Increased fragility of erythrocytes from amyotrophic lateral sclerosis (ALS) patients provoked by mechanical stress.

Erythrocytes from patients with amyotrophic lateral sclerosis (ALS) and controls were suspended in an electrolyte-substrate medium and subjected to mechanical stress by centrifugation under standardized conditions. Subsequent spectrophotometric analysis of the medium disclosed a significantly higher degree of haemolysis in samples from ALS-patients than from controls. The observation gives further evidence for the existence of an abnormality of the red cells in the disease. The nature and possible significance of this abnormality in relation to the pathogenesis of ALS is as yet unknown, but notably there was no significant correlation between the degree of cell abnormality as manifested by haemolysis and the duration of the disease in the individual patient.