Expression of Class II Human Leukocyte Antigens on Human Endothelial Cells Shows High Interindividual and Intersubclass Heterogeneity.

SIGNIFICANCE STATEMENT: Donor-specific antibodies against class II HLA are a major cause of chronic kidney graft rejection. Nonetheless, some patients presenting with these antibodies remain in stable histological and clinical condition. This study describes the use of endothelial colony-forming cell lines to test the hypothesis of the heterogeneous expression of HLA molecules on endothelial cells in humans. Flow cytometry and immunofluorescence staining revealed substantial interindividual and interlocus variability, with HLA-DQ the most variable. Our data suggest that the expression of HLA class II is predicted by locus. The measurement of endothelial expression of HLA class II in the graft could present a novel paradigm in the evaluation of the alloimmune risk in transplantation and certain diseases. BACKGROUND: HLA antigens are important targets of alloantibodies and allospecific T cells involved in graft rejection. Compared with research into understanding alloantibody development, little is known about the variability in expression of their ligands on endothelial cells. We hypothesized individual variability in the expression of HLA molecules. METHODS: We generated endothelial colony forming cell lines from human peripheral blood mononuclear cells ( n =39). Flow cytometry and immunofluorescence staining were used to analyze the cells, and we assessed the relationship between HLA-DQ expression and genotype. Two cohorts of kidney transplant recipients were analyzed to correlate HLA-DQ mismatches with the extent of intragraft microvascular injury. RESULTS: Large variability was observed in the expression of HLA class II antigens, not only between individuals but also between subclasses. In particular, HLA-DQ antigens had a low and heterogeneous expression, ranging from 0% to 85% positive cells. On a within-patient basis, this expression was consistent between endothelial cell colonies and antigen-presenting cells. HLA-DQ5 and -DQ6 were associated with higher levels of expression, whereas HLA-DQ7, -DQ8, and -DQ9 with lower. HLA-DQ5 mismatches among kidney transplant recipients were associated with significant increase in graft microvascular. CONCLUSION: These data challenge the current paradigm that HLA antigens, in particular HLA class II, are a single genetic and post-translational entity. Understanding and assessing the variability in the expression of HLA antigens could have clinical monitoring and treatment applications in transplantation, autoimmune diseases, and oncology.

Association of HLA Typing and Alloimmunity With Posttransplantation Membranous Nephropathy: A Multicenter Case Series.

RATIONALE & OBJECTIVES: Posttransplantation membranous nephropathy (MN) represents a rare complication of kidney transplantation that can be classified as recurrent or de novo. The clinical, pathologic, and immunogenetic characteristics of posttransplantation MN and the differences between de novo and recurrent MN are not well understood. STUDY DESIGN: Multicenter case series. SETTING & PARTICIPANTS: We included 77 patients from 5 North American and European medical centers with post-kidney transplantation MN (27 de novo and 50 recurrent). Patients with MN in the native kidney who received kidney allografts but did not develop recurrent MN were used as nonrecurrent controls (n = 43). To improve understanding of posttransplantation MN, we compared de novo MN with recurrent MN and then contrasted recurrent MN with nonrecurrent controls. FINDINGS: Compared with recurrent MN, de novo MN was less likely to be classified as primary MN (OR, 0.04; P < 0.001) and had more concurrent antibody-mediated rejection (OR, 12.0; P < 0.001) and inferior allograft survival (HR for allograft failure, 3.2; P = 0.007). HLA-DQ2 and HLA-DR17 antigens were more common in recipients with recurrent MN compared with those with de novo MN; however, the frequency of these recipient antigens in recurrent MN was similar to that in nonrecurrent MN controls. Among the 93 kidney transplant recipients with native kidney failure attributed to MN, older recipient age (HR per each year older, 1.03; P = 0.02), recipient HLA-A3 antigen (HR, 2.5; P = 0.003), steroid-free immunosuppressive regimens (HR, 2.84; P < 0.001), and living related allograft (HR, 1.94; P = 0.03) were predictors of MN recurrence. LIMITATIONS: Retrospective case series, limited sample size due to rarity of the disease, nonstandardized nature of data collection and biopsies. CONCLUSIONS: De novo and recurrent MN likely represent separate diseases. De novo MN is associated with humoral alloimmunity and guarded outcome. Potential predisposing factors for recurrent MN include recipients who are older, recipient HLA-A3 antigen, steroid-free immunosuppressive regimen, and living related donor kidney.

