66 research outputs found
Optimisation and validation of a PCR for Antigen Receptor Rearrangement (PARR) assay to detect clonality in canine lymphoid malignancies
PCR for antigen receptor gene rearrangements (PARR) analysis is being increasingly used to assist diagnosis of canine lymphoma. In this study, PARR was carried out on consecutive samples received as part of routine diagnostic practice from 271 patients: 195 with lymphoid malignancies, 53 with reactive conditions and 23 with other neoplasms. Initially, published primer sets were used but later minor primer modifications were introduced and primers were rationalised to give a PARR panel that provides a good compromise between sensitivity and cost. Results were compared to diagnoses made by histology or cytology, coupled with immunophenotyping by flow cytometry or immunohistochemistry where possible. After exclusion of 11 poor quality samples, 230/260 (88%) gave a clear result with 162/163 (99%) of samples classified as clonal and 56/67 (84%) classified as polyclonal giving results concordant with the cytological/histological diagnosis. Among 30 samples with equivocal results, 21 had clonal peaks in a polyclonal background and nine showed little amplification. These were from patients with a range of neoplastic and non-neoplastic conditions emphasising the need to interpret such results carefully in concert with other diagnostic tests. The combination of primer sets used in this study resulted in a robust, highly specific and sensitive assay for detecting clonality
Development of an electrochemical CCL17/TARC biosensor toward rapid triage and monitoring of classic Hodgkin lymphoma
A point-of-care blood test for the detection of an emerging biomarker, CCL17/TARC, could prove transformative for the clinical management of classic Hodgkin lymphoma (cHL). Primary care diagnosis is challenging due to nonspecific clinical presentation and lack of a diagnostic test, leading to significant diagnostic delays. Treatment monitoring encounters false-positive and negative results, leading to avoidable chemotherapy toxicity, or undertreatment, impacting patient morbidity and mortality. Here, we present an amperometric CCL17/TARC immunosensor, based on the utilization of a thiolated heterobifunctional cross-linker and sandwich antibody assay, to facilitate novel primary care triage and chemotherapy monitoring strategies for cHL. The immunosensor shows excellent analytical performance for clinical testing; linearity (R2 = 0.986), detection limit (194 pg/mL), and lower and upper limits of quantitation (387â50âŻ000 pg/mL). The biosensor differentiated all 42 newly diagnosed cHL patients from healthy volunteers, based on serum CCL17/TARC concentration, using blood samples collected prior to treatment intervention. The immunosensor also discriminated between paired blood samples of all seven cHL patients, respectively, collected prior to treatment and during chemotherapy, attributed to the decrease in serum CCL17/TARC concentration following chemotherapy response. Overall, we have shown, for the first time, the potential of an electrochemical CCL17/TARC biosensor for primary care triage and chemotherapy monitoring for cHL, which would have positive clinical and psychosocial implications for patients, while streamlining current healthcare pathways
The Retrovirus XMRV Is not Directly Involved in the Pathogenesis of Common Types of Lymphoid Malignancy
Background: Anovel retrovirus, xenotropic murine leukemia virus-related virus (XMRV), has been detected in prostate cancer samples and in peripheral blood mononuclear cells (PBMC) from patients with chronic fatigue syndrome. In addition, the virus has been identified in PBMCs from healthy controls. These data suggest that XMRV is circulating in the human population. XMRV is closely related to murine leukemia viruses, which cause lymphoid malignancies in mice. The aim of this study was to determine whether-XMRV is directly associated with common forms of human lymphoma or leukemia. Methods: DNA samples from 368 patients with lymphoid malignancies and 139 patients with benign lymphadenopathy or other malignant disease were screened for XMRV, using three specific and sensitive quantitative PCR assays. Results: XMRV was not detected in any sample using any of the three assays. Conclusions: The data suggest that this virus is not directly involved in the pathogenesis of common types of lymphoid malignancy and that XMRV is not a prevalent blood borne infection, at least in the United Kingdom. Impact: There is no evidence that XMRV is associated with lymphoid malignancies, and further studies should resolve inconsistencies in results of studies examining XMRV prevalence. Cancer Epidemiol Biomarkers Prev. 20(10); 2232-6. (C) 2011 AAC
Identifying EpsteinâBarr virus peptide sequences associated with differential IgG antibody response
Background: Epstein-Barr virus (EBV) infection contributes to cancers in a fraction of seropositive individuals, but much remains to be learned about variation in EBV-directed humoral immunity in cancer-free adults.
