ABO and Rh Blood Group Antigens and Natural Anti-A and ANTI-B Antibodies in the Neonates

Abstract

ABO blood group is determined by the presence or absence of A and B antigens on the surface of RBC and of anti-A and anti-B antibodies in the serum. The relatively weak expression of A and B antigens in newborns due to their developing immune systems poses challenges in accurately detecting naturally occurring IgM antibodies against these antigens. This difficulty in immunoserological methods contributes to the potential for errors in determining the blood groups of newborns. Despite this, the Rh antigen expression in newborns remains comparable to that in adults. Nonetheless, various factors contribute to diverse blood typing results in newborns, including the utilization of alternative testing methods. The complexity of blood typing is magnified when using samples from the umbilical vein. Furthermore, compared to adults, the exploration of ABO antigen expression in newborns is limited, and the identification of specific subgroups such as A1 and A2 is even rarer. This underscores the need for standardized testing procedures and further research to enhance our understanding of antigen expression patterns in newborns. Based on the aforementioned details, the primary objective of our study was to delve into specific aspects related to blood group characterization in newborns. This encompassed exploring the expression of A, B, AB, and D antigens on the surface of red blood cells (RBCs) and detecting anti-A and anti-B antibodies in the plasma of newborns. These analyses were conducted using samples obtained from the heels of 208 newborns and were typed by forward and reverse blood typing methods with monoclonal antibodies and srandart erythrocytes. The distribution of phenotypic groups within the ABO system among the newborns was not uniform. The r allele was identified with the highest frequency in the analyzed samples (0.6), while the prevalence of the p allele significantly lags at 0.3. The q allele has the lowest frequency (0.1). In our study, we propose that for the majority of cases (43.94±3.5%) among the studied newborns, there was an absence of naturally occurring anti-A and anti-B antibodies (n=87). In a specific scenario, within the O(I) blood group nwborns, partial synthesis of these antibodies was detected in 14.14±2.4% (n=28). Meanwhile, 41.92±3.5% of the newborns in our study exhibited natural antibodies similar to those found in adults. We didn’t find any difficulties in typing the Rh blood group antigens in the newborns. In conclusion, our study's findings indicate that newborns, in certain instances, exhibit strongly pronounced natural anti-A and anti-B antibodies within the ABO system. However, in the majority of cases, these antibodies are not evident. Majority of cases erythrocyte A and B antigens were weakly expressed and for detecting these images optic microscopes were used.