Characterization and refinement of monoclonal anti-human globulins that lack reactivity with human IgG4.
Amino Acid Sequence
Animals
Antibodies, Monoclonal
/ analysis
CHO Cells
Cricetinae
Cricetulus
Epitopes
/ chemistry
Erythrocytes
/ immunology
Humans
Immunoglobulin G
/ blood
Immunoglobulins
/ chemistry
Immunologic Tests
Isoantibodies
/ analysis
Mice
Mice, Inbred C57BL
Mice, Transgenic
Protein Binding
Sequence Analysis, Protein
Journal
Transfusion
ISSN: 1537-2995
Titre abrégé: Transfusion
Pays: United States
ID NLM: 0417360
Informations de publication
Date de publication:
05 2020
05 2020
Historique:
received:
10
02
2019
revised:
18
02
2020
accepted:
06
03
2020
pubmed:
6
5
2020
medline:
9
9
2020
entrez:
6
5
2020
Statut:
ppublish
Résumé
Anti-red blood cell (RBC) alloantibodies consisting of only the immunoglobulin G (IgG) 4 subtype are typically considered clinically insignificant. A US Food and Drug Administration-approved monoclonal anti-human globulin (16H8) is nonreactive with IgG4, which has been considered a benefit to avoid testing interference from IgG4. However, 16H8 also does not recognize two natural IgG3 variants (IgG3-03 and IgG3-13). Thus, 16H8 may miss clinically significant alloantibodies in some settings. Novel mouse anti-human IgG hybridomas were generated and screened for reactivity with 32 human variants of anti-KEL1 across different IgG subtypes, as well as mutants to allow epitope mapping. Anti-IgG reactivity was determined using KEL1+ RBCs bound by each IgG variant as targets. Binding of anti-IgG was determined by flow cytometry. 16H8 recognized an epitope involving amino acid 419, which is glutamate in IgG4, IgG3-03, and IgG3-13, explaining the lack of 16H8 reactivity with these subtypes/isoallotypes. A new monoclonal antibody (PUMA8) was isolated that, like 16H8, was nonreactive with IgG4 but without blind spots for known variants of IgG1, IgG2, or IgG3. PUMA8 recognized an epitope containing arginine at position 355, which is glutamine in IgG4. However, a recently described new IgG4 variant with an arginine at position 355 results in PUMA8 reactivity. PUMA8 represents an alternative to 16H8 that avoids IgG4 but without blind spots for IgG3 variants. However, PUMA8 reacts with one recently described IgG4 variant. In addition to relevance to immunohematology, these studies highlight the importance of patient variation with regards to assay performance in an era of personalized medicine.
Sections du résumé
BACKGROUND
Anti-red blood cell (RBC) alloantibodies consisting of only the immunoglobulin G (IgG) 4 subtype are typically considered clinically insignificant. A US Food and Drug Administration-approved monoclonal anti-human globulin (16H8) is nonreactive with IgG4, which has been considered a benefit to avoid testing interference from IgG4. However, 16H8 also does not recognize two natural IgG3 variants (IgG3-03 and IgG3-13). Thus, 16H8 may miss clinically significant alloantibodies in some settings.
STUDY DESIGN AND METHODS
Novel mouse anti-human IgG hybridomas were generated and screened for reactivity with 32 human variants of anti-KEL1 across different IgG subtypes, as well as mutants to allow epitope mapping. Anti-IgG reactivity was determined using KEL1+ RBCs bound by each IgG variant as targets. Binding of anti-IgG was determined by flow cytometry.
RESULTS
16H8 recognized an epitope involving amino acid 419, which is glutamate in IgG4, IgG3-03, and IgG3-13, explaining the lack of 16H8 reactivity with these subtypes/isoallotypes. A new monoclonal antibody (PUMA8) was isolated that, like 16H8, was nonreactive with IgG4 but without blind spots for known variants of IgG1, IgG2, or IgG3. PUMA8 recognized an epitope containing arginine at position 355, which is glutamine in IgG4. However, a recently described new IgG4 variant with an arginine at position 355 results in PUMA8 reactivity.
CONCLUSION
PUMA8 represents an alternative to 16H8 that avoids IgG4 but without blind spots for IgG3 variants. However, PUMA8 reacts with one recently described IgG4 variant. In addition to relevance to immunohematology, these studies highlight the importance of patient variation with regards to assay performance in an era of personalized medicine.
Substances chimiques
Antibodies, Monoclonal
0
Epitopes
0
Immunoglobulin G
0
Immunoglobulins
0
Isoantibodies
0
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
1060-1068Informations de copyright
© 2020 AABB.
Références
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