Methods: A protein microarray was used to probe serum from 175 Taiwanese and 141 Northern European adults for immunoglobulin G (IgG) antibody responses to 115 different peptide sequences, representing protein segments or protein variants, from 45 EBV proteins. It was posited that this antibody-based approach could identify EBV peptide sequences representing immunodominant regions relevant for B-cell immunity.
Results: Analyses of 45 EBV proteins with multiple protein segments or variants printed on the array identified eight EBV peptide sequences that appear to play a role in immunogenicity. This included: (1) three proteins with segments/regions associated with IgG reactivity (BALF5, LMP1, LMP2A); and (2) five proteins with sequence variants/amino acid changes associated with IgG reactivity (BDLF4, EBNA3A, EBNA3B, EBNA-LP, LF1).
Conclusion: This examination of IgG antibody responses against 115 EBV peptide sequences in 316 cancer-free adults represents an important step toward identifying specific EBV protein sequences that play a role in generating B-cell immunity in humans
HLA expression in relation to HLA type in classic Hodgkin lymphoma patients
Several human leukocyte antigen (HLA) alleles are strongly associated with susceptibility to classic Hodgkin lymphoma (cHL), also in subgroups stratified for presence of the EpsteinâBarr virus (EBV). We tested the hypothesis that the pressure on cHL tumour cells to lose HLA expression is associated with HLA susceptibility alleles. A meta-analysis was carried out to identify consistent protective and risk HLA alleles in a combined cohort of 839 cHL patients from the Netherlands and the United Kingdom. Tumour cell HLA expression was studied in 338 cHL cases from these two cohorts and correlated to the presence of specific susceptibility HLA alleles. Carriers of the HLA-DRB1*07 protective allele frequently lost HLA class II expression in cHL overall. Patients carrying the HLA-DRB1*15/16 (DR2) risk allele retained HLA class II expression in EBVâ cHL and patients with the HLA-B*37 risk allele retained HLA class I expression more frequently than non-carriers in EBV+ cHL. The other susceptibility alleles showed no significant differences in expression. Thus, HLA expression by tumour cells is associated with a subset of the protective and risk alleles. This strongly suggests that HLA associations in cHL are related to peptide binding capacities of specific HLA alleles
Evaluation of the antibody response to the EBV proteome in EBV-associated classic Hodgkin lymphoma
The humoral immune response to EpsteinâBarr virus (EBV) in classical Hodgkin lymphoma (cHL) stratified by EBV tumor status is unclear. We examined IgG and IgA antibody responses against 202 protein sequences representing 86 EBV proteins using a microarray and sera from 139 EBVâpositive cHL cases, 70 EBVânegative cHL cases and 141 populationâbased controls frequency matched to EBVâpositive cHL cases on sex and age by area (UK, Denmark and Sweden). We leveraged existing data on the proportion of circulating Bâcells infected by EBV and levels of serum CCL17, a chemokine secreted by cHL tumor cells, from a subset of the cHL cases in the UK. Total IgG but not IgA response level was significantly different between EBVâpositive cHL cases and controls. The distinct serological response included significant elevations in 16 IgG antibodies and 2 IgA antibodies, with odds ratioshighest vs. lowest tertileâ>â3 observed for the following EBV proteins: LMP1 (oncogene), BcLF1 (VCAp160, two variants) and BBLF1 (two variants). Our cHL IgG signature correlated with the proportion of circulating EBVâinfected Bâcells, but not serum CCL17 levels. We observed no differences in the antiâEBV antibody profile between EBVânegative cHL cases and controls. BdRF1(VCAp40)âIgG and BZLF1(Zta)âIgG were identified as the serological markers best able to distinguish EBVâpositive from EBVânegative cHL tumors. Our results support the hypothesis that differences in the EBV antibody profile are specific to patients with EBVâpositive cHL and are not universally observed as part of a systematically dysregulated immune response present in all cHL cases
