Objective To investigate the interference of thyroglobulin antibodies ( TgAb ) on the measurement of thyroglobulin ( Tg) by 2 chemiluminescence immunoassays ( CLIAs) .Methods Data of 199 315 individuals with determined TgAb and Tg , including physical checkup subjects , differentiated thyroid carcinoma ( DTC) patients and patients with other diseases , were retrospectively collected in Peking Union Medical College Hospital from November 2012 to April 2015.The correlation between serum Tg level and serum TgAb concentration was analyzed and the positive rate of TgAb in physical checkup subjects was calculated.Furthermore, 290 serum samples with different TgAb concentration were applied in the recovery test by adding in confirmed serum Tg .The correlation between the recovery of confirmed serum Tg and TgAb concentrations was evaluated using Pearson correlation analysis .Results The serum Tg was all decreased with the elevated TgAb concentration in each group of subjects .The positive rate of TgAb was 10.84%(8 416/77 634) in physical checkup subjects .It was higher in females than in males and was increased with age.Recovery test showed that the average recoveries of confirmed serum Tg in TgAb-negative serum were 107.28%(86.30%-117.60%) and 107.94% (85.60%-124.10%) respectively in Roche and Beckman systems.But in TgAb-positive serum samples , the average recoveries in Roche and Beckman systems were 88.59% (35.85% -141.53%) and 95.77% (36.48% -131.78%) respectively, and 12.63%(24/190) and 13.68%(26/190) samples displayed a recovery less than 80%.The recovery rate of confirmed serum Tg showed a significantly negative correlation with elevated TgAb concentration , with r=-0.239 (P=0.001) in Roche and r=-0.251 (P<0.001) in Beckman.Conclusions TgAb-positive serum, especially with high concentration of TgAb , significantly interfered the measurement of Tg .Thus, serum TgAb should be determined together with serum Tg to explore whether there was an interference .To avoid misdiagnosis and inappropriate therapy , clinician should be informed once serum TgAb displayed positive.

OBJECTIVE: To explore the molecular reasons of weak expression of B antigen on the red cell. METHODS: Serological test for blood group was carried out, including red cell and plasma grouping, and anti-A1 and anti-H testing, and confirming weak A or B antigens by adsorption and elution. Exons 1-7 were sequenced directly, and one of them was cloned and sequenced. RESULTS: All of the 23 samples showed the weak B antigen by serological method. The alleles of the subgroups were identified by DNA sequencing, including 2 Bel subgroup, 4 B3 subgroup, 14 Bw subgroup, 2 CisAB subgroup and a novel allele. The novel allele showed a nucleotide substitution 662G>A in the exon 7, and the sequence was submitted to Blood Group Antigen Gene Mutation Database, and the novel allele was named Bel10. CONCLUSION Nucleotide substitution in exon results in blood subgroup, which showed that the antigens were weakened, and Bw phenotype was the most frequently subgroup.
ABO Blood-Group System/genetics* ; Alleles ; Exons ; Genotype ; Humans ; Nucleotides ; Phenotype

【Objective】 To investigate the HBV infection of TMA initially reactive but discriminatory test non-reactive samples(NDR) after the individual donation nucleic acid detection(ID-NAT)of TMA, and analyze its serological and molecular biological characteristics, so as to improve the safety of blood transfusion. 【Methods】 121 970 samples of blood donors in the center from January 1, 2021 to December 31, 2021 were routinely tested by serology and nucleic acid of ID NAT, and 21 HBsAg(-)/ NDR samples were random collected. After the plasma samples were concentrated by ultra-high speed centrifugation, the gene sequences of BCP/PC, pre-S/S and S region were amplified by Nested PCR. The S region sequence was also sequenced to analyze the viral genotype and amino acid variation. At the same time, the original TMA retest discriminatory test was adopted, and Roche MPX 2.0 was used for ID-NAT, and the samples was not virus-concentrated.NDR samples were supplemented with electrochemiluminescence for anti-HBc and anti-HBs quantitative detection. 【Results】 Of the 121 970 samples screened, 117(0.096%) were found to be HBsAg(-)/NDR samples, of which 21 samples underwent a confirmation test. Sixteen(76.2%) cases were positive for HBV DNA by TMA retest, 7(33.3%) positive for HBV DNA by Roche MPX 2.0 ID-NAT, 9(42.9%) confirmed by Nested PCR, and 8(38.1%) positive by any two methods. Test results of serological markers were as follows: 17(80.9%) positive anti-HBc and 8(38.1%) positive anti-HBs. Eight infected cases were confirmed to have occult hepatitis B infection(OBI). The gene sequence of S region was successfully amplified and sequenced in 3 cases, all of which belonged to C type. Two mutations occurred in specimen S-2, all of which were outside MHR. There were 13 mutations in sample S-6, 6 mutations outside MHR and 7 mutations inside MHR. 【Conclusion】 Nearly 40% of NDR samples can still be detected as HBV DNA positive after virus concentration. Anti-HBc has a high detection rate, and there may be a potential risk of HBV transmission. The current NAT detection sensitivity should be improved. The amino acid mutation of S gene sequence may be related to OBI formation.

