Abstract 290: Lower Limb Revascularization of Patients with Peripheral Artery Disease Reduces Human Enterovirus Infection of the Gastrocnemius

Abstract

Introduction: Peripheral artery disease (PAD), caused by obstruction of arteries supplying the lower extremities, is characterized by leg muscle degeneration. Recently, we showed that infectious human enterovirus (HEV), which has been implicated in other myodegenerative diseases, is present in ischemic muscle of PAD patients and that viral copy numbers correlate with disease severity. Hypothesis: We tested the hypothesis that prevalence of infectious HEV and viral copy number in the gastrocnemius of patients with PAD decrease in response to revascularization. Methods: Gastrocnemius biopsies were collected from controls (N=14) and from PAD patients (N=17), before and after revascularization. Biopsies were examined for the presence of HEV RNA, viral capsid protein, viral RNA copy number, and viral infectivity and for viral sub-genotype. Results: HEV RNA was detected in biopsies of 65% (11/17) of PAD patients and in none of the controls. After revascularization, the gastrocnemius of 5 patients who were HEV positive before surgery no longer harbored detectable virus. The prevalence of HEV infection was reduced from 65% (11/17 patients) before surgery to 35% (6/17 patients) after surgery. Positive-strand viral RNA copy numbers were decreased significantly after revascularization. Mean positive-strand copy number (average 10 2.61 copies/mg muscle wet weight) in post-surgical biopsies that were HEV-positive were lower (p<0.001) compared to mean copy number (average 10 5.46 copies/mg muscle wet weight) in pre-surgical biopsies that were HEV-positive. Copy numbers of negative-strand (template) viral RNA were also decreased after revascularization. Viral replication was confirmed by detection of negative-strand viral RNA in all specimens positive for HEV. Cultures of HeLa and human skeletal muscle cells treated with muscle homogenates showed HEV replication and the presence of HEV capsid protein. By sequence analysis, HEV in PAD muscle exhibited 97% homology with Coxsackievirus B1. Conclusion: Our data introduce HEV infection as a potential mechanism for degeneration of ischemic muscle in PAD patients and demonstrate that revascularization of PAD patients reduces both prevalence of HEV infection and viral copy number in the gastrocnemius.