Detection of SARSâCoVâ2 in respiratory samples from cats in the UK associated with humanâtoâcat transmission
Objectives: The aim of the study was to find evidence of SARSâCoVâ2 infection in UK cats. Design: Tissue samples were tested for SARSâCoVâ2 antigen using immunofluorescence and for viral RNA by in situ hybridisation. A set of 387 oropharyngeal swabs that had been submitted for routine respiratory pathogen testing was tested for SARSâCoVâ2 RNA using reverse transcriptase quantitative PCR. Results: Lung tissue collected postâmortem from cat 1 tested positive for both SARSâCoVâ2 nucleocapsid antigen and RNA. SARSâCoVâ2 RNA was detected in an oropharyngeal swab collected from cat 2 that presented with rhinitis and conjunctivitis. High throughput sequencing of the viral genome revealed five single nucleotide polymorphisms (SNPs) compared to the nearest UK human SARSâCoVâ2 sequence, and this human virus contained eight SNPs compared to the original WuhanâHuâ1 reference sequence. An analysis of the viral genome of cat 2 together with nine other felineâderived SARSâCoVâ2 sequences from around the world revealed no shared catâspecific mutations. Conclusions: These findings indicate that humanâtoâcat transmission of SARSâCoVâ2 occurred during the COVIDâ19 pandemic in the UK, with the infected cats developing mild or severe respiratory disease. Given the ability of the new coronavirus to infect different species, it will be important to monitor for humanâtoâcat, catâtoâcat and catâtoâhuman transmission
Evaluating the effects of SARS-CoV-2 Spike mutation D614G on transmissibility and pathogenicity
SummaryGlobal dispersal and increasing frequency of the SARS-CoV-2 Spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of Spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large data set, well represented by both Spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the Spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant.</jats:p
Recommended from our members
Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity.
Global dispersal and increasing frequency of the SARS-CoV-2 spike protein variant D614G are suggestive of a selective advantage but may also be due to a random founder effect. We investigate the hypothesis for positive selection of spike D614G in the United Kingdom using more than 25,000 whole genome SARS-CoV-2 sequences. Despite the availability of a large dataset, well represented by both spike 614 variants, not all approaches showed a conclusive signal of positive selection. Population genetic analysis indicates that 614G increases in frequency relative to 614D in a manner consistent with a selective advantage. We do not find any indication that patients infected with the spike 614G variant have higher COVID-19 mortality or clinical severity, but 614G is associated with higher viral load and younger age of patients. Significant differences in growth and size of 614G phylogenetic clusters indicate a need for continued study of this variant
Recommended from our members
A genome-wide association study of Hodgkin Lymphoma identifies new susceptibility loci at 2p16.1 (REL), 8q24.21, and 10p14 (GATA3)
To identify predisposition loci for classical Hodgkin Lymphoma (cHL) we conducted a genome-wide association study of 589 cHL cases and 5,199 controls with validation in 4 independent samples totaling 2,057 cases and 3,416 controls. We identified three new susceptibility loci at 2p16.1 (rs1432295, REL; odds ratio [OR]=1.22, Pcombined=1.91Ă10â8), 8q24.21 (rs2019960, PVT1; OR=1.33, Pcombined=1.26Ă10â13) and 10p14 (rs501764, GATA3; OR=1.25, Pcombined=7.05Ă10â8). Furthermore, we confirmed the role of the MHC in disease etiology by revealing a strong HLA association (rs6903608; OR=1.70, Pcombined=2.84Ă10â50). These data provide new insight into the pathogenesis of cHL
- âŚ