Low IDL-B and high LDL-1 subfraction levels in serum of ALS patients

Converging evidence highlights that lipid metabolism plays a key role in ALS pathophysiology. Dyslipidemia has been described in ALS patients and may be protective but peripheral lipoprotein subclasses have never been studied.

We collected sera from 30 ALS patients and 30 gender and age-matched controls. We analyzed 11 distinct lipoprotein subclasses by linear polyacrylamide gel electrophoresis (Lipoprint, Quantimetrix Corporation, USA). We also measured lipoprotein (a), apolipoprotein B, and apolipoprotein E levels.

ALS patients had significant higher total cholesterol, HDL-cholesterol, and LDL-cholesterol levels than controls (p<0.0001, p=0.0007, and p=0.0065, respectively). The LDL-1 subfraction concentration was higher (1.03±0.41 vs. 0.71±0.28mmol/L; p=0.0006) and the IDL-B subfraction lower (6.5±2% vs. 8.0±2%; p=0.001) in ALS patients than controls.

Our preliminary work confirmed the association between ALS and dyslipidemia. The low IDL-B levels may explain the hepatic steatosis frequently reported in ALS. The high levels of the cholesterol-rich LDL-1 subfraction is consistent with previously reported hypercholesterolemia.

This study describes, for the first time, the distribution of serum lipoproteins in ALS patients, with low IDL-B and high LDL-1 subfraction level.