Life-long hematopoiesis depends on the support of mesenchymal stromal cells within the bone marrow. Therefore, changes in the hematopoietic compartment that occur during development and aging ...probably correlate with variation in the composition of the stromal cell microenvironment. Mesenchymal stromal cells are a heterogeneous cell population and various subtypes may have different functions. In accordance with others, we show that CD271 and CD146 define distinct colony-forming-unit-fibroblast containing mesenchymal stromal cell subpopulations. In addition, analysis of 86 bone marrow samples revealed that the distribution of CD271(bright)CD146(-) and CD271(bright)CD146(+) subsets correlates with donor age. The main subset in adults was CD271(bright)CD146(-), whereas the CD271(bright)CD146(+) population was dominant in pediatric and fetal bone marrow. A third subpopulation of CD271(-)CD146(+) cells contained colony-forming-unit-fibroblasts in fetal samples only. These changes in composition of the mesenchymal stromal cell compartment during development and aging suggest a dynamic system, in which these subpopulations may have different functions.
Vasoplegia after routine cardiac surgery is associated with severe postoperative complications and increased mortality. It is also prevalent in patients undergoing implantation of pulsatile flow left ...ventricular assist devices (LVAD). However, less is known regarding vasoplegia after implantation of newer generations of continuous flow LVADs (cfLVAD). We aim to report the incidence, impact on outcome and predictors of vasoplegia in these patients.
Adult patients scheduled for primary cfLVAD implantation were enrolled into a derivation cohort (n = 118, 2006-2013) and a temporal validation cohort (n = 73, 2014-2016). Vasoplegia was defined taking into consideration low mean arterial pressure and/or low systemic vascular resistance, preserved cardiac index and high vasopressor support. Vasoplegia was considered after bypass and the first 48 h of ICU stay lasting at least three consecutive hours. This concept of vasoplegia was compared to older definitions reported in the literature in terms of the incidence of postoperative vasoplegia and its association with adverse outcomes. Logistic regression was used to identify independent predictors. Their ability to discriminate patients with vasoplegia was quantified by the area under the receiver operating characteristic curve (AUC).
The incidence of vasoplegia was 33.1% using the unified definition of vasoplegia. Vasoplegia was associated with increased ICU length-of-stay (10.5 6.9-20.8 vs 6.1 4.6-10.4 p = 0.002), increased ICU-mortality (OR 5.8, 95% CI 1.9-18.2) and one-year-mortality (OR 3.9, 95% CI 1.5-10.2), and a higher incidence of renal failure (OR 4.3, 95% CI 1.8-10.4). Multivariable analysis identified previous cardiothoracic surgery, preoperative dopamine administration, preoperative bilirubin levels and preoperative creatinine clearance as independent preoperative predictors of vasoplegia. The resultant prediction model exhibited a good discriminative ability (AUC 0.80, 95% CI 0.71-0.89, p < 0.01). Temporal validation resulted in an AUC of 0.74 (95% CI 0.61-0.87, p < 0.01).
In the era of the new generation of cfLVADs, vasoplegia remains a prevalent (33%) and critical condition with worse short-term outcomes and survival. We identified previous cardiothoracic surgery, preoperative treatment with dopamine, preoperative bilirubin levels and preoperative creatinine clearance as independent predictors.
Large-scale clinical studies on detection of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) have shown that quantification of MRD levels is needed for reliable MRD-based risk ...group classification. Recently, we have shown that 'real-time' quantitative PCR (RQ-PCR) can be applied for this purpose using patient-specific immunoglobulin (Ig) and T cell receptor (TCR) gene rearrangements as PCR targets with TaqMan probes at the position of the junctional region and two germline primers. Now, we tested an alternative approach on 35 immunoglobulin heavy chain (IGH) gene rearrangements, by designing three germline JH TaqMan probes to be used in combination with one of six corresponding germline JH primers and one allele specific oligonucleotide (ASO) primer complementary to the junctional region. In nine cases in which both approaches were compared, at least similar (n = 4) or slightly higher (n= 5) maximal sensitivities were obtained using an ASO primer. The ASO primer approach reached maximal sensitivities of at least 10(-4) in 33 out of 35 IGH rearrangements. The reproducible range for accurate quantification spanned four to five orders of magnitude in 31 out of 35 cases. In 13 out of 35 rearrangements the stringency of PCR conditions had to be increased to remove or diminish background signals; this only concerned the frequently occurring JH4, JH5 and JH6 gene rearrangements. After optimization of the conditions (mainly by increasing the annealing temperature), only occasional aspecific amplification signals were observed at high threshold cycle (CT) values above 42 cycles and at least six cycles above the CT value of the detection limit. Hence, these rare aspecific signals could be easily discriminated from specific signals. We conclude that the here presented set of three germline JH Taq-Man probes and six corresponding germline JH primers can be used to develop patient-specific RQ-PCR assays, which allow accurate and sensitive MRD analysis in almost all IGH gene rearrangements. These results will facilitate standardized RQ-PCR analysis for MRD detection in large clinical studies.
