+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

An international study of how laboratories handle and evaluate patient samples after detecting an unexpected APTT prolongation



An international study of how laboratories handle and evaluate patient samples after detecting an unexpected APTT prolongation



Clinical Chemistry and Laboratory Medicine 53(10): 1593-1603



An unexpectedly detected prolonged activated partial thromboplastin time (APTT) can be a harmless laboratory finding, but can also reflect a thrombotic tendency or a bleeding disorder. The assistance of laboratory professionals in the interpretation of an unexpectedly detected prolonged APTT (uAPTT) is often required. The way in which uAPTTs are evaluated in laboratories was assessed in this international study with the aim of determining whether laboratory professionals are able to fulfill this need. Postanalytical practices after uAPTT were investigated and the mixing study methodology (if used) was studied by circulating a case report with a questionnaire to staff in the invited laboratories. In addition, the interpretations of those staff regarding the presence or absence of inhibitors in three APTT mixing study scenarios were examined. Large within- and between-country variations were detected in both postanalytical practices and mixing study methodologies among the 990 responding laboratories, 90% of which were in 13 countries. Shortcomings regarding the investigation of uAPTTs leading to potentially incorrect or delayed clinical diagnoses were found in 88% of the laboratories. Of the laboratories to which the interpretative questions were sent, 49% interpreted all mixing study scenarios correctly. uAPTTs were investigated appropriately and all mixing study scenarios interpreted correctly in parallel in only 9.6% of the participating laboratories. The clinical requirement for the assistance of laboratory professionals in the interpretation of uAPTTs cannot be met at most of the participating laboratories. Laboratory professionals should be trained in the evaluation of ordinary laboratory tests, such as that for uAPTTs.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 057183517

Download citation: RISBibTeXText

PMID: 26023801

DOI: 10.1515/cclm-2014-1183


Related references

Comparison of heparin-induced prolongation of APTT in 12 different laboratories in Kyushu area. Rinsho Byori. Japanese Journal of Clinical Pathology 61(7): 576-582, 2013

APTT prolongation and skin eruption possibly associated with lamotrigine monotherapy in a paediatric patient. Epileptic Disorders 13(4): 452-455, 2011

A patient with isolated prolongation of aPTT without hemorrhagic diathesis anamnesis: severe, hereditary factor XII deficiency. Therapeutische Umschau. Revue Therapeutique 56(9): 509-512, 1999

Applying a direct aPTT ratio (PlatelinLS/ActinFS) permits to identify rapidly and reliably a bleeding-related factor deficiency or a lupus anticoagulant sequential to an isolated prolongation of aPTT in paediatric pre-operative screening. European Journal of Haematology 96(6): 578-585, 2016

Extensive prolongation of aPTT with argatroban in an elderly patient with improving renal function, normal hepatic enzymes, and metastatic lung cancer. Annals of PharmacoTherapy 39(6): 1119-1123, 2005

Comment: extensive prolongation of aPTT with argatroban in an elderly patient with improving renal function, normal hepatic enzymes, and metastatic lung cancer. Annals of PharmacoTherapy 39(11): 1955-6; Author Reply 1956-7, 2005

Comparison of the aPTT with alternative tests for monitoring direct thrombin inhibitors in patient samples. American Journal of Clinical Pathology 141(5): 665-674, 2014

International study to evaluate PCR methods for detection of Trypanosoma cruzi DNA in blood samples from Chagas disease patients. Plos Neglected Tropical Diseases 5(1): E931-E931, 2011

General practitioners surveyed on ethical conflicts. How do you handle the "reluctant" patient? How do you handle the patient demanding unnecessary treatment?. Lakartidningen 99(1-2): 21-24, 2002

Validation of a questionnaire to evaluate patient safety in clinical laboratories. Gaceta Sanitaria 26(6): 560-565, 2013

Spontaneous hematomas and isolated prolongation of aPTT. Praxis 100(10): 603-606, 2011

Analysis of thromboelastography, PT, APTT and fibrinogen in intraosseous and venous samples-an experimental study. Scandinavian Journal of Trauma Resuscitation and Emergency Medicine 24(1): 131, 2016

Prekallikrein (Fletcher Factor) Deficiency and Prolongation of APTT Reaction. Medizinische Klinik 98(10): 587-590, 2003

Prolongation of PT and APTT under excessive anticoagulant in plasma from rats and dogs. Journal of Toxicological Sciences 23(2): 149-153, 1998

Prevalent factor XII deficiency in cancer patients with isolated aPTT prolongation. Blood Research 50(2): 114-117, 2015