title: Peripheral blood CD4 + T-lymphocyte counts during Pneumocystis carinii pneumonia in immunocompromised patients without HIV infection.
abstract: OBJECTIVE
  To assess the potential use of peripheral blood CD4 + T-lymphocyte counts (CD4 + counts) as a clinically useful biological marker to identify specific immunocompromised patients (without HIV infection) at high risk for Pneumocystis carinii pneumonia (PCP).
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Three hundred seventy-five-bed tertiary-care urban referral teaching hospital, and 250-bed community-based referral hospital.
  
  
  METHODS
  One hundred seventy-one consecutive confirmed HIV-seronegative hospitalized and ambulatory adults, including 22 patients with active PCP, 8 patients with bacterial pneumonia, 24 persons in two groups considered at high clinical risk, 38 persons in two groups considered at low or undefined risk, and 79 persons in four groups considered not at risk for PCP (including healthy individuals).
  
  
  RESULTS
  Compared to counts in healthy individuals, median CD4 + counts were significantly decreased in patients with active PCP (61 cells/microL vs 832 cells/microL; p = 0.001) where 91% of patients had a CD4 + count < 300 cells/microL at the time of PCP diagnosis. Median CD4 + counts were also reduced in the high clinical risk groups of recent organ transplant recipients (117 cells/microL; p = 0.007), 64% with < 300 cells/microL, and patients receiving chemotherapy (221 cells/microL; p<0.01), 80% with < 300 cells/microL. For the low or undefined clinical risk groups, the median CD4 + counts were not significantly reduced, although 39 to 46% of individuals receiving long-term corticosteroid therapy (alone or in combination with other agents) had CD4 + counts < 300 cells/microL. Median CD4 + counts in individuals considered not at risk for PCP were similar to those in healthy subjects. Compared to counts in patients with active PCP, median CD4 + counts were significantly higher in bacterial pneumonia patients (486 cells/microL; p<0.05), but similar to those in healthy subjects.
  
  
  CONCLUSIONS
  These data suggest that for immunosuppressed persons without HIV infection (especially in low or undefined PCP risk groups), CD4 + counts may be a useful clinical marker to identify specific individuals at particularly high clinical risk for PCP and may help to guide chemoprophylaxis.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Beth Israel Deaconess Medical Center, and Harvard Medical School, Boston 02215, USA.
authors.forename: N G
authors.initials: NG
authors.lastname: Mansharamani
authors.forename: D
authors.initials: D
authors.lastname: Balachandran
authors.forename: I
authors.initials: I
authors.lastname: Vernovsky
authors.forename: R
authors.initials: R
authors.lastname: Garland
authors.forename: H
authors.initials: H
authors.lastname: Koziel
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D006678:HIV / Q000276:immunology; D015483:HIV Antibodies / Q000032:analysis; D015658:HIV Infections / Q000276:immunology; D006801:Humans; D016867:Immunocompromised Host / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011020:Pneumonia, Pneumocystis / Q000097:blood / Q000276:immunology*; D011379:Prognosis; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D015483:HIV Antibodies