Urine hemosiderin: a novel marker to assess the severity of chronic venous disease.

Abstract

Impaired venous drainage in severe chronic venous insufficiency (CVI) leads to microcirculatory overload, characterized by erythrocyte diapedesis and subsequent extravascular hemolysis, resulting in typical dermal hemosiderin deposition. We hypothesized that hemosiderin, normally absent, could be present in the urine in CVI. The three-phase study included 117 patients with CVI and 12 healthy control subjects, all of whom had undergone clinical examination and duplex scanning. In phase 1, current methods were used to test urine for hemosiderin in 61 persons: 12 healthy control subjects, 24 patients with mild CVI (clinical class C1 to C3), and 25 patients with severe CVI (clinical class C4 to C6). In phase 2, the concentration of urinary hemosiderin was determined in 45 consecutive patients with CVI, CEAP class 1 to 6. A score of 0 was assigned when typical hemosiderin granules were absent at microscopic examination, a score of 1 when one to three granules per field were detected; 2 when four to six granules were detected; and 3 when more than six granules were observed. Phase 3 included 23 patients with CVI (clinical class 2 to 6). Hemosiderin concentration was determined and a score assigned before patients underwent surgical procedures to correct primary CVI. Both hemosiderin testing and duplex scanning were repeated after 6 months. Phase 1: Urine hemosiderin testing to determine presence or absence of CVI in patients with reflux detectable at duplex scanning yielded the following values: positive predictive value, 96% (95% confidence interval [CI], 86% to 100%); negative predictive value, 88% (CI, 68% to 97%); sensitivity, 94% (CI, 72% to 99%); specificity, 91% (CI, 83% to 99%); and diagnostic accuracy, 95% (CI, 86% to 99%). Phase 2: Hemosiderinuria score enabled classification of clinical severity of CVI. Mean scores, respectively, were clinical class 1, 0.18 +/- 0.12; class 2, 0.75 +/- 0.47; class 3, 1.67 +/- 0.21; class 4, 1.86 +/- 0.26; class 5, 2.50 +/- 0.28; and class 6, 1.92 +/- 0.21 (P <.001). Phase 3: At 6-month follow-up, hemosiderin score was improved, from 2.48 +/- 0.12 preoperatively to 0.78 +/- 0.18 postoperatively (P <.0001). A score of 0 or 1 was associated with successful surgery, whereas a score of 2 or 3 reflected persistence of reflux. Determination of presence of hemosiderin in the urine is a new, sensitive, cost-effective, noninvasive, and repeatable test that enables detection of substantial microcirculatory overload in patients with CVI.