Erythrocyte rheology is altered in haemophilia patients with advanced arthropathy. A case-control study

Haemophilia goes along with a lack of clotting factors, which can lead to bleedings mostly being of intraarticular nature. These patients (PwH) suffer from health implications attributed to the resulting haemophilc arthropathy. Even though the haemostatic system is widely studied in PwH, little is known about red blood cell (RBC) rheology. This study aims to explore RBC rheology focussing on deformability and aggregation in PwH and to describe potential influencing factors. 27 PwH and 27 healthy controls (HC) were included in this study. RBC deformability (EImax, SS½, SS½/EImax ratio) and aggregation (AI, Shear stress at disc min) were measured using ektacytometry and obtained from syllectograms. Haematological parameters were determined. The Haemophilia Joint Health Score (HJHS) was assessed indicating musculoskeletal impairment. Pain and pain sensitivity were measured using numeric rating scales and pressure algometry. Subjective physical functioning was assessed via questionnaires. PwH possess higher HJHS scores than HC (p < .001) with a range of 11-69 points. All RBC deformability parameters (p ≤ .007) and Shear stress at disc min (p < .001) are impaired in PwH compared to HC. Regarding haematological parameters, only red cell distribution width (p = .049) and haemoglobin (p = .024) were different. PwH reveal higher pain states (p ≤ .002) and lower physical functioning (p < .001). This study is the first to investigate RBC rheology in PwH with haemophilic arthropathy and shows that RBC rheological properties, particularly deformability, are impaired in this population. These observations might be attributed to advanced joint restrictions and higher pain states in PwH resulting in lower physical activity as well as to present co-morbidities and co-medication.