196 results found
Jesuthasan A, Roufosse C, Ramaswami A, 2023, Biopsy-proven fungal pyelonephritis complicating delayed graft function in a renal transplant patient, BMJ CASE REPORTS, Vol: 16
de Nattes T, Beadle J, Toulza F, et al., 2023, A Simple Molecular Tool for the Assessment of Kidney Transplant Biopsies., Clin J Am Soc Nephrol
Background The Banff Classification for Allograft Pathology recommendations for the diagnosis of kidney transplant rejection includes molecular assessment of the transplant biopsy. However, implementation of molecular tools in clinical practice is still limited, partly due to the required expertise and financial investment. The reverse transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) assay is a simple, rapid and inexpensive assay that permits simultaneous evaluation of a restricted gene panel using paraffin-embedded tissue blocks. The aim of this study was to develop and validate a RT-MLPA assay for diagnosis and classification of rejection. Methods A retrospective cohort of 220 kidney transplant biopsies from two centres, which included with 52 antibody-mediated rejection, 51 T cell-mediated rejection and 117 no-rejection controls was assessed. A 17-gene panel was identified, based on relevant pathophysiological pathways. A support vector machine classifier was developed. A subset of 109 biopsies was also assessed using the Nanostring B-HOT panel to compare the two assays. Results The support vector machine classifier train and test accuracy scores were 0.84 and 0.83, respectively. In the test cohort, the F1-score for antibody mediated rejection, T cell-mediated rejection and control were 0.88, 0.86 and 0.69, respectively. Using ROC curves, AUC for class predictions were 0.96, 0.89 and 0.91, respectively, with a weight-average at 0.94. Classifiers' performances were highest for antibody mediated rejection diagnosis with 94% correct predictions, compared to 88% correct predictions for control biopsies and 60% for T-cell mediated rejection biopsies. Gene expression levels assessed by RT-MLPA or Nanostring correlated: r = 0.68, p < 0.001, and gene expression profiles obtained with these assays were comparable in 81% of samples. Conclusions The 17-gene panel RT-MLPA assay, developed here for formalin-fixed paraffin-embedded kidney transplant
Prendecki M, Gulati K, Pisacano N, et al., 2023, Syk activation in circulating and tissue innate immune cells in antineutrophil cytoplasmic antibody-associated vasculitis, Arthritis and Rheumatology, Vol: 75, Pages: 84-97, ISSN: 2326-5205
OBJECTIVE: Syk is a cytoplasmic protein tyrosine kinase that plays a role in signaling via B cell and Fc receptors (FcR). FcR engagement and signaling via Syk is thought to be important in antineutrophil cytoplasm antibody (ANCA) IgG-mediated neutrophil activation. This study was undertaken to investigate the role of Syk in ANCA-induced myeloid cell activation and vasculitis pathogenesis. METHODS: Phosphorylation of Syk in myeloid cells from healthy controls and ANCA-associated vasculitis (AAV) patients was analyzed using flow cytometry. The effect of Syk inhibition on myeloperoxidase (MPO)-ANCA IgG activation of cells was investigated using functional assays (interleukin-8 and reactive oxygen species production) and targeted gene analysis with NanoString. Total and phosphorylated Syk at sites of tissue inflammation in patients with AAV was assessed using immunohistochemistry and RNAscope in situ hybridization. RESULTS: We identified increased phosphorylated Syk at critical activatory tyrosine residues in blood neutrophils and monocytes from patients with active AAV compared to patients with disease in remission or healthy controls. Syk was phosphorylated in vitro following MPO-ANCA IgG stimulation, and Syk inhibition was able to prevent ANCA-mediated cellular responses. Using targeted gene expression analysis, we identified up-regulation of FcR- and Syk-dependent signaling pathways following MPO-ANCA IgG stimulation. Finally, we showed that Syk is expressed and phosphorylated in tissue leukocytes at sites of organ inflammation in AAV. CONCLUSION: These findings indicate that Syk plays a critical role in MPO-ANCA IgG-induced myeloid cell responses and that Syk is activated in circulating immune cells and tissue immune cells in AAV; therefore, Syk inhibition may be a potential therapeutic option.
