Analysis of newborn blood type by real-time PCR technology

• Main Authors: Ko-Ming Hou, 侯克明
• Other Authors: Chang-Yu Chen
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/69883497493498750206

碩士 === 輔英科技大學 === 醫學檢驗生物技術系碩士班 === 102 === Blood type is antibody triggered by allogeneic antigen in the red blood cell membrane. Thirty-three human blood group system and 328 kinds of antigen have been identified by International Society Blood Transfusion (ISBT). ABO blood group system is the first one to be found and most important. Red blood cell phenotyping and serotyping in the traditional serology is analyzed by antigen-antibody binding. The correct blood type is determined by the compatibility of both phenotyping and serotyping. The expression of ABH antigen is usually weaker in newborn, with only 25-50% of that in adults. In addition, the serum ABO antibodies in newborn secrete after 3-6 months old. The phenotyping can be analyzed but serotyping is not available in newborn. ABO incompatibility causes the most serious transfusion reactions in transfusion medicine. The factors of indetermination of ABO blood type include age (newborn or elderly), leukemia, congenital gammaglobulinemia, chimerism, bone marrow transplantation, ABO subtype, colorectal cancer and Hodgkin’s disease, etc. All these clinical conditions could lead to misjudgment of the blood type. ABO blood group loci are located on chromosome 9q34.2 and containing seven exons. The main coding sequence is between exon 6 and exon 7. The presence of ABO blood group antigens is not limited in red blood cells. It is widely distributed in epithelial and endothelial cells and is often seen in secretions and body fluid. It is a tissue antigen. The study was performed by extracting DNA from peripheral blood and oral mucosa samples, and analyzed the two single nucleotide polymorphism ( SNP) sites (nucleotides 261 and 796) of ABO gene by real-time quantitative polymerase chain reaction. The result was then compared with that obtained by traditional serologic tests. In this study a total of 85 donors (21 adults and 64 newborns) were recruited and DNAs were extracted from the peripheral blood and oral mucosa samples. Among the adults (21 subjects), the result of ABO genotypes revealed AA type: 0, AO type: 3, BB type: 1, BO-type: 8, OO type: 8, and AB-type: 1, while among the newborns (64 subjects), AA type: 1, AO type: 14, BB type: 3, BO type: 14, OO type: 26, and AB type: 6. The results are consistent with those obtained with traditional methods. In conclusions, the new molecular technique can be used as a complementary method for traditional serological tests to distinguish ABO blood group. It can be achieved more rapidly and accurately, especially in newborns, of whom the expression of ABH antigen is weaker. With the use of the easily available samples with nucleated cells, such as oral mucosa, for ABH antigen identification will reduce the number and amount of blood sampling in newborns. Hoping that this newly developed molecular technique can be applied to other problematic samples with blood typing in the future, to enhance turn-around time and to shorten patient’s waiting time for blood transfusion, and to improve sensitivity and specificity of ABO typing.