Transcobalamin (TC) 11, the cellular membrane carrier of vitamin B 12 has recently attracted attention as an acute phase reactant in autoimmune disorders and reticuloendothelial malignancies. In a prospective clinical evaluation, 20 patients presenting with proven metastatic renal adenocarcinoma underwent nephrectomy and were followed till death, or at least 3 years. Two patients obtained a complete remission. TCII was significantly elevated (P < 0.005) preoperatively and varied with activity of the carcinoma, supplementing the erythrocyte sedimentation rate and fibrinogen. The postoperative response and pattern of TCII activity correlated with disease progression. No relation was found to liver metastases. This study supports the recent findings of TCII as an indicator of activity in disorders affecting the immune mechanisms probably acting as an acute phase reactant, and is a useful supplement in renal adenocarcinoma. Cuncer 52:1700-1704, 1983. w o GROUPS of cobalamin (vitamin B 12) binding T proteins, R-binding proteins and transcobalamin (TC) I1 have been identified in human plasma. R-binding protein is a collective name given to immunologically related cobalamin-binding proteins of unknown function; this family of binders includes plasma TCII. TCII is responsible for the transport of cobalamin into the cells.' Increased plasma concentrations of R-binding proteins have been observed in sporadic cases of carcin ~m a , * . ~ and the TCII concentration in plasma is often increased in autoimmune diseases4 and during infect i o n ~, ~
probably as an acute phase reactant. Renal adenocarcinoma can be associated with a variety of systemic manifestations: elevated erythrocyte sedimentation rate (ESR),6.7 fever, cachexia, fatigue, peripheral neuropathy, amyloidosis, immune complex glo- merulonephritis,' hyperfibrinogenemia,' hepatic dysfunction,'.'' and hypercalcemia. lo When distant metastases lead to initial diagnosis of renal adenocarcinoma, or are found at the initial examination of the patients, the 5-year prognosis for survival is very poor in the range From the