The incidence of multidrug and full class resistance in HIV-1 infected patients is decreasing over time (2001–2006) in Portugal

Abstract

Despite improvements in HIV treatment, the prevalence of multidrug resistance and full class resistance is still reported to be increasing. However, to investigate whether current treatment strategies are still selecting for multidrug and full class resistance, the incidence, instead of the prevalence, is more informative. Temporal trends in multidrug resistance (MDR defined as at most 1 drug fully susceptible) and full class resistance (FCR defined as no drug in this class fully susceptible) in Portugal based on 3394 viral isolates genotyped from 2000 to 2006 were examined using the Rega 6.4.1 interpretation system. From July 2001 to July 2006 there was a significant decreasing trend of MDR with 5.7%, 5.2%, 3.8%, 3.4% and 2.7% for the consecutive years (P = 0.003). Multivariate analysis showed that for every consecutive year the odds of having a new MDR case decreased with 20% (P = 0.003). Furthermore, a decline was observed for NRTI-and PI-FCR (both P < 0.001), whereas for NNRTI-FCR a parabolic trend over time was seen (P < 0.001), with a maximum incidence in 2003-'04. Similar trends were obtained when scoring resistance for only one drug within a class or by using another interpretation system. In conclusion, the incidence of multidrug and full class resistance is decreasing over time in Portugal, with the exception of NNRTI full class resistance which showed an initial rise, but subsequently also a decline. This is most probably reflecting the changing drug prescription, the increasing efficiency of HAART and the improved management of HIV drug resistance. This work was presented in part at

Non-B HIV Type 1 Subtypes among Men Who Have Sex with Men in Rome, Italy

“…In particular, in drug-naive MSM individuals, resistance (3.9%) is lower than that observed in other studies performed on the same risk class [52][53][54] and in other studies performed on heterogeneous risk classes. [55][56][57][58] The prevalence of resistance in antiretroviral-treated MSM individuals is around 60%, with a decreased trend over the years 2004-2006 (data not shown), in line with that observed in recent studies; 59,60 this diminished trend could explain the low prevalence of drug resistance in naive patients.…”

HIV-1 genotypic resistance profile of patients failing antiretroviral therapy in Paraná, Brazil

“…25,[46][47][48] No decrease in the prevalence of mutations has been observed in the sample from Paraná over the years, but some European studies did show an overall decrease in prevalence of TR and PR mutations, refl ecting a better response to HAART. [40][41][42][43][44][45][46][47][48][49][50][51][52] Differences in gender related prevalence are not widely described, but Di Giambenedetto et al (2007), according to data from some mutations in Paraná, considered male sex an independent predictor of drug resistance. 50 In terms of NNRTIs as future treatment options for this group of patients, it has been found that mutations on RT codons 181 and 190 occurred in more than 20% of patients, which could compromise etravirine effi cacy if used in a suboptimal regimen.…”

Análisis genético de las mutaciones presentes en las poblaciones virales en pacientes con infección por VIH-1 en Ecuador

“…Los resultados de la CV elevada y de recuentos bajos de LTCD4+ en pacientes tratados indican un fallo a la terapia de largo tiempo de evolución 19 . Los pacientes que porten virus con resistencia a todos los medicamentos de un grupo (FCR) o a todos ellos (MDR) en poblaciones minoritarias tendrán opciones terapéuticas seriamente comprometidas en un futuro, lo que indica un fallo de terapia de larga evolución, lo que conduce a la acumulación de mutaciones de resistencia 14 . El principal objetivo del tratamiento ARV es prolongar la vida de los pacientes con una calidad adecuada y al realizar pruebas de resistencia el tratamiento se enfoca de forma óptima para lograr este objetivo.…”

“…Se consideró que las muestras de los pacientes tenían resistencia cuando presentaron RI o RA. Se clasificó como resistencia a todos los fármacos de una clase (del inglés full class resistance o FCR) cuando no existía ningún ARV sensible a la clase en cuestión 14 . La multi-resistencia o resistencia a todas las clases de fármacos estudiados (del inglés multidrug resistance o MDR) se definió como los virus resistentes a todos los medicamentos de las tres clases, pudiendo encontrarse un solo medicamento de una clase sensible 14 .…”