A Cytokine-Based Diagnostic Program in Pediatric Aplastic Anemia and Hypocellular Refractory Cytopenia of Childhood.

BACKGROUND: Distinguishing hypocellular refractory cytopenia of childhood (RCC) from aplastic anemia (AA) is challenging. Thus far, no studies have compared the cytokine profiles in patients with AA to those with hypocellular RCC. In the present study, we addressed whether thrombopoietin (TPO) and interleukin 17 (IL-17) plasma levels are useful for differentiating between the two diseases. METHODS: We measured the endogenous plasma concentrations of TPO and IL-17 in 29 patients with AA, 34 patients with hypocellular RCC, and 31 healthy controls using sensitive enzyme-linked immunosorbent assays. RESULTS: The TPO and IL-17 plasma levels were significantly lower in patients with hypocellular RCC than in patients with AA (P < 0.001 and P = 0.007, respectively). The multivariate logistic regression analysis identified moderate disease severity, TPO levels of <1,369.8 pg/ml (TPO-low group, n = 32; odds ratio (OR), 13.40; 95% confidence intervals (CI), 3.001-51.254; P < 0.001), and IL-17 levels of <22.2 pg/ml (IL-17-low group, n = 33; OR, 4.11; 95% CI, 1.033-19.404; P = 0.031) as independent factors discriminating hypocellular RCC from AA. Importantly, 25 (78.1%) of 32 patients in the TPO-low group and 25 (75.8%) of 33 patients in the IL-17-low group were diagnosed as having hypocellular RCC. Moreover, 22 (71%) of 31 patients in the TPO-high group and 21 (70%) of 30 patients in the IL-17-high group were diagnosed as having AA. CONCLUSIONS: TPO and IL-17 levels are useful for differentiating hypocellular RCC from AA. Prospective studies are required to confirm our findings.