Thrombosis and infections associated with PICC in onco-hematological patients, what is their relevance?

PURPOSE: Peripherally inserted central venous catheters (PICC) in the onco-hematological patients may be associated with thrombosis or infections that may have short- to medium-term repercussions. MATERIAL AND METHODS: Single-centre retrospective analysis of a prospectively collected cohort. Primary objective was to establish the PICC-thrombosis and infections incidence. Secondary objectives were to analyze profile of patients suffering from these complications and variables associated with an increased likelihood of developing these events. RESULTS: 549 patients were recruited. 58.5% (n = 321) were oncology patients and 41.5% (n = 228) hematology patients. The incidence of PICC-associated thrombosis was 3.5% (n = 19). Thrombosis was associated with progression of the underlying malignant pathology in 10.6% (n = 2) of cases. No association was found between clinical variables analysed and development of thrombosis. Incidence of PICC-associated infections was 7.65% (n = 42). In the 30 days prior to PICC infection, 57.1% (n = 24) had a febrile syndrome of another focus, 73.8% (n = 11) had been hospitalized, 49.5% (n = 25) had a neutrophil count of 0-500 cells/mm3 and 47.6% (n = 20) had an episode of neutropenic fever. Variables significantly associated with the development of infection were hematological patients, high-flow PICC, 3-lm PICC or PICC insertion because of administration of vesicant therapy. CONCLUSIONS: Incidence of PICC-associated thrombosis is low and apparently less prognostically aggressive than other forms of thrombosis associated with cancer, without identify predictive factors. Infection was more prevalent and the identification of risk factors in our series could facilitate its prevention.

Targeted long-read sequencing identifies and characterizes structural variants in cases of inherited platelet disorders.

BACKGROUND: Genetic diagnosis of inherited platelet disorders (IPDs) is mainly performed by high-throughput sequencing (HTS). These short-read-based sequencing methods sometimes fail to characterize the genetics of the disease. OBJECTIVES: To evaluate nanopore long-read DNA sequencing for characterization of structural variants (SVs) in patients with IPDs. METHODS: Four patients with a clinical and laboratory diagnosis of Glanzmann thrombasthenia (GT) (P1 and P2) and Hermansky-Pudlak syndrome (HPS) (P3 and P4) in whom HTS missed the underlying molecular cause were included. DNA was analyzed by both standard HTS and nanopore sequencing on a MinION device (Oxford Nanopore Technologies) after enrichment of DNA spanning regions covering GT and HPS genes. RESULTS: In patients with GT, HTS identified only 1 heterozygous ITGB3 splice variant c.2301+1G>C in P2. In patients with HPS, a homozygous deletion in HPS5 was suspected in P3, and 2 heterozygous HPS3 variants, c.2464C>T (p.Arg822∗) and a deletion affecting 2 exons, were reported in P4. Nanopore sequencing revealed a complex SV affecting exons 2 to 6 in ITGB3 (deletion-inversion-duplication) in homozygosity in P1 and compound heterozygosity with the splice variant in P2. In the 2 patients with HPS, nanopore defined the length of the SVs, which were characterized at nucleotide resolution. This allowed the identification of repetitive Alu elements at the breakpoints and the design of specific polymerase chain reactions for family screening. CONCLUSION: The nanopore technology overcomes the limitations of standard short-read sequencing techniques in SV characterization. Using nanopore, we characterized novel defects in ITGB3, HPS5, and HPS3, highlighting the utility of long-read sequencing as an additional diagnostic tool in IPDs.

Platelet transcriptome analysis in patients with germline RUNX1 mutations.

BACKGROUND: Germline 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. OBJECTIVES: To extend the characterization of RUNX1 variants and evaluate their effects by transcriptome analysis. METHODS: Three 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. RESULTS: In 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. CONCLUSION: Platelet 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.

Src-related thrombocytopenia: a fine line between a megakaryocyte dysfunction and an immune-mediated disease.

Src-related thrombocytopenia (SRC-RT) is a rare autosomal dominant, inherited platelet disorder resulting from the p.E527K heterozygous germline gain-of-function variant of Src. To date, genetic diagnosis of the disease has only been reported in 7 patients from 3 unrelated families. The clinical features ranged from isolated thrombocytopenia to complex syndromic manifestations characterized by thrombocytopenia, bleeding, myelofibrosis, splenomegaly, and bone disease. We report a new 3-generation kindred with the Src p.E527K variant. Patients presented with rather variable platelet counts (38-139 × 109/L), mildly impaired platelet function, >15% immature platelet fraction, and with a significant proportion of large-giant platelets. Four adults from the family were diagnosed with immune thrombocytopenia (ITP) and underwent splenectomy, achieving sustained platelet counts >75 × 109/L for several years; increases in platelet counts were also observed after corticosteroid therapy. Four of 7 Src p.E527K variant carriers showed immune defects and recurrent infections. In addition, a range of neurological symptoms, from specific language impairment to epilepsy, was seen in some family members. Patient platelets exhibited constitutive Src, Bruton tyrosine kinase, and phospholipase Cγ2 activation, and after stimulating CD19 cells by crosslinking surface immunoglobulin M, phosphorylated extracellular signal-regulated kinase (ERK) was significantly increased in B cells from individuals carrying the Src p.E527K substitution. In summary, in addition to causing impaired platelet production, SRC-RT may associate immune dysregulation and increased platelet consumption. In families in whom several members are responsive to ITP-directed therapies, an underlying Src p.E527K variant should be excluded.

Non-vitamin K Antagonist Oral Anticoagulants and Drug-Food Interactions: Implications for Clinical Practice and Potential Role of Probiotics and Prebiotics.

Non-vitamin K antagonist oral anticoagulants (NOACs) are a therapeutic option to prevent stroke in patients with atrial fibrillation (AF). In fact, NOACs have become the recommended choice by international clinical practice guidelines over vitamin K antagonists (VKA), because of their efficacy and safety profile, especially in newly initiated patients. The more predictable pharmacokinetic and pharmacodynamic profile of this family of drugs allows preventing anticoagulation drug monitoring. Furthermore, NOACs have significantly fewer drug and food interactions in comparison with VKAs. Despite this, there are no studies that compare the effects on the quality of anticoagulation of NOACs with the intake of potential interactions drugs of P-glycoprotein and cytochrome P450 (CYP). This review brings an overview of NOACs pharmacokinetics profile and their potential drug-food interactions. We also briefly discuss the potential role of prebiotics and probiotics in patients under therapy with NOACs.