D-dimer assay in Gaucher disease: correlation with severity of bone and lung involvement.

The D-dimer assay as a marker of cross-linked fibrin may also be an indicator of active microvascular thrombosis, even in patients without overt hypercoagulation. In type I Gaucher disease, there is tremendous phenotypic variability that cannot be ascribed solely to different genotypes. Thus, there are no predictive tests to ascertain patients at risk for bone involvement, such as avascular necrosis, or lung disease, particularly pulmonary hypertension, which are two of the major causes of morbidity in Gaucher disease and which are slow to respond to enzyme replacement therapy. Previous studies to correlate these parameters with thrombophilic profiles have not been conclusive. Levels of D-dimers were assayed and compared to the presence of avascular necrosis and abnormally elevated TI gradient among other variables, in 118 unselected adult patients (52 males) with Gaucher disease. Of these, 19 patients had very mild Gaucher disease (Severity Score Index, SSI < 5) and 23 had severe disease (SSI > 15); 29 had avascular necrosis; 37 were splenectomized (due to massive splenomegaly and hypersplenism). As an indirect measure of pulmonary hypertension, TI gradient was used: 90 patients had normal TI gradients (<25 mmHg), and 12 patients had abnormal TI gradients (>30 mmHg). There were significant correlations between D-dimers and avascular necrosis, splenectomy, and elevated TI gradient. Thus, the D-dimer assay may be potentially predictive of bone and lung involvement in Gaucher disease.