Anti-ganglioside antibodies in a large cohort of European patients with systemic lupus erythematosus: Clinical, serological, and HLA class II gene associations

Objective. To assay anti-ganglioside antibodies (aGM(1)) in sera of a large cohort of European patients with systemic lupus erythematosus (SLE) to def ine thr prevalence of these autoantibodies in SLE; to evaluate the associat ion of aGM(1) with clinical manifestations and other autoantibodies found i n SLE; and to search for aGM(1) association with HLA class II alleles. Methods. Four hundred forty-eight patients with SLE were consecutively enro lled in 8 centers from 6 European countries. All sera were tested for antin uclear antibodies by immunofluorescence on HEp-2 cells as substrate, anti-d sDNA, aGM(1), aCL, a beta(2)-glycoprotein I (a beta(2)-GPI) antibodies by E LISA, and antineutrophil cytoplasmic antibodies (ANCA) by immunofluorescenc e and by ELISA. Genomic typing for HLA class II loci was performed by polym erase chain reaction-sequence specific oligonucleotide probe method. Clinic al assessment was done at the time of enrolment. Results. We found 41.9% of patients with clinical signs of neuropsychiatric involvement; 15.5% of patients were positive for aGM(1), 8% of the IgG iso type and 8.6% of the IgM isotype; aGM(1)-IgG were associated with neuropsyc hiatric manifestations (NPM) (RR = 3.7), with migraine (RR = 2.4), with OBS (RR = 7.3), and with peripheral neuropathy (RR = 8.5). aGM(1)-IgM were ass ociated with NPM (RR = 4) and with depression (RR = 3.4). Furthermore, the genetic study showed that aGM(1)-IgG were associated with HLA-DQB1*0404 (RR = 7.2) while aGM(1)-IgM were associated with HLA-DQB1*0605 (RR = 33.3). No associations were found between aGM(1) and anti-dsDNA, aCL, a beta(2)GPI, or ANCA. Conclusion. Our results show aGM(1), can be found in patients with SLE. aGM (1) may play a pathogenetic role for some NPM in this condition.