Demographics and outcome of patients with congenital haemophilia in Sarawak, Malaysia

INTRODUCTION: Sarawak has a population that is geographically and characteristically widely varied. This study aimed to determine the demographic profile of patients in Sarawak, Malaysia. Materials and Methods - A cross-sectional study was conducted in 2019 at four major haemophilia treatment centres in Kuching, Sibu, Bintulu and Miri Hospitals, Sarawak. Demographic and clinical data were collected with consents from patients.

RESULTS AND DISCUSSION: Ninety-six haemophilia patients were identified - 79(82.3%) haemophilia A(HA) and 17(17.7%) haemophilia B(HB). Severe haemophilia patients were noted in 45.6% (36/79) of HA and 64.7% (11/17) of HB. In all 44.3% of the HA and 52.9% of the HB population had no identifiable family history of haemophilia. Two-thirds of the patients with severe HA were on prophylaxis [24/36 (66.7%)] and only onethird [4/11 (36.4%)] in severe HB. Inhibitors developed in 9/79 (11.4%) of the HA population [3/79 (3.8%) high responders]. The median inhibitor titre was not significantly different between the different treatment groups - on demand versus prophylaxis (1.0BU versus 2.0BU; z statistic -1.043, p-value 0.297, Mann-Whitney test). None of the patients developed inhibitory alloantibodies to factor IX. Four HA patients (5.1%) underwent immune tolerance induction where one case had a successful outcome. Three severe HA patients received emicizumab prophylaxis and showed remarkable reduction in bleeding events with no thromboembolic events being reported. One female moderate HA patient received PEGylated recombinant anti-haemophilic factor. Eleven patients underwent radiosynovectomy. One mild HB patient succumbed to traumatic intracranial bleeding. Our data reported a prevalence (per 100,000 males) of 5.40 cases for all severities of HA, 2.46 cases for severe HA; 1.16 cases for all severities of HB, and 0.75 cases for severe HB. The overall incidence of HA and HB was 1 in 11,500 and 1 in 46,000, respectively.

CONCLUSION: This study outlines the Sarawakian haemophilia landscape and offers objective standards for forward planning. Shared responsibilities among all parties are of utmost importance to improve the care of our haemophilia population.