Assessing the Utilization of HIV Genotype Resistance Testing: Insight from Italian Infectious Diseases Units.

Abstract

Purpose: We aimed to assess the utilization of Genotype Resistance Testing (GRT) by Infectious Diseases Units across Italy.

Methods: A cross-sectional study was conducted involving a questionnaire distributed to the Infectious Diseases Unit in Italy. A web-based survey using Google Forms software was utilized and spread via email or cellphone.

Results: Responses were obtained from 101 Infectious Diseases Units. Among these centers, only seven (6.9%) reported not performing GRT at any time. Of the 94 centers performing GRT, 52 (55.3%) sent blood samples to external laboratories. Notably, only 6/35 (17.1%) small centers had internal laboratories, compared to 14/35 (40.0%) medium centers and 22/24 (91.7%) large centers (p<0.001). Most centers requested GRT for treatment-naïve individuals and all cases of virological failure. Only 24 (25.5%) requested GRT of HIVDNA before treatment changes. Regarding virological failure, most centers (38, 40.4%) requested GRT when HIV-RNA levels exceeded 200 copies/mL, while 26 (27.7%) requested it at levels exceeding 50 copies/mL. Additionally, 18 (19.1%) and 12 (12.8%) centers requested GRT at thresholds of 500 copies/mL and 1000 copies/mL, respectively. Regarding the specific GRT test used, 34 (36.2%) were unsure, while 16 (17.0%) reported using both Next-Generation Sequencing (NGS) and Sanger methods. Furthermore, 30 (31.9%) and 14 (14.9%) centers exclusively used NGS and Sanger, respectively. Most centers reported receiving GRT results within one month (n=72, 76.6%), while 22 (23.4%) centers obtained results within two weeks. However, 22 (23.4%) centers typically experienced more than one-month delays. Finally, most participants (86, 91.5%) regarded GRT as a crucial routine test for the treatment of naïve PLWH.

Conclusion: This study demonstrates that most Infectious Diseases Units in Italy continue to consider GRT an essential test for newly diagnosed PLWH in clinical practice. However, the utilization of GRT on HIV-DNA remains limited. Further efforts are required to decrease turnaround time in centers experiencing prolonged delays in obtaining results.