Circulating levels of tumour necrosis factor-alpha and its soluble receptors are increased in the blood of patients with amyotrophic lateral sclerosis

An immunologic pathogenesis for amyotrophic lateral sclerosis (ALS) has bee n recently proposed. We tested the whole tumour necrosis factor (TNF) syste m in the serum of 51 ALS patients at different stages of the disease and 36 healthy controls. Antigenic TNF-alpha and its soluble receptors (sTNF-Rs), measured by ELISA, were significantly higher in ALS patients than in healt hy controls. However, biologically active TNF-alpha, corresponding to the s TNF-Rs-unbound trimeric TNF alpha molecule and assayed by its cytotoxic act ivity on a sensitive cell line, was similar between ALS patients and health y controls. Neither antigenic TNF-alpha, bioactive TNF-alpha nor sTNF-Rs co rrelated with disease severity, disease duration, or weight loss. In conclu sion, we reported an activation of the TNF system in ALS. The role of this activation in the pathogenesis of the disease remains elusive. (C) 2000 Els evier Science Ireland Ltd. All rights reserved.