ISSN 2997-1036
International Journal of Hematology | Vol. 4, No. 4, April 2013 | pp. 25–32
DOI: 10.46882/2013/IJH/000040
Short Communication
Title: Prevalence of prolonged activated partial thromboplastin time due to intrinsic pathway factor deficiencies in elective pre-operative screening
Names of Authors: B. C. Akpan¹, D. E. Usman²
Authors’ Affiliations: ¹Department of Haematology, University of Calabar, Calabar, Nigeria; ²Department of Clinical Pharmacology, Ahmadu Bello University, Zaria, Nigeria
Abstract: Unsuspected coagulation abnormalities detected during pre-operative screening can cause cancellations or delays in elective surgical procedures. This study evaluated the causes of an isolated prolonged activated partial thromboplastin time discovered during routine pre-operative assessments in 75 asymptomatic adult patients. A 1:1 mixing study with normal pooled plasma was performed to differentiate factor deficiencies from circulating inhibitors, followed by specific factor assays. Corrected mixing study profiles confirmed an intrinsic pathway factor deficiency in 68.0% (51 of 75) of the cases. Factor XII deficiency was the most common cause, identified in 28.0% of the cohort, followed by Factor XI deficiency in 14.6% and Factor IX deficiency in 12.0%. A circulating lupus anticoagulant was confirmed in 18.6% of patients with non-corrected mixing studies. Asymptomatic Factor XII deficiency does not require therapeutic intervention or surgical delay because it does not cause clinical bleeding. Routine pre-operative screening panels should include immediate plasma mixing steps to prevent unnecessary surgical cancellations for benign coagulation abnormalities.
Keywords: Activated partial thromboplastin time, pre-operative screening, mixing study, Factor XII deficiency, intrinsic pathway
Manuscript Timeline: Received: January 15, 2013; Revised: February 22, 2013; Accepted: March 11, 2013; Published: April 18, 2013