoretic analysis data were verified and manually corrected. Interpretation was performed using Stanford's Genotypic Resistance Interpretation Algorithm or by a built-in algorithm included in ViroSeq System. Results In the treatment-naive group 14,1% of tested patients have acquired HIV-1 strains harbouring resistance-associated mutations. In the therapy-experienced group among 75 analyzed patients 58 (77%) were found to be carrying drug resistant mutants. In this group 14 persons (19%) had at least one resistance-associated mutation in all three drug classes. Among therapy-experienced patients the prevalence of K65R was very low (1,3%). Conclusion The results of both analysed groups indicate the necessity of resistance testing in Poland. In the group of patients never exposed to ART in 14,1% cases viral variants resistant to at least one of the drugs were identified. The problem of resistance intensifies with consecutive regimen failures limiting the remaining treatment options. A shift has been observed in the route of HIV-1 infection in Poland. The obtained data also documents a change in HIV subtype pattern in Poland. The low prevalence of K65R mutation may result in very potent salvage therapy options based on TDF. Presented data documents high prevalence of drug resistance in Poland and justifies the necessity of DR testing.