1. Novel manifestations of immune dysregulation and granule defects in gray platelet syndrome.
- Author
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Sims MC, Mayer L, Collins JH, Bariana TK, Megy K, Lavenu-Bombled C, Seyres D, Kollipara L, Burden FS, Greene D, Lee D, Rodriguez-Romera A, Alessi MC, Astle WJ, Bahou WF, Bury L, Chalmers E, Da Silva R, De Candia E, Deevi SVV, Farrow S, Gomez K, Grassi L, Greinacher A, Gresele P, Hart D, Hurtaud MF, Kelly AM, Kerr R, Le Quellec S, Leblanc T, Leinøe EB, Mapeta R, McKinney H, Michelson AD, Morais S, Nugent D, Papadia S, Park SJ, Pasi J, Podda GM, Poon MC, Reed R, Sekhar M, Shalev H, Sivapalaratnam S, Steinberg-Shemer O, Stephens JC, Tait RC, Turro E, Wu JKM, Zieger B, Kuijpers TW, Whetton AD, Sickmann A, Freson K, Downes K, Erber WN, Frontini M, Nurden P, Ouwehand WH, Favier R, and Guerrero JA
- Subjects
- Biopsy, Blood Proteins genetics, Case-Control Studies, Cohort Studies, Cytoplasmic Granules metabolism, Diagnosis, Differential, Gene Frequency, Genetic Association Studies, Humans, Immune System physiology, Immune System Diseases blood, Immune System Diseases diagnosis, Immune System Diseases genetics, Immune System Diseases pathology, Mutation, Cytoplasmic Granules pathology, Genetic Heterogeneity, Gray Platelet Syndrome classification, Gray Platelet Syndrome genetics, Gray Platelet Syndrome immunology, Gray Platelet Syndrome pathology, Immune System pathology, Phenotype
- Abstract
Gray platelet syndrome (GPS) is a rare recessive disorder caused by biallelic variants in NBEAL2 and characterized by bleeding symptoms, the absence of platelet α-granules, splenomegaly, and bone marrow (BM) fibrosis. Due to the rarity of GPS, it has been difficult to fully understand the pathogenic processes that lead to these clinical sequelae. To discern the spectrum of pathologic features, we performed a detailed clinical genotypic and phenotypic study of 47 patients with GPS and identified 32 new etiologic variants in NBEAL2. The GPS patient cohort exhibited known phenotypes, including macrothrombocytopenia, BM fibrosis, megakaryocyte emperipolesis of neutrophils, splenomegaly, and elevated serum vitamin B12 levels. Novel clinical phenotypes were also observed, including reduced leukocyte counts and increased presence of autoimmune disease and positive autoantibodies. There were widespread differences in the transcriptome and proteome of GPS platelets, neutrophils, monocytes, and CD4 lymphocytes. Proteins less abundant in these cells were enriched for constituents of granules, supporting a role for Nbeal2 in the function of these organelles across a wide range of blood cells. Proteomic analysis of GPS plasma showed increased levels of proteins associated with inflammation and immune response. One-quarter of plasma proteins increased in GPS are known to be synthesized outside of hematopoietic cells, predominantly in the liver. In summary, our data show that, in addition to the well-described platelet defects in GPS, there are immune defects. The abnormal immune cells may be the drivers of systemic abnormalities such as autoimmune disease., (© 2020 by The American Society of Hematology.)
- Published
- 2020
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