PARTICIPATION OF CRYOGLOBULINEMIA IN THE SEVERE PERIPHERAL NEUROPATHIES OF PRIMARY SJOGRENS-SYNDROME

A peripheral neuropathy is encountered in 10 to 50% of patients with p rimary Sjogren's syndrome (pSS). The pathogenesis of this complication remains unknown, but severe Eases of peripheral neuropathies seem to result from a vasculitis. Since about 20% of pSS are associated with a cryoglobulinaemia, we initiated a retrospective study to assess the p articipation of cryoglobulinaemia in the severe peripheral neuropathie s (SPN) of pSS. We found 6 cases of SPN (presence of pain and/or muscl e weakness) in a group of 115 pSS (5%) : 3 polyneuropathies and 3 mono neuritis multiplex. In all cases, the involvement was sensoromotor and axonal, Four patients had a biopsy documented cutaneous vasculitis, a nd 2 of them had also a muscular lymphocytic vasculitis. A cryoglobuli naemia was detected in sera of 5 patients. Althought the research was negative in the remaining patient, the presence of an IgM monoclonal g ammapathy and of an hypo-complementaemia suggested also the presence o f a cryoglobulinaemia. Complement was activated in the 6 cases. Treatm ent was agressive: oral corticosteroid (6 cases), methylprednisolone p ulses (4 cases), chloraminophen (1 case), plasma exchanges (2 cases), intravenous immunoglobulins (1 case), A stabilization or a partial reg ression of the neuropathies were observed in 1 case and 5 cases, respe ctively. This was associated with a reduction of cryoglobulin level an d complement activation in 5 cases and 6 cases, respectively. This stu dy suggests that SPN of pSS result from a cryoglobulin-mediated vascul itis.