Peripheral neuropathy without cryoglobulinemia in patients with hepatitis C virus infection.

BACKGROUND: An association between essential mixed cryoglobulinemia and hepatitis C virus infection has been documented by many reports. Some clinical manifestations such as purpura, arthralgia, vascular lesions and peripheral neuropathies are also connected with the presence of detectable cryoglobulins. The association between HCV infection, the presence of mixed cryoglobulinemia and peripheral neuropathy is well documented. The aim of this study was to define the possible presence of peripheral neuropathy in HCV patients without detectable cryoglobulins and the possible association with the different genotypes. METHODS: Twenty patients (11 females, 9 males) with chronic HCV hepatitis and without detectable cryoglobulins were submitted to neurological and electrophysiological studies to detect a possible peripheral neurological involvement. In all patients the HCV infection was assumed by the presence of antibodies to HCV with ELISA assay and then confirmed with recombinant immunoblot assay. HCV genotyping was obtained by INNO LIPA in 15 out of 20 patients. In 4 patients a sural nerve biopsy was possible. RESULTS: Genotype 1b was present in 80% of patients, while 1a in 13.3% and 4 in 6.6%. Thirteen patients had positive neurological anamnesis (65%), while neurological examination was positive in 40% of the cases. Electromyographic study was positive in 50% of subjects. The sural nerve biopsies agreed with axonal degeneration in amyelinated fibres. CONCLUSIONS: Our results suggest a possible peripheral neurological system involvement in patients with HCV infection without cryoglobulins.