[De novo purine biosynthesis. In vitro measurement in hyperuricemia (author's transl)]

De novo purine biosynthesis has been investigated in circulating blood lymphocytes in vitro. N-formyl-glycinamide ribonucleotide (FGAR) has been mesured using 14C-formate incorporation in the presence of azaserine, a metabolic inhibitor blocking the metabolical pathway at the level of FGAR synthesis. Such a synthesis was measured in 20 healthy controls, 24 patients with primary gout (11 on allopurinol therapy) and 26 patients with chronic renal failure and secondary hyperuricemia (8 on allopurinol therapy). Among gouty patients without allopurinol therapy, FGAR synthesis was normal in 5 and increased in the others. FGAR synthesis was decreased in patients with renal failure whatever the therapy. However, FGAR synthesis remained increased in patients with a primary gout complicated with renal insufficiency. The test we propose for de novo purine biosynthesis measurement is simple and of value to analyse the patho-physiology of hyperuricemia and its therapy. The test allows an acurate discrimination between primary and secondary hyperuricemia in the presence of renal insufficiency.