Serum Interleukin-9 Concentration Is Associated with the Hemoglobin Level and Renal Function in Patients with Multiple Myeloma.

Background. Multiple myeloma (MM) is one of the most common types of hematological malignancies, but its pathogenesis is poorly understood. Interleukin-9 (IL-9) is a growth factor, mainly produced by helper T cells. A series of observations suggested that IL-9 might act as a factor promoting oncogenesis. This study was aimed at detecting the serum concentrations of IL-9 in patients with MM, and to investigate its potential clinical significance. Methods. The serum IL-9 levels in 34 patients with MM and 15 normal controls were quantified by using the Enzyme Linked Immunosorbent Assay (ELISA). Results. Our results showed that the serum IL-9 concentration in MM patients was significantly higher than that in the controls (p<0.0001). Interestingly, the IL-9 level in serum was found to be negatively associated with the hemoglobin concentration among the newly diagnosed MM patients (p=0.0108, r=-0.5850). Moreover, MM patients with renal dysfunction showed a significant increase in serum IL-9 concentration over those with normal renal function (p=-0.0395). Conclusion. These findings may imply a novel role of IL-9 in anemia and/or renal dysfunction development in MM.