Long-standing Thrombocytopenia Research Articles

Platelet transcriptome analysis in patients with germline RUNX1 mutations

BackgroundGermline mutations in RUNX1 can cause a familial platelet disorder that may lead to acute myeloid leukemia, an autosomal dominant disorder characterized by moderate thrombocytopenia, platelet dysfunction, and a high risk of developing acute myeloid leukemia or myelodysplastic syndrome. Discerning the pathogenicity of novel RUNX1 variants is critical for patient management. ObjectivesTo extend the characterization of RUNX1 variants and evaluate their effects by transcriptome analysis. MethodsThree unrelated patients with long-standing thrombocytopenia carrying heterozygous RUNX1 variants were included: P1, who is a subject with recent development of myelodysplastic syndrome, with c.802 C>T[p.Gln268∗] de novo; P2 with c.586A>G[p.Thr196Ala], a variant that segregates with thrombocytopenia and myeloid neoplasia in the family; and P3 with c.476A>G[p.Asn159Ser], which did not segregate with thrombocytopenia or neoplasia. Baseline platelet evaluations were performed. Ultrapure platelets were prepared for platelet transcriptome analysis. ResultsIn P1 and P2, but not in P3, transcriptome analysis confirmed aberrant expression of genes recognized as RUNX1 targets. Data allowed grouping patients by distinct gene expression profiles, which were partitioned with clinical parameters. Functional studies and platelet mRNA expression identified alterations in the actin cytoskeleton, downregulation of GFI1B, defective GPVI downstream signaling, and reduction of alpha granule proteins, such as thrombospondin-1, as features likely implicated in thrombocytopenia and platelet dysfunction. ConclusionPlatelet phenotype, familial segregation, and platelet transcriptomics support the pathogenicity of RUNX1 variants p.Gln268∗ and p.Thr196Ala, but not p.Asn159Ser. This study is an additional proof of concept that platelet RNA analysis could be a tool to help classify pathogenic RUNX1 variants and identify novel RUNX1 targets.

Gray Platelet Syndrome-Unusual Presentation with Spontaneous Splenic Rupture: A Case Report and Literature Review.

Gray platelet syndrome (GPS) is a rare hereditary hemorrhagic disorder characterized by macrothrombocytopenia and the absence of alpha-granules in platelets. Clinically, mild-to-moderate bleeding is the main manifestation, often accompanied by thrombocytopenia, splenomegaly, and myelofibrosis. Here, we present a case of a 15-year-old male patient with a history of hepatosplenomegaly, and thrombocytopenia for 8 years, who presented with sudden generalized abdominal pain. Despite initial suspicion of gastroenteritis, diagnostic imaging revealed an extensive hemoperitoneum. Subsequent genetic testing confirmed the diagnosis of GPS, which had not been previously identified. This case highlights the importance of considering inherited platelet disorders should be considered in adolescents with long-standing thrombocytopenia, and emphasizes the need for thorough evaluation in patients with suggestive symptoms.

Leukocytoclastic Vasculitis Masquerading as Chronic Idiopathic Thrombocytopenic Purpura.

Idiopathic thrombocytopenic purpura and leukocytoclastic vasculitis can present in a similar fashion and can be very hard to differentiate clinically without a biopsy. This can cause diagnostic dilemma and delay in management. A thorough evaluation is recommended to determine etiology, although about half are idiopathic. A patient aged 79 years with longstanding thrombocytopenia secondary to chronic idiopathic thrombocytopenic purpura presented with a rash. Although it was thought to be secondary to idiopathic thrombocytopenic purpura, a biopsy revealed presence of leukocytoclastic vasculitis. Although most leukocytoclastic vasculitis cases are mild and resolve without intervention, many go undiagnosed due to biopsy delays. Health care professionals should determine and treat the underlying cause.

Whole exome sequencing for diagnosis of hereditary thrombocytopenia.

