Role of Serum Lipoprotein at the Site of Iloprost Therapy in the Treatment of Painful Bone Marrow Edema

Abstract

The authors hypothesized that the emergence of painful bone marrow edema occurs through microembolisms in the bone marrow that may be reflected in elevated plasma parameters of hypofibrinolysis or a disturbance of the lipid metabolism and that treatment with iloprost may lead to a decrease in or normalization of the elevated serum parameters and, therefore, to pain reduction. Twenty-one patients (12 men and 9 women; mean age, 50 years [range, 22-70 years]) with painful bone marrow edema and elevated lipoprotein(a) (Lp[a]) serum values were treated with intravenous iloprost. Before and 6 weeks after iloprost therapy, the serum concentrations of Lp(a), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were determined. At 6-week follow-up, 17 patients reported complete resolution of their symptoms. For these patients, complete bone marrow edema resolution was observed on magnetic resonance imaging. Four patients reported that their symptoms were either the same or had worsened but had partial bone marrow edema resolution on magnetic resonance imaging. In these patients, Lp(a) values either increased or remained the same. Hence, the total success rate of iloprost treatment was 86% at a mean follow-up of 17 months (range, 3-45 months). Before iloprost therapy, mean ApoA1, ApoB, and Lp(a) values were 159.8, 108.3, and 69.1 mg/dL, respectively. Six weeks after iloprost therapy, mean ApoA1, ApoB, and Lp(a) values decreased to 147.6 (P=.011), 98.4 (P=.042), and 38.3 (P<.001) mg/dL, respectively. The results of this study indicate a possible role of hypofibrinolysis or a disturbance in the lipid metabolism in the emergence of painful bone marrow edema.