Postnatal Development of Red Cell Le^a and Le^b Antigens in Chinese Infants

Abstract

Lewis phenotyping of 487 blood samples from Chinese newborn infants and young children, revealed that 50% of cord cells were Le(a-b+) and 50% Le(a-b-). The weak Le^b antigen of Le(a-b+) cord cells is most likely produced by the newborn infant rather than of maternal origin and it appears that these infants eventually develop by way of an intermediate Le(a+b+) stage into the adult Le(a-b+) phenotype. Most infants with Le(a-b-) cord cells, but not all, appear to develop through a transitional Le(a+b-) stage, into Le (a+b+) by about 1 month of age, most likely continuing as such into adulthood. This development of Le(a-b-) cord cells into the adult Le(a+b+) phenotype is postulated to be the result of the weak secretor gene Se(i). Those infants with Le(a-b-) cord cells that do not convert to Le(a+b+) during the first month of life, most likely remain as such into adulthood. The blood of 120 adult voluntary blood donors, used as controls, reconfirmed adult Chinese phenotypic frequencies of approximately 70% Le(a-b+),22% Le(a+b+) and 8% Le(a-b-).

Lewis and Secretor Gene Effects on Lewis Antigen and Postnatal Development of Lewis Blood Type

“…Lin and Shieh [22] reported that 50% of cord cells were Le(a-b+) and 50% were Le(a-b-) in a Chinese population. These differences between these Japanese and Chinese populations are considered to be due to both the potency of the mouse monoclonal anti-Le b antibodies used and a weak secretor gene Se w being very heterogeneous in Chinese [22].…”

Flow Cytometric Analyses of the Subclasses of Red Cell IgG Antibodies

“…Although red cell IgG anti bodies can easily be demonstrated using the DAT and IAT antiglobulin tests, these tests are not well suited for the quantification of antibodies or the prediction of the severity of clinical hemolysis [14]. Moreover, IgG subclassing of sensitized red cells is often not feasible using standard ag glutination techniques [2,10,11], Enzyme immunoassays have recently been developed for the quantitation and sub class analysis of IgG antibodies, but only for eluates from red cells [15]. Flow cytometry has also been found to yield acceptable quantitative results [16], In this study, the red cells of newborns with a weakly positive DAT in the gel centrifugation test were also positive using flow cytometry.…”

“…G-6PD deficiency is a second factor involved in hyperbilimbinemia in Taiwanese new borns with an incidence of about 4.6% [6], and G-6PD-deficient infants have been found to have higher bilirubin levels than nondeficient infants [9], Although, the above men tioned factors contribute to some extent to the high inci dence of neonatal hyperbilimbinemia in Taiwanese infants, however, to date, no pathophysiological basis for the major ity of cases of hyperbilirubinemia in our population has been established. In order to study the postnatal development of red cell Lea and Leb antigens, we phenotyped red cells of487 infants and young children [2], In that study, among 120 neonates who had cord blood samples taken, 83 also had samples tak en between 48 and 72 h of age, and 36 also had additional blood samples taken between 4 and 7 days of age. Phenotyping of all these blood samples revealed that only the Le (a-b+) and Le (a-b-) phenotypes were present in cord cells (50% each).…”

“…Most of the IgG subclass deter minations, however, are being performed with agglutination techniques, but these assays often fail to produce reliable results and are difficult to standardize [2,10,11].…”

“…Several attempts have been made, including quantifi cation of antibodies, subclass analysis, and functional bioassays [1], The IgG3 subclass, when compared with the IgGl sub class, has a higher potential for inducing phagocytosis and monocyte adherence in vitro [2][3][4][5][6][7][8]. Some investigators For the flow cytometric measurements, fluorescence intensity was determined using Lysis II software in terms of median channels (loga rithmic amplification) without channel markers.…”