| 1. |
- Clausen, Frederik Banch, et al.
(författare)
-
Recommendation for validation and quality assurance of non-invasive prenatal testing for foetal blood groups and implications for IVD risk classification according to EU regulations
- 2022
-
Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007 .- 1423-0410. ; 117:2, s. 157-165
-
Forskningsöversikt (refereegranskat)abstract
- Background and Objectives: Non-invasive assays for predicting foetal blood group status in pregnancy serve as valuable clinical tools in the management of pregnancies at risk of detrimental consequences due to blood group antigen incompatibility. To secure clinical applicability, assays for non-invasive prenatal testing of foetal blood groups need to follow strict rules for validation and quality assurance. Here, we present a multi-national position paper with specific recommendations for validation and quality assurance for such assays and discuss their risk classification according to EU regulations. Materials and Methods: We reviewed the literature covering validation for in-vitro diagnostic (IVD) assays in general and for non-invasive foetal RHD genotyping in particular. Recommendations were based on the result of discussions between co-authors. Results: In relation to Annex VIII of the In-Vitro-Diagnostic Medical Device Regulation 2017/746 of the European Parliament and the Council, assays for non-invasive prenatal testing of foetal blood groups are risk class D devices. In our opinion, screening for targeted anti-D prophylaxis for non-immunized RhD negative women should be placed under risk class C. To ensure high quality of non-invasive foetal blood group assays within and beyond the European Union, we present specific recommendations for validation and quality assurance in terms of analytical detection limit, range and linearity, precision, robustness, pre-analytics and use of controls in routine testing. With respect to immunized women, different requirements for validation and IVD risk classification are discussed. Conclusion: These recommendations should be followed to ensure appropriate assay performance and applicability for clinical use of both commercial and in-house assays.
|
|
| 2. |
- Gassner, Christoph, et al.
(författare)
-
International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology Report of Basel and three virtual business meetings : Update on blood group systems
- 2022
-
Ingår i: Vox Sanguinis. - : Wiley. - 1423-0410 .- 0042-9007. ; 117:11, s. 1332-1344
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVES: Under the ISBT, the Working Party (WP) for Red Cell Immunogenetics and Blood Group Terminology is charged with ratifying blood group systems, antigens and alleles. This report presents the outcomes from four WP business meetings, one located in Basel in 2019 and three held as virtual meetings during the COVID-19 pandemic in 2020 and 2021.MATERIALS AND METHODS: As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. New blood group systems and antigens were approved and named according to the serologic, genetic, biochemical and cell biological evidence presented.RESULTS: Seven new blood group systems, KANNO (defined numerically as ISBT 037), SID (038), CTL2 (039), PEL (040), MAM (041), EMM (042) and ABCC1 (043) were ratified. Two (039 and 043) were de novo discoveries, and the remainder comprised reported antigens where the causal genes were previously unknown. A further 15 blood group antigens were added to the existing blood group systems: MNS (002), RH (004), LU (005), DI (010), SC (013), GE (020), KN (022), JMH (026) and RHAG (030).CONCLUSION: The ISBT now recognizes 378 antigens, of which 345 are clustered within 43 blood group systems while 33 still have an unknown genetic basis. The ongoing discovery of new blood group systems and antigens underscores the diverse and complex biology of the red cell membrane. The WP continues to update the blood group antigen tables and the allele nomenclature tables. These can be found on the ISBT website (http://www.isbtweb.org/working-parties/red-cell-immunogenetics-and-blood-group-terminology/).
|
|
| 3. |
- Hult, Annika, et al.
(författare)
-
Weak A phenotypes associated with novel ABO alleles carrying the A(2)-related 1061C deletion and various missense substitutions.
- 2010
-
Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 50, s. 1471-1486
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The 1061delC single-nucleotide polymorphism (SNP) has been reported mostly in the context of the common A(2)[A201] allele and typically produces an A(2) phenotype. This study evaluated new A(weak) alleles, each containing 1061delC. STUDY DESIGN AND METHODS: Twenty samples were referred to our laboratory for analysis due to suspected A(weak) phenotypes originally detected at the referring centers. ABO Exons 1 through 7 and flanking intronic regions were sequenced. A antigen expression on red blood cells was analyzed by flow cytometry. Plasma enzyme activity was studied in one case. Molecular three-dimensional modeling techniques studied the potential effects of amino acid changes on the resulting glycosyltransferases (GTs). RESULTS: Thirteen alleles were discovered, each featuring 1061delC with at least 1 of 12 additional SNPs in the coding region. One of these SNPs disrupts the translation initiation codon. Another constitutes the first reported change in the DVD motif. One SNP found in three alleles causes a substitution of one of the four amino acids that differentiates the wild-type A and B enzymes but plasma enzyme analysis by two methods showed only slightly decreased or normal A(2) activity. Flow cytometric analysis semiquantified the A antigen levels in 16 cases featuring 10 of the alleles and ranged from very weak to nearly A(2) levels. However, the majority of the samples displayed A(x)-like patterns. Molecular modeling of some of the GT variants indicated conformational changes that may explain the diminished A expression observed. CONCLUSION: Missense SNPs were identified in 13 novel A(2)-like alleles, which produced a variety of A subgroup phenotypes.
|
|
| 4. |
- Storry, Jill R., et al.
