Plasma chitotriosidase activity in beta-thalassemia major: a comparative study between Sicilian and Sardinian patients.

BACKGROUND Chitotriosidase is a functional chitinase secreted by activated macrophages, which is extremely increased in plasma of patients with Gaucher disease (beta-glucocerebrosidase deficiency). Recently, we found that chitotriosidase plasma levels were increased to a variable extent in Sicilian patients with beta-thalassemia major. The aim of this study is to elucidate the possible mechanisms underlying chitotriosidase overproduction in beta-thalassemia major. METHODS Plasma chitotriosidase was measured in 134 patients with beta-thalassemia major (64 from Sardinia and 70 from Sicily), which are treated chronically by blood transfusions leading to systemic iron overload. They all have peripheral anemia and enormous enlargement of the reticulo-endothelial system. RESULTS Plasma chitotriosidase activity was found most frequently elevated among Sardinian (48.4%) than Sicilian (17.1%) patients. In either group, the highest levels of plasma chitotriosidase were observed in patients with the highest degree of iron overload, suggesting that this factor could trigger chitotriosidase overproduction. CONCLUSIONS The higher rate of subjects with increased plasma chitotriosidase values among Sardinian than Sicilian could be related to distinct molecular basis of beta-thalassemia and environmental features.