title: Screening of blood donors for idiopathic CD4+ T-lymphocytopenia.
abstract: BACKGROUND
  The recent recognition of idiopathic CD4+ T-lymphocytopenia (ICL) had led to concern that an unknown immunodeficiency virus may be transmissible by transfusion.
  
  
  METHODS
  To evaluate the prevalence and significance of low CD4+ values among blood donors, CD4+ data on 2030 blood donors who were negative for antibody to human immunodeficiency virus type 1 (HIV-1) were compiled. Those with CD4+ values below ICL cutoffs (< 300 CD4+ T cells/microL, or < 20% CD4+ T cells) were recalled for follow-up investigations. Serial CD4+ data on 55 homosexual men who seroconverted during prospective follow-up and data on 139 anti-HIV-1-positive blood donors initially evaluated in 1986 were reviewed as well.
  
  
  RESULTS
  Five seronegative donors (0.25%) had absolute CD4+ counts < 300 cells per microL and/or < 20 percent. On follow-up, all five donors had immunologic findings within normal ranges, lacked HIV risk factors, and tested negative for HIV types 1 and 2 and human T-lymphotropic virus type I and II infections by antibody and polymerase chain reaction assays. Four of five donors reported transient illness shortly after their low CD4+ count donations. The median interval from HIV-1 seroconversion to an initial CD4+ value below ICL CD4+ cutoffs was 63 months for infected homosexual men. Of 139 HIV-1-infected blood donors studied 1 to 2 years after seropositive donations, 34 (24%) had CD4+ counts < 300 cells per microL and/or < 20 percent.
  
  
  CONCLUSIONS
  Low CD4+ counts are rare among anti-HIV-1-negative volunteer blood donors and are generally associated with transient illnesses. If any unknown virus progresses similarly to HIV-1, CD4+ count donor screening would be a poor surrogate for its detection.
authors.affiliation: Irwin Memorial Blood Centers, San Francisco, California.
authors.forename: M P
authors.initials: MP
authors.lastname: Busch
authors.forename: J E
authors.initials: JE
authors.lastname: Valinsky
authors.forename: T
authors.initials: T
authors.lastname: Paglieroni
authors.forename: H E
authors.initials: HE
authors.lastname: Prince
authors.forename: G J
authors.initials: GJ
authors.lastname: Crutcher
authors.forename: G F
authors.initials: GF
authors.lastname: Gjerset
authors.forename: E A
authors.initials: EA
authors.lastname: Operskalski
authors.forename: E
authors.initials: E
authors.lastname: Charlebois
authors.forename: C
authors.initials: C
authors.lastname: Bianco
authors.forename: P V
authors.initials: PV
authors.lastname: Holland
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000097:blood; D001782:Blood Donors; D015496:CD4-Positive T-Lymphocytes; D018023:HIV Seronegativity; D006679:HIV Seropositivity; D015497:HIV-1; D015498:HIV-2; D006716:Homosexuality; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D011446:Prospective Studies; D018344:T-Lymphocytopenia, Idiopathic CD4-Positive / Q000175:diagnosis*