Age- and sex-related variations in platelet count in Italy: a proposal of reference ranges based on 40987 subjects' data

BACKGROUND AND OBJECTIVES: Although several studies demonstrated that platelet count is higher in women, decreases with age, and is influenced by genetic background, most clinical laboratories still use the reference interval 150-400×10(9) platelets/L for all subjects. The present study was to identify age- and sex-specific reference intervals for platelet count. METHODS: We analysed electronic records of subjects enrolled in three population-based studies that investigated inhabitants of seven Italian areas including six geographic isolates. After exclusion of patients with malignancies, liver diseases, or inherited thrombocytopenias, which could affect platelet count, reference intervals were estimated from 40,987 subjects with the non parametric method computing the 2.5° and 97.5° percentiles. RESULTS: Platelet count was similar in men and women until the age of 14, but subsequently women had steadily more platelets than men. The number of platelets decreases quickly in childhood, stabilizes in adulthood, and further decreases in oldness. The final result of this phenomenon is that platelet count in old age was reduced by 35% in men and by 25% in women compared with early infancy. Based on these findings, we estimated reference intervals for platelet count ×10(9)/L in children (176-452), adult men (141-362), adult women (156-405), old men (122-350) and, old women (140-379). Moreover, we calculated an extended reference interval that takes into account the differences in platelet count observed in different geographic areas. CONCLUSIONS: The age-, sex-, and origin-related variability of platelet count is very wide, and the patient-adapted reference intervals we propose change the thresholds for diagnosing both thrombocytopenia and thrombocytosis in Italy

Generation of induced pluripotent stem cell line, CSSi002-A (2851), from a patient with juvenile huntington disease

Huntington Disease (HD) is an autosomal dominant disorder characterized by motor, cognitive and behavioral features caused by a CAG expansion in the HTT gene beyond 35 repeats. The juvenile form (JHD) may begin before the age of 20 years and is associated with expanded alleles as long as 60 or more CAG repeats. In this study, induced pluripotent stem cells were generated from skin fibroblasts of a 8-year-old child carrying a large size mutation of 84 CAG repeats in the HTT gene. HD appeared at age 3 with mixed psychiatric (i.e. autistic spectrum disorder) and motor (i.e. dystonia) manifestations

Phosphorylation of huntingtin at residue T3 is decreased in Huntington’s disease and modulates mutant huntingtin protein conformation

Posttranslational modifications can have profound effects on the biological and biophysical properties of proteins associated with misfolding and aggregation. However, their detection and quantification in clinical samples and an understanding of the mechanisms underlying the pathological properties of misfolding- and aggregation-prone proteins remain a challenge for diagnostics and therapeutics development. We have applied an ultrasensitive immunoassay platform to develop and validate a quantitative assay for detecting a posttranslational modification (phosphorylation at residue T3) of a protein associated with polyglutamine repeat expansion, namely Huntingtin, and characterized its presence in a variety of preclinical and clinical samples. We find that T3 phosphorylation is greatly reduced in samples from Huntington\u2019s disease models and in Huntington\u2019s disease patients, and we provide evidence that bona-fide T3 phosphorylation alters Huntingtin exon 1 protein conformation and aggregation properties. These findings have significant implications for both mechanisms of disease pathogenesis and the development of therapeutics and diagnostics for Huntington\u2019s disease

Sticky Platelet Syndrome and the role of Glycoprotein receptors: A review of literature.

