OLIGOCLONAL BANDING OF IGG IN CSF, BLOOD-BRAIN-BARRIER FUNCTION, AND MRI FINDINGS IN PATIENTS WITH SARCOIDOSIS, SYSTEMIC LUPUS-ERYTHEMATOSUS, AND BEHCETS-DISEASE INVOLVING THE NERVOUS-SYSTEM

A retrospective study of CSF and serum analysis from a total of 43 pat ients with sarcoidosis, 20 with systemic lupus erythematosus, and 12 w ith Behcet's disease with neurological involvement found local synthes is of oligoclonal IgG using isoelectric focusing and immunoblotting in 51%, 25%, and 8% respectively at some stage in their disease. Blood-b rain barrier breakdown, when assessed with an albumin ratio found 47% of patients with sarcoidosis, 30% of those with systemic lupus erythem atosus, and 42% of patients with Behcet's disease exhibiting abnormal barrier function at some time. Serial CSF analysis showed that clinica l relapses were associated with worsening barrier function and in some patients the development of local oligoclonal IgG synthesis; converse ly steroid treatment led to a statistically significant improvement in barrier function, and in two patients a loss of oligoclonal IgG bands . A higher proportion of patients had MRI abnormalities than oligoclon al IgG or blood-brain barrier breakdown, MRT being abnormal in 16 of 1 9 patients with sarcoidosis, three of four patients with systemic lupu s erythematosus, and seven of nine patients with Behcet's disease, alt hough this may have been due to temporal factors. In the differential diagnosis of chronic neurological disorders, locally synthesised oligo clonal IgG cannot distinguish between diseases, but the loss of bands seen in two patients contrasts with what is seen in multiple sclerosis , and thus may be a useful diagnostic clue.