1.Dentification and blood transfusion therapy of anti-C, e alloantibodies with anti-e, Jkb mimicking alloantibodies
Xin ZOU ; Sifei MA ; Hongmei YANG ; Xiaojie FAN
Chinese Journal of Blood Transfusion 2024;37(2):214-218
【Objective】 To investigate the differential diagnosis of 1 anti-C, e alloantibodies combined with anti-e, Jkb mimicking alloantibodies by absorption-elution test and titer integral method. 【Methods】 ABO, Rh and Kidd blood group antigens were identified by tube method. Two sets of panel cells were used for antibody screening and antibody specificity identification by saline method, polyamine method and microcolumn gel method.The antibody was further confirmed by multiple absorption-elution tests and titer integral method. RHCE and JK gene were sequenced by multiple PCR. 【Results】 Serological gene sequencing analysis showed that the ABO blood group of the patient was A type with Rh subtype ccDEE and was positive for direct antiglobulin test (DAT). Multiple absorption-elution tests and titer integral method demonstrated that the serum of the patient contained anti-C, e alloantibodies along with anti-e, Jkb mimicking autoantibodies and there were anti-e, Jkb mimicking autoantibodies on red blood cells(RBCs). According to gene sequencing analysis, there was G>C at exon 676 of the RHCE gene, and the remaining exons were not mutated, suggesting that the RHCE phenotype was ccEE. The 838 G/A heterozygote of exon 9 in JK gene, Jk blood group phenotype was Jk (a+ b+ ). Cross matched type A ccDEE and Jk(a+ b-) RBCs were transfused, and no adverse reactions occurred. 【Conclusion】 Serology combined with molecular biology to identify the phenotype of the patient′s RBCs, absorption-elution test and titer integral method to identify the antibody of the patient′s serum can detect the alloantibody type, thus providing strategies for targeted blood transfusion.
2.Optimization of temperature parameters for screening unexpected antibodies in Rh system by manual polybrene test
Xin ZOU ; Minjie CHEN ; Sifei MA ; Hongmei YANG
Chinese Journal of Blood Transfusion 2025;38(1):97-100
[Objective] To explore the temperature parameters affecting the polybrene test and determine the optimal temperature conditions for detecting unexpected antibodies of the Rh system. [Methods] The reaction of IgG human anti-D antibody with different dilutions (undiluted, 1∶2, 1∶4, 1∶8, 1∶16, 1∶32,1∶64) with D antigen-positive red blood cells was detected by manual polybrene test (MPT). Different temperatures (25℃ and 37℃) were set, and the reaction time with low ionic medium was 4 minutes. The agglutination integral value of anti-D and red cell depolymerization time were compared to observe the effect of enhanced agglutination reaction, thereby establishing the test temperature reaction conditions for enhancing the MPT. The same reaction condition was applied to 36 blood samples containing unexpected antibodies of the Rh system, and the effect of enhanced MPT was observed in comparison with the polybrene method and the antiglobulin test (column agglutination). [Results] With all other conditions held constant, when low ionic medium was added, the incubation temperature of 25℃ and 37℃ resulted in different total agglutination integral values for anti-D (20.9±2.025 vs 25.5±2.635), and the comparison showed a significant difference (P<0.05). When the antibody dilution was 1∶16, the incubation temperature of 25℃ and 37℃ resulted in different agglutination integral values (3.9±0.738 vs 5.8±0.632), and the comparison showed a significant difference (P<0.05). Erythrocyte depolymerization time (62.8±8.149 vs 90.1±10.713) was significantly different (P<0.05). At a dilution of 1∶32, the incubation temperatures of 25℃ and 37℃ resulted in different agglutination integral values (2.5±0.527 vs 4.3±0.675), as well as different red blood cell dissociation times (35.4±7.792 vs 57.4±10.885)(P<0.05), and the comparison showed a significant difference (P<0.05), with no differences observed in the other groups. In the detection of 36 Rh system unexpected antibody samples, when the antibody titer was ≤2, the enhanced polybrene method had a higher positive rate, and when the antibody titer was ≥4, the detection rates of the three methods were consistent. [Conclusion] The reference temperature condition for the modified MPT is incubation at 37℃ for 4 min after the addition of low ionic medium. The application of this temperature condition to unexpected antibody samples of Rh system could achieve a significant enhancement effect, thereby increasing transfusion safety for the treatment of emergency patients, and is worth popularizing.