Congophilic Fibrillary Glomerulonephritis: A Case Series.

RATIONALE & OBJECTIVE: Congo Red positivity with birefringence under polarized light has traditionally permitted classification of organized glomerular deposits as from amyloid or nonamyloid diseases. The absence of congophilia has been used to differentiate fibrillary glomerulonephritis (GN) from amyloidosis. We describe a series of fibrillary GN cases in which the deposits are Congo Red-positive (congophilic fibrillary GN) and discuss the role of DNAJB9 in distinguishing congophilic fibrillary GN from amyloidosis. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: Analysis of the clinicopathologic characteristics of 18 cases of congophilic fibrillary GN. Mass spectrometry was performed and compared with 24 cases of Congo Red-negative fibrillary GN, 145 cases of amyloidosis, and 12 apparently healthy individuals. DNAJB9 immunohistochemistry was obtained for a subset of cases. RESULTS: The proteomic signature of amyloid was not detected using mass spectrometry among cases of congophilic fibrillary GN. DNAJB9, a recently discovered proteomic marker for fibrillary GN, was detected using mass spectrometry in all cases of fibrillary GN regardless of congophilia and was absent in cases of amyloidosis and in healthy individuals. DNAJB9 immunohistochemistry confirmed the mass spectrometry findings. The congophilic fibrillary GN cases included 11 men and 7 women with a mean age at diagnosis of 65 years. Concomitant monoclonal gammopathy, hepatitis C virus infection, malignancy, or autoimmune disease was present in 35%, 22%, 17%, and 11% of patients, respectively. No patient had evidence of extrarenal amyloidosis. Patients presented with proteinuria (100%), nephrotic syndrome (47%), hematuria (78%), and chronic kidney disease (83%). After a mean follow-up of 23 months, 31% of patients progressed to end-stage kidney disease and the remaining 69% had persistently reduced kidney function. LIMITATIONS: Retrospective nature. Blinded pathology evaluations were not performed. CONCLUSIONS: The congophilic properties of organized fibrillary deposits should not be solely relied on in differentiating fibrillary GN from renal amyloidosis. Mass spectrometry and DNAJB9 immunohistochemistry can be useful in making this distinction.

IL-6 production by monocytes is associated with graft function decline in patients with borderline changes suspicious for acute T-cell-mediated rejection: a pilot study.

Although borderline changes (BL) suspicious for acute T-cell-mediated rejection represent a diagnostic category, its clinical relevance is questioned leading to heterogeneous therapeutic management. We hypothesized that measuring IL-6 secretion by peripheral blood mononuclear cells identifies patients with ongoing graft damage. We examined the association between secreted IL-6 and the change in estimated glomerular filtration rate at 6 months after the biopsy (ΔeGFR). We then conducted phenotypic and functional studies on patient and mouse innate immune cells in the blood and the kidney. In a training set, ΔeGFR was strongly associated with IL-6 levels, showing a clinically meaningful decline of 4.6 ± 1.5 ml/min per increase in log10 IL-6 (P = 0.001). These results were consistent after adjustment and were reproduced in a validation cohort. Phenotyping of peripheral blood cells revealed that the main source of IL-6 was CD14+ CD16- CCR2+ HLA-DR+ CD86+ CD11c+ inflammatory monocytes. There was a significant correlation between IL-6 secretion and interstitial dendritic cell density in the biopsy. Finally, characterization of mouse kidney dendritic cells revealed that they share features with macrophages and function as effector cells secreting IL-6. In conclusion, measuring IL-6 secreted by peripheral blood cells can be useful in the management of patients with BL in the absence of a concurrent inflammatory condition.

Higher calcineurin inhibitor levels predict better kidney graft survival in patients with de novo donor-specific anti-HLA antibodies: a cohort study.

