Increased retinol binding protein in the sera of patients with severe ischemic damage of the liver after transplantation.

OBJECTIVE: To study retinol binding protein variation in the serum of patients who have undergone liver transplantation. METHODS: Retinol binding protein was retrospectively determined by the immunonephelometric method on serum from 14 patients who had undergone orthotopic liver transplantation 2 weeks after the surgery and then once a month during the first year posttransplantation. The patients were divided into two groups on the basis of early (first 10 days) postoperative graft function: group I, 6 patients with severe ischemic damage; and II 8 patients with moderate-severe liver dysfunction. RESULTS: The men retinol binding protein level at one year of follow-up was persistently higher in group I than in group II (83.1 +/- 33.4 vs 44.6 +/- 20.7 mg/L, p < 0.001). Interestingly, retinol binding protein levels remained higher in patients of group I event when the other biochemical parameter of liver function returned to normal. The increase in retinol binding protein serum levels was independent of variation in other parameters of liver and kidney function, but was correlated with an increase in transthyretin and retinol levels. CONCLUSION: Our results show a close relationship between a permanent high retinol binding protein level and severe graft injury after liver transplantation. However, the mechanism underlying the increase remains to be defined.

Importance of pyridoxal-5'-phosphate addition to the assay medium for the measurement of catalytic concentrations of plasma aspartate and alanine aminotransferases in patients undergoing antineoplastic chemotherapy.

Using 98 plasma samples from cancer patients undergoing antineoplastic chemotherapy, we compared the activities of aspartate aminotransferase and alanine aminotransferase measured by two different methods, with and without the addition of pyridoxal-5'-phosphate to the assay medium. Pyridoxal-5'-phosphate caused an increase of 1 to 20 U/l in aspartate aminotransferase and alanine aminotransferase activity in 90 and 78 patient plasma samples, respectively. Increases of aspartate aminotransferase and alanine aminotransferase activity of more than 20 U/l were observed in 8 and 20 samples, respectively. In 8 cases, the increase in alanine aminotransferase activity was greater than 50 U/l, whereas a similar increase in aspartate aminotransferase activity was decreased in only 2 cases. The considerable pyridoxal-5'-phosphate activation in aminotransferase activity observed in the plasma of a significant number of patients suggests that the use of the method with pyridoxal-5'-phosphate is advisable for a correct measurement of the catalytic concentration of aminotransferases in the plasma of patients undergoing chemotherapy.