Gama R, Murphy E, Salisbury J, et al., 2022, A rare case of nephrotic syndrome and Tangier disease, CEN CASE REPORTS, ISSN: 2192-4449
Roufosse C, Cook H, Dominy K, et al., 2022, Diagnostic application of transcripts associated with antibody-mediated rejection in kidney transplant biopsies, Nephrology Dialysis Transplantation, Vol: 37, Pages: 1576-1584, ISSN: 0931-0509
BackgroundThe diagnosis of antibody-mediated rejection (AMR) is reached using the Banff Classification for Allograft Pathology, which now includes gene expression analysis. In this study, we investigate the application of “Increased Expression Of Thoroughly Validated Gene Transcripts/Classifiers Strongly Associated With AMR” as a diagnostic criteria.MethodWe used qRT-PCR for 10 genes associated with AMR in a retrospective cohort of 297 transplant biopsies, including biopsies that met the full diagnostic criteria for AMR, even without molecular data (AMR, n = 27); biopsies that showed features of AMR, but that would only meet criteria for AMR with increased transcripts (AMRsusp, n = 49) and biopsies that would never meet criteria for AMR (No-AMR, n = 221).ResultsA 10-gene AMR score trained by a receiver-operating characteristic to identify AMR found 16 cases with a high score amongst the AMRsusp cases (AMRsusp-high) that had significantly worse graft survival than those with a low score (AMRsusp-low) (n = 33). In both univariate and multivariate Cox regression analysis, the AMR 10-gene score was significantly associated with an increased hazard ratio for graft loss in the AMRsusp group (HR 1.109, p = 0.004 and HR 1.138, p = 0.012), but not in the whole cohort. Net reclassification index and integrated discrimination improvement analyses demonstrated improved risk classification and superior discrimination respectively for graft loss when considering the gene score in addition to histological and serological data, but only in the AMRsusp group, not the whole cohort.ConclusionsThis study provides evidence that a gene score strongly associated with AMR helps identify cases at higher risk of graft loss in biopsies that are suspicious for AMR but don’t meet full criteria.
Roufosse C, Becker JU, Rabant M, et al., 2022, Proposed Definitions of Antibody-Mediated Rejection for Use as a Clinical Trial Endpoint in Kidney Transplantation, TRANSPLANT INTERNATIONAL, Vol: 35, ISSN: 0934-0874
- Author Web Link
- Citations: 2
Becker JU, Seron D, Rabant M, et al., 2022, Evolution of the Definition of Rejection in Kidney Transplantation and Its Use as an Endpoint in Clinical Trials, TRANSPLANT INTERNATIONAL, Vol: 35, ISSN: 0934-0874
- Author Web Link
- Citations: 3
Seron D, Rabant M, Becker JU, et al., 2022, Proposed Definitions of T Cell-Mediated Rejection and Tubulointerstitial Inflammation as Clinical Trial Endpoints in Kidney Transplantation, TRANSPLANT INTERNATIONAL, Vol: 35, ISSN: 0934-0874
- Author Web Link
- Citations: 1
Gray-Rodriguez S, Jensen M, Otero-Jimenez M, et al., 2022, Detection of SARS-CoV-2 within enteric neurons and in brain, Publisher: WILEY, ISSN: 0305-1846
Tempest-Roe S, Prendecki M, McAdoo S, et al., 2022, Inhibition of spleen tyrosine kinase decreases donor specific antibody levels in a rat model of sensitization, Scientific Reports, Vol: 12, ISSN: 2045-2322
Antibody mediated rejection is a major cause of renal allograft loss. Circulating preformed donor specific antibodies (DSA) can result as a consequence of blood transfusion, pregnancy or prior transplantation. Current treatment strategies are limited due to partial or transient efficacy, adverse side-effects or patient unsuitability. Previous in vivo studies exploring autoimmune diseases have shown that spleen tyrosine kinase (SYK) signalling is involved in the development of pathogenic autoantibody. The role of SYK in allogenic antibody production is unknown, and we investigated this in a rodent model of sensitization, established by the transfusion of F344 whole blood into LEW rats. Two-week treatment of sensitized rats with selective SYK inhibitor fostamatinib strongly blocked circulating DSA production without affecting overall total immunoglobulin levels, and inhibition was sustained up to 5 weeks post-completion of the treatment regimen. Fostamatinib treatment did not affect mature B cell subset or plasma cell levels, which remained similar between non-treated controls, vehicle treated and fostamatinib treated animals. Our data indicate fostamatinib may provide an alternative therapeutic option for patients who are at risk of sensitization following blood transfusion while awaiting renal transplant.
