Faculty Bibliography

Translocations in myeloma are thought to occur solely in mature B cells in the germinal center through class switch recombination (CSR). We used a targeted captured technique followed by massively parallel sequencing to determine the exact breakpoints in both the immunoglobulin heavy chain (IGH) locus and the partner chromosome in 61 presentation multiple myeloma samples. The majority of samples (62%) have a breakpoint within the switch regions upstream of the IGH constant genes and are generated through CSR in a mature B cell. However, the proportion of CSR translocations is not consistent between cytogenetic subgroups. We find that 100% of t(4;14) are CSR-mediated; however, 21% of t(11;14) and 25% of t(14;20) are generated through DH-JH recombination activation gene-mediated mechanisms, indicating they occur earlier in B-cell development at the pro-B-cell stage in the bone marrow. These 2 groups also generate translocations through receptor revision, as determined by the breakpoints and mutation status of the segments used in 10% and 50% of t(11;14) and t(14;20) samples, respectively. The study indicates that in a significant number of cases the translocation-based etiological events underlying myeloma may arise at the pro-B-cell hematological progenitor cell level, much earlier in B-cell development than was previously thought.

The combination of serum β2-microglobulin and albumin levels has been shown to be highly prognostic in myeloma as the International Staging System (ISS). The aim of this study was to assess the independent contributions of ISS stage and cytogenetic abnormalities in predicting outcomes. A retrospective analysis of international studies looking at both ISS and cytogenetic abnormalities was performed in order to assess the potential role of combining ISS stage and cytogenetics to predict survival. This international effort used the International Myeloma Working Group database of 12 137 patients treated worldwide for myeloma at diagnosis, of whom 2309 had cytogenetic studies and 5387 had analyses by fluorescent in situ hybridization (iFISH). Comprehensive analyses used 2642 patients with sufficient iFISH data available. Using the comprehensive iFISH data, combining both t(4;14) and deletion (17p), along with ISS stage, significantly improved the prognostic assessment in terms of progression-free survival and overall survival. The additional impact of patient age and use of high-dose therapy was also demonstrated. In conclusion, the combination of iFISH data with ISS staging significantly improves risk assessment in myeloma.

Inositol-requiring enzyme 1 alpha (IRE1α) is a transmembrane sensor protein with both kinase and ribonuclease activity, which plays a crucial role in the unfolded protein response (UPR). Protein misfolding in the endoplasmic reticulum (ER) lumen triggers dimerization and subsequent trans-autophosphorylation of IRE1α. This leads to the activation of its endoribonuclease (RNase) domain and splicing of the mRNA of the transcriptional activator XBP1, ultimately generating an active XBP1 (XBP1s) implicated in multiple myeloma survival. Previously, we have identified human IRE1α as a target for the development of kinase inhibitors that could modulate the UPR in human cells, which has particular relevance for multiple myeloma and other secretory malignancies. Here we describe the development and validation of a 384-well high-throughput screening assay using DELFIA technology that is specific for IRE1α autophosphorylation. Using this format, a focused library of 2312 potential kinase inhibitors was screened, and several novel IRE1α kinase inhibitor scaffolds were identified that could potentially be developed toward new therapies to treat multiple myeloma.

OBJECTIVES/OBJECTIVE:The goal of this study was to prospectively assess blood pressure (BP) and echocardiographic parameters to delineate the incidence and nature of the hypertension burden in this cohort. BACKGROUND:Few data are available on the long-term outcomes of aortic stenting. METHODS:Thirty-one patients with successfully stented coarctation during childhood (mean age 12.4 years) underwent 24-h ambulatory BP monitoring (ABPM), exercise BP measurement, and echocardiographic assessment. RESULTS:Mean time after stent implantation was 5.3 ± 4 years. Hypertension was noted on one-off right-arm BP assessment in 3 patients (10%), but on the basis of the 24-h ABPM assessment in 14 patients (45%). Twenty-four of 31 patients (80%) had an abnormally elevated exercise BP response. Peak exercise BP correlated with left ventricular mass index (r = 0.51; p < 0.05), which was also significantly increased in the entire cohort (mean = 91.3 g/m(2); p < 0.05). In patients with significant somatic growth since implantation, the indexed diameter of the stent (to aortic diameter) had significantly decreased from the 48th percentile at the implantation to the 4th percentile during the study (p < 0.05). There was no difference in any parameter between patients with native or those with recurrent coarctation. CONCLUSIONS:Hypertension is endemic in patients with stented coarctation, irrespective of the absence of residual obstruction. Due to abnormal BP homeostasis, hypertension should be aggressively pursued by ABPM assessment and exercise stress testing in this population. Relative hypoplasia of the stented arch after somatic growth may contribute to this tendency and should provoke consideration of elective serial redilation of coarctation stents.

