Maurizio Marconi

Genomewide association study using a high-density single nucleotide polymorphism array and case-control design identifies a novel essential hypertension susceptibility locus in the promoter region of endothelial NO synthase

Essential hypertension is a multifactorial disorder and is the main risk factor for renal and cardiovascular complications. The research on the genetics of hypertension has been frustrated by the small predictive value of the discovered genetic variants. The HYPERGENES Project investigated associations between genetic variants and essential hypertension pursuing a 2-stage study by recruiting cases and controls from extensively characterized cohorts recruited over many years in different European regions. The discovery phase consisted of 1865 cases and 1750 controls genotyped with 1M Illumina array. Best hits were followed up in a validation panel of 1385 cases and 1246 controls that were genotyped with a custom array of 14 055 markers. We identified a new hypertension susceptibility locus (rs3918226) in the promoter region of the endothelial NO synthase gene (odds ratio: 1.54 [95% CI: 1.37–1.73]; combined P=2.58 · 10−13). A meta-analysis, using other in silico/de novo genotyping data for a total of 21 714 subjects, resulted in an overall odds ratio of 1.34 (95% CI: 1.25–1.44; P=1.032 · 10−14). The quantitative analysis on a population-based sample revealed an effect size of 1.91 (95% CI: 0.16–3.66) for systolic and 1.40 (95% CI: 0.25–2.55) for diastolic blood pressure. We identified in silico a potential binding site for ETS transcription factors directly next to rs3918226, suggesting a potential modulation of endothelial NO synthase expression. Biological evidence links endothelial NO synthase with hypertension, because it is a critical mediator of cardiovascular homeostasis and blood pressure control via vascular tone regulation. This finding supports the hypothesis that there may be a causal genetic variation at this locus.

The long intergenic noncoding RNA landscape of human lymphocytes highlights the regulation of T cell differentiation by linc-MAF-4

Long noncoding RNAs are emerging as important regulators of cellular functions, but little is known of their role in the human immune system. Here we investigated long intergenic noncoding RNAs (lincRNAs) in 13 subsets of T lymphocytes and B lymphocytes by next-generation sequencing–based RNA sequencing (RNA-seq analysis) and de novo transcriptome reconstruction. We identified over 500 previously unknown lincRNAs and described lincRNA signatures. Expression of linc-MAF-4, a chromatin-associated lincRNA specific to the TH1 subset of helper T cells, was inversely correlated with expression of MAF, a TH2-associated transcription factor. Downregulation of linc-MAF-4 skewed T cell differentiation toward the TH2 phenotype. We identified a long-distance interaction between the genomic regions of the gene encoding linc-MAF-4 and MAF, where linc-MAF-4 associated with the chromatin modifiers LSD1 and EZH2; this suggested that linc-MAF-4 regulated MAF transcription through the recruitment of chromatin modifiers. Our results demonstrate a key role for lincRNA in T lymphocyte differentiation.

Preparation of Leukocyte-Free Platelets for Transfusion by Filtration through Cotton Wool

Abstract. Filtration through Imugard filters of random platelet concentrates or platelets obtained by plateletpheresis allow the preparation of leukocyte‐free platelets for transfusion. The procedure is simple and determines only a small platelet loss (less than 10%). Filtered platelets seem to function normally in vivo. The use of leukocyte‐free red cell and platelet transfusions for the support of patients suffering from leukemia or aplastic anemia could prevent major complications, such as refractoriness to platelet transfusion and to bone marrow transplantation.

Donors with a rare pheno (geno) type

H. W. Reesink, C. P. Engelfriet, H. Schennach, C. Gassner, S. Wendel, R. Fontão-Wendel, M. A. de Brito, P. Sistonen, J. Matilainen, T. Peyrard, B. N. Pham, P. Rouger, P. Y. Le Pennec, W. A. Flegel, I. von Zabern, C. K. Lin, W. C. Tsoi, I. Hoffer, K. Barotine-Toth, S. R. Joshi, K. Vasantha, V. Yahalom, O. Asher, C. Levene, M. A. Villa, N. Revelli, N. Greppi, M. Marconi, Y. Tani, C. C. Folman, M. de Haas, M. M. W. Koopman, E. Beckers, D. S. Gounder, P. Flanagan, L. Wall, E. Aranburu Urtasun, H. Hustinx, C. Niederhauser, E. Massey, A. Gray, M. Needs, G. Daniels, T. Callaghan, C. Flickinger, S. J. Nance & G. M. Meny

Management of alloimmune thrombocytopenia

Fetal alloimmune thrombocytopenia is caused by maternal sensitization to paternally-derived antigens on fetal platelets, most commonly HPA-1a.1 It occurs in approximately 1 in 1000 live births and is the commonest cause of severe fetal and neonatal thrombocytopenia, and of intracranial hemorrhage in neonates born at term.2 Since there is currently no routine screening, first-time cases of fetal alloimmune thrombocytopenia are generally identified following the birth of a markedly thrombocytopenic neonate. Antenatal management is thus only possible in subsequent pregnancies. Intracranial hemorrhage is the most devastating complication of fetal alloimmune thrombocytopenia and often occurs antenatally. Assessment of projected clinical severity is thus based on the development of intracranial hemorrhage in a previous sibling. If there is such a history of intracranial hemorrhage, the chance of this complication occurring again in the next pregnancy is extremely high in an untreated, antigen-positive sibling.3 Administration of intravenous immunoglobulin (IVIG) to the mother, initially given in conjunction with dexamethasone, was first used to prevent recurrence of antenatal intracranial hemorrhage in 1988.4 This approach of providing IVIG-based medical therapy administered to the mother to increase the fetal platelet count has since been extensively investigated in hundreds of maternal-fetal pairs.5 The efficacy of IVIG-based therapy has been supported by numerous studies6–16 (Table 1A) but not by others17–19 (Table 1B). The studies presented in Tables 1A and 1B surprisingly report virtually identical percentages of cases of intracranial hemorrhage: 2.7% versus 2.9%, respectively. However, overall mean birth platelet counts differed markedly between the two groups. While platelet counts are considered to be surrogate markers of intracranial hemorrhage, fortunately, the likelihood of fetal and neonatal intracranial hemorrhage, in the absence of this complication having occurred in a previous sibling, is relatively low.

