High Sensitivity of Monochloroacetic Acid 1% Clot Lysis Test for Diagnosis of Severe FXIII Deficiency

Abstract number: P1389

Eshghi¹ P, Sanei-Moghaddam² E, Anwar³ R, Jazebi⁴ H, Ala⁵ F

¹¹Department of Pediatrics, Ali-Asghar Hospital, Zahedan Medical University, Zahedan, Iran ²²Iranian Blood Transfusion Organization, Sistan andBaluchistan Division, Zahedan, Iran ³³Molecular Medicine Unit, University of Leeds, St James's University Hospital, Leeds, UK ⁴⁴Coagulation Laboratory, Comprehensive Hemophilia Care Center, Tehran, Iran ⁵⁵National Blood Service, Edgbaston, Birmingham, UK

Introduction:  Congenital FXIII deficiency is a rare disorder. Although timely diagnosis is crucial because of high risk of intracranial bleeding, especially during the early childhood, all routine coagulation tests are normal. it necessitate screening for FXIII deficiency with clot solubility tests, but exact diagnosis is confirmed only by measurement of FXIII activity, FXIII antigenicity or plasma concentration of FXIII, which are expensive and not available, especially in developing countries which the most cases has been reported from them(IRAN and PAKISTAN). So it seems necessary to study about the diagnostic value of the clot lysis tests.

Method:  All of the new bleeding children in the southeast of Iran (from January 2001 to April 2004) with normal routine coagulation tests (Platelet, BT, PT, PTT, TT) were assessed by the clot solubility test in 1% monochloroacetic acid, and also by a functional assay for serum FXIIIa (Pefakit, Pentapharm Ltd., Basel, Switzerland) [became available to us in January 2001] based on the method described by Kohler et al. Then we compare the results to evaluate the positive predictive value and sensitivity of the screening tests for diagnosis of severe FXIII deficiency.

Result:  the clot solubility tests were abnormal in all of the 13 clinically suspected new cases with normal routine coagulation tests during the study. 1°Cases out of them were confirmed (<5% serum FXIIIa activity). So, we found 100% (10/10) sensitivity and 76.9% (10/13) positive predictive value of screening tests for severe FXIII deficiency.

Conclusion:  although our available functional assay kits were not enough to use them for the patients with normal clot solubility, so this study can not be conclusive for specificity and negative predictive value of screening tests, but they are highly sensitive and suitable for diagnosis of FXIII deficiency.