Treatment

TREATMENT FOR DISEASES ASSOCIATED TO THE HTLV-I AND HTLV-II

Tropical spastic paraparesis (TSP)/myelopathy associated to the HTLV-I (HAM), adult T cells leukemia/lymphoma (ATL), and uveitis associated to the HTLV-1 (HU) are, actually, the three clinical entities that, to a great extent, are associated to the HTLV-I infection. TSP/HAM is a myelopathy characterized by an insidious beginning, chronic and progressive evolution of a spastic paraparesis, generally followed by sphincter disturbances and erectile dysfunction, although at a variable level usually light, which could be referred to sensitive symptoms. It predominates in certain regions, such as Caribbean islands, African subequatorial regions, Latin America, and the islands South of Japan, places with high prevalence of this infection, where it is responsible for 40% to 60% of myelopathies of undetermined etiology (35,36,37,38,39).

During physical examination, it could be often found a deficiency pyramidal syndrome with release of the lower limbs with expressive spasticity. A hyperreflexia in the upper limbs could be present, but rarely followed by functional deficit . Frequent complaints associated to sphincter disturbs could be more characterized and quantified through urodynamic test, which could also be helpful for clinical follow-up regarding as for the response to possible treatments.

TSP/HAM affects more women (2:1) from 40 years of age on. Incubation time takes long, however, in people contaminated through blood transfusion, this period could to reduced to less than 10 years. The attack rate is low, around 5.1 to 128/1000.000 inhabitants in the endemic regions, with 1% to 4% risk in patient carriers of the HTLV-1 infection, conditioned to genetic, environmental, and viral factors (39,40). Therefore, it is important to emphasize that the majority of individuals carriers of this infection (98-99%) will not develop symptoms related to the HTLV-I during his/her lifetime.

The criteria for treatment can vary, however the asymptomatic cases should not be treated considering the low probability for developing the disease. Thus, only patients diagnosed with clinical entities correlated to the HTLV-1 infection should be specifically treated. TSP/HAM TREATMENT. Once configured the TSP/HAM diagnosis, according to the defined criteria (34), a therapeutic approach must be considered. A variety of strategic therapeutic references can be found through literature, using antiviral, immunomodulators, and immunosuppression medications (39). However, the majority consists of non-control studies and less casuistic report, generally based on hypothesis that an immune response plays a determinant role in the progression of the disease. Short-lived and limited positive effects, meanwhile, are points of intersection of almost all forms of treatment available today. Different drugs with distinct forms of prescription have been already tested. Kataoka et cols (1993) found useful effect of the vitamin C, in a dosage of 40mg/kg, five days a week, in a study involving seven patients (1).

Pentoxyphylline, a xanthene's derivate, showed positive in clinical and spontaneous lymphocytary proliferation aspects, due to its suppressive effect of the tumor necrosis factor (TNF)-alpha expression in a study involving 15 patients (2). Yet, other report showed valuable results with the use of heparin in 7/10 of the patients studied.

Phosphomicin, an antibiotic with immunomodulatory activity and the cyclosporine A, showed in vitro effects on the levels of cytokines and on the spontaneous lymphocytary proliferation respectively, and it has been suggested as potential drug for clinical application to the TSP/HAM treatment (3,5). Rolipram, a phosphodiesterase inhibitor, type IV, a medication originally described as an antidepressant agent for its suppressive action on the production of TNF-alpha, has also been suggested as a potential therapeutic agent for the TSP/HAM (6).