Human monoclonal antibodies (mAbs) which bind to human TNFα. Autoantibodies of both the IgM and IgG isotypes are disclosed. A preferred human monoclonal antibody is known as B5 (F78-1A10-B5 mAb) and it binds to recombinant human TNFα (rhTNFα) in ELISA format with a titer comparable to three high affinity neutralizing mouse mAbs. It also binds to cell surface TNFα and prevents TNFα secretion by human monocyte cell lines.