Blood Viscosity and the expression of inflammatory and adhesion markers in Homozygous S sickle cell disease with chronic leg ulcers

To determine differences in pro‐inflammatory (TNF‐α & IL‐1β), anti‐inflammatory (IL‐10) , adhesion markers (ICAM‐1) concentrations and whole blood viscosity (WBV) at a low shear rate of 46 sec −1 and a high shear rate of 230 sec −1 in persons with homozygous sickle cell disease (SS) with and without chronic leg ulceration and in AA genotype controls. Seventy‐four age‐matched participants (42 males and 32 females) were recruited into the study: 31 SS patients (mean age±sd; 30.3±10 yrs) without leg ulcers (SS n ), 24 SS patients (age; 37.9±10.1 yrs) with leg ulcers (SS u ) and 19 (age; 32.5±9.1 yrs) asymptomatic AA genotype. T here were no differences in WBV at low or high shear rates in the sickle cell group compared with AA controls at native haematocrits. TNF‐α ( p <0.001), IL‐1β ( p <0.04) and IL‐10 ( p <0.001), were greater in sickle cell group compared with AA controls. WBV adjusted for haematocrit, in the SS u group at 46 sec −1 and at 230 sec‐1 were 1.9 (95%CI 1.2,3.1) and 2.3 (95%CI 1.2,4.4) times greater than SS n group. IL 1β (median, IQR: 0.96, 1.7 vs. 0, 0.87; p <0.01) and ICAM (226.5, 156.48 vs. 107.63, 121.5 p <0.005) were greater in SS u group compared with SS n . There was no difference in TNF‐α (2, 3.98 vs. 0, 2.66) & IL‐110 (13.34, 5.95 vs. 11.92, 2.99) concentrations between SS u and SS n . Elevated WBV, Inflammation, and cell‐cell interactions are involved in pathogenesis of leg ulcers in sickle cell disease