Perivascular Fibrosis in the Bone Marrow in Sickle Cell Disease

Abstract Context.—Magnetic resonance imaging of bone marrow in homozygous sickle cell disease (hemoglobin [Hb] SS) shows nonhomogeneous, mottled signals that increase with age and number of crises. The pattern of these signals is reminiscent of the underlying vascular architecture, but histopathology of this tissue has not been adequately studied. Objective.—To elucidate the histopathology of blood vessels in the bone marrow in sickle cell disease. Design.—Retrospective histochemical morphometric study of bone marrow arteries by point counting in HbSS (13 cases) and sickle cell Hb C (HbSC) (8 cases) compared to nonanemic normal controls (HbAA) (10 cases). All patients were nondiabetic, normotensive, younger than 37 years, and matched for age group. Results.—The mean point count for perivascular fibrous tissue was significantly greater in the HbSS group (P < .001) in both small (P < .001) and medium-sized (P = .002) vessels, and in both age groups (pediatric, P < .001; adult, P = .005) compared with the Hb...