The development of de novo anti-HLA donor-specific antibodies (dnDSA) is associated with poorer outcomes in kidney transplant recipients. Despite this, antibody screening post-transplant is not widespread, largely because the optimal management of patients with dnDSA remains undetermined. We hypothesized that in this population, calcineurin inhibitor blood levels would be an independent predictor of graft loss. We analyzed a cohort of unsensitized patients for whom anti-HLA antibody screening was performed prospectively post-transplant. During the screening period between January 2005 and April 2016, 42 patients developed dnDSA. There was no difference in the clinical characteristics or the histological scores of patients biopsied for clinical indication versus those biopsied solely due to detection of dnDSA. Cox modeling revealed a strong relationship between mean tacrolimus levels following dnDSA detection and graft loss, with a hazard ratio of 0.49 (95% CI, 0.33-0.75), which persisted following adjustment for established independent predictors (HR, 0.52, 95% CI, 0.30-0.89). Kaplan-Meier analysis by tertiles of tacrolimus levels and receiver operating curve analysis concurred to show that a threshold of 5.3 ng/ml could be predictive of graft loss. These data suggest that anti-HLA antibody monitoring post-transplant could guide maintenance immunosuppression and improve graft outcomes.

X-linked Alport syndrome presenting in mother and son with the same unique histopathological features.

Alport syndrome has been linked to three different genes, that is, COL4A3, COL4A4 and COL4A5. It is characterized by progressive and non-specific glomerulosclerosis with irregular thickening of the glomerular basement membrane (GBM). At times, the histopathologic picture is dominated by lesions that are consistent with focal and segmental glomerulosclerosis or IgA nephropathy. Here, we report the cases of two related individuals (mother and son) who were diagnosed with COL4A5-related Alport syndrome due to a missense variant (p.Gly1170Ser) in a G-X-Y repeat and found to present the same highly unusual histopathological abnormalities on their kidney biopsies. One of the abnormalities shared, which does not appear to have been reported, was reduced COL4A5 immunolabeling that was limited to Bowman's capsule even though the ultrastructure of the GBM was distorted. The other abnormality was superimposed segmental IgA deposition in both individuals, accompanied by mesangial changes in the mother. We feel that these findings provide novel insight into the mechanisms of disease manifestation in Alport syndrome. They suggest, in particular, that collagen expression and/or assemblies in Bowman's capsule is more vulnerable to missense mutations in COL4A5 than elsewhere in the kidney. Our findings also suggest that certain coinherited gene polymorphisms act as unexpectedly important phenotypic determinants in COL4A-related disorders.

T follicular helper cells expansion in transplant recipients correlates with graft infiltration and adverse outcomes.

Introduction: The process of immunization following vaccination in humans bears similarities to that of immunization with allografts. Whereas vaccination aims to elicit a rapid response, in the transplant recipient, immunosuppressants slow the immunization to alloantigens. The induction of CD4+CXCR5+ T follicular helper (Tfh) cells has been shown to correlate with the success of vaccine immunization. Method: We studied a cohort of 65 transplant recipients who underwent histological evaluation concurrent with PBMC isolation and follow-up sampling to investigate the phenotypic profiles in the blood and allotissue and analyze their association with clinical events. Results: The proportion of circulating Tfh cells was heterogeneous over time. Patients in whom this compartment increased had lower CCR7-PD1+CD4+CXCR5+ T cells during follow-up. These patients exhibited more alloreactive CD4+ T cells using HLA-DR-specific tetramers and a greater proportion of detectable circulating plasmablasts than the controls. Examination of baseline biopsies revealed that expansion of the circulating Tfh compartment did not follow prior intragraft leukocyte infiltration. However, multicolor immunofluorescence microscopy of the grafts showed a greater proportion of CXCR5+ T cells than in the controls. CD4+CXCR5+ cells were predominantly PD1+ and were in close contact with B cells in situ. Despite clinical stability at baseline, circulating Tfh expansion was associated with a higher risk of a composite of anti-HLA donor-specific antibodies, rejection, lower graft function, or graft loss. Conclusion: In otherwise stable patients post-transplant, circulating Tfh expansion can identify ongoing alloreactivity, detectable before allograft injury. Tfh expansion is relevant clinically because it predicts poor graft prognosis. These findings have implications for immune surveillance.

The estrogen signaling pathway reprograms prostate cancer cell metabolism and supports proliferation and disease progression.

