Auto‐Antibodies to Tumour Necrosis Factor a in Healthy Humans and Patients with Inflammatory Diseases and Gram‐Negative Bacterial Infections

Abstract
A semi-quantitative immunoblotting method was developed to screen for scrum auto-antibodies against tumour necrosis factor α (TNFα). Forty nitrocellulose strips containing identical amounts of human recombinant TNFα (rTNFα) were prepared for each set-up, and the anti-TNFα antibody immunoreactivities were scored according to the density of the resulting colour reaction. A significant number of sera from apparently healthy donors contained detectable auto-antibodies to TNFα (40%), while the strongest reaction was observed in 8%. A higher prevalence of anti-TNFα antibodies was found in ten from patients with Gram-negative bacterial septicaemia (66%), cystic fibrosis with chronic Pseudomonas aeruginosa lung infection (72%), and various rheumatic diseases (61%). The antibodies in sera from these patients belonged primarily to the IgG and IgM classes, the latter exhibiting the strongest response. Longitudinally collected serum samples from patients in septic endotoxin shock revealed that the anti-TNFα antibodies were induced initially during septicaemia, reaching maximum reactivities within the first week and returning to tow or undetectable levels on days 9-20.