title: Prolonged bleeding time and lupus anticoagulant: a second paradox in the antiphospholipid syndrome.
abstract: OBJECTIVE
  Systemic lupus erythematosus and antiphospholipid syndrome (APS) often appear concomitantly. Lupus nephritis and antiphospholipid antibody-related ischemic nephropathy cannot be distinguished clinically, although their etiology and treatment differ greatly. Examination of a renal biopsy sample is therefore essential in order to provide the correct treatment. We have observed that patients with lupus anticoagulant (LAC), a serologic marker for APS, often have a prolonged bleeding time, which is a contraindication for performing a percutaneous renal biopsy. We undertook this study to evaluate systematically the bleeding time in 27 consecutive patients.
  
  
  METHODS
  The bleeding time was measured in 27 patients who were persistently positive for LAC and who were not exposed to aspirin or nonsteroidal antiinflammatory drugs. Platelet function and von Willebrand factor (vWF) parameters were subsequently assessed in patients with a prolonged bleeding time.
  
  
  RESULTS
  Twenty-one of 27 patients (78%) had a prolonged bleeding time despite a normal platelet count in the majority of patients (81%). Platelet functioning and vWF parameters in these 21 patients were normal, except for those in 1 patient with a mild storage pool disease.
  
  
  CONCLUSIONS
  With this study, we introduce yet another paradox in the phenomenon of APS. Although a prolonged bleeding time is generally accepted to be a sign of defective primary hemostasis, LAC is associated with thrombosis. Further studies are needed to elucidate the mechanism behind this disturbance of primary hemostasis.
authors.affiliation: Department of Rheumatology and Clinical Immunology, University Medical Center, 3508 GA Utrecht, The Netherlands.
authors.forename: R T
authors.initials: RT
authors.lastname: Urbanus
authors.forename: H B
authors.initials: HB
authors.lastname: de Laat
authors.forename: P G
authors.initials: PG
authors.lastname: de Groot
authors.forename: R H W M
authors.initials: RH
authors.lastname: Derksen
mesh_terms: D000328:Adult; D016736:Antiphospholipid Syndrome / Q000097:blood*; D001760:Bleeding Time; D005260:Female; D006801:Humans; D016682:Lupus Coagulation Inhibitor / Q000097:blood*; D008875:Middle Aged; D010976:Platelet Count; D010979:Platelet Function Tests; D014841:von Willebrand Factor / Q000032:analysis
chemical_list: D016682:Lupus Coagulation Inhibitor; D014841:von Willebrand Factor