ABSTRACT
TNF is a protein produced by various cell types, mainly monocytes, and has been originally shown to induce necrosis of tumors in vivo. Serum TNF-alpha levels were demonstrated by radioimmunoassay in 17 patients with bronchogenic carcinoma [9 cases with small cell carcinoma and 8 with squamous cell carcinoma]. TNF level was significantly increased in 14 patients [65 +/- 12 ng/L] in comparison with the control group [19 +/- 6 ng/L]. The highest TNF level was encountered in patients with small cell carcinoma, especially in those with bone marrow metastasis [3 cases]. The variation in the TNF level may be due to a variation in immunogenicity of different pathological types or a variation in the TNF receptor numbers of affinity on different cell types. TNF may have a role in the progress of the disease and the bone marrow Involvement