Elevated plasma chemokine CCL18/PARC in β-thalassemia

Plasma CCL18/PARC, a member of the CC chemokine family, has been found to be several ten-fold increased in symptomatic Gaucher type I patients. Elevated plasma chitotriosidase levels are a well-known abnormality in Gaucher patients, however, its diagnostic use is limited by the frequent genetic deficiency in the protein. Like the situation in Gaucher disease, lipids accumulate in macrophages of patients suffering from β-thalassemia, and, in both conditions, increased chitotriosidase levels occur. We here report that plasma CCL18/PARC is also significantly increased in patients with β-thalassemia major (range 76.8-4977.8, median = 650.8 ng/ml, n = 36 and control range 10-72, median = 33 ng/ml n = 36 respectively, P < 0.001). The CCL18/PARC levels are lower than in Gaucher patients (range 174.8-10798.7, median 2538.2 ng/ml, n = 28, P < 0.001). In our cohort of β-thalassemic patients, CCL18/PARC showed a significant negative correlation to iron chelation therapy and a significant positive correlation to ferritin and chitotriosidase levels, the latter only in the patients with the wild type genotype for the enzyme. Our study demonstrates that β-thalassemic patients have increased CCL18/PARC levels that could be of value in monitoring iron overload and compliance to therapy.