Serum osteopontin and CD44 levels in lymphoreticular malignancies in children

Osteopontin (OPN) is an adhesive glycoprotein that interacts with a variety of cell surface receptors, including several integrins and CD44. OPN is expressed and secreted by numerous human malignancies. CD44 play an important role in tumor growth and metastasis. We aimed to evaluate serum levels of osteopontin and CD44 in patients with lymphorethicular malignancies in childhood.

We studied serum levels of CD44 and OPN levels of 54 patients (26, 18 and 10 patients with non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL) and acute lymphoblastic leukemia (ALL), respectively) at the diagnosis.

The mean levels of OPN were significantly higher in patients (5.42±8.24 ng/ml) than in controls (3.89 ±1.96 ng/ml). The mean levels of CD44 levels were also significantly higher in patients (3.82±2.31 ng/ml) than in controls (1.96±0.62 ng/ml), and significantly higher in the advanced stages than in early stages. The mean levels of the CD44 in NHL, HL and ALL were 3.49±2.00, 3.56±1.74, and 5.15±3.50 respectively. OPN and CD44 levels were found to be increased in parallel (p=0.003). A more advanced disease and/or poor prognostic factors were seen in 9 patients who had both serum CD44 and OPN levels higher than 2SD of the control.

Elevated levels of both CD44 and OPN at the diagnosis may predict an unfavorable outcome in childhood leukemias and lymphomas (Tab. 2, Fig. 3, Ref. 44).