【Objective】 To investigate the serological and molecular characteristics of twenty blood samples carrying ABO^*AW.37 allele and to analyze ABO allelic enhancement. 【Methods】 The ABO phenotype of the twenty samples was determined by serological methods and the genotype of 1-7 ABO exons was analyzed by Sanger sequencing. 【Results】 Sequencing analysis showed that all twenty samples contained a c. 940A>G(p.Lys314Glu) mutation of A allele, which was defined as ABO^*AW.37. When ABO^*AW.37 and B alleles were inherited simultaneously in 9 cases, in forward typing anti-A antibodies all agglutinated and the serological phenotype was AwB. Among the 11 cases with ABO^*AW.37 and O alleles inherited simultaneously, there was no agglutination of anti-A in forward typing. For absorption and elution tests, 5 cases were weakly positive and the serological phenotype was Ael, while 6 cases were negative for absorption and elution tests and the serological phenotype was O type. 【Conclusion】 Allelic enhancement occured when both ABO^*AW.37 allele and B allele were inherited simultaneously. When ABO^* AW.37 was inherited simultaneously with O allele, the serological phenotype was Ael or O type and attention should be paid to blood type identification.

To develop a clinical diagnosis technique for bluetongue virus infection, we established serotype-specific methods to detect serotype 4 of bluetongue virus (BTV-4). Two monoclonal antibodies (mAbs) against VP2 protein of BTV-4, named 4A-1G7 and 4B-1B6, were used as competitive antibodies in the competitive enzyme-linked immunosorbent assays (C-ELISA). We detected 50 negative serum samples from sheep, goats and cattle by C-ELISA. The cut-off values of 4A-1G7 and 4B-1B6 mAbs were 49% and 40%, respectively. The results of the sensitivity, specificity and repeatability by detecting standard positive serum, were consistent with the general standard of Office International Des Epizooties. Furthermore, serum samples of BTV-4, BTV-18 and BTV-20 infection could be screened out through the combined C-ELISAs by 4A-1G7 and 4B-1B6 mAbs. Thus, this technique may diagnose BTV-4, BTV-18 and BTV-20 infections.

To confirm the B cell epitope recognized by monoclonal antibody (MAb) 3G11 of bluetongue virus type 8 (BTV-8) VP2 protein prepared in our laboratory, antigen epitopes recognized by 3G11 were screened and identified by phage display technology. KLLAT sequence was found by sequencing of blue spot after four rounds panning and 283LL284 of common short peptide sequence was obtained after comparison to amino acid sequence of BTV-8 VP2 protein. The peptide sequences KLLAA, KALAT, KLAAT and KLLAT were synthesized and identified by indirect ELISA. KLLAA and KLLAT bound strongly with supernatant and as cites of 3G11 cells and reacted specifically with BTV-8 positive standard sera. Further sequence analysis showed that amino acid sequence 283LL284 was conserved among different serotypes of BTV-8 strains, and283LL284 was the key amino acids of antigen epitopes recognized by 3G11. This study laid the foundation to establish type 8 BTV specific immunological detection methods.