biostudies-literatureUnknown7(2)Rejto J<h4>Background</h4>Although the phenotype of severe hemophilia has been well studied, there are still knowledge gaps in nonsevere hemophilia.<h4>Objectives</h4>The objective of this study was to characterize the clinical bleeding phenotype in nonsevere hemophilia and its association with different factor VIII/IX assessments.<h4>Methods</h4>This was a cross-sectional, multicenter study to investigate the bleeding phenotype in adults with nonsevere hemophilia by the number of bleeding and joint bleeding in the past 5 years, a joint score, and the International Society on Thrombosis and Haemostasis bleeding assessment tool (ISTH-BAT). Factor levels were analyzed by 1-stage (lowest in history and at study inclusion) and chromogenic assay (at study inclusion). Patients were enrolled between March 2015 and May 2019.<h4>Results</h4>Of the 111 patients (86 with mild and 25 with moderate hemophilia), 57 patients (54.8%) reported any bleeding and 24 (23.1%) any joint bleeding in the past 5 years. A joint score ≥1 was found in 44 patients (41.9%), an ISTH-BAT ≥4 in 100 patients (90.1%), and an ISTH-BAT joint item ≥1 in 50 patients (45.0%). Within the ISTH-BAT, muscle and joint bleeds showed the largest difference between mild and moderate hemophilia. The lowest factor VIII/IX level in patients' history was best associated with bleeding outcomes. Factor was inversely associated with joint bleeds (incidence rate ratio 0.88; 95% CI, 0.79-0.98), joint score, and ISTH-BAT (odds ratios from proportional odds ordinal logistic regression 0.92; 95% CI, 0.87-0.97; and 0.89; 95% CI, 0.86-0.93, respectively).<h4>Conclusion</h4>The occurrence of joint bleeding differentiated persons with mild and moderate hemophilia. The ISTH-BAT and lowest factor in patients' history provided valuable information of the bleeding phenotype in nonsevere hemophilia.Research and practice in thrombosis and haemostasis100047https://www.ebi.ac.uk/biostudies/studies/S-EPMC9999231biostudies-literatureBleeding phenotype in nonsevere hemophilia by International Society on Thrombosis and Haemostasis bleeding assessment tool, bleeding frequency, and the joint status.PMC9999231Gebhart JAy CPabinger IRejto JKraemmer DKonigsbrugge OGabler CSchuster GGrilz EFeistritzer CSunder-Plaßmann RQuehenberger PfalseBleeding phenotype in nonsevere hemophilia by International Society on Thrombosis and Haemostasis bleeding assessment tool, bleeding frequency, and the joint status.<h4>Background</h4>Although the phenotype of severe hemophilia has been well studied, there are still knowledge gaps in nonsevere hemophilia.<h4>Objectives</h4>The objective of this study was to characterize the clinical bleeding phenotype in nonsevere hemophilia and its association with different factor VIII/IX assessments.<h4>Methods</h4>This was a cross-sectional, multicenter study to investigate the bleeding phenotype in adults with nonsevere hemophilia by the number of bleeding and joint bleeding in the past 5 years, a joint score, and the International Society on Thrombosis and Haemostasis bleeding assessment tool (ISTH-BAT). Factor levels were analyzed by 1-stage (lowest in history and at study inclusion) and chromogenic assay (at study inclusion). Patients were enrolled between March 2015 and May 2019.<h4>Results</h4>Of the 111 patients (86 with mild and 25 with moderate hemophilia), 57 patients (54.8%) reported any bleeding and 24 (23.1%) any joint bleeding in the past 5 years. A joint score ≥1 was found in 44 patients (41.9%), an ISTH-BAT ≥4 in 100 patients (90.1%), and an ISTH-BAT joint item ≥1 in 50 patients (45.0%). Within the ISTH-BAT, muscle and joint bleeds showed the largest difference between mild and moderate hemophilia. The lowest factor VIII/IX level in patients' history was best associated with bleeding outcomes. Factor was inversely associated with joint bleeds (incidence rate ratio 0.88; 95% CI, 0.79-0.98), joint score, and ISTH-BAT (odds ratios from proportional odds ordinal logistic regression 0.92; 95% CI, 0.87-0.97; and 0.89; 95% CI, 0.86-0.93, respectively).<h4>Conclusion</h4>The occurrence of joint bleeding differentiated persons with mild and moderate hemophilia. The ISTH-BAT and lowest factor in patients' history provided valuable information of the bleeding phenotype in nonsevere hemophilia.2023-01-01T00:00:00Z2023 Feb2025-04-04T18:50:34.625Z2025-04-04T18:50:34.625ZS-EPMC99992313690876910.1016/j.rpth.2023.100047