HTLV tax-rex DNA and antibodies in idiopathic amyotrophic lateral sclerosis

In an attempt to verify the possible role of retrovirus in idiopathic amyotrophic lateral sclerosis (ALS), the sera of 21 ALS patients admitted to the Neurological Unit of the Don Gnocchi Foundation in Milan, Italy, and of 9 ALS patients from Ulm University in Germany have been evaluated for the presence of antibodies to the human T-lymphotropic viruses (HTLV-I and HTLV-II). The sera of 30 healthy individuals and 20 HIV-infected but HTLV-negative subjects have been also studied as control. Moreover, the HTLV tax-rex and pol DNA sequence have been searched in the peripheral blood mononuclear cells (PBMCs) of 15 ALS patients and 15 HIV-positive HTLV-negative subjects using a nested PCR currently employed in our laboratory for the study of HTLV infections. Antibodies to one or more HTLV proteins have been found by using a Western blot (WB) kit in the sera of 10 Italian and 7 German ALS cases, while all the healthy controls were negative and only one HIV-positive subject had antibodies to HTLV gp21. HTLV tax-rex sequences have been found in the PBMCs of 6 ALS patients while all the controls were negative. All 15 ALS cases and controls were negative for HTLV pol DNA indicating that only the most conserved region of the HTLV genome could be detected. On the whole our data indicate that some ALS patients have antibodies to HTLV proteins and that the tax-rex region of the HTLV genome can be found in their PBMCs.