Brigitte K Flesch1,2, Angelika Reil2, Núria Nogués3, Carme Canals3, Peter Bugert4, Torsten J Schulze4,5, Elly Huiskes6, Leendert Porcelijn6, Petter Höglund7, Paul Ratcliffe7, Marlies Schönbacher8, Hans Kerchrom9, Josina Kellershohn10, Behnaz Bayat10. 1. German Red Cross Blood Service Rhineland-Palatinate and Saarland, Bad Kreuznach, Germany. 2. German Red Cross Blood Service West, Hagen, Germany. 3. Immunohematology Laboratory, Blood and Tissue Bank, Barcelona, Spain. 4. Institute of Transfusion Medicine and Immunology, Medical Faculty Mannheim, Heidelberg University, German Red Cross Blood Service of Baden-Württemberg, Hessen gGmbH, Mannheim, Germany. 5. Institute Springe, German Red Cross Blood Service NSTOB, Springe, Germany. 6. Department of Immunohematology Diagnostics, Sanquin, Amsterdam, The Netherlands. 7. Center for Hematology and Regenerative Medicine, Karolinska University Hospital, Stockholm, Sweden. 8. Department of Blood Group Serology and Transfusion Medicine, Medical University of Vienna, Vienna, Austria. 9. Centre Hospitalier Universitaire de Nantes, Nantes, France. 10. Institute for Clinical Immunology and Transfusion Medicine, Justus Liebig University, Giessen, Germany.
Abstract
BACKGROUND: The human neutrophil antigen 2 (HNA-2), which is expressed on CD177, is undetectable in 3-5% of the normal population. Exposure of these HNA-2<sub>null</sub> individuals to HNA-2-positive cells can cause immunization and pro-duction of HNA-2 antibodies, which can induce immune neutropenia and transfusion-related acute lung injury. In HNA-2-positive individuals, neutrophils are divided into a CD177<sup>pos.</sup> and a CD177<sup>neg.</sup> subpopulation. The molecular background of HNA-2 deficiency and the bimodal expression pattern, however, are not completely decoded. STUDY DESIGN: An international collaboration was conducted on the genetic analysis of HNA-2-phenotyped blood samples, including HNA-2-deficient individuals, mothers, and the respective children with neonatal immune neutropenia and regular blood donors. RESULTS: From a total of 54 HNA-2<sub>null</sub> individuals, 43 were homozygous for the CD177 *787A>T substitution. Six carried the CD177 *c.1291G>A single nucleotide polymorphism. All HNA-2-positive samples with >40% CD177<sup>pos.</sup> neutrophils carried the *787A wild-type allele, whereas a lower rate of CD177<sup>pos.</sup> neutrophils was preferentially associated with *c.787AT heterozygosity. Interestingly, only the *c.787A allele sequence was detected in complementary DNA (cDNA) sequence analysis carried out on all *c.787AT heterozygous individuals. However, cDNA analysis after sorting of CD177<sup>pos.</sup> and CD177<sup>neg.</sup> neutrophil subsets from HNA-2-positive individuals showed identical sequences, which makes regulatory elements within the promoter unlikely to affect CD177 gene transcription in different CD177 neutrophil subsets. CONCLUSION: This comprehensive study clearly demonstrates the impact of single nucleotide polymorphisms on the expression of HNA-2 on the neutrophil surface but challenges the hypothesis of regulatory epigenetic effects being implicated in the bimodal CD177 expression pattern.
BACKGROUND: The human neutrophil antigen 2 (HNA-2), which is expressed on CD177, is undetectable in 3-5% of the normal population. Exposure of these HNA-2<sub>null</sub> individuals to HNA-2-positive cells can cause immunization and pro-duction of HNA-2 antibodies, which can induce immune neutropenia and transfusion-related acute lung injury. In HNA-2-positive individuals, neutrophils are divided into a CD177<sup>pos.</sup> and a CD177<sup>neg.</sup> subpopulation. The molecular background of HNA-2 deficiency and the bimodal expression pattern, however, are not completely decoded. STUDY DESIGN: An international collaboration was conducted on the genetic analysis of HNA-2-phenotyped blood samples, including HNA-2-deficient individuals, mothers, and the respective children with neonatal immune neutropenia and regular blood donors. RESULTS: From a total of 54 HNA-2<sub>null</sub> individuals, 43 were homozygous for the CD177 *787A>T substitution. Six carried the CD177 *c.1291G>A single nucleotide polymorphism. All HNA-2-positive samples with >40% CD177<sup>pos.</sup> neutrophils carried the *787A wild-type allele, whereas a lower rate of CD177<sup>pos.</sup> neutrophils was preferentially associated with *c.787AT heterozygosity. Interestingly, only the *c.787A allele sequence was detected in complementary DNA (cDNA) sequence analysis carried out on all *c.787AT heterozygous individuals. However, cDNA analysis after sorting of CD177<sup>pos.</sup> and CD177<sup>neg.</sup> neutrophil subsets from HNA-2-positive individuals showed identical sequences, which makes regulatory elements within the promoter unlikely to affect CD177 gene transcription in different CD177 neutrophil subsets. CONCLUSION: This comprehensive study clearly demonstrates the impact of single nucleotide polymorphisms on the expression of HNA-2 on the neutrophil surface but challenges the hypothesis of regulatory epigenetic effects being implicated in the bimodal CD177 expression pattern.
Authors: Claudia Eulenberg-Gustavus; Sylvia Bähring; Philipp G Maass; Friedrich C Luft; Ralph Kettritz Journal: J Exp Med Date: 2017-05-30 Impact factor: 14.307