Background
In childhood immune thrombocytopenia (ITP), an autoimmune bleeding disorder, there is a need for better prediction of individual disease courses and treatment outcomes.
Objective
To ...predict the response to intravenous immunoglobulins (IVIg) and ITP disease course using genetic and immune markers.
Methods
Children aged younger than 7 years with newly diagnosed ITP (N = 147) from the Treatment With or Without IVIG for Kids with ITP study were included, which randomized children to an IVIg or observation group. A total of 46 variables were available: clinical characteristics, targeted genotyping, lymphocyte immune phenotyping, and platelet autoantibodies.
Results
In the treatment arm, 48/80 children (60%) showed a complete response (platelets ≥100 × 109/L) that lasted for at least 1 month (complete sustained response CSR) and 32 exhibited no or a temporary response (absence of a sustained response ASR). For a biological risk score, five variables were selected by regularized logistic regression that predicted ASR vs CSR: (1) hemoglobin; (2) platelet count; (3) genetic polymorphisms of Fc‐receptor (FcγR) IIc; (4) the presence of immunoglobulin G (IgG) anti‐platelet antibodies; and (5) preceding vaccination. The ASR sensitivity was 0.91 (95% confidence interval, 0.80‐1.00) and specificity was 0.67 (95% confidence interval, 0.53‐0.80). In the 67 patients of the observation arm, this biological score was also associated with recovery during 1 year of follow‐up. The addition of the biological score to a predefined clinical score further improved the discrimination of favorable ITP disease courses.
Conclusions
The prediction of disease courses and IVIg treatment responses in ITP is improved by using both clinical and biological stratification.
Human IgG3 displays the strongest effector functions of all IgG subclasses but has a short half-life for unresolved reasons. Here we show that IgG3 binds to IgG-salvage receptor (FcRn), but that ...FcRn-mediated transport and rescue of IgG3 is inhibited in the presence of IgG1 due to intracellular competition between IgG1 and IgG3. We reveal that this occurs because of a single amino acid difference at position 435, where IgG3 has an arginine instead of the histidine found in all other IgG subclasses. While the presence of R435 in IgG increases binding to FcRn at neutral pH, it decreases binding at acidic pH, affecting the rescue efficiency-but only in the presence of H435-IgG. Importantly, we show that in humans the half-life of the H435-containing IgG3 allotype is comparable to IgG1. H435-IgG3 also gave enhanced protection against a pneumococcal challenge in mice, demonstrating H435-IgG3 to be a candidate for monoclonal antibody therapies.
Abstract Background Quantitative real-time (q)PCR for detection of minimal residual disease (MRD) in children with neuroblastoma (NB) can evaluate molecular bone marrow (BM) response to therapy, but ...the prognostic value of tumour kinetics in the BM during induction treatment remains to be established. The purpose of this study was to analyse at which time points MRD detection by sequential molecular assessment of BM was prognostic for overall survival (OS). Methods In this single centre study, qPCR was performed with five NB-specific markers: PHOX2B , TH , DDC , GAP43 and CHRNA3 , on 106 retrospectively analysed BM samples of 53 patients >1 year with stage 4 neuroblastoma. The prognostic impact of MRD at diagnosis ( n = 39), at 3 months after diagnosis ( n = 38) and after completing induction chemotherapy ( n = 29) was assessed using univariate and bivariate Cox regression analyses. Results There was no correlation between tumour load at diagnosis and outcome ( p = 0.93). Molecular BM remission was observed in 11/38 (29%) of patients at 3 months after diagnosis and associated with favourable outcome (5-y-OS 62 ± 15.0% versus 19 ± 8%; p = 0.009). After completion of induction chemotherapy, BM of 41% (12/29) of the patients was still MRD positive, which was associated with poor outcome (5-y-OS 0% versus 52 ± 12%; p < 0.001). For both time points, the prognostic value of molecular response remained significant in bivariate analysis. Conclusions MRD detection measured by a panel of NB specific-PCR targets could identify fast responders, who clear their BM early during treatment. Fast molecular response was a prognostic factor, associated with better outcome. Our data indicate that MRD analysis during induction therapy should be included in prospective MRD studies.
Treating older adults with psoriasis can be challenging owing to comorbidities, concomitant medication use, and consequent safety risks. Although many studies focus on the effectiveness and safety of ...systemic antipsoriatic therapies in the general population, their effectiveness in older adults with psoriasis has not been systematically assessed.
To evaluate the effectiveness and safety of systemic antipsoriatic therapies in patients 65 years or older.
A systematic literature search was conducted in Embase, MEDLINE, and the Cochrane Central Register of Controlled Trials (CENTRAL) on November 11, 2019. No date limit was used. Randomized clinical trials, cohort studies, large case series, and meta-analyses assessing efficacy (or effectiveness) and/or safety of systemic antipsoriatic therapies in patients 65 years or older were included.
