Demonstration of T‐Transferase Deficiency in Tn‐Polyagglutinable Blood Samples

Abstract

The [human] serum and red cell membranes from 7 Tn individuals were tentatively characterized for the UDP-galactose: N-acetyl-D-galactosamine-.beta.-D-galactosyltransferase and UDP-galactose: N-acetyl-D-glucosamine-.beta.-4-D-galactosyltransferase activities using p-nitrophenyl-2-acetamido-2-deoxy-.alpha.-D-galactopyranoside and p-nitrophenyl-2-acetamido-2-deoxy-.beta.-D-glucopyranoside, respectively, as low MW acceptors. In 5 cases, Tn-positive and Tn-negative red cells were separated by Polybrene differential aggregation. The .beta.-3-D [T-transferase] and .beta.-4-D-galactosyltransferases activities are found in serum and red cell membranes from all normal individuals. Polybrene-positive cells (normal sialic acid content) from Tn bloods have normal or higher T-transferase and .beta.-4-D-galactosyltransferase activities. Polybrene-negative cells (low sialic acid content) from Tn bloods have a selective deficiency in T-transferase activity, but normal or increased .beta.-4-D-galactosyltransferase activity. The serum from all Tn individuals behaves like normal sera with respect to the 2 galactosyltransferase activities. The serum may be used as source of enzyme for conversion in vitro of Tn to T-reactive erythrocytes. Tn-polyagglutination may result from a somatic mutation in stem cells of hematopoietic tissue which involves a single genetic step in red cell glycoprotein synthesis. Evidence of a dual population of erythrocytes in each Tn blood sample was presented. T-transferase found in serum may be produced in unidentified cells of the organism. No difference was noticed between apparently healthy Tn donors and Tn patients.