Nephrology

Background: Malondialdehyde (MDA) is by-product of lipid peroxidation as in oxidized low- density lipoprotein. Antibodies against phosphorylcholine have been previously evaluated in prevalent hemodialysis dialysis patients. We here studied the association between IgM antibodies against MDA (anti- MDA) and risk of death in patients undergoing hemodialysis.

Aim: To see the association of natural IgM antibodies against MDA with all-cause mortality in prevalent hemodialysis patients.

Methods: Low levels of IgM anti-MDA conjugated with human serum albumin concentrations were measured by direct Enzyme Linked Immune-Sorbent Assay (ELISA). The association between IgM anti-MDA and five-year all-cause mortality was investigated. We performed post hoc data analyses in 210 prevalent hemodialysis patients (median age 66 years; 44% female). The patients with an anti-MDA value below cut-off value are compared with a crude hazard ratio. Cox regression analysis, after adjusted by age, gender, diabetes, cardiovascular disease, dialysis vintage and level of interleukin 6, the association between lower IgM anti-MDA level and all-cause mortality was performed.

Results: Among 210 hemodialysis patients, 137 patients (65%) had a IgM anti- MDA level >71.3 U/mL (cut-off value derived from receiver operating characteristic analysis). The patients with an anti-MDA value below cut- off value had a higher mortality rate with a crude Hazard Ratio (HR) of 1.95 (95% CI 1.33-2.88). In Cox regression analysis, after adjusted by age, gender, diabetes, cardiovascular disease, dialysis vintage and level of interleukin 6, the association between lower IgM anti- MDA level and all-cause mortality remained significant (HR 1.79; 95% CI 1.19 - 2.70).

Conclusion: Low levels of natural IgM antibodies against MDA are independently associated with all-cause mortality in prevalent hemodialysis patients.