Hereditary thrombocytopenia comprises extremely diverse diseases that are difficult to diagnose by phenotypes alone. Definite diagnoses are helpful for patient (Pt) management.To evaluate the role of whole exome sequencing (WES) in these Pts.Cases with unexplained long-standing thrombocytopenia and/or suggestive features were enrolled to the observational study. Bleeding scores and blood smear were evaluated. The variant pathogenicity from WES was determined by bioinformatics combined with all other information including platelet aggregometry, flow cytometry, and electron microscopy (EM).Seven unrelated Pts were recruited. All were female with macrothrombocytopenia. Clinical bleeding was presented in four Pts; extra-hematological features were minimal and family history was negative in every Pt. WES successfully identified all the 11 responsible mutant alleles; of these, four have never been previously reported. Pt 1 with GNE-related thrombocytopenia showed reduced lectin binding by flow cytometry, increased glycogen granules by EM and a novel homozygous mutation in GNE. Pts 2 and 3 had phenotypic diagnoses of Bernard Soulier syndrome and novel homozygous mutations in GP1BB and GP1BA, respectively. Pt 4 had impaired microtubule structures, concomitant delta storage pool disease by EM and a novel heterozygous TUBB1 mutation. Pt 5 had sitosterolemia showing platelets with reduced ristocetin responses and a dilated membrane system on EM with compound heterozygous ABCG5 mutations. Pts 6 and 7 had MYH9 disorders with heterozygous mutations in MYH9.This study substantiates the benefits of WES in identifying underlying mutations of macrothrombocytopenia, expands mutational spectra of four genes, and provides detailed clinical features for further phenotype-genotype correlations.

Clinical Spectrum of Germline Mutations with Predisposition to Myeloid Neoplasms- 2016 World Health Organization Classification Update

▪Background: The 2016 revision to the World Health Organization (WHO) classification of myeloid neoplasms has specifically categorized germline mutations that are associated with myeloid clonal evolution (Arber et al. Blood 2016). This group consists of myeloid neoplasms with an isolated germline predisposition (CEBPA, DDX41), myeloid neoplasms associated with congenital thrombocytopenia (ETV6, RUNX1, ANKRD26) and germline myeloid neoplasms with multi-organ dysfunction (GATA2, chromosomal breakage disorders, telomere biology disorders etc). We carried out this study to describe the clinical spectrum of germline disorders with predisposition to myeloid neoplasms as categorized by the 2016 WHO classification revision.Methods: After Institutional Review Board (IRB) approval, the adult and pediatric bone marrow failure syndrome database (1990-2016) and the electronic medical record were queried for germline disorders involving GATA2, CEBPA, DDX41, ETV6, RUNX1, ANKRD26, Down syndrome and Noonan syndrome. Chromosomal breakage assays (Diepoxybutane/Mitomycin-C), flow-fluorescent in-situ hybridization (FISH) for telomere length assessment, Fanconi anemia complementation assays and Sanger/Next Generation sequencing (NGS) for the aforementioned germline disorders with myeloid predisposition were carried out in Clinical Laboratory Improvement Amendments (CLIA)-certified laboratories. These disorders were then classified based on the 2016 WHO classification revision.Results: 54 individuals (37 families) were included in the study. Eleven (20%) patients belonging to 5 families were identified as having germline mutations with a preexisting platelet disorder: ETV6 (n=1), ANKRD26 (n=5), RUNX1 (n=5). Forty-three (79%) patients (32 families) had inherited syndromes with multi-organ dysfunction: GATA2 (n=11, 26%), bone marrow failure syndromes (n=14, 33%) and telomere biology disorder (n=14, 33%). There was one patient with neurofibromatosis with a germline PTPN11 mutation who developed juvenile myelomonocytic leukemia, while there were three patients with Down syndrome; 2 with transient abnormal myelopoiesis and one who developed acute megakaryocytic leukemia. The clinical phenotype, prevalence and characteristics of myeloid clonal evolution and outcomes are presented in Table 1. No patients with germline CEBPA or DDX41 mutations were identified.Patients with germline platelet disorders did not have any prominent non-hematological manifestations. Erythrocytosis (20%) with long-standing thrombocytopenia (100%) was a unique feature associated with ANKRD26 mutations. Non-hematologic clues such as human papillomavirus (HPV)-driven warts, primary lymphedema (Emberger syndrome) and frequent atypical infections with monocytopenia were seen in patients with germline GATA2 mutations, and preceded myeloid clonal evolution (morphologic, cytogenetic and molecular). Notably, the age at presentation and penetrance of myeloid transformation was variable, with individuals from the same family developing symptoms during the first decade of life and others remaining asymptomatic to date (fifth decade). Somatic ASXL1 mutations were detected in all 3 (100%) patients with GATA2 mutations and in one patient with ANKRD26 mutation that developed myeloid clonal evolution. In our study myeloid clonal evolution was seen in 40% with RUNX1 mutations, 27% with GATA2 mutations, and 20% with ANKRD26 mutations. We could not calculate the same for bone marrow failure syndromes as the total number of cases seen are still being assessed. Outcomes with allogeneic stem cell transplantation were favorable in appropriately selected patients (Table 1).Conclusion: The 2016 WHO revision to the classification of myeloid neoplasms highlights the importance of recognition and molecular characterization of germline mutations (syndromic and non-syndromic) with risk for myeloid clonal evolution. While some of these disorders (GATA2, Fanconi anemia, telomere biology disorders) may have important non-hematological clues, many present with isolated thrombocytopenia (RUNX1, ETV6). The age and frequency of myeloid evolution is highly variable. Acquisition of somatic ASXL1 mutations at the time of clonal myeloid transformation highlights the role of epigenetic dysregulation in disease evolution. [Display omitted] DisclosuresKenderian:Novartis: Patents & Royalties, Research Funding.