Clinical effectiveness of platelets in additive solution treated with two commercial pathogen-reduction technologies

Two noninferiority, randomized, controlled trials were conducted in parallel comparing the safety and efficacy of platelets treated with Intercept or Mirasol pathogen‐reduction technologies versus standard platelets.

Outcomes of an automated procedure for the selection of effective platelets for patients refractory to random donors based on cross-matching locally available platelet products.

In 1999, we implemented an automated platelet cross‐matching (XM) programme to select compatible platelets from the local inventory for patients refractory to random donor platelets. In this study, we evaluated platelet count increments in 40 consecutive refractory patients (8·3% of 480 consecutive platelet recipients) given 569 cross‐match‐negative platelets between April 1999 and December 2001. XM was performed automatically with a commercially available immunoadherence assay. Pre‐, 1‐ and 24‐h post‐transfusion platelet counts (mean ± SD) for the 569 XM‐negative platelet transfusions containing 302 ± 71 × 109 platelets were 7·7 ± 5·5, 32·0 ± 21·0 and 16·8 ± 15·5 × 109/l respectively. Increments were significantly higher (P < 0·05, t‐test) than those observed in the same patients given 303 random platelet pools (dose = 318 ± 52 × 109 platelets) during the month before refractoriness was detected, when pre‐, 1‐ and 24‐h post‐transfusion counts were 7·0 ± 8·6, 15·9 ± 16·1 and 9·6 ± 12·8 × 109/l respectively. The cost of the platelet XM disposable kit per transfusion to produce 1‐h post‐transfusion platelet count increments >10 × 109/l was euro 447. This programme enabled the rapid selection of effective platelets for refractory patients, from the local inventory.

Harvesting of Autologous Blood Stem Cells after a Mobilising Regimen with Low-dose Cyclophosphamide

Although high-dose cyclophosphamide (HD-CTX) is commonly used as a mobilising regimen for autologous peripheral blood stem cell (PBSC) collection, significant morbidity and insufficient harvesting may complicate the procedure. Alternative regimens and lower doses of cyclophosphamide (CTX) have been investigated as possible ways of overcoming these difficulties. Low-dose CTX (1.5 g/m 2 ) was administered to 102 lymphoma patients as an autologous PBSC mobilising regimen. The collection of 6 2 10 6 CD34+ cells/kg was chosen as the target of the apheresis sessions, whereas 3 2 10 6 /kg were considered the minimum necessary to perform autologous stem cell transplantation (ASCT) safely. The apheretic sessions were started a median of eight days after CTX administration; a median of two aphereses was required. More than 6 2 10 6 CD34+ cells/kg were collected from 78 patients, between 3 and 6 2 10 6 /kg from 19, and fewer than 3 2 10 6 /kg from 5, two of whom underwent bone marrow harvesting and one a successful second PBSC harvesting session using the same mobilising regimen. Eighty-two patients underwent autografting, six of whom received a second transplant after relapse (five using autologous PBSCs coming from the first apheretic course). Low-dose CTX proved to be a safe and effective regimen for autologous PBSC mobilization and also compared favourably with alternative regimens in terms of the rate of harvesting insufficiency. This does not imply that low-dose CTX is the best mobilising regimen for all patients, and the identification of prognostic factors predicting mobilising potential may help in choosing the best individualised regimen.

Increasing transfusion safety by reducing human error.

Transfusion of the wrong blood is a rare but measurable event that may result in serious complications and whose main cause is human error. Any preventive strategy should be based on a careful assessment of the incidence of these events and of their causes, and requires a standardized confidential reporting system, to avoid underreporting, covering also near misses. Creating or revising written procedures and monitoring their implementation are indispensable to improve blood safety, but human error can occur in spite of these measures. Technologic instruments are now available to fill the gap between written and implemented procedures, forcing the operator to carry out the critical steps in the process according to the adopted guidelines.

Does echocardiography play a role in the clinical diagnosis of congenital absence of pericardium? A case presentation and a systematic review

Congenital absence of pericardium is an uncommon cardiac defect with variable clinical presentations. The detection of this malformation is clinically relevant because of potential complications such as fatal myocardial strangulation, myocardial ischemia and sudden death. Physical examination, chest radiograph and ECG are not helpful for the diagnosis. Echocardiography may accurately identify abnormalities in myocardial wall motion and in cardiac silhouette that may strongly suggest the diagnosis that is confirmed by magnetic resonance imaging (MRI) or computed tomography scan. A case presentation and a review of the literature with emphasis on the role of echocardiography are presented.