title: The evolving role of CD4 cell counts in HIV care.
abstract: The role of the CD4 cell count in the management of people living with HIV is once again changing, most notably with a shift away from using CD4 assays to decide when to start antiretroviral therapy (ART). This article reflects on the past, current and future role of CD4 cell count testing in HIV programmes, and the implications for clinicians, programme managers and diagnostics manufacturers.
  
  
  
  Following the results of recent randomized trials demonstrating the clinical and public health benefits of starting ART as soon as possible after HIV diagnosis is confirmed, CD4 cell count is no longer recommended as a way to decide when to initiate ART. For patients stable on ART, CD4 cell counts are no longer needed to monitor the response to treatment where HIV viral load testing is available. Nevertheless CD4 remains the best measurement of a patient's immune and clinical status, the risk of opportunistic infections, and supports diagnostic decision-making, particularly for patients with advanced HIV disease.
  
  
  
  As countries revise guidelines to provide ART to all people living with HIV and continue to scale up access to viral load, strategic choices will need to be made regarding future investments in CD4 cell count and the appropriate use for clinical disease management.
authors.affiliation: aDepartment of HIV and Global Hepatitis Programme, World Health Organization, Geneva, Switzerland bDivision of Infectious Diseases and HIV Medicine, Department of Medicine cClinical Infectious Diseases Research Initiative, Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa dMycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
authors.forename: Nathan
authors.initials: N
authors.lastname: Ford
authors.forename: Graeme
authors.initials: G
authors.lastname: Meintjes
authors.forename: Marco
authors.initials: M
authors.lastname: Vitoria
authors.forename: Greg
authors.initials: G
authors.lastname: Greene
authors.forename: Tom
authors.initials: T
authors.lastname: Chiller
mesh_terms: D018791:CD4 Lymphocyte Count / Q000379:methods* / Q000706:statistics & numerical data* / Q000639:trends; D016903:Drug Monitoring / Q000379:methods / Q000706:statistics & numerical data; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy* / Q000473:pathology; D006291:Health Policy; D006801:Humans; D019562:Viral Load / Q000379:methods / Q000706:statistics & numerical data