Gray-Rodriguez S, Jensen MP, Otero-Jimenez M, et al., 2022, Multisystem screening reveals SARS-CoV-2 in neurons of the myenteric plexus and in megakaryocytes, Journal of Pathology, Vol: 257, ISSN: 0022-3417
SARS-CoV-2, the causative agent of COVID-19, typically manifests as a respiratory illness although extrapulmonary involvement, such as in the gastrointestinal tract and nervous system, as well as frequent thrombotic events, are increasingly recognised. How this maps onto SARS-CoV-2 organ tropism at the histological level, however, remains unclear. Here, we perform a comprehensive validation of a monoclonal antibody against the SARS-CoV-2 nucleocapsid protein (NP) followed by systematic multisystem organ immunohistochemistry analysis of the viral cellular tropism in tissue from 36 patients, 16 post-mortem cases and 16 biopsies with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 status from the peaks of the pandemic in 2020 and four pre-COVID post-mortem controls. SARS-CoV-2 anti-NP staining in the post-mortem cases revealed broad multiorgan involvement of the respiratory, digestive, haematopoietic, genitourinary and nervous systems, with a typical pattern of staining characterised by punctate paranuclear and apical cytoplasmic labelling. The average time from symptom onset to time of death was shorter in positively versus negatively stained post-mortem cases (mean = 10.3 days versus mean = 20.3 days, p = 0.0416, with no cases showing definitive staining if the interval exceeded 15 days). One striking finding was the widespread presence of SARS-CoV-2 NP in neurons of the myenteric plexus, a site of high ACE-2 expression, the entry receptor for SARS-CoV-2, and one of the earliest affected cells in Parkinson's disease. In the bone marrow, we observed viral SARS-CoV-2 NP within megakaryocytes, key cells in platelet production and thrombus formation. In 15 tracheal biopsies performed in patients requiring ventilation, there was a near complete concordance between immunohistochemistry and PCR swab results. Going forward, our findings have relevance to correlating clinical symptoms to the organ tropism of
Arturs C, Roufosse C, 2021, Forging the tools for a computer-aided workflow in transplant pathology, LANCET DIGITAL HEALTH, Vol: 4, Pages: E2-E3
- Author Web Link
- Citations: 1
Aguiar PV, Ramirez-Bajo MJ, Sanchez Salom L, et al., 2021, P.156: Transcriptomic Profile in Pancreas Biopsies for Monitoring Graft Rejection., Transplantation, Vol: 105
Prendecki M, Gulati K, Turner-Stokes T, et al., 2021, Characterisation of an enhanced preclinical model of experimental MPO-ANCA autoimmune vasculitis, Journal of Pathology, Vol: 255, Pages: 107-119, ISSN: 0022-3417
Experimental autoimmune vasculitis (EAV) is a model of antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) induced by immunisation of susceptible rat strains with myeloperoxidase (MPO). Animals develop circulating MPO-ANCA, pulmonary haemorrhage and glomerulonephritis, although renal injury is mild and recovers spontaneously without treatment. In this study we aimed to augment the severity of glomerulonephritis. Following induction of EAV on day 0, a sub-nephritogenic dose of nephrotoxic serum (NTS) containing heterologous antibodies to glomerular basement membrane was administered on day 14. This resulted in a significant increase in disease severity at day 28 compared to MPO immunisation alone - with more urinary abnormalities, infiltrating glomerular leucocytes, and crescent formation that progressed to glomerular and tubulointerstitial scarring by day 56, recapitulating important features of human disease. Importantly, the glomerulonephritis remained pauci-immune, and was strictly dependent on the presence of autoimmunity to MPO, as there was no evidence of renal disease following administration of sub-nephritogenic NTS alone or after immunisation with a control protein in place of MPO. Detailed phenotyping of glomerular leucocytes identified an early infiltrate of non-classical monocytes following NTS administration that, in the presence of autoimmunity to MPO, may initiate the subsequent influx of classical monocytes which augment glomerular injury. We also showed that this model can be used to test novel therapeutics by using a small molecule kinase inhibitor (fostamatinib) that rapidly attenuated both glomerular and pulmonary injury over a four-day treatment period. We believe that this enhanced model of MPO-AAV will prove useful for the study of glomerular leucocyte behaviour and novel therapeutics in AAV in the future. This article is protected by copyright. All rights reserved.
