title: Reliability of absolute lymphocyte count as a marker to assess the need to initiate antiretroviral therapy in HIV-infected children.
abstract: BACKGROUND
  CD4 counts are a standard laboratory measure of disease progression in HIV-infected children. However, CD4 counting is done by flow cytometry and may not always be possible in every centre treating HIV-infected children in resource-limited countries. Absolute Lymphocyte Count (ALC) can be derived easily by performing a routine white blood cell count. The World Health Organization (WHO) in 2006 had recommended ALC to identify HIV-infected children in need of ART in resource-limited settings, when CD4 cell count is not available.
  
  
  OBJECTIVE
  This study aims to assess the reliability of using ALC as a marker for starting antiretroviral therapy (ART) in HIV-infected children in a tertiary hospital setting.
  
  
  METHODS
  Retrospective analysis of 46 HIV-infected children who presented at a pediatric HIV clinic at a tertiary referral centre from 2002-2005.
  
  
  METHODS
  Using WHO 2006 guidelines for cutoff values of ALC and 2008 guidelines for CD4% as a comparative standard, a retrospective analysis was done on ART-naοve HIV-infected children who underwent baseline CD4% and ALC, and sensitivity and specificity of ALC was calculated.
  
  
  METHODS
  Fischer exact two-tailed analysis was used to correlate ALC and CD4 and need for starting ART.
  
  
  RESULTS
  Sensitivity of ALC was 27.6% (72.4% were false negatives), specificity was 70.6%, with positive predictive value of 61.5%. On comparison across all clinical stages of disease, only 13/46 children (28.2%) would have been started on ART according to ALC cutoffs versus 29/46 children (63.04%) using CD4 criteria (P value=0.0015). In children with WHO clinical Stage 1 or 2 of disease, only 1/11 (9.1%) children were identified by ALC as requiring ART as opposed to 6/11 (54.5%) children by CD4% (P=0.0635).
  
  
  CONCLUSIONS
  ALC is an unreliable marker to determine the need for starting ART in HIV-infected children.
authors.affiliation: Department of Pediatrics, Pediatric HIV Clinic, B. J. Wadia Hospital for Children, Mumbai, Maharashtra, India.
authors.forename: I
authors.initials: I
authors.lastname: Shah
authors.forename: S
authors.initials: S
authors.lastname: Parikh
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D018791:CD4 Lymphocyte Count; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D015658:HIV Infections / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D007194:India; D007223:Infant; D008297:Male; D017410:Practice Guidelines as Topic; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D062606:Tertiary Care Centers; D014944:World Health Organization
chemical_list: D019380:Anti-HIV Agents; D015415:Biomarkers