The Sd^a Blood Group Antigen in Tissues and Body Fluids

Abstract

In man the Sd^a antigen is present in most secretions with the greatest concentration in urine. There is little difference in the amount of Sd^a substance in the urine of newborn infants, pregnant women and normal adults but there is a much greater amount in the saliva of newborn infants than in adults. Approximately half the people whose red cells group as Sd(a-) secrete Sd^a substance in the urine. Anti-Sd^a antibody is present in 50% of Sd(a-) non-secretors of Sda substance, though most of these antibodies only react with the strongest Sd(a+) cells. The greatest Sda activity has been found in human meconium, guinea pig urine and guinea pig kidney. Activity can be detected in the urine of many animal species. The kidneys of 5 bird species did not contain Sd^a.

Precipitin Reaction between Sd^a-Active Human Tamm- Horsfall Glycoprotein and Anti-Sd^a Serum

“…The peculiarity of this blood group is that the human naturally occurring antibodies agglutinate only a pro portion of red cells, even from donors with high expression of Sda antigen. Morton et al [6] found a positive activity also in body tis sues and fluids. Because of the high presence of Sda activity in urine they proposed a reac tion for the determination of Sda antigenic constitution based on the inhibition of Sda agglutination by urine.…”

The Serology of Sd^a Effects of Transfusion and Pregnancy

“…The presence or ab sence of the antigen on red cells, but not in urine, is related to pregnancy. Macvie et al [1] and Morton et al [3] found an increased percentage of pregnant women with Sd(a-) red cells. Many of these patients had Sd(a+) red cells following delivery.…”

“…The Sd blood group system was first de scribed in 1967 by Macvie et al [1] and Ren ton et al [2], Approximately 96% of the pop ulation have the Sda antigen present on their red blood cells or in their urine [3]. Rare individuals have a very strong Sda antigen, denoted as Sd(a++) [4].…”

“…Reactive sera were further tested against three cord blood cells. Urine inhibition tests using Sd(a+) urine [3] and a dithiothreitol reduction test were performed [8].…”

Interaction of a human blood group Sd(a−) Tamm‐Horsfall glycoprotein with applied lectins

“…The blood group substances with Sd ~ activity occur in most human secretions, with the highest concentration in urine and meconium [1][2][3][4]. It was found that the GalNAc~I ~ residues make an important contribution to the Sd a determinant structure in Tamm-Horsfall glycoprotein (THGP) [5].…”