Secretor status

Hutson, A. M., Airaud, F., LePendu, J., Estes, M. K., and Atmar, R. L. (2005). Norwalk virus infection associates with secretor status genotyped from sera. /. Med. Virol. 77,116-120. 

Price Evans (E7) found a good correlation between the titer of blood group substances and the fucose concentration in gastric juice of persons with established blood group and salivary ABH secretor status. 

The physiological genetics of human blood factors (C5) now includes an association between ABO blood groups, secretor status, and the slow-moving LPSAP band in the starch-gel zymogram for serum alkaline phosphatase. 

Since there is no difference in the amount of alkaline phosphatase in the intestinal mucosa of subjects of various blood types and secretor status (L2) and since this enzyme is presumed to be L-phenylalanine-sensitive (L14), then the difference in the relative amount of heat-stable LPSAP in persons with or without the slow band may relate to events... 

The genetic factor recognized by blood type and secretor status could be operating at one or more of the following loci intestinal mucosa, rate of absorption, rate of secretion, function and level of lipoprotein lipase and the reticuloendothelial system, neuraminidase level in intestinal contents and other tissues. In this latter connection, blood group carbohydrates are found on the cell walls of the epithelium of the microvilli of the intestine. 

It was possible, in the preceding section, to arrive at a biochemical classification in normal healthy subjects. The moieties measured are simply the alkaline phosphatase activity of unheated and heated serum in the presence of n- and L-phenylalanine, respectively. Depending on the individual s blood type, secretor status, and sex, the mean values and relative proportions of each may differ. 

Another consideration is that properties of sera from individuals of a particular blood type and secretor status may resemble those of bone disease. If such individuals were blood type A nonsecretors with predominantly heat-sensitive non-LPSAP in the bone position and underwent substrate or hormonal induction, their hyperphosphatasemic sera would be indistinguishable in starch-gel patterns, LPSAP, and heat sensitivity from sera in Paget s disease. 

The use of the L-phenylalanine inhibition and heat sensitivity does serve (as illustrated in Cases A, B, C, and D) to separate into a separate category those sera whose biochemical patterns are abnormal in type compared to the pattern of a normal individual of the same blood tjqie, sex, and secretor status. If the heat sensitivity of the non-LPSAP is higher than expected, one has grounds to consider the presence of a bone phosphatase. Its amount can be quantitated readily. 

When one takes into consideration the physiological factors which can operate to modify enzyme proteins, one must also include as a fundamental basis of departure the genetic constitution of the individual. At present the traits are associated with ABO blood groups and secretor status. But who knows when the genetic factor may directly explain the individual serum alkaline phosphatase distribution in terms of specific enzymes ... 

L2. Langman, M. J. S., Leuthold, E., Robson, E. B., Harris, J., Huffman, J. E., and Harris, H., Influence of diet on the intestinal component of serum alkaline phosphatase in people of different ABO blood groups and secretor status. Nature 212, 41-43 (1966). 

The enzyme of human milk is present in all women of blood-group A, irrespective of secretor status. In non-secretors, however, the //-dependent al,2-fucosyltransferase is absent and so the al,3-A-acetylegalactosaminyl-transferase can never function synthetically because of the lack of its substrate. This is a good demonstration of the necessary sequential action of gjycosyltransferases in oligosaccharide assembly. 

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