Background: Children with bleeding disorders, such as hemophilia and von Willebrand disease (VWD), have an increased risk of acquiring transfusion-transmitted infections (TTI). Screening methods to exclude blood donations that are at risk of transmitting infection from donors to recipients are critical to preventing disease transmission. Nucleic acid testing (NAT) is the latest blood donor-screening method. This study aimed to determine the incidence of hepatitis C virus (HCV) infection in children with hemophilia and VWD at Dr. Cipto Mangunkusumo Hospital with a history of blood transfusion before and after implementation of a NAT screening method. Methods: A cohort retrospective study was conducted on children aged 0‒18 years with bleeding disorders and a history of blood transfusion. In our center, all blood transfusions before 2015 were screened using non-NAT methods, while all blood transfusions were screened using NAT starting in 2015. Eligible patient characteristics were collected from medical records. From July to December 2019, blood samples were obtained from eligible patients for anti-HCV examination. HCV RNA examinations were performed on subjects with reactive anti-HCV results, and the relative risk was calculated. Results: In total, 108 eligible participants were included in this study. We observed that 91 (94.3%) patients had history of receiving non-NAT blood transfusions, while 17 (15.7%) patients received NAT-screened blood transfusions. The proportion of anti-HCV reactivity in the non-NAT group and that in the NAT group were 3.3% (3/91) and 0% (0/17), respectively. Conclusion None of the patients exhibited reactivity to anti-HCV after implementing the NAT screening method.

Background: Factor VIII (FVIII) inhibitor diagnosis and surveillance in Indonesia are challenging owing to geographic conditions and the lack of laboratory facilities nationwide for inhibitor assays. This study aimed to determine the prevalence of FVIII inhibitors in children diagnosed with hemophilia A (HA) in Indonesia. Methods: A cross-sectional study was conducted in 12 hospitals in eight provinces of Indonesia between 2020 and 2021. Factor VIII inhibitor screening was performed in a central hemostasis laboratory for all children with HA (≤18 yr) who had received a minimum of 10 exposure days to clotting factor concentrates. The FVIII inhibitor titer was determined using the Bethesda assay. Results: Children (388) were enrolled in this study, including 219 (56.4%), 131 (33.8%), and 38 (9.4%) with severe, moderate, and mild HA, respectively. The prevalence of children who developed FVIII inhibitors was 37 out of 388 (9.6%). Factor VIII inhibitors were found in 25/219 (11.4%) severe, 11/131 (8.3%) moderate, and 1/38 (2.6%) children with mild HA. Thirteen children had low-titer inhibitors and 24 had high-titer inhibitors, with a median of 9.44 (1.48‒412.0) Bethesda Units. Among 13 children with low-titer inhibitors, eight underwent a confirmation test, of which five tested negative and were classified as transient. A significant difference in annual joint bleeding rate was found between patients with low and high inhibitor titers and those without inhibitors (P ＜0.001). Conclusion Factor VIII inhibitor prevalence in Indonesia was relatively low. However, the risk factors that may contribute to FVIII inhibitor development among Indonesian patients require further study.