FAS promoter polymorphisms and serum sFas level are associated with increased risk of nerve damage in Bangladeshi patients with Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disorder of the peripheral nervous system triggered by molecular mimicry between pathogen lipopolysaccharides and host nerve gangliosides. Polymorphisms in the Fas receptor ( FAS ) and Fas ligand ( FASL ) genes may potentially alter the elimination of autoreactive immune cells and affect disease susceptibility or disease severity in GBS. We detected single nucleotide polymorphisms (SNPs) in FAS (-1377G/A and -670A/G) and FASL (-843C/T) in a prospective cohort of 300 patients with GBS and 300 healthy controls from the Bangladeshi population. Genotype distributions were not significantly different between patients with GBS and healthy controls. The FAS -670 AG heterozygous ( P = 0.0005, OR = 2.5, 95% CI = 1.5–4.2) and GG homozygous ( P = 0.0048, OR = 2.6, 95% CI = 1.3–5.0) genotypes were more common in patients with anti-GM1 antibodies than patients without anti-GM1 antibodies. The FAS -670 G allele was more prevalent in anti-GM1 antibody-positive than -negative patients ( P = 0.0002, OR = 1.9, 95% CI = 1.4–2.7) and also in patients with the axonal subtype than demyelinating subtype ( P < 0.0001, OR = 4.8, 95% CI = 2.3–10.1). The 1377G/-670G GG haplotype was significantly associated with the axonal subtype ( P < 0.0001) and anti-ganglioside antibody-positivity ( P = 0.0008) in GBS. Serum sFas (237.5 pg/mL vs. 159.5 pg/mL; P < 0.0001) and sFasL (225.1 pg/mL vs. 183.4 pg/mL; P = 0.0069) were elevated in patients with GBS compared to healthy controls, and among patients with high serum sFas was associated with severe GBS ( P = 0.0406). In conclusion, this study indicates FAS-FASL promoter SNPs may promote the production of cross-reactive anti-ganglioside antibodies in GBS.