[Immunological background of plasma protein abnormalities--the relation between inflammation and malignant neoplasm]

Mechanisms causing negative findings of serum C-reactive protein (CRP) in inflammatory disorders and malignant neoplasms were investigated. Patients with advanced prostate cancer manifesting negative CRP and alpha 2M deficiency were found. This finding suggests that alpha 2M, a carrier protein of interleukin-6, mediates CRP synthesis by the liver. Mechanism of synthesis of acute phase proteins including CRP, SAA and others was shown to be different in response to inflammation, alpha 2M-dependence in alpha 2M deficiency, the production of CRP and SAA by human hepatoma cells (HepG2) and the processes on the transcriptional activation of acute phase protein genes. In cases of prostate cancer associated with serum alpha 2M deficiency metastasis to the bones was noted. This finding suggests that alpha 2M inhibits metastasis of prostate cancer. It was suggested that the alpha 2M deficiency develops from complex formation of alpha 2M with proteases including PSA and u-PA, and accelerated catabolism of the complex rather than suppressed production of alpha 2M.