Alpha 2-Antiplasmin Deficiency

Laboratory Evaluation

A specific assay for alpha 2-antiplasmin deficiency is performed when a patient has a bleeding diathesis that cannot be identified by the usual screening assays. Both alpha 2-antiplasmin antigen and activity levels can be measured.

Two types of alpha 2-antiplasmin deficiency exist:

  1. Type 1 – Decreased antigen and activity levels
  2. Type 2 – Low activity level with normal antigen level

Homozygous patients usually have undetectable levels while heterozygous patients have levels 40% – 60% of normal. The normal plasma concentration is 0.7 mg/L.

Imaging techniques are used for acute events, as applicable. The utilization of imaging techniques depends on the site of bleeding and the necessity of imaging. The unique intramedullary hematomas are visualized by magnetic resonance imaging as homogenous hyperintense signals in the medulla and hypointense signals surrounding the lesion.