An Unusual Difficulty in Blood Grouping: Interference by Soluble Antigen in a Patient's Serum

Abstract

A difficulty encountered in determining the blood group of a patient has drawn attention to an unusual aspect of immunochemistry. The phenomenon occurred in a patient with a pseudomucinous ovarian cyst and it is believed that a large amount of B blood group substance escaped from the cyst into the blood circulation. This substance in the serum partially neutralized the anti-B agglutinin of the testing serum and only weak agglutination, which could easily have been overlooked, was produced in the first blood grouping test.The distribution of blood group substances in human tissues and secretions has been investigated by numerous workers and has been reviewed by Kabat [l]. Alcohol soluble, water insoluble lipo-proteins with the characteristics of the A and B antigens are present in red cells of all subjects of appropriate blood group. In the majority of subjects there are also water soluble antigenic materials of blood group specificity in the serum and secretions. The presence or absence of the soluble antigens in the serum and secretions is determined by the presence or absence of a single dominant gene which is inherited independently of the blood group. In European populations approximately 80 yo are secretors. The secretor-status can be demonstrated by showing that the saliva or serum of the individual under test neutralises anti-A or anti-B agglutinins. Morgan and van Heyningen [2] who have worked intensively on the chemical nature of the blood group substances, have shown that pseudo-mucinous ovarian cysts of secretors contain large amounts of appropriate group substances. These cyst fluids are a valuable source of supply of human material for investigation, but as far as is known the group specific substances in the cysts have not previously caused difficulty in blood grouping.

A closer look into blood group discrepancy arising due to an underlying malignancy

“…The first report of such association was in 1959 when Barber and Dunsford reported excess of blood group A substance in a female patient with gastric carcinoma resulting in a blood group discrepancy 6 . This finding has also been reported to occur in pancreatic, ovarian, colonic, and bile duct carcinoma and, pseudomucinous ovarian cysts 1, 7, 8. Secretions from tumor cells enter the blood stream either directly or through ascitic fluid absorption 8 .…”