Just like the androgen receptor (AR), the estrogen receptor α (ERα) is expressed in the prostate and is thought to influence prostate cancer (PCa) biology. Yet the incomplete understanding of ERα functions in PCa hinders our ability to fully comprehend its clinical relevance and restricts the repurposing of estrogen-targeted therapies for the treatment of this disease. Using 2 human PCa tissue microarray cohorts, we first demonstrate that nuclear ERα expression was heterogeneous among patients, being detected in only half of the tumors. Positive nuclear ERα levels were correlated with disease recurrence, progression to metastatic PCa, and patient survival. Using in vitro and in vivo models of the normal prostate and PCa, bulk and single-cell RNA-Seq analyses revealed that estrogens partially mimicked the androgen transcriptional response and activated specific biological pathways linked to proliferation and metabolism. Bioenergetic flux assays and metabolomics confirmed the regulation of cancer metabolism by estrogens, supporting proliferation. Using cancer cell lines and patient-derived organoids, selective estrogen receptor modulators, a pure anti-estrogen, and genetic approaches impaired cancer cell proliferation and growth in an ERα-dependent manner. Overall, our study revealed that, when expressed, ERα functionally reprogrammed PCa metabolism, was associated with disease progression, and could be targeted for therapeutic purposes.

Pembrolizumab-Induced Anti-GBM Glomerulonephritis: A Case Report.

Immune checkpoint inhibitors are known to have a wide range of autoimmune toxicities, such as acute interstitial nephritis. Immunotherapy induced glomerulonephritis has been described, but anti-glomerular basement membrane disease (anti-GBM) is rarely reported. We present a case report of a 60-year-old woman with squamous cell carcinoma of the cervix who was treated with pembrolizumab, an anti-programmed cell death protein 1, and who developed severe acute kidney injury 4 months after therapy initiation. The immune workup showed a positive serum anti-GBM antibody (24 U/mL). The kidney biopsy showed crescentic glomerulonephritis with linear immunoglobulin G2 glomerular basement membrane staining, compatible with anti-GBM glomerulonephritis. The patient was treated with plasmapheresis, IV steroids, and cyclophosphamide, but she developed kidney failure, necessitating dialysis. Few case reports, such as the present case, provide a possible link between anti-GBM glomerulonephritis and immune checkpoint inhibitors, warranting early clinical suspicion and investigation in patients who are treated with these agents and subsequently develop acute kidney injury.

The ever wider clinical spectrum of RMND1-related disorders and limitedness of phenotype-based classifications.

RMND1 has been identified as a mitochondriopathy-associated gene less than 12 years ago. The most common phenotype related to this gene is an early onset, severe form of encephalomyopathy that leads to death in a medium time of three years after birth. However, milder and later onset presentations have been reported in some individuals, including two in whom the mitochondriopathy was identified at ~ 40 years of age, and the early onset presentations have been the object of no reports in those who survived beyond age 10. It is thus unclear how lethal RMND1-related conditions really are. We herein describe the oldest case to have been identified hitherto with this condition, i.e., that of a white female who was 61 at the time of diagnosis but was still active in her everyday life. The gene defect identified was nonetheless associated with many manifestations including ovarian insufficiency and sensorineural hearing loss (two features of what is currently designated as Perrault syndrome) as well as chronic renal failure, asymptomatic myopathy, leukopenia, and a few others. In our opinion, this case is of great translational interest for at least three reasons. First, it hints towards the possibility of near-normal life expectancies in some if not many individuals with RMND1 insufficiency. Second, it underlines the wide clinical spectrum associated with this gene. Third, it brings us to question the use of eponyms and syndromic features to identify the true etiology of multisystemic phenotypes. KEY MESSAGES: RMND1-related conditions typically manifest at an early age with a progressive and lethal form of encephalomyopathy. More benign presentations have been described with some being categorized as Perrault syndrome but none have been diagnosed after the age of 45. The clinical spectrum and presenting age of RMND1-related mitochondriopathies are probably much more varied than implied in the current literature. The case reported in this manuscript illustrates the limitedness of phenotype-based classifications of genetic disorders to identify the defect at cause.

Isocitrate dehydrogenase 1 sustains a hybrid cytoplasmic-mitochondrial tricarboxylic acid cycle that can be targeted for therapeutic purposes in prostate cancer.

