In this study the investigators are going to evaluate the efficacy pentoxifyline in HTLV-1 patients with neurological diseases: HAM/TSP or neurogenic bladder. In some laboratory experiments the investigators observed that this drug had the capacity to reduce the immune response in HTLV-1 infected cells. Since the exacerbated immune response is know to cause neurological disease in patients with HTLV-1 the investigators hope that pentoxifyline can alleviate symptoms and delay the progress of HAM/TSP in patients.

The human T-lymphotropic virus type 1 (HTLV-1) infects 20 million individuals worldwide and is the causative agent of HTLV associated myelopathy/ tropical spastic paraparesis (HAM/TSP). Although only 5% of HTLV-infected individuals will develop HAM/TSP, the investigatorts have observed that about 30% have neurological complaints and/or neurogenic bladder associated with HTLV-1. The immunopathogenesis of those diseases is related to the exaggerated immune response with high production of cytokines and induced neurological injury. So far there is not any effective drug against HTLV-1 and modulation of the immune response can help to alleviate the clinical manifestations of those patients and prevent the progression of symptoms. The preliminary data show that pentoxifylline has ability to decrease production of TNF-α and IFN-γ in patients with HTLV-1 infection and patients with HAM/TSP. The proposal entitled "Evaluation of the efficacy of pentoxifylline in attenuating the neurological disease associated with HTLV-1 and negatively modulate the immune pathological response" extends the previous studies in order to determine the ability of pentoxifylline in modulate the immune response and modify the course of the clinical manifestations in patients infected with HTLV-1. The influence on the immune response in the expression of disease will be determined in a therapeutic trial with two groups of patients: 1) patients with neurogenic bladder associated with HTLV-1, 2) patients with HAM/TSP. Primary end point is clinical and neurological exam and secondary end point are measure of proinflammatory cytokines (TNF-α, IFN-γ, IL-1 and IL-6) and chemokines that attract T cells to sites of inflammation (CXCL9 and CXCL10).

Inclusion Criteria:

• Age ≥ 18 and ≤ 80 years;
• Confirmed HTLV-1 infection with Western Blot analysis;
• HAM/TSP diagnosed patients according to the WHO
• Patients with HTLV-1 and neurogenic bladder diagnosed by clinical and urodynamic study
• Disease duration < 5 years

Exclusion Criteria:

• Neurological diseases with functional limitations.
• Co-infection with Hepatitis B or C, Syphilis, Chagas Disease or HIV
• Use of immunossupressive drugs
• Immune disease
• Pregnancy