The IL-18, IL-12, and IFN-γ expression in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients, HTLV-1 carriers, and healthy subjects.

Interleukin (IL)-12, IL-18, and interferon gamma (IFN-γ) can induce Th1-inflammatory responses in favor of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) manifestation. In this study, the gene expression and plasma levels of these cytokines were evaluated. The peripheral blood mononuclear cells (PBMCs) in 20 HAM/TSP patients, 21 asymptomatic carriers (ACs), and 21 healthy subjects (HSs) were assessed for the expression of IL-18, IL-12, and IFN-γ, using qRT-PCR. The plasma level of IL-18 and IFN-γ were measured by an ELISA method. The mean of HTLV-1 proviral load (PVL) in the HAM/TSPs was 1846.59 ± 273.25 and higher than ACs at 719.58 ± 150.72 (p = 0.001). The IL-12 was considerably expressed only in nine ACs, five HAM/TSPs, and all HSs. Furthermore, the gene expression and plasma levels of IL-18 were lower in the HTLV-1-positive group than the control group (p = 0.001 and 0.012, respectively); however, there was no significant difference between the ACs and HAM/TSPs. The IFN-γ level was higher in the HTLV-1-positive group (p < 0.001) than HSs. Although there were no correlation between plasma levels of IL-18 and IFN-γ with PVL in the ACs, a positive correlation was observed between plasma IL-18 levels and PVL (r = 0.654, p = 0.002). The highest levels of IFN-γ were observed in the HAM/TSPs which has a significant correlation with HTLV-1-HBZ (r = 0.387, p = 0.05) but not with Tax. However, no significant correlation was found between PVL and proinflammatory pattern. Apart from the IFN-γ as a lymphokine, as a host factor, and HTLV-1-HBZ, as a viral agent, the other proinflammatory monokines or HTLV-1 factors are among the less-effective agents in the maintenance of HAM/TSP.

No Evidence of HTLV-II Infection Among Immonoblot Indeterminate Samples Using Nested PCR in Mashhad, Northeast of Iran.

OBJECTIVE(S): Although HTLV-I infection is endemic in different geographical parts of the world including Northeast of Iran, there have been no documents of HTLV-II infection in this region. It is reported that one possible reason for seroindeterminate state in HTLV western blot is HTLV-II virus. This study aimed to investigate the presence of HTLV-II among blood donors with seroindeterminate western blot results. MATERIALS AND METHODS: Three ml whole blood obtained from 50 blood donors referring to Mashhad Blood Transfusion Organization who had reactive Elisa for HTLV-I and seroindeterminate HTLV western blot state. A conventional PCR was applied to detect HTLV-I provirus using specific primers while a nested PCR was designed with specific external and internal primers for the detection of HTLV-II. RESULTS: The average age of participants, 39 males and 11 females, was 37.12± 14.36 years. The average OD of the Elisa assay was 1.767± 1.195. The most common indeterminate patterns were Rgp46-II alone (n=12, 27.3%), Rgp46-I alone (n=7, 15.9%), and Rgp46-I with GD21 (n=7, 15.9%).After introducing the DNA to the PCR tests, results revealed 10 (20%) HTLV-I PCR positive samples while no HTLV-II positive sample was detected by nested PCR. There were no significant age, blood group, Optical Density of the Elisa assay, and western blot indeterminate pattern differences between HTLV-I PCR positive and negative samples. Conclusion : No HTLV-II positive sample was detected in this study which confirms the absence of HTLV-II infection in this region. However, high frequency of HTLV-I PCR positive samples among the seroindeterminate cases implies on the important role of molecular techniques for further confirmation of the infection.