(författare)
-
International Society of Blood Transfusion Working Party on Red Cell Immunogenetics and Blood Group Terminology : Report of the Dubai, Copenhagen and Toronto meetings
- 2019
-
Ingår i: Vox Sanguinis. - : Wiley. - 0042-9007. ; 114:1, s. 95-102
-
Tidskriftsartikel (refereegranskat)abstract
- Background and objectives: The International Society of Blood Transfusion (ISBT) Working Party for Red Cell Immunogenetics and Blood Group Terminology meets in association with the ISBT congress and has met three times since the last report: at the international meetings held in Dubai, United Arab Emirates, September 2016 and Toronto, Canada, June 2018; and at a regional congress in Copenhagen, Denmark, June 2017 for an interim session. Methods: As in previous meetings, matters pertaining to blood group antigen nomenclature and classification were discussed. New blood group antigens were approved and named according to the serologic and molecular evidence presented. Results and conclusions: Fifteen new blood group antigens were added to eight blood group systems. One antigen was made obsolete based on additional data. Consequently, the current total of blood group antigens recognized by the ISBT is 360, of which 322 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known system. Clinically significant blood group antigens continue to be discovered, through serology/sequencing and/or recombinant or genomic technologies.
|
|
| 5. |
- Storry, Jill R, et al.
(författare)
-
The Vel blood group system : a review
- 2017
-
Ingår i: Immunohematology. - 0894-203X. ; 33:2, s. 56-59
-
Forskningsöversikt (refereegranskat)abstract
- CONCLUSIONS: The blood group antigen Vel has been one of immunohematology's greatest enigmas: the variation in antigen strength from one individual to another, the property of anti-Vel to readily hemolyze Vel+ red blood cells (RBCs), and the difficulty to screen for sufficient numbers of Vel- blood donors had made Vel a tough nut to crack. In 2013, a small, previously unknown protein called small integral membrane protein 1 (SMIM1) was identified on the RBC by three independent research groups using different approaches, and all three groups demonstrated that Vel- RBCs lacked SMIM1. This discovery correlated with homozygosity for deletion c.64_60del in SMIM1 and meant that for the first time there was a universal method to screen for Vel- blood donors. This finding was not the whole answer, however, and an explanation behind the variability in antigen strength was later shown to be due to polymorphism in SMIM1 intron 2, a region that is responsible for gene transcription. Clinically, anti-Vel is important and has caused severe transfusion reactions, although hemolytic disease of the fetus and newborn caused by anti-Vel is uncommon. However, while screening for Vel- blood donors has become easier, the function of SMIM1 is still unknown, and despite its well-conserved sequence across the animal kingdom, the enigma continues.
|
|
| 6. |
- Westman, Julia, et al.
(författare)
-
Large deletions involving the regulatory upstream regions of A4GALT give rise to principally novel P1PK-null alleles.
- 2014
-
Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 54:7, s. 1831-1835
-
Tidskriftsartikel (refereegranskat)abstract
- Cells of the clinically important p histo-blood group phenotype lack P1, P(k) , and P glycosphingolipid antigens. All cases investigated so far are due to alterations in the 4-α-galactosyltransferase-encoding Exon 3 of A4GALT. Repetitive elements in the genome can mediate DNA rearrangements, the most abundant being the Alu family of repeats.
|
|
| 7. |
- Westman, Julia, et al.
(författare)
-
P1/P2 genotyping of known and novel null alleles in the P1PK and GLOB histo-blood group systems.
- 2013
-
Ingår i: Transfusion. - : Wiley. - 1537-2995 .- 0041-1132. ; 53:11, s. 2928-2939
-
Tidskriftsartikel (refereegranskat)abstract
- The rare but clinically important null phenotypes of the P1PK and GLOB blood group systems are due to alterations in A4GALT and B3GALNT1, respectively. A recently identified single-nucleotide polymorphism in Exon 2a of A4GALT predicts the common P1 and P2 phenotypes but rare variants have not been tested.
|
|
