Immunohistochemical detection of HCV in nerves and muscles of patients with HCV associated peripheral neuropathy and myositis.

Background: Chronic hepatitis C Virus (HCV) infection may be associated with numerous extrahepatic manifestations, such as mixed cryoglobulinaemia, membranoproliferative glomerulonephritis, sicca syndrome. Cryoglobulinaemia (CG) is a condition characterized by the presence of serum proteins that reversibly precipitate in the cold. The objective of the present work was to study the histopathological changes in neuromuscular biopsies in patients with HCV associated peripheral neuropathy, or myopathy; with and without cryoglobulinemia, and to assess the presence of HCV in nerve and muscle tissues of those patients which might clarify some pathogenetic mechanisms for neuropathy, and myopathy associated with HCV.

Methods: The study was conducted on 17 cases of HCV infected patients with peripheral neuropathy and myositis. All patients were subjected to thorough laboratory investigations, neurological examination, electrophysiologic studies including nerve conduction, and needle EMG studies.

Results: Histopathological examination of nerve biopsies showed features of vascultis in 2/10 cases, interstitial inflammatory infiltrates in 5/10. Muscle biopsies showed intense inflammatory reaction, degenerative changes in the muscles of 3/10 cases diagnosed as myositis. Immunohistochemical results, showed in nerve biopsies, 7/10 cases with positive reaction for HCV with nuclear and perinuclear staining.. Two patients showed positive reaction in the epineural, and endoneural blood vessels and a negative reaction in nerve bundles, while in five patients, reaction was only positive in the nerve bundles. In muscle biopsies, 7/10 cases showed positive reaction for HCV in the nuclei of the muscle fibers, including the cases presented with myositis.

Conclusion: The presence of HCV particles in nerve and muscle biopsies of patients with peripheral neuropathy suggests a virus triggered immune mediated mechanism.