POLYNEUROPATHY WITH ENDONEURIAL IMMUNE-COMPLEX DEPOSITION AS THE FIRST MANIFESTATION OF SYSTEMIC LUPUS-ERYTHEMATOSUS

A 72-year-old male presented with progressive sensorimotor polyneuropa thy. Later weight loss, proteinuria and deteriorating renal function w ere noted. The electrophysiological examinations revealed extensive, s ymmetrical demyelinating and axonal polyneuropathy. Frozen sections ob tained from sural nerve biopsy sample showed the presence of immune co mplexes and complements in the walls of the epi- and endoneurial blood vessels, and perineurium suggestive of systemic lupus erythematous (S LE). IgG and Clq deposits were also present along the basement membran es of Schwann cells. The electron microscopy confirmed the presence of immune complex deposition. Diagnosis of SLE was proven by positive se rology (anti-nuclear antibodies, anti-Sm, anti-RNP, anti-double-strand ed DNA) and renal biopsy showing membranous lupus nephritis with exten sive immune complex deposition in the tubular basement membranes. Desp ite combined immunosuppressive treatment for 10 months, the patient di ed of complications of generalized immune complex vasculitis. The mani festation of SLE in elderly patients, especially in males, is very rar e. Moreover, the polyneuropathy is an unusual initial symptom of SLE. Immune complex deposition in Schwann cell basement membrane probably p lays an important role in the pathomechanism of sensorimotor polyneuro pathy in SLE.