Prekallikrein Deficiency – Acquired

At a Glance

What Tests Should I Request to Confirm My Clinical Dx? In addition, what follow-up tests might be useful?

Acquired prekallikrein deficiency is very rare. It could arise from antibodies to the protein. There are few acquired inhibitors to prekallikrein reported. Its deficiency is not associated with bleeding.

Test results consistent with acquired prekallikrein deficiency include activated partial thromboplastin time (aPTT) that is mildly prolonged (35-45 seconds) with evidence on a mixing study or a specific prekallikrein inhibitor assay that something in the patient’s plasma can be transferred to normal plasma and produce the defect.(Table 1)

Table 1

Test Results Indicative of the Disorder

Are There Any Factors That Might Affect the Lab Results? In particular, does your patient take any medications - OTC drugs or Herbals - that might affect the lab results?

Anticoagulants like heparin, enoxaparin, fondaparinux, hirudin, argatroban, bivalirudin, or dabigatran can interfere with any clot-based assay.

What Lab Results Are Absolutely Confirmatory?

Low prekallikrein assay with evidence of an inhibitor to prekallikrein on a mixing study is absolutely confirmatory.

Are There Any Factors That Might Affect the Lab Results? In particular, does your patient take any medications - OTC drugs or Herbals - that might affect the lab results?

Anticoagulants, high plasma lipids, and high serum bilirubin may affect lab results.