Kapp ME, Fogo AB, Roufouse C, et al., 2021, Renal Considerations in COVID-19: Biology, Pathology, and Pathophysiology., ASAIO J, Vol: 67, Pages: 1087-1096
Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged into a worldwide pandemic of epic proportion. Beyond pulmonary involvement in coronavirus disease 2019 (COVID-19), a significant subset of patients experiences acute kidney injury. Patients who die from severe disease most notably show diffuse acute tubular injury on postmortem examination with a possible contribution of focal macro- and microvascular thrombi. Renal biopsies in patients with proteinuria and hematuria have demonstrated a glomerular dominant pattern of injury, most notably a collapsing glomerulopathy reminiscent of findings seen in human immunodeficiency virus (HIV) in individuals with apolipoprotein L-1 (APOL1) risk allele variants. Although various mechanisms have been proposed for the pathogenesis of acute kidney injury in SARS-CoV-2 infection, direct renal cell infection has not been definitively demonstrated and our understanding of the spectrum of renal involvement remains incomplete. Herein we discuss the biology, pathology, and pathogenesis of SARS-CoV-2 infection and associated renal involvement. We discuss the molecular biology, risk factors, and pathophysiology of renal injury associated with SARS-CoV-2 infection. We highlight the characteristics of specific renal pathologies based on native kidney biopsy and autopsy. Additionally, a brief discussion on ancillary studies and challenges in the diagnosis of SARS-CoV-2 is presented.
Roufosse C, 2021, Super-Resolved Imaging for Translational Research and Diagnosis in Renal Pathology, 13th Joint Meeting of the British-Division-of-The-International-Academy-of-Pathology and The-Pathological-Society-of-Great-Britain-and-Ireland (Manchester Pathology), Publisher: WILEY, Pages: S11-S11, ISSN: 0022-3417
Adam BA, Murakami N, Reid G, et al., 2021, Gene Expression Profiling in Kidney Transplants with Immune Checkpoint Inhibitor?Associated Adverse Events, CLINICAL JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY, Vol: 16, Pages: 1376-1386, ISSN: 1555-9041
- Author Web Link
- Citations: 7
Kousios A, Mcadoo S, Blakey S, et al., 2021, Masked crystalline light chain tubulopathy and podocytopathy with focal segmental glomerulosclerosis: a rare MGRS-associated renal lesion, Histopathology, Vol: 79, Pages: 265-268, ISSN: 1365-2559
Monoclonal Gammopathy of Renal Significance (MGRS) encompasses a wide spectrum of histopathology. Characterizing rare forms of MGRS-related renal pathology remains work in progress. Light chain crystalline podocytopathy in the context of MGRS, either in isolation or combined with proximal tubulopathy (LCPT) has rarely been described. Unravelling MGRS pathologies is critical for patient management and often requires ancillary techniques for antigen retrieval to demonstrate light chain (LC) restriction on immunofluorescence (IF).