CLLU1, located at chromosome 12q22, encodes a transcript specific to chronic lymphocytic leukemia and has potential prognostic value. We assessed the value of CLLU1 expression in the LRF CLL4 randomized trial. Samples from 515 patients with chronic lymphocytic leukemia were collected immediately before the start of treatment. After RNA extraction and cDNA synthesis, CLLU1 expression was assessed by quantitative polymerase chain reaction. In total, 247 and 268 samples were identified as having low and high CLLU1 expression, respectively. The median follow-up was 88 months. High CLLU1 expression was significantly correlated with unmutated IGHV genes, ZAP-70 and CD38 positivity, and absence of 13q deletion (all r>0.2, P<0.0001). At 6 years, patients with high CLLU1 expression had significantly worse progression-free survival (9% versus 17%; P=0.03) and overall survival (42% versus 57%; P=0.0003) than patients with low CLLU1 expression. Among patients with mutated IGHV genes, overall survival at 6 years was 50% in those with high CLLU1 expression and 76% in those with low CLLU1 expression (P=0.005). However, CLLU1 expression was not an independent predictor of overall survival in a multivariate model including TP53 aberrations, beta-2 microglobulin level, age and IGHV mutation status. Nor did it predict response to treatment. CLLU1 expression analysis helps to refine the prognosis of patients with chronic lymphocytic leukemia who have mutated IGHV genes.

Percutaneous transcatheter device closure for post-myocardial infarction ventricular septal defect is a feasible alternative to open surgical patch repair. Patient selection, imaging, timing of intervention, technique, and results are discussed.

Graft-versus-host disease (GvHD) is a common complication following haematopoietic stem cell transplant but little is published about the impact of this condition on hospital readmission rates. We report a retrospective analysis of readmission rates and associated costs in 187 consecutive allogeneic transplant patients to assess the impact of GvHD. The overall readmission rate was higher in patients with GvHD (86% (101/118) vs. 59% (41/69), p < 0.001). The readmission rate was higher both in the first 100 d from transplant (p = 0.02) and in the first year following transplant (p < 0.001). 151/455 (33%) of all readmission episodes occurred within 100 d of transplant. The mean number of inpatient days was significantly higher in patients with grade III/IV acute GvHD (101 d) compared with those with grade I/II GvHD (70 d; p = 0.003). The mean cost of readmission was higher in patients with GvHD (£28 860) than in non-GvHD patients (£13 405; p = 0.002) and in patients with grade III/IV GvHD (£40 012) compared with those patients with grade I/II GvHD (£24 560; p = 0.038). Survival was higher in those with grade I/II GvHD (55%) compared to grade III/IV GvHD (14%; p < 0.001). This study shows the high economic burden and poor overall survival associated with grade III/IV GvHD.

BACKGROUND:Biomarker identification is becoming increasingly important for the development of personalized or stratified therapies. Metabolomics yields biomarkers indicative of phenotype that can be used to characterize transitions between health and disease, disease progression and therapeutic responses. The desire to reproducibly detect ever greater numbers of metabolites at ever diminishing levels has naturally nurtured advances in best practice for sample procurement, storage and analysis. Reciprocally, since many of the available extensive clinical archives were established prior to the metabolomics era and were not processed in such an 'ideal' fashion, considerable scepticism has arisen as to their value for metabolomic analysis. Here we have challenged that paradigm. METHODS:We performed proton nuclear magnetic resonance spectroscopy-based metabolomics on blood serum and urine samples from 32 patients representative of a total cohort of 1970 multiple myeloma patients entered into the United Kingdom Medical Research Council Myeloma IX trial. FINDINGS/RESULTS:Using serial paired blood and urine samples we detected metabolite profiles that associated with diagnosis, post-treatment remission and disease progression. These studies identified carnitine and acetylcarnitine as novel potential biomarkers of active disease both at diagnosis and relapse and as a mediator of disease associated pathologies. CONCLUSIONS:These findings show that samples conventionally processed and archived can provide useful metabolomic information that has important implications for understanding the biology of myeloma, discovering new therapies and identifying biomarkers potentially useful in deciding the choice and application of therapy.