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Lupus anticoagulants in two children--bleeding due to nonphospholipid-dependent antiprothrombin antibodies

Karin Knobe1, Ulf Tedgård, Torben Ek

  • 1Malmö Centre for Thrombosis and Haemostasis, Skåne University Hospital, SE-205 02 Malmö, Sweden. karin.knobe@med.lu.se

European Journal of Pediatrics
|April 25, 2012
PubMed

Insights

Bleeding in children with lupus anticoagulants (LA) is rare. A specific antibody causing low prothrombin activity, not LA, likely caused bleeding in these cases.

Area of Science:

  • Hematology
  • Immunology
  • Pediatrics

Background:

  • Lupus anticoagulants (LA) are antiphospholipid antibodies associated with thrombosis.
  • Bleeding complications in patients with LA are uncommon.

Observation:

  • Two children presented with significant bleeding (ecchymoses and scrotal bleeding).
  • Both patients had prolonged activated partial thromboplastin time (APTT) and tested positive for LA.
  • Unusually, the Owren prothrombin time (PT) was also prolonged in both cases.

Findings:

  • Extended laboratory analysis revealed LA and a specific nonphospholipid-dependent antiprothrombin antibody.
  • This antibody led to acquired hypoprothrombinemia (low prothrombin activity).
  • The bleeding resolved when prothrombin time normalized, despite persistent LA and prolonged APTT.

Implications:

  • Acquired hypoprothrombinemia due to specific antibodies should be considered in bleeding patients with LA.
  • This finding highlights a rare cause of bleeding in the presence of lupus anticoagulants.
  • Understanding specific antibody-mediated coagulation factor deficiencies is crucial for accurate diagnosis and management.
Abstract

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