Associate Professor Tien Sim Leng is a Senior Consultant Haematologist at Singapore General Hospital (SGH). He is the Head of SGH Blood Bank at the Haematology Laboratory and Cytogenetics Laboratory. He also serves as the Director of the SGH Haemophilia Treatment and Training Center. He holds the position of Clinical Associate Professor at National University of Singapore, Adjunct Associate Professor at Duke-NUS Graduate Medical School and former Adjunct Associate Professor at Nanyang Technological University, Singapore.

He was the President of the 5^th Congress of Asian-Pacific Society on Thrombosis and Haemostasis held in Singapore in 2008. He was the Organising Chairman of the Malmo Program 2013 International Haemophilia Course in Singapore. He is a former Vice-Chairman and current Council Member of the Chapter of Haematology, College of Physicians, Academy of Medicine in Singapore, as well as a current member of the Singapore Society of Haematology. Currently, he is the Chairman of the Hospital Blood Transfusion Committee.

He practices both clinical and laboratory Haematology, including Transfusion Medicine. To date, he has at least 200 abstract presentations and 70 publications in peer-reviewed journals. He co-authored a book on Biomedical Ethics and Medical Law in Blood Transfusion Practice, and has received over 40 Research Grants. He is a reviewer for Annals, Academy of Medicine, Singapore Medical Journal, Thrombosis Journal, NMRC and BMRC Research Grants.

Abstract

The management of Haemophilia has advanced over the years. With the current trend towards the use of various replacement and non-replacement clotting products, and moving towards gene therapy in Haemophilia Care, laboratory testing has to keep pace with its progress. In order to provide optimal care for persons with Haemophilia, Haemophilia treaters and laboratorians must address critical issues in laboratory testing.

For diagnosis of mild Haemophilia A, World Federation of Haemophilia (WFH) recommends that both one-stage Factor VIII assay and the chromogenic FVIII-C assay have to be used at its initial testing.

The use of long-acting recombinant Factor VIII products may require chromogenic assay in its potency labelling and post-infusion measurement of Factor VIII. For inhibitor assessment in patients on emicizumab, it is important to ensure that chromogenic FVIII assays with bovine reagents are being used in the laboratory.

Among people with Haemophilia, WFH recommends genetic testing to identify the specific underlying genetic variant associated with their disorder. The utility of genetic testing for Haemophilia goes beyond conventional prenatal diagnosis and genetic counselling to assessment of bleeding severity, risk of developing inhibitor, resolving assay discrepancies, more accurate diagnosis, and gene therapy.