title: Acquired protein S deficiency in children infected with human immunodeficiency virus.
abstract: OBJECTIVE
  To determine the prevalence of an acquired deficiency of protein S, a coagulation inhibitor, in children infected with the human immunodeficiency virus (HIV) and to identify clinical and laboratory features associated with this coagulation abnormality.
  
  
  METHODS
  A convenience sample of HIV-infected children, ages 2 to 18 years, was evaluated for total, free and functional protein S; total and functional protein C; prothrombin and activated partial thromboplastin times; fibrinogen; antithrombin III activity; dilute Russell viper venom time; IgG anticardiolipin antibodies; von Willebrand factor antigen; C4b-binding protein; CD4+ T lymphocyte counts; HIV p24 antigen concentration; and serum beta 2-microglobulin concentrations.
  
  
  RESULTS
  Thirty-four subjects were evaluated. Twenty-four subjects were infected perinatally and 10 by transfusion. Nine of the subjects were CDC Class N (asymptomatic), 13 were Class A/B (symptomatic without AIDS-defining condition) and 12 were Class C (AIDS). None had previously documented thrombosis, nephrosis or significant hepatic dysfunction. Twenty-six subjects (76.5%) had decreased free protein S, and 19 (55.9%) had functional protein S < 2 SD below the mean of laboratory controls. Decreased functional protein S was seen in 33.3% of Class N, 53.8% of Class A/B and 75.0% of Class C subjects. The prevalence of decreased total and functional protein S was greater in those with absolute CD4+ T lymphocyte counts < 200/mm3 compared to those with CD4+ counts > or = 200/mm3 (75.0% vs. 38.9%; chi square, 4.48, P = 0.034). A trend toward negative correlation was observed between protein S and duration of HIV infection only for Class N subjects. No linear correlation was seen between protein S and CD4+ T lymphocyte counts; and no significant relationships were observed between protein S values and CMV status, HIV p24 antigen, C4b-binding protein, von Willebrand factor antigen, IgG anti-cardiolipin antibodies or serum beta 2-microglobulin values.
  
  
  CONCLUSIONS
  Acquired protein S deficiency is common in HIV-infected children. The high prevalence of this anticoagulant abnormality suggests an increased risk for thrombotic complications in this population.
authors.affiliation: Division of Clinical Immunology, University of Southern California School of Medicine, Los Angeles, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Sugerman
authors.forename: J A
authors.initials: JA
authors.lastname: Church
authors.forename: J C
authors.initials: JC
authors.lastname: Goldsmith
authors.forename: G E
authors.initials: GE
authors.lastname: Ens
mesh_terms: D000293:Adolescent; D015704:CD4 Antigens / Q000032:analysis; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D005260:Female; D015658:HIV Infections / Q000150:complications* / Q000175:diagnosis; D006801:Humans; D016014:Linear Models; D008297:Male; D015995:Prevalence; D017293:Protein S / Q000032:analysis; D018455:Protein S Deficiency / Q000150:complications* / Q000175:diagnosis / Q000453:epidemiology; D012307:Risk Factors; D012494:Sampling Studies; D013601:T-Lymphocytes / Q000502:physiology; D013927:Thrombosis / Q000517:prevention & control*
chemical_list: D015704:CD4 Antigens; D017293:Protein S