The initial search yielded 11 096 results, of which 31 unique articles with 39 561 patients were included in analysis. Overall, limited data were available per systemic agent, and overall quality of the included studies on conventional systemic therapies was low. At the end of the induction phase (12-16 weeks after start of treatment), a reduction of 75% in Psoriasis Area and Severity Index was achieved in 49% of 74 methotrexate sodium users 65 years or older, 46% to 52.6% of 178 older cyclosporin users, 27% to 47.8% of 108 older acitretin users, 15.6% to 64% of 256 etanercept users 65 years or older, 66.7% to 93% of 43 infliximab users 65 years or older, 60.7% to 65% of 100 adalimumab users 65 years or older, 56.5% of 46 ustekinumab users 65 years or older, and 86.4% of 67 secukinumab users 65 years or older. Effectiveness of acitretin, etanercept, adalimumab, and secukinumab appeared not to be associated with age; studies regarding other systemic antipsoriatic therapies did not provide age group comparisons. Older age was significantly associated with renal function deterioration in cyclosporin users and with lymphopenia in fumaric acid esters users (hazard ratio, 2.42; 95% CI, 1.65-3.55; P < .001). Infections were the most frequently reported adverse event in patients 65 years or older using biologics, but no significant association with age was found.
On the basis of limited available evidence, age alone should not be a limiting factor in psoriasis management. Awareness of comorbidities and concomitant medication use is very important, as well as appropriate dosing and frequent laboratory and clinical monitoring. More real-world evidence and (sub)analyses of prospective cohort studies on the effectiveness and safety of systemic therapies in older adults are critical to optimize personalized, effective, and safe antipsoriatic management in this growing patient group.
As a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In ...particular, the splenic microenvironment has been demonstrated to play a prominent role in adaptive immune responses to enveloped viral infections and alloantigens. During both types of immunizations, antigen-specific immunoglobulins G (IgGs) have been characterized by the reduced amount of fucose present on N-linked glycans of the fragment crystallizable (Fc) region. These glycans are essential for mediating the induction of immune effector functions. Therefore, we hypothesized that a spleen may modulate humoral responses and serve as a preferential site for afucosylated IgG responses, which potentially play a role in immune thrombocytopenia (ITP) pathogenesis. To determine the role of the spleen in IgG-Fc glycosylation, we performed IgG subclass-specific liquid chromatography-mass spectrometry (LC-MS) analysis of Fc glycosylation in a large cohort of individuals splenectomized due to trauma, due to ITP, or spherocytosis. IgG-Fc fucosylation was consistently increased after splenectomy, while no effects for IgG-Fc galactosylation and sialylation were observed. An increase in IgG1- and IgG2/3-Fc fucosylation level upon splenectomy has been reported here for the first time, suggesting that immune responses occurring in the spleen may be particularly prone to generate afucosylated IgG responses. Surprisingly, the level of total IgG-Fc fucosylation was decreased in ITP patients compared to healthy controls. Overall, our results suggest a yet unrecognized role of the spleen in either the induction or maintenance of afucosylated IgG responses by B cells.
Red blood cell (RBC) alloimmunization is a serious complication of blood transfusions, challenging selection of compatible units for future transfusions. Genetic characteristics may be associated ...with the risk of RBC alloimmunization and may therefore serve to identify high-risk patients. The aim of this systematic review was to summarize the available evidence on genetic risk factors for RBC alloimmunization. Electronic databases were searched up to April 2020 for studies (Search terms included transfusion, alloimmunization and genetic). A total of 2581 alloimmunized cases and 26,558 controls were derived from 24 studies. The alleles that were most frequently studied and that demonstrated significant associations in a meta-analysis with alloimmunization to the Duffya antigen were HLA-DRB1*04 (Odds Ratio 7.80 (95%CI 4.57–13.33)), HLA-DRB1*15 (OR 3.76 (95%CI 2.14–6.59)), and HLA-DRB1*03 (OR 0.12 (95%CI 0.05–0.29)). Furthermore, significant associations with anti-K formation was found for the alleles HLA-DRB1*10 (OR 2.64 (95%CI 1.41–4.95)), HLA*DRB1*11 (OR 2.11, (95%CI 1.34–3.32)), and HLA-DRB1*13 (OR 1.71 (95%CI 1.26–2.33)). Overall, the available evidence was of moderate to low quality, hampering interpretation of reported results. There is an urgent need for high quality evidence on genetic risk factors for RBC alloimmunization.
•RBC alloimmunization is a serious complication of transfusions, challenging selection of units for future transfusions.•Several HLA-DRB1 alleles are associated with alloimmunization to the Fya and K antigen.•Prevention of RBC alloimmunization requires a robust risk assessment, including genetic and clinical markers.
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