title: Viral load as a surrogate end point in HIV disease.
abstract: OBJECTIVE
  To examine the role of viral load as a surrogate end point for HIV disease progression and death.
  
  
  METHODS
  A MEDLINE search was conducted for the years 1990-March 2001. In addition, relevant articles were cross-referenced to screen for additional information.
  
  
  METHODS
  Data regarding the validity of viral load as a surrogate end point for disease progression or death are cited. Emphasis was placed on randomized, controlled trials, but descriptive studies are also included.
  
  
  RESULTS
  Recently, viral load has emerged as an important biomarker for monitoring HIV disease and antiretroviral therapy. Both baseline viral load and changes in viral load with time predict HIV disease progression and death. In fact, disease progression increases consistently once viral load exceeds 10,000 copies/mL, and AIDS and death primarily occur in patients with viral loads > 100,000 copies/mL. Changes that occur in viral load after initiation of antiretroviral therapy, however, do not fully explain the entire treatment effect. Also, separate comparisons of antiretroviral regimens may demonstrate similar differences in viral load changes but not similar differences in disease progression.
  
  
  CONCLUSIONS
  Viral load is an important monitoring parameter for HIV disease and antiretroviral therapy. However, changes in viral load do not explain the entire clinical improvement that occurs after initiation of therapy. Although viral load is a clinically important surrogate end point for HIV disease, it cannot fully account for all associated treatment effects.
authors.affiliation: Department of Pharmacy Practice, College of Pharmacy, Ferris State University, Lansing, MI, USA. smithc@ferris.edu
authors.forename: Curtis L
authors.initials: CL
authors.lastname: Smith
authors.forename: Gary E
authors.initials: GE
authors.lastname: Stein
mesh_terms: D023241:Antiretroviral Therapy, Highly Active; D015415:Biomarkers; D018791:CD4 Lymphocyte Count; D018450:Disease Progression; D023381:Endpoint Determination; D015658:HIV Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D006801:Humans; D016239:MEDLINE; D011788:Quality of Life; D013810:Therapeutic Equivalency; D019562:Viral Load / Q000379:methods / Q000706:statistics & numerical data*
chemical_list: D015415:Biomarkers