title: CD4+ T-cell Count may not be a Useful Strategy to Monitor Antiretroviral Therapy Response in HTLV-1/HIV Co-infected Patients.
abstract: 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.
authors.affiliation: Africa Health Research Institute (AHRI), University of KwaZulu-Natal, Durban, South Africa.|College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Alain
authors.initials: A
authors.lastname: Vandormael
authors.affiliation: Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil.
authors.forename: Filipe
authors.initials: F
authors.lastname: Rego
authors.affiliation: Africa Health Research Institute (AHRI), University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Siva
authors.initials: S
authors.lastname: Danaviah
authors.affiliation: Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil.
authors.forename: Luiz
authors.initials: L
authors.lastname: Carlos Junior Alcantara
authors.affiliation: Center for Infectious Disease and Microbiology Translational Research, University of Minnesota, Saint Paul, MN, United States.
authors.forename: David R
authors.initials: DR
authors.lastname: Boulware
authors.affiliation: College of Health Sciences, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa.|Centre for the AIDS Programme of Research in South Africa (CAPRISA), University of KwaZulu-Natal, Durban, South Africa.
authors.forename: Tulio
authors.initials: T
authors.lastname: de Oliveira
mesh_terms: D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D018791:CD4 Lymphocyte Count; D060085:Coinfection / Q000188:drug therapy*; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy*; D015490:HTLV-I Infections / Q000150:complications*; D006801:Humans; D008297:Male; D013019:South Africa; D019562:Viral Load
chemical_list: D044966:Anti-Retroviral Agents
keywords: ART; CD4+ count; HIV; HTLV-1; South Africa; co-infection; treatment failure