Search

Using molecular methods three or five major variants of HTLV-I have been identified; moreover two subtypes of HTLV-II defined as HTLV-IIa and HTLV-IIb with six variants within each of these groups have been described. In the present study we analysed proviral DNA obtained from the peripheral blood mononuclear cells (PBMCs) of a significant group of Italian intravenous drug users (IVDUs), prison inmates and blood donors (BDs) who were HTLV antibody positive. Restriction fragment length polymorphism (RFLP) of amplified LTR region with ApaI, NdeI, DraI, SacI and MaeIII endonucleases was used to define the HTLV-I subtypes, while the different variants of HTLV-IIa and -IIb were defined by RFLP of the LTR region with the AvaII, BglI, SauI, XhoI and BanII endonucleases. The four HTLV-I isolated from BDs were characterized as C type. All the 11 HTLV-II detected in the IVDUs were HTLV-IIb4, while among the prisoners one HTLV-IIb5 and five HTLV-IIb4 were found. Interestingly, in the BDs group two HTLV-IIa0 and one HTLV-IIb4 were detected. It should also be noted that 82% of the IVDUs and 50% of the prisoners were coinfected with HIV, while all the BDs were HIV negative. These data indicate that HTLV-IIb4 is the predominant genotype in Italian IVDUs and prisoners, while the significant variability observed in the BD HTLV-II isolates could be due to the different source of infection among this group.

Objectives: A study was performed to determine whether persistent or latent viruses are reactivated during the acute attack in relapsing remitting multiple sclerosis (MS)., Material and Methods: DNA of herpes simplex virus type 1 and 2 (HSV-1 and -2), human cytomegalovirus (HCMV), Epstein-Barr virus (EBV), JC virus (JCV) and HTLV-I was searched, using nested polymerase chain reaction (PCR), in peripheral blood mononuclear cells (PBMCs) collected from 14 MS patients on the first day and, twice a week, during an acute attack of the disease., Results: Viral DNA was detected, in at least one PBMC sample, in all the patients. Interestingly, EBV DNA was found in 42.8% of the patients on the first day, while a sharp increase of the HTLV tax-rex DNA frequency (35.7%) was observed on the tenth day., Conclusions: In MS relapse EBV DNA detection is an early, frequent event, while the finding of tax-rex, but not of other HTLV-I genomic regions, is a secondary phenomenon, suggesting that these two factors could interact in the pathogenesis of MS relapses.

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.