Barba T, Oberbarnscheidt MH, Rabeyrin M, et al., 2021, THE BIATHLETE'S DILEMMA: UNRAVELLING THE MOLECULAR MECHANISMS OF THE IMMUNE PRIVILEGE OF GRAFT ENDOTHELIUM DURING TCMR, Publisher: WILEY, Pages: 9-9, ISSN: 0934-0874
Gulati K, Roufosse C, McAdoo SP, 2021, Diffuse crescentic glomerulonephritis presenting with preserved renal function, RHEUMATOLOGY, Vol: 60, Pages: 18-20, ISSN: 1462-0324
- Author Web Link
- Citations: 1
Garcia E, Lightley J, Kumar S, et al., 2021, Application of direct stochastic optical reconstruction microscopy (dSTORM) to the histological analysis of human glomerular disease, JOURNAL OF PATHOLOGY CLINICAL RESEARCH, Vol: 7, Pages: 438-445
Cicalese PA, Rizvi SA, Roufosse C, et al., 2021, DEEP LEARNING DIAGNOSIS OF ANTIBODY-MEDIATED REJECTION (AMR) ON GLOMERULAR TRANSECTIONS, 58th Congress of the European-Renal-Association (ERA)-European-Dialysis-and-Transplant-Association (EDTA), Publisher: OXFORD UNIV PRESS, ISSN: 0931-0509
Nikolopoulou A, Teixeira C, Cook H, et al., 2021, Membranous nephropathy associated with viral infection, Clinical Kidney Journal, Vol: 14, Pages: 876-883, ISSN: 2048-8505
BackgroundMembranous nephropathy (MN) can be associated with hepatitis infection and less commonly with human immunodeficiency virus (HIV) infection. The significance of anti-phospholipase A2 receptor (PLA2R) and anti-thrombospondin type 1 domain-containing 7A (THSD7A) antibodies in this setting is unclear.MethodsWe describe the clinical, histopathological and outcome data of 19 patients with MN and hepatitis B virus (HBV), hepatitis C virus (HCV) or HIV infection identified through our renal biopsy database and the association with anti-PLA2R antibodies and anti-THSD7A antibodies.ResultsThe cohort consisted of 19 patients, 8 male and 11 female, with a median age of 42 years (range 23–74). HBV infection was found in six cases, HCV in four and HIV in nine (two HIV patients had HBV co-infection and one HCV co-infection). PLA2R staining on biopsy was positive in 10/19 patients: 4 with HBV-MN, 3 with HCV-MN and 3 with HIV-MN and circulating anti-PLA2R antibodies were detected in 7/10 cases. THSD7A staining on biopsy was positive in three PLA2R-negative cases, one with HBV-MN and two with HIV-MN. Mean proteinuria was higher in the PLA2R-positive group and the median urinary protein:creatinine ratio (uPCR) was 963 mg/mmol (range 22–2406) compared with the PLA2R-negative group [median uPCR 548 mg/mmol (range 65–1898); P = 0.18 Mann–Whitney]. Spontaneous remission occurred in 6/19 patients and after-treatment remission occurred in 7/11 patients. Renal function was preserved in all but two patients who required haemodialysis 2 and 11 years from diagnosis.ConclusionsWe describe a cohort of patients with MN associated with viral infection, including rare cases of HIV-MN with PLA2R and THSD7A positivity. The mechanism of coincidental or viral-related MN needs to be investigated further.