A 69-Year-Old Man with Long-standing Thrombocytopenia

A 69-year-old man presented with a long-standing thrombocytopenia and microcytic anemia. The automated platelet count was 67 × 103/μL (reference interval, 150–450 × 103/μL); therefore, EDTA-dependent pseudothrombocytopenia was excluded. The hemoglobin concentration was 10.5 g/dL (reference interval, 14–18 g/dL). The patient denied having petechiae and reported no excessive bleeding in daily life. The patient had no …

Incidence and Etiology of Overt Gastrointestinal Bleeding in Adult Patients with Aplastic Anemia

Patients with thrombocytopenia caused by various neoplastic and primary bone marrow diseases are susceptible to major hemorrhage. There are few reports addressing the incidence and outcome of gastrointestinal (GI) bleeding in patients with aplastic anemia characterized by long-standing thrombocytopenia. We sought to retrospectively determine the incidence, etiology, clinical outcomes, and risk factors associated with overt GI bleeding in patients with aplastic anemia. We analyzed the medical records of 508 patients with aplastic anemia after excluding patients below 15 years of age or those who underwent stem cell transplantation between January 1, 2002, and December 31, 2007. A total of 32 patients developed overt GI bleeding during this period. We evaluated the site, etiology, outcomes, and major risk factors in these patients who developed GI bleeding episodes. The incidence of GI bleeding was 6.3% (32 of 508 patients) in adult patients with aplastic anemia. The incidence increased to 12.6% (28 of 222 patients) in patients with severe disease. One patient died from massive GI bleeding. Bleeding sites included the esophagus (two patients, 6.3%), stomach (five, 16.3%), duodenum (two, 6.3%), small intestine (five, 15.6%), large intestine (seven, 21.6%), and unknown site (11, 34.4%). Lower GI bleeds mainly caused by neutropenic enterocolitis (NEC) and solitary ulcer developed more frequently than upper GI bleeds. The major risk factors for GI bleeding included old age (P = 0.004, odds ratio (OR) = 1.039), severe aplastic anemia (P < 0.001, OR = 11.934), non-response to therapy (P = 0.001, OR = 5.652), and major bleeding history in another organ (P < 0.001, OR = 6.677). Overt GI bleeding in patients with aplastic anemia more frequently develops in the lower tract than in the upper tract. The risk of GI bleeding is higher in patients with the following risk factors: older age, severe disease, poor response to treatment, and major bleeding history in another organ.

Infectious mononucleosis with thrombocytopenic purpura.

Abstract A case of infectious mononucleosis with longstanding thrombocytopenia, not responsive to corticosteroid therapy, is presented. Rapid normalization of the platelet level was revealed by splenectomy. The patient is the fourth known case in which it has been necessary to perform splenectomy. A study made with 51Cr‐labelled homologous platelets showed a very short half‐life, along with a high spleen/liver ratio of the activity. These examinations have not previously been performed in this condition.