ABH glycosyltransferase levels in sera and red cell membranes from Hz and Hm variant bloods

α-2-L-Fucosyltransferase Activity in Sera of Individuals with H-Deficient Red Cells and Normal H Antigen in Secretions

“…H/h sera gave values between 9,500 and 21,400 cpm while H/h sera gave values between 24,000 and 36,400 cpm, confirming the H dosage effect described using the same serum samples [Le Pendu et al, 1983a]. this activity [Mulet et al, 1978;Watkins, 1978;Daniels, 1980]. Two reasons can be put forward in order to explain the previous negative results: (1) Loss of activity due to transportation and storage: Due to the very labile nature of the a-2-L-fucosyltransfer ase, the serum samples have to be as fresh as possible and thawing should be avoided.…”

“…a-2-L-Fucosyltransferase activity was found in the sera of 4 H-deficient secretor individuals (Hz). This activity represented about 5-10% of the activity present in the serum of normal H phenotypes.a-2-L-Fucosyltransferase activity has been found in the serum of all the individu als with normal ABH phenotypes [Schenkel-Brunner et al, 1972 ;Chester et al, 1976 ;Mulet et al, 1977], However, previous work ers were unsuccessful in finding a-2-L-fucosyltransferase activity in serum of H-defi cient phenotypes irrespective of their secre tor status [Mulet et al, 1978 ;Watkins, 1978 ;Daniels, 1980], In this paper we report the finding of a low but definite a-2-L-fucosyltransferase activity in serum of H-deficient secretor individuals and the levels of this activity are compared to the levels of the corresponding activity found in other secre tor and nonsecretor H genotypes. …”

“…The remaining 90-95% should originate in the hematopoietic tissue [Mulet et al, 1978;Watkins, 1978], Nevertheless, no dif ference could be found between secretors and nonsecretors in H/h or H/H individuals Discussion 4 individuals were characterized as Hdeficient secretors since they had only very small amounts of A, B or H antigens on their erythrocytes but secreted normal amounts of these antigens in their saliva. They had only weak anti-H antibodies in their serum.…”

Some Notes on the Specificity of Anti-A^1 Reagents

“…The same relationship was found in A2 samples C. R. and S. C. with 4 x 105 and 1.2 x 105 A antigenic sites/cell, respectively, where only the former could be agglutinated by the three reagents. Activities of D. biflorus lectin and Table II [16,17]. An A^ woman has also been reported to transmit an Ax gene to her offspring [20].…”

Probable Biosynthetic Pathway for the Synthesis of the B Antigen from B(h) Variants

“…In addition, indirect evidence recently suggested some secondary defect of H which is possibly due to an abnormality in the syn thesis of the H precursor substance itself [19].…”