Cicalese PA, Rizvi SA, Wang V, et al., 2021, MorphSet: Improving Renal Histopathology Case Assessment Through Learned Prognostic Vectors, International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), Publisher: SPRINGER INTERNATIONAL PUBLISHING AG, Pages: 319-328, ISSN: 0302-9743
Naesens M, Haas M, Loupy A, et al., 2020, Does the definition of chronic active T cell-mediated rejection need revisiting?, AMERICAN JOURNAL OF TRANSPLANTATION, Vol: 21, Pages: 1689-1690, ISSN: 1600-6135
- Author Web Link
- Citations: 2
Dattani R, Corbett RW, Galliford J, et al., 2020, The Effect of Kidney Biopsy on Glomerular Filtration Rate: A Frequent Patient Concern, AMERICAN JOURNAL OF NEPHROLOGY, Vol: 51, Pages: 903-906, ISSN: 0250-8095
- Author Web Link
- Citations: 1
Roufosse C, Drachenberg C, Renaudin K, et al., 2020, Molecular assessment of antibody-mediated rejection in human pancreas allograft biopsies, Clinical Transplantation, Vol: 34, Pages: 1-13, ISSN: 0902-0063
Pancreas transplant longevity is limited by immune rejection, which is diagnosed by graft biopsy using the Banff Classification. The histological criteria for antibody-mediated rejection (AMR) are poorly reproducible and inconsistently associated with outcome. We hypothesized that a 34-gene set associated with antibody-mediated rejection in other solid organ transplants could improve diagnosis in pancreas grafts. The AMR 34-gene set, comprising endothelial, natural killer cell and inflammatory genes, was quantified using the NanoString platform in 52 formalin-fixed, paraffin-embedded pancreas transplant biopsies from 41 patients: 15 with pure AMR or mixed rejection, 22 with T cell-mediated rejection/borderline and 15 without rejection. The AMR 34-gene set was significantly increased in pure AMR and mixed rejection (P = .001) vs no rejection. The gene set predicted histological AMR with an area under the receiver operating characteristic curve (ROC AUC) of 0.714 (P = .004). The AMR 34-gene set was the only biopsy feature significantly predictive of allograft failure in univariate analysis (P = .048). Adding gene expression to DSA and histology increased ROC AUC for the prediction of failure from 0.736 to 0.770, but this difference did not meet statistical significance. In conclusion, assessment of transcripts has the potential to improve diagnosis and outcome prediction in pancreas graft biopsies.
Tennekoon HD, Kousios A, Gardiner R, et al., 2020, Anticoagulant-related nephropathy in a renal transplant recipient., Kidney International Reports, Vol: 5, Pages: 2089-2096, ISSN: 2468-0249
Neil D, Moran L, Horsfield C, et al., 2020, Ultrastructure of cell trafficking pathways and coronavirus: how to recognise the wolf amongst the sheep, JOURNAL OF PATHOLOGY, Vol: 252, Pages: 346-357, ISSN: 0022-3417
- Author Web Link
- Citations: 10
Toulza F, Dominy K, Cook H, et al., 2020, Technical considerations when designing a gene expression panel for renal transplant diagnosis, Scientific Reports, Vol: 10, ISSN: 2045-2322
Gene expression analysis is emerging as a new diagnostic tool in transplant pathology, in particular for the diagnosis of antibody-mediated rejection. Diagnostic gene expression panels are defined on the basis of their pathophysiological relevance, but also need to be tested for their robustness across different preservatives and analysis platforms. The aim of this study is the investigate the effect of tissue sampling and preservation on candidate genes included in a renal transplant diagnostic panel. Using the NanoString platform, we compared the expression of 219 genes in 51 samples, split for formalin-fixation and paraffin-embedding (FFPE) and RNAlater preservation (RNAlater). We found that overall, gene expression significantly correlated between FFPE and RNAlater samples. However, at the individual gene level, 46 of the 219 genes did not correlate across the 51 matched FFPE and RNAlater samples. Comparing gene expression results using NanoString and qRT-PCR for 18 genes in the same pool of RNA (RNAlater), we found a significant correlation in 17/18 genes. Our study indicates that, in samples from the same routine diagnostic renal transplant biopsy procedure split for FFPE and RNAlater, 21% of 219 genes of potential biological significance do not correlate in expression. Whether this is due to fixatives or tissue sampling, selection of gene panels for routine diagnosis should take this information into consideration.
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