The deoxyuridine suppression test performed on phytohaemagglutinin-stimulated peripheral blood cells fails to reflect in vivo vitamin B12 or folate deficiency.
Because phytohaemagglutinin-stimulated lymphocytes acquire folate deficiency in vitro, we have re-examined the claim that the deoxyuridine suppression test (dU-test) based on such cells helps to diagnose megaloblastic states. dU-test results were obtained from the phytohaemagglutinin-stimulated blood cells of 77 patients at 6 concentrations of dU. 21 megaloblastic patients with cobalamin or folate deficiency did not have a mean blood dU-test result significantly higher than that of 21 normoblastic patients at any concentration of dU. Among all patients, however, there was a weak correlation between the blood and marrow dU-test results. Folic acid corrected the blood dU-test results more in the normoblastic than the megaloblastic patients, and a difference between the two groups appeared, but a large overlap persisted. Blood dU-test results tend to be higher in megaloblastic patients, but acquired folate deficiency obscures the distinction from normoblastic patients so that the test is not of diagnostic value.
Matthews
J H
JH
Department of Haematology, St. Mary's Hospital Medical School, London, U.K.
Wickramasinghe
S N
SN
D000368:Aged; D001773:Blood Cells / Q000378:metabolism*; D003857:Deoxyuridine; D005260:Female; D005492:Folic Acid; D005494:Folic Acid Deficiency / Q000175:diagnosis*; D006801:Humans; D002955:Leucovorin; D008297:Male; D009994:Osmolar Concentration; D010835:Phytohemagglutinins; D014806:Vitamin B 12 Deficiency / Q000175:diagnosis*
D010835:Phytohemagglutinins; D005492:Folic Acid; D002955:Leucovorin; D003857:Deoxyuridine