Thrombotic events are mainly caused by defects in circulating plasma proteins and platelets. Normally, the formers include hereditary clotting defects [e.g. deficiencies in protein-S (PS), in protein-C (PC), in anti-thrombin (AT) genes, or factor V Leiden, and Prothrombin G20210A substitution] and autoimmune diseases [(anti-phospholipidantibodies syndrome (APA)]. Although these conditions are well-described in literature, prothrombotic platelet disorders are less well understood. The sticky platelet syndrome (SPS) is a congenital, autosomal dominant disorder, associated with both arterial and venous thromboembolic events. In pregnant women, complications such as fetal growth retardation and fetal loss have been reported. It is characterized by in vitro platelets hyperaggregability (platelet-rich plasma; PRP) triggered by different agonists responsible for its subclassifcation: adenosine diphosphate (ADP) plus epinephrine (type I), epinephrine alone (type II, the most frequent), or ADP alone (type III). Clinically, patients may present with acute myocardial infarction (AMI), transient cerebral ischemic attacks (TIA), angina pectoris, stroke, peripheral arterial thrombosis, retinal thrombosis, and venous thrombosis (VT) even during oral anticoagulant therapy. Conversely, low-dose aspirin treatment ameliorates the clinical symptoms and normalizes hyperaggregability. Clinical symptoms, especially arterial, often present following emotional stress. Combinations of SPS with other congenital prothrombotic defects have been described. Actually, a precise and definite etiology of this defect is not recognized, but receptors on the platelet surface are considered strongly involved candidates. Normal levels of platelet factor 4 (PF4) and beta-thromboglobulin (TG) in plasma suggest that the platelets are not activated at all times; accordingly they appear to become hyperactive upon ADP or adrenaline release. In vivo clumping could temporarily or permanently occlude a vessel, leading to the described clinical manifestations.The syndrome appears to be prominent particularly in patients with unexplained arterial vascular occlusions. Despite the presence of studies investigating the role of platelet glycoprotein in SPS, the precise defect(s) responsible for the syndrome remains unknown

From candidate gene to genome-wide association studies in cardiovascular disease.

Continuous updating of the genotyping technology has led to improvement of genetic study design. The recent advances in technology coupled with the advances in our understanding of the molecular mechanisms have allowed a more comprehensive examination of the role of genetics, environment and their interaction in determining the individual risk of cardiovascular disease (CVD). Initial candidate gene studies identified a limited number of polymorphisms associated with disease, explaining only a minor part of trait variance. Furthermore, results were not often concordant, with meta-analyses not reaching the statistical power to confirm an association in many cases. The advent of the genome-wide design furnished an enormous quantity of information and decreased time of genotyping, while increased complexity of analyses and costs. Their results were more concordant, even when they suggested associations between CVD and polymorphisms distant from codifying regions or in genes involved in previously unsuspected pathways. Future results from genome-wide studies coupled with results from functional studies and investigation on gene-environment interactions will allow improvement of cardiovascular risk assessment and discovery of new targets for therapy and prevention. In this review, a brief history of cardiovascular genetics is reported, from candidate gene to genome wide association studies, that led to the identification of association between CVD and SNPs in the 9p21 region, firstly thought a gene desert without importance

From candidate gene to genome-wide association studies in cardiovascular disease.

Continuous updating of the genotyping technology has led to improvement of genetic study design. The recent advances in technology coupled with the advances in our understanding of the molecular mechanisms have allowed a more comprehensive examination of the role of genetics, environment and their interaction in determining the individual risk of cardiovascular disease (CVD). Initial candidate gene studies identified a limited number of polymorphisms associated with disease, explaining only a minor part of trait variance. Furthermore, results were not often concordant, with meta-analyses not reaching the statistical power to confirm an association in many cases. The advent of the genome-wide design furnished an enormous quantity of information and decreased time of genotyping, while increased complexity of analyses and costs. Their results were more concordant, even when they suggested associations between CVD and polymorphisms distant from codifying regions or in genes involved in previously unsuspected pathways. Future results from genome-wide studies coupled with results from functional studies and investigation on gene-environment interactions will allow improvement of cardiovascular risk assessment and discovery of new targets for therapy and prevention. In this review, a brief history of cardiovascular genetics is reported, from candidate gene to genome wide association studies, that led to the identification of association between CVD and SNPs in the 9p21 region, firstly thought a gene desert without importance

Variability of platelet indices and function: acquired and genetic factors.

Each individual has an inherent variable risk of bleeding linked to genetic or acquired abnormal platelet number or platelet dysfunction. In contrast, it is less obvious that the variability of platelet phenotypes (number, mean platelet volume, function) may contribute to the variable individual risk of thrombosis. Interindividual variability of platelet indices or function may be either due to acquired factors, such as age, sex, metabolic variables, smoke, dietary habits, and ongoing inflammation, or due to genetic factors. Acquired variables explain a small portion of the heterogeneity of platelet parameters. Genetic factors, instead, appear to play a major role, although a consistent portion of such a genetic variance has not yet been attributed to any specific genetic factor,possibly due to the high number of DNA loci potentially involved and to the limited effect size of each individual SNP. A portion of variance remains thus unexplained, also due to variability of test performance. A major contradiction in present platelet knowledge is, indeed, the difficulty to reconcile the universally accepted importance of platelet indices or function and the lack of reliable platelet parameters in cardiovascular risk prediction models. Trials on antiplatelet drugs were generally designed to select a homogeneous sample, whose results could be applied to an "average subject," tending to exclude the deviation/extreme values. As the current indications for antiplatelet treatment in primary or secondary prevention of ischemic vascular disease still derive from the results of such clinical trials where platelet function and its variability was not investigated, we cannot at present rely upon any current platelet test to either initiate, or monitor, or modify or stop treatment with any antiplatelet drug. Evidence is, however, increasing that traditional platelet aggregometry and other more recently developed platelet function assays could be useful to optimize antiplatelet therapy and to predict major adverse cardiac events.The observation of interindividual differences in platelet response to antiplatelet drugs has enlarged the spectrum and the possible clinical relevance of the variability of platelet indices or function. The development of "personalized medicine" will benefit from the concepts discussed in this chapter

