CD4+ T-cell Count may not be a Useful Strategy to Monitor Antiretroviral Therapy Response in HTLV-1/HIV Co-infected Patients

• Published in: Current HIV research Vol. 15; no. 3; p. 225
• Main Authors: Vandormael, Alain, Rego, Filipe, Danaviah, Siva, Carlos Junior Alcantara, Luiz, Boulware, David R, de Oliveira, Tulio
• Format: Journal Article
• Language: English
• Published: Netherlands 01.01.2017
• Subjects: Adult; Anti-Retroviral Agents - therapeutic use; CD4 Lymphocyte Count; Coinfection - drug therapy; Drug Monitoring - methods; Female; HIV Infections - complications; HIV Infections - drug therapy; HTLV-I Infections - complications; Humans; Male; South Africa; Viral Load; ART; HIV; co-infection; treatment failure; CD4+ count; South Africa; HTLV-1
• ISSN: 1873-4251
• DOI: 10.2174/1570162X15666170216114917

HTLV-1/HIV co-infection is known to elevate the CD4+ T-cell counts of treatment-naïve persons. We investigated whether HTLV-1/HIV co-infected patients continued to have elevated CD4+ T-cell counts after developing virologic failure on antiretroviral therapy (ART). The data is taken from a drug resistance study located in the KwaZulu-Natal province of South Africa. All participants (N=383) presented for repeated CD4+ T-cell count and HIV viral load level testing between January 2006 and March 2014. We used a random-coefficient model to estimate the change in CD4+ T-cell count and HIV viral load level by HTLV-1/HIV co-infection status over time, adjusting for age, sex, and duration of virologic failure. HTLV-1/HIV co-infected participants (n=8) had higher CD4+ T-cell counts, with a positive difference of 117.2 cells/μL at the ART initiation date (p-value=0.001), 114.7 cells/μL (pvalue< 0.001) 12 months after this date, and 112.3 cells/μL (p-value=0.005) 24 months after this date, holding all else constant. In contrast, there was no difference in the HIV viral load level by HTLV-1/HIV co-infected status throughout the observation period. We show that HTLV-1/HIV co-infected participants continued to have elevated CD4+ T-cell counts after developing virologic failure on ART, despite no difference in their HIV viral load levels when compared with HIV mono-infected participants. Our results indicate that CD4+ T-cell count testing may not be a useful strategy to monitor ART response in the presence of HTLV-1/HIV co-infection.