The androgen receptor (AR) is an established orchestrator of cell metabolism in prostate cancer (PCa), notably by inducing an oxidative mitochondrial program. Intriguingly, AR regulates cytoplasmic isocitrate dehydrogenase 1 (IDH1), but not its mitochondrial counterparts IDH2 and IDH3. Here, we aimed to understand the functional role of IDH1 in PCa. Mouse models, in vitro human PCa cell lines, and human patient-derived organoids (PDOs) were used to study the expression and activity of IDH enzymes in the normal prostate and PCa. Genetic and pharmacological inhibition of IDH1 was then combined with extracellular flux analyses and gas chromatography-mass spectrometry for metabolomic analyses and cancer cell proliferation in vitro and in vivo. In PCa cells, more than 90% of the total IDH activity is mediated through IDH1 rather than its mitochondrial counterparts. This profile seems to originate from the specialized prostate metabolic program, as observed using mouse prostate and PDOs. Pharmacological and genetic inhibition of IDH1 impaired mitochondrial respiration, suggesting that this cytoplasmic enzyme contributes to the mitochondrial tricarboxylic acid cycle (TCA) in PCa. Mass spectrometry-based metabolomics confirmed this hypothesis, showing that inhibition of IDH1 impairs carbon flux into the TCA cycle. Consequently, inhibition of IDH1 decreased PCa cell proliferation in vitro and in vivo. These results demonstrate that PCa cells have a hybrid cytoplasmic-mitochondrial TCA cycle that depends on IDH1. This metabolic enzyme represents a metabolic vulnerability of PCa cells and a potential new therapeutic target.

A transcriptional biosensor to monitor single cancer cell therapeutic responses by bioluminescence microscopy.

When several life-prolonging drugs are indicated for cancer treatment, predictive drug-response tumor biomarkers are essential to guide management. Most conventional biomarkers are based on bulk tissue analysis, which cannot address the complexity of single-cell heterogeneity responsible for drug resistance. Therefore, there is a need to develop alternative drug response predictive biomarker approaches that could directly interrogate single-cell and whole population cancer cell drug sensitivity. In this study, we report a novel method exploiting bioluminescence microscopy to detect single prostate cancer (PCa) cell response to androgen receptor (AR)-axis-targeted therapies (ARAT) and predict cell population sensitivity. Methods: We have generated a new adenovirus-delivered biosensor, PCA3-Cre-PSEBC-ITSTA, which combines an integrated two-step transcriptional amplification system (ITSTA) and the activities of the prostate cancer antigen 3 (PCA3) and modified prostate-specific antigen (PSEBC) gene promoters as a single output driving the firefly luciferase reporter gene. This system was tested on PCa cell lines and on primary PCa cells. Single cells, exposed or not to ARAT, were dynamically imaged by bioluminescence microscopy. A linear discriminant analysis (LDA)-based method was used to determine cell population sensitivities to ARAT. Results: We show that the PCA3-Cre-PSEBC-ITSTA biosensor is PCa-specific and can dynamically monitor single-cell AR transcriptional activity before and after ARAT by bioluminescence microscopy. After biosensor transduction and bioluminescence microscopy single-cell luminescence dynamic quantification, LDA analysis could discriminate the cell populations overall ARAT sensitivity despite heterogeneous single-cell responses. Indeed, the biosensor could detect a significant decrease in AR activity following exposure to conventional ARAT in hormone-naive primary PCa cells, while in castration-resistant PCa patients, treatment response correlated with the observed clinical ARAT resistance. Conclusion: The exploitation of bioluminescence microscopy and multi-promoter transcriptionally-regulated biosensors can aptly define the overall treatment response of patients by monitoring live single cell drug response from primary cancer tissue. This approach can be used to develop predictive biomarkers for drug response in order to help clinicians select the best drug combinations or sequences for each patient.

The Progression of Interstitial Fibrosis and Tubular Atrophy at 6 Months Is an Independent Predictor of Poor Graft Outcomes in Kidney Transplant Recipients.

