OLIGOCLONAL IgG BANDS IN THE CEREBROSPINAL FLUID OF PORTUGUESE PATIENTS WITH MULTIPLE SCLEROSIS Negative results indicate benign disease

ABSTRACT- We assessed the frequency of cerebrospinal fluid (CSF) restricted oligoclonal IgG bands (IgG-OCB) in Portuguese multiple sclerosis (MS) patients and its relationship with outcome. Paired CSF/serum samples of 406 patients with neurological disorders were submitted to isoelectric focusing with immunodetection of IgG. Ninety-two patients had definite MS; non-MS cases were assembled in groups inflammatory/infectious diseases (ID, n=141) and other/controls (OD, n=173). We found in the MS group: mean duration, 38.9 months; clinically isolated syndromes, 24%; relapsing/remitting course (RR), 65%; in RR patients the mean EDSS was 2.1 and the mean index of pro g ression was 0.31. Positive patterns significantly p redominated in MS (82.6%; ID, 40.4%; OD, 3.5%). The sensitivity and the specificity of positive IgG-OCB for MS diagnosis was 82.6 % and 79.9%, respectively. The sole statistically significant difference in the MS g roup was the lower pro g ression index observed in negative cases. We conclude that the frequency of positive IgG-OCB patterns in our MS patients fits most values reported in the literature, and that negative results indicate benign disease. KEY WORDS: multiple sclerosis, CSF, oligoclonal bands, IgG, isoelectric focusing. Bandas oligoclonais da IgG no líquido céfalo-raquidiano de doentes portugueses com esclerose múltipla: resultados negativos indicam doença benign