PERIPHERAL NEUROPATHY IN HCV-RELATED MIXED CRYOGLOBULINEMIA

Objective: To evaluate the prevalence and features of peripheral neuropathy in HCV‐related mixed cryoglobulinemia (MC). Methods: 133 consecutive patients (23 males and 110 females, age range 23–73 years) with MC (double immunodiffusion) were studied. Immuno‐fixation electrophoresis was performed in 127 cases: in 117 a type II, and in 10 type III MC was found. In all the patients circulating anti‐HCV antibodies and in 79/87 HCV‐RNA were detected. ENG was performed in 52 patients and sural nerve biopsy in 16. Results: Neurological examination revealed a peripheral neuropathy in 107 patients (80.4%): 50 had a distal symmetric sensory‐motor polyneuropathy, 55 multiple mononeuropathies, 2 a mononeuropathy. During the course of the illness, mononeuropathies tend to overlap giving a polyneuropathy. ENG showed neuropathic features in 48/52 patients (92.3%), 8 of them without clinical symptoms of peripheral neuropathy. Axonal damage, mainly sensitive, more expressed in the lower limbs, was the commonest electroneurographic finding. Sural nerve biopsy showed axonal degeneration with perineurial and endoneurial microangiopathy, rare cellular infiltrates, erytrocyte diapedesis. Conclusions: Peripheral neuropathy is a common, early, and often severe complication in HCV‐related MC. The pattern of nerve changes suggests a vascular mediated damage. Hypoxia and immunological factors may be concurrent pathogenetic mechanisms.