Interstitial fibrosis and tubular atrophy (IFTA) found on 1-y surveillance biopsies has been associated with poor graft outcomes. However, its progression over time and relationship to outcomes are less well defined. Methods: We studied implantation and 6-mo surveillance biopsies and examined the association between the progression of IFTA (ΔIFTA) and a composite of censored graft loss or doubling of serum creatinine in 248 adult kidney recipients. Results: The percentage of patients with ΔIFTA of 1 or ≥2 was 35% and 22%, respectively. Positive ΔIFTA was a risk factor for the composite endpoint (hazard ratio, 1.36; 95% confidence interval, 1.03-1.79). This estimate was robust to adjustment for recipient and donor baseline characteristics, baseline IFTA, tacrolimus levels, and rejection status. ΔIFTA was associated with decreased estimated glomerular filtration rate at 3 and 5 y. IFTA+i was a predictor in the cohort; however, IFTA progression was not limited to those with a mononuclear cell interstitial inflammation (Banff "i") score above zero. Notably, donor age was a predictor of IFTA at 6 mo, but not of ΔIFTA, whereas rejection, donor diabetes, and recipient smoking status were. Conclusions: Progression of IFTA at 6 mo can predict outcomes. ΔIFTA was not related to donor age but may be linked to other risk factors influencing decision-making for donor versus recipient selection.

ETA receptors are present in human aortic vascular endothelial cells and modulate intracellular calcium.

Using immunofluorescence and real 3-D confocal microscopy, our results showed the presence of ET-1, ETA, and ETB receptors in isolated human aortic vascular endothelial cells (hVECs). The level of the peptide and its receptors was significantly higher in the nucleus (including the nuclear envelope membranes) than in the cytosol (including the cell membrane). Furthermore, using the Western blot technique we demonstrated the presence of both ETA and ETB receptors. Using intact and isolated human hVECs and the Fura-2 calcium (Ca2+) measurement technique, we showed that ET-1 induced a dose-dependent increase of total intracellular free Ca2+, with an EC50 of 1.3 x 10-10 mol/L. The specific ETA receptor antagonist ABT-627 (10-7 mol/L), but not the ETB receptor antagonist A-192621 (10-7 mol/L), prevented the ET-1 (10-9 mol/L) induced increase of total intracellular Ca2+. In conclusion, these results clearly show that similar to ETB receptors, ETA receptors are also present in human aortic vascular endothelial cells and their levels are higher than ETB in the nucleus when compared with the cytosol. Furthermore, we suggest that ETA, but not ETB, receptors mediate the effect of ET-1 on total intracellular Ca2+ of human aortic vascular endothelial cells.

GLUT1 expression in high-risk prostate cancer: correlation with 18F-FDG-PET/CT and clinical outcome.

BACKGROUND: Tumour 18F-FDG-uptake is of prognostic value in high-risk and metastatic prostate cancer (PCa). The aim of this study is to investigate the underlying glucose metabolism mechanisms of 18F-FDG-uptake on PET/CT imaging in PCa. METHODS: Retrospective analysis was conducted for 94 patients diagnosed with a Gleason sum ≥8 adenocarcinoma of the prostate at biopsy between July 2011 and July 2014 who underwent 18F-FDG-PET/CT imaging before radical prostatectomy (RP). 18F-FDG-uptake in primary lesion was measured by a blinded reader using maximum standardised uptake value (SUVmax). GLUT1, GLUT12 and HK2 expression were blindly scored after immunohistochemistry on specimens RP by three pathologists. Correlations between GLUT1, GLUT12 and HK2, and SUVmax were assessed using Spearman's rank correlation test. Survival probabilities were based on the Kaplan-Meier method. RESULTS: With a median follow-up of 4.5 years, 56% (n = 53) of patients had biochemical recurrence (BCR), 7% (n = 7) progressed to castration-resistant prostate cancer (CRPC) disease, 13% (n = 12) developed metastasis and 6% (n = 6) died. Correlation was found between GLUT1 expression and SUVmax level (r = 0.25, p = 0.02). In addition, SUVmax was significantly higher in tumours with high GLUT1 expression (n = 17, 5.74 ± 1.67) than tumours with low GLUT1 expression (n = 71, 2.68 ± 0.31, p = 0.004). Moreover, a significant association was found between GLUT1 expression levels and SUVmax level (p = 0.005), lymph node status (p = 0.05), volume of cancer (p = 0.01), CRPC disease progression (p = 0.02) and metastasis development (p = 0.04). No significant difference between GLUT12 and HEX2 expression and SUVmax have been found. CONCLUSIONS: GLUT1 expression in PCa tumours correlates with 18F-FDG-uptake and poor prognostic factors. These results suggest that this transporter is involved in the molecular mechanism of 18F-FDG-uptake in high-risk PCa and raise interest in targeting metabolic dependencies of PCa cells as a selective anticancer strategy.

Linezolid-associated acute interstitial nephritis and drug rash with eosinophilia and systemic symptoms (DRESS) syndrome.

