First report of HHV-8 viral load and seroprevalence of major blood-borne viruses in Iranian patients with systemic sclerosis.

Background: Systemic sclerosis (SSc) is characterized by autoimmune manifestations, and viral infections may have a key role in the development and progression of it. This study aimed to investigate the seroprevalence of major blood-borne viruses and HHV-8 viral load in Iranian SSc patients.

Methods: In this cross-sectional study, 90 patients with a confirmed history of SSc and 90 healthy blood donors were enrolled. The frequency of HHV-8, CMV, EBV, HIV, HBV, and HCV antibodies and HHV-8 viral load were evaluated by enzyme-linked immunosorbent assay and real-time PCR assay, respectively.

Results: HHV-8 IgG antibody was diagnosed in 61 (67.8%) patients and 3 (3.3%) healthy individuals (p<0.0001), but its genomic DNA was not detected in the patients or healthy blood donors. CMV and EBV antibodies were detected in 100% and 88.9% of SSc patients without any significant difference with healthy population (p>0.05). None of the patients or healthy population was positive for HBsAg and HIVAb; however, HCVAb was detected in two patients.

Conclusion: According to the results, HHV-8 antibody was uniquely increased in SSc population while its frequency in healthy population was very low. Since none of the SSc patients were positive for HHV-8 genomic DNA, the high prevalence of HHV-8 antibody in this group was not related to the real history of infection. Therefore, antibody-mediated epitope mimicry can play a role to get the high rate of seropositivity and lead to pathogeneses of SSc. Besides, CMV and EBV viral load monitoring in SSc patients can help the physician to prescribe the viral drugs to suppress the viral replication and avoid the crucial effect of reactivation.