Association of anti-glycolipid IgG with respiratory function decline in amyotrophic lateral sclerosis

Effective treatments for amyotrophic lateral sclerosis (ALS) remain limited, underscoring the need to identify robust biomarkers associated with disease severity and prognosis. This study investigated whether immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-glycolipid antibodies are associated with clinical manifestations of ALS, particularly decline in respiratory function.

This was a retrospective observational cohort study of the patients with ALS. Among patients with definite or probable limb-onset ALS, 11 patients in the glycolipid IgG-positive group were compared with 15 patients in the IgG-negative group, and 5 patients in the glycolipid IgM-positive group were compared with 9 patients in the IgM-negative group, with adjustment for age. Associations between anti-glycolipid antibody status and respiratory function were assessed using Kaplan-Meier survival analysis and Cox proportional hazards models.

The time to decline of percent forced vital capacity (%FVC) below 80% and 60% was significantly shorter in the IgG-positive group than in the IgG-negative group (p = 0.002 and p = 0.025, respectively). Cox proportional hazards analysis demonstrated that IgG antibody positivity was an independent risk factor for earlier decline in %FVC to 80%.

These findings suggest that anti-glycolipid IgG antibodies may be associated with respiratory function decline in ALS. Larger comprehensive studies will be required to validate these results and to elucidate the underlying pathophysiological mechanisms.