Multiple sclerosis is associated with enhanced B cell responses to the ganglioside GDIa

The occurrence and role of autoantibodies to gangliosides and other lipid-c ontaining components of the central nervous system in Multiple Sclerosis (M S) ore unsettled. Using sensitive ELISAs, we measured IgG and IgM antibody titers and absorbances to the three major gangliosides GDIa GDIb and GMI, a nd to sulfatides, cardiolipin and myelin proteins in paired serum and cereb rospinol fluid (CSF) from patients with untreated MS optic neuritis (ON), a cute aseptic meningo-encephalitis (AM) and other neurological diseases (OND ). Twenty-three per cent of 30 MS (P<0.04) and 18% of 32 ON Patients (P<0.0 5) presented elevated IgG antibody titers to GDIa in serum compared to 9% o f patients with OND. Six (40%) of the patients with malignant MS had elevat ed serum IgG antibody titers to GDIa compared to one (6%) of the patients w ith benign MS (P<0.04). In CSF, elevated IgG antibody titers to GD I a were measured in 13% of MS and 20% of ON patients compared to 4% of patients wi th OND (P<0.03 and P<0.02, respectively). The augmented IgG response to GDI a in serum also separated MS from Guillain-Barre syndrome. Compared to OND increased IgM absorbances to sulfatides and cardiolipin were observed in CS F of patients with MS, but also in AM. Elevated IgG antibody titers to myel in proteins were found more often in MS patients' serum and MS, ON and AM P atients' CSF compared to OND. The data implicate that among the multitude o f enhanced B-cell responses occurring in MS and ON, that directed to GDIa i s common and more discriminative, and should be evaluated in future MS trea tment studies.