Monitoring of Active Human Herpes Virus 6 Infection in Iranian Patients with Different Subtypes of Multiple Sclerosis

Abstract

Background . Recently, it has been suggested that human herpes virus 6 (HHV6) may play a role in the pathogenesis of multiple sclerosis (MS). Our purpose is to determine the incidence of reactivated HHV6 in MS patients. Methods . Viral sequence analyzed by qPCR in the peripheral blood mononuclear cells (PBMCs), serum, and saliva samples of different subtypes of MS patients ( n = 78 ) and healthy controls ( n = 123 ). HHV6 IgG and IgM antibody levels measured by ELISA technique in the plasma samples of both groups. Likewise, cerebrospinal fluid (CSF) samples of some MS patients ( n = 38 ) were analyzed for viral sequence. Results . Results demonstrate increased levels of anti-HHV6-IgG (78.2% versus 76.4% in controls; P = NS ), and IgM (34.6% versus 6.5% in controls; P < 0.05 ) in MS patients. Furthermore, RRMS and SPMS patients showed relatively higher anti-HHV6 IgG and IgM compared to PPMS ( P < 0.001 ). Moreover, load of cell-free viral DNA was higher in RRMS and SPMS patients and detected in 60.2% (47/78) of MS patients, compared with 14.6% (18/123) of healthy controls ( P < 0.001 ). Moreover, load of cell-free viral DNA was higher in RRMS and SPMS patients and detected in 60.2% (47/78) of MS patients, compared with 14.6% (18/123) of healthy controls ( P < 0.001 ). Conclusions . The results extend the observation of an increased frequency of systemic reactivated HHV6 infection in MS patients with developed stages of disease.