Linezolid is a recent addition to the antibiotic armamentarium against Gram-positive bacteria, including multiresistant staphylococci and enterococci. Linezolid is relatively well tolerated and is not believed to be nephrotoxic. However, we report the case of an 88-year-old woman who was treated for prosthetic joint infection and methicillin-resistant Staphylococcus aureus bacteremia with vancomycin followed by linezolid therapy. On day 7 of linezolid treatment, the patient developed severe pruritus, macular rash, facial edema, eosinophilia, marked increase in serum creatinine level, and mild hepatitis. Renal biopsy showed acute interstitial nephritis with eosinophilic cells. Discontinuation of linezolid and a short course of prednisone led to rapid improvement of renal function. This case of linezolid-associated acute interstitial nephritis within the context of a drug rash with eosinophilia and systemic symptoms (DRESS) syndrome in a patient treated with linezolid raises concerns about the presumed renal safety of this drug. Clinicians should be aware of this potential life-threatening adverse reaction and monitor kidney function while patients are using linezolid.

Allogeneic dendritic cells stimulated with antibodies against HLA class II polarize naive T cells in a follicular helper phenotype.

Follicular helper T cells (Tfh) are crucial for the production of high-affinity antibodies, such as alloantibodies, by providing the signals for B-cell proliferation and differentiation. Here, we demonstrate that human allogeneic dendritic cells (DC) stimulated with antibodies against HLA class II antigens preferentially differentiate human naive CD4+ T cells into Tfh cells. Following coculture with DCs treated with these antibodies, CD4+ T cells expressed CXCR5, ICOS, IL-21, Bcl-6 and phosphorylated STAT3. Blockade of IL-21 abrogated Bcl-6, while addition of the IL-12p40 subunit to the coculture increased CXCR5, Bcl-6, phosphorylated STAT3 and ICOS, indicating that they were both involved in Tfh polarization. We further phenotyped the peripheral T cells in a cohort of 55 kidney transplant recipients. Patients with anti-HLA-II donor-specific antibodies (DSA) presented higher blood counts of circulating Tfh cells than those with anti-HLA-I DSAs. Moreover, there was a predominance of lymphoid aggregates containing Tfh cells in biopsies from patients with antibody-mediated rejection and anti-HLA-II DSAs. Collectively, these data suggest that alloantibodies against HLA class II specifically promote the differentiation of naive T cells to Tfh cells following contact with DCs, a process that might appear in situ in human allografts and constitutes a therapeutic target.

Impact of the Current Versus the Previous Diagnostic Threshold on the Outcome of Patients With Borderline Changes Suspicious for T Cell-mediated Rejection Diagnosed on Indication Biopsies.

BACKGROUND: Since the borderline changes suspicious for acute T cell-mediated rejection (BL) category was broadened, there has been a debate regarding the right threshold for tubulitis and interstitial inflammation scores. METHODS: We studied a first cohort of 111 patients with BL found on an indication biopsy between 2006 and 2016 and compared those with scores of t1i0 (BLt1i0) to those with higher scores (BL≥t1i1). A second cohort of 56 patients with BL was used for external validation. We used a composite endpoint of death-censored graft failure or doubling of the serum creatinine level postbiopsy. RESULTS: In the first cohort, 68% (75/111) of the BL cases fell in the BLt1i0 group. At 5 years, the occurrence of the composite endpoint was 5% and 14% for BLt1i0 and BL≥t1i1, respectively. In contrast, the endpoint occurred in 5% of nonrejectors and 21% of patients with T cell-mediated rejection. In the validation cohort, 8% versus 36% of BLt1i0 and BL≥t1i1 reached the endpoint, respectively. Multivariable Cox modeling revealed that BLt1i0 patients had a prognosis similar to that of nonrejectors (adjusted hazard ratio, 0.6; 95% confidence interval, 0.1-2.2; P = 0.40) but better than that of patients with BL≥t1i1 (hazard ratio, 3.8; 95% confidence interval, 1.3-11.5; P = 0.02). Sensitivity analyses restricted to death-censored graft loss or using time posttransplant as the time of reference provided similar results. CONCLUSIONS: In summary, patients with BLt1i0 have a different prognosis to that of BL≥t1i1 patients, which brings into question the current diagnostic thresholds.