title: Absolute Lymphocyte Count as a Surrogate Marker of CD4 Count in Monitoring HIV Infected Individuals: A Prospective Study.
abstract: BACKGROUND
  CD4 cell count has been proposed to be substituted by Absolute lymphocyte count in monitoring HIV infected individuals as methods of CD4 cell count and plasma viral estimation require expensive, specialized equipments and highly trained personnel.
  
  
  OBJECTIVE
  To assess the clinical utility of the Absolute Lymphocyte Count (ALC) to serve as a surrogate marker for predicting a CD4 count < 200 cells/μl in patients with HIV infection in resource poor countries.
  
  
  METHODS
  A prospective study of 61 patients with HIV/AIDS was conducted. Sensitivity, specificity, Positive Predictive Value (PPV), Negative Predictive Value (NPV) of various ALC cut-offs were computed for CD4 cell count < 200 cells/μl for age < 30 or age ≥ 30 years. Pearson correlation, Linear regression and Receiver Operating Characteristics (ROC), were used.
  
  
  RESULTS
  For patients aged ≥ 30 years, sensitivity, specificity, positive and negative predictive value of ALC <1200 cells/μl to predict CD4 cell count < 200 cells/μl were 34.48%, 67.5%, 43.48%, 58.69% respectively. For subjects aged < 30 years, these values were 27.27%, 67.5%, 18.75%, 77.14%, respectively. A ALC < 1643 was found to have maximal sensitivity for predicting a CD4 cell count <200/ μl.
  
  
  CONCLUSIONS
  Our data revealed good correlation between ALC and CD4 cell counts but ALC cut-off of 1200 was not a surrogate marker for CD4 cell count < 200 cells/μl. As we increase the cut-off to <1643/ μl it could be the cost-effective surrogate marker for CD4 cell counts < 200 cells/μl in resource limited settings.
authors.affiliation: Assistant Professor, Department of Pathology, Pacific Medical College and Hospital , Udaipur, India .
authors.forename: Preeti Balkisanji
authors.initials: PB
authors.lastname: Agrawal
authors.affiliation: Senior Associate Professor, Department of Pathology, BJ Medical College , Pune, India .
authors.forename: Sharda Raju
authors.initials: SR
authors.lastname: Rane
authors.affiliation: Professor, Department of Pathology, RCSM Govt Medical College , Kolhapur, India .
authors.forename: Meenal Vitthal
authors.initials: MV
authors.lastname: Jadhav
keywords: Acquired immune deficiency syndrome; Highly active antiretroviral therapy; Total lymphocyte count