Variability of platelet indices and function: acquired and genetic factors.

Each individual has an inherent variable risk of bleeding linked to genetic or acquired abnormal platelet number or platelet dysfunction. In contrast, it is less obvious that the variability of platelet phenotypes (number, mean platelet volume, function) may contribute to the variable individual risk of thrombosis. Interindividual variability of platelet indices or function may be either due to acquired factors, such as age, sex, metabolic variables, smoke, dietary habits, and ongoing inflammation, or due to genetic factors. Acquired variables explain a small portion of the heterogeneity of platelet parameters. Genetic factors, instead, appear to play a major role, although a consistent portion of such a genetic variance has not yet been attributed to any specific genetic factor, possibly due to the high number of DNA loci potentially involved and to the limited effect size of each individual SNP. A portion of variance remains thus unexplained, also due to variability of test performance. A major contradiction in present platelet knowledge is, indeed, the difficulty to reconcile the universally accepted importance of platelet indices or function and the lack of reliable platelet parameters in cardiovascular risk prediction models. Trials on antiplatelet drugs were generally designed to select a homogeneous sample, whose results could be applied to an "average subject," tending to exclude the deviation/extreme values. As the current indications for antiplatelet treatment in primary or secondary prevention of ischemic vascular disease still derive from the results of such clinical trials where platelet function and its variability was not investigated, we cannot at present rely upon any current platelet test to either initiate, or monitor, or modify or stop treatment with any antiplatelet drug. Evidence is, however, increasing that traditional platelet aggregometry and other more recently developed platelet function assays could be useful to optimize antiplatelet therapy and to predict major adverse cardiac events.The observation of interindividual differences in platelet response to antiplatelet drugs has enlarged the spectrum and the possible clinical relevance of the variability of platelet indices or function. The development of "personalized medicine" will benefit from the concepts discussed in this chapter

Type 2 diabetes and polymorphisms on chromosome 9p21: a meta-analysis.

BACKGROUND AND AIMS: Genome-wide association studies found some variants on chromosome 9p21 associated with type 2 diabetes (T2D). We performed a meta-analysis to estimate strength, accuracy and feature of the association of polymorphisms in 9p21 with T2D. METHODS AND RESULTS: Articles were retrieved screening electronic databases and cross references. Twenty-two publications were identified, for a total of 38,455 T2D patients and 60,516 controls. Twenty-one studies investigated the role of the SNP rs10811661; in some studies three additional SNPs (rs564398, rs10757278, rs1333040) were genotyped. Population attributable risk (PAR) was computed as: risk allele frequency 17(OR-1)/OR, using the per-allele odds ratio (OR). The risk allele (T) of rs10811661 was associated with T2D in most of the studies. In meta-analysis the overall per-allele OR was 1.24 (95% CI: 1.21-1.27; P < 10(-15)), with no difference according to ethnicity (P = 0.45), and low heterogeneity (P = 0.040) across studies partly explained by sample size. Modeling of inheritance suggested an additive effect of the T allele. PAR of T2D related to this polymorphism was 15% for Caucasians and 13% for Asians. The overall odds ratio for the T allele of the SNP rs564398 was 1.08 (95% CI: 1.05-1.12; PAR = 6%). The other SNPs showed negligible associations. CONCLUSIONS: This meta-analysis provides accurate and comprehensive estimates of the association of some genetic variants at chromosome 9p21 and T2D. A relatively small but significant role of the T allele of the rs10811661 SNP in increasing by 21-27% the risk of T2D in an additive way was apparent