HaemophiliaVolume 22, Issue 4 p. e345-e346 Letter to the Editor M1761K mutation in the von Willebrand factor A3 domain associated with impaired collagen binding and without platelet dysfunction D. M. Ong, D. M. Ong Department of Haematology, Alfred Health, Melbourne, Vic., AustraliaSearch for more papers by this authorH. Aumann, H. Aumann Department of Haematology, Alfred Health, Melbourne, Vic., AustraliaSearch for more papers by this authorR. K. Andrews, R. K. Andrews Australian Centre for Blood Diseases, Monash University, Melbourne, Vic., AustraliaSearch for more papers by this authorE. E. Gardiner, E. E. Gardiner Australian Centre for Blood Diseases, Monash University, Melbourne, Vic., AustraliaSearch for more papers by this authorS. E. Rodgers, S. E. Rodgers Haematology Division, SA Pathology, Adelaide, SA, AustraliaSearch for more papers by this authorA. K. Davis, Corresponding Author A. K. Davis Department of Haematology, Alfred Health, Melbourne, Vic., Australia Correspondence: Dr Amanda Davis, The Alfred Hospital, Commercial Rd, Prahran, Melbourne, Vic. 3181, Australia. Tel.: +61 3 9076 8008; fax: +61 3 9076 3424; e-mail: am.davis@alfred.org.auSearch for more papers by this author D. M. Ong, D. M. Ong Department of Haematology, Alfred Health, Melbourne, Vic., AustraliaSearch for more papers by this authorH. Aumann, H. Aumann Department of Haematology, Alfred Health, Melbourne, Vic., AustraliaSearch for more papers by this authorR. K. Andrews, R. K. Andrews Australian Centre for Blood Diseases, Monash University, Melbourne, Vic., AustraliaSearch for more papers by this authorE. E. Gardiner, E. E. Gardiner Australian Centre for Blood Diseases, Monash University, Melbourne, Vic., AustraliaSearch for more papers by this authorS. E. Rodgers, S. E. Rodgers Haematology Division, SA Pathology, Adelaide, SA, AustraliaSearch for more papers by this authorA. K. Davis, Corresponding Author A. K. Davis Department of Haematology, Alfred Health, Melbourne, Vic., Australia Correspondence: Dr Amanda Davis, The Alfred Hospital, Commercial Rd, Prahran, Melbourne, Vic. 3181, Australia. Tel.: +61 3 9076 8008; fax: +61 3 9076 3424; e-mail: am.davis@alfred.org.auSearch for more papers by this author First published: 28 June 2016 https://doi.org/10.1111/hae.12976Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume22, Issue4July 2016Pages e345-e346 RelatedInformation

In some mild haemophilia A patients (discrepant phenotype), coagulation FVIII levels by one-stage assay (FVIII-1st) are more than double those by classical two-stage coagulation assay (FVIII-2st), and may fall within the normal range. Our aim was to assess automated two-stage chromogenic FVIII assays (FVIII-chr) for diagnosis of mild discrepant haemophilia A. Three chromogenic FVIII kits (Biophen, Coamatic and Dade-Behring) were evaluated, using recommended and extended incubation times. Samples were tested from patients with discrepant haemophilia (n = 7) and equivalent mild haemophilia (agreement between FVIII-1st and FVIII-2st, n = 4). For equivalent haemophilia, FVIII-chr were consistent with FVIII-1st and FVIII-2st for all kits at all incubation times. For discrepant haemophilia, using recommended incubation times, mean FVIII-chr using Biophen reagents was 22 IU/dl (range 13-31), with Coamatic 26 (17-34) and with Dade-Behring 41 (33-47), compared with 36 (27-44) for FVIII-1st and 8 (6-9) for FVIII-2st. FVIII-chr decreased as incubation time was increased with Biophen and Coamatic, but decreased less with Dade-Behring. FVIII-chr using the Dade-Behring kit gave similar results to FVIII-1st and is not suitable for diagnosis of mild discrepant haemophilia A. FVIII-chr by Biophen and Coamatic kits is suitable for diagnosis of these patients, especially with an extended incubation time.

SummaryPlatelet aggregometry is widely used to investigate platelet function but its performance is poorly standardized between laboratories. The aim of this work was to document the platelet aggregation methods used in specialist laboratories enrolled in the Haematology Quality Assurance Program of the Royal College of Pathologists of Australasia. A questionnaire requesting many details of methodology was distributed and from the responses, we determined a consensus view. Consensus was defined here as >70% agreement among respondents in answer to a question and this was seen for a number of aspects of the preanalytical, analytical and interpretive phases. However, for many questions there was a wide variation in responses. Sixteen laboratories provided a breakdown of the types of abnormal results typically seen in a 12‐month period. In these laboratories a total of 1400 patients were tested and 390 (27%) had abnormal platelet function. Although it was common to diagnose the cause as aspirin or an aspirin‐like defect or a release/storage pool disorder, the range of experience was wide and other rare defects were reported. We conclude that whilst there are a number of points of agreement between laboratories in platelet function testing, standardization could be improved.

The use of anticoagulant drugs requires a knowledge of the essential elements of their pharmacology and mechanisms of action. This article illustrates the marked differences for the drugs warfarin, heparin and aspirin.