Relationship between the clinical efficacy of pentoxifylline treatment andelevation of serum T helper type 2 cytokine levels in patients with human T-lymphotropic virus type I-associated myelopathy

Object Previously, we reported the efficacy of pentoxifylline (PTX) treatme nt in human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM ), Here, we clarify the relationship between the clinical efficacy of PTX t reatment and elevation of T helper type 2 (Th2) cytokine levels in HAM pati ents. Patients and methods PTX (300mg) was administered daily by the oral r oute to 12 HAM patients for 4 weeks. We assessed the relationship between t he changes in neurological status (motor disability scores, the degree of s pasticity on neurological examination, and the time required to walk 10 m) and the changes in serum and cerebrospinal fluid (CSF) levels of interferon -gamma (IFN-gamma) as a Th1 cytokine and interleukin-4 and -10 (IL-4 and -1 0) as Th2 cytokines measured by an EASIA (enzyme-amplified sensitivity immu noassay) kit. Results PTX treatment induced incremental increases in the le vels of IL-4 and IL-10 in both sera and CSF of 6 HAM patients, Clinical imp rovement was associated with this elevation in IL-4 and IL-10, PTX treatmen t also induced a decrease in IFN-gamma levels in the sera of 6 HAM patients , but this was not correlated with clinical improvement. Conclusion These r esults suggest that the correction of the immunological imbalance in Th1 to Th2 cytokine responses, with upregulation of IL-4 and IL-10, may account f or the clinical improvement in HAM patients treated with PTX.