Tenofovir-Induced Fanconi Syndrome Presenting with Life-Threatening Hypokalemia: Review of the Literature and Recommendations for Early Detection.

Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor that has been widely used for the treatment of patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. However, in the HBV monoinfection scenario, only five cases of TDF-associated Fanconi syndrome have been reported thus far, two of them providing a confirmatory kidney biopsy. Here, we describe the case of a 68-year-old woman with chronic hepatitis B (CHB) who developed TDF-induced Fanconi syndrome that reverted after TDF withdrawal from tenofovir alafenamide. Though the overall risk of TDF-associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular functions should be monitored in patients exposed to TDF.

Increase of HO-1 Expression in Critically Ill COVID-19 Patients Is Associated with Poor Prognosis and Outcome.

Heme-oxygenase (HO)-1 is a cytoprotective enzyme with strong antioxidant and anti-apoptotic properties and previous reports have also emphasized the antiviral properties of HO-1, either directly or via induction of interferons. To investigate the potential role of HO-1 in patients with coronavirus disease 2019 (COVID-19), the present study assessed changes in HO-1 expression in whole blood and tissue samples. Upregulation of HO-1 protein was observed in lung, liver, and skin tissue independently of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) presence. A significant increase of blood HO-1 mRNA levels was observed in critically ill COVID-19 patients compared to those in severe COVID-19 patients and healthy controls. This increase was accompanied by significantly elevated levels of serum ferritin and bilirubin in critically ill compared to patients with severe disease. Further grouping of patients in survivors and non-survivors revealed a significant increase of blood HO-1 mRNA levels in the later. Receiver operating characteristic (ROC) analysis for prediction of ICU admission and mortality yielded an AUC of 0.705 (p = 0.016) and 0.789 (p = 0.007) respectively indicating that HO-1 increase is associated with poor COVID-19 progression and outcome. The increase in HO-1 expression observed in critically ill COVID-19 patients could serve as a mechanism to counteract increased heme levels driving coagulation and thrombosis or as an induced protective mechanism.

Histone Deacetylase (HDAC) Inhibitors: A Promising Weapon to Tackle Therapy Resistance in Melanoma.

Melanoma is an aggressive malignant tumor, arising more commonly on the skin, while it can also occur on mucosal surfaces and the uveal tract of the eye. In the context of the unresectable and metastatic cases that account for the vast majority of melanoma-related deaths, the currently available therapeutic options are of limited value. The exponentially increasing knowledge in the field of molecular biology has identified epigenetic reprogramming and more specifically histone deacetylation (HDAC), as a crucial regulator of melanoma progression and as a key driver in the emergence of drug resistance. A variety of HDAC inhibitors (HDACi) have been developed and evaluated in multiple solid and hematologic malignancies, showing promising results. In melanoma, various experimental models have elucidated a critical role of histone deacetylases in disease pathogenesis. They could, therefore, represent a promising novel therapeutic approach for advanced disease. A number of clinical trials assessing the efficacy of HDACi have already been completed, while a few more are in progress. Despite some early promising signs, a lot of work is required in the field of clinical studies, and larger patient cohorts are needed in order for more valid conclusions to be extracted, regarding the potential of HDACi as mainstream treatment options for melanoma.

Validation of the International IgA Nephropathy Prediction Tool in the Greek Registry of IgA Nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) is among the commonest glomerulonephritides in Greece and an important cause of end-stage kidney disease (ESKD) with an insidious chronic course. Thus, the recently published International IgAN prediction tool could potentially provide valuable risk stratification and guide the appropriate treatment module. This study aimed to externally validate this prediction tool using a patient cohort from the IgAN registry of the Greek Society of Nephrology. METHODS: We validated the predictive performance of the two full models (with or without race) derived from the International IgAN Prediction Tool study in the Greek Society of Nephrology registry of patients with IgAN using external validation of survival prediction models (Royston and Altman). The discrimination and calibration of the models were tested using the C-statistics and stratified analysis, coefficient of determination ( R D 2 ) for model fit, and the regression coefficient of the linear predictor (ßPI), respectively. RESULTS: The study included 264 patients with a median age of 39 (30-51) years where 65.2% are men. All patients were of Caucasian origin. The 5-year risk of the primary outcome (50% reduction in estimated glomerular filtration rate or ESKD) was 8%. The R D 2 for the full models with and without race when applied to our cohort was 39 and 35%, respectively, and both were higher than the reported R D 2 for the models applied to the original validation cohorts (26.3, 25.3, and 35.3%, respectively). Harrel's C statistic for the full model with race was 0.71, and for the model without race was 0.70. Renal survival curves in the subgroups (<16th, ~16 to <50th, ~50 to <84th, and >84th percentiles of linear predictor) showed adequate separation. However, the calibration proved not to be acceptable for both the models, and the risk probability was overestimated by the model. CONCLUSIONS: The two full models with or without race were shown to accurately distinguish the highest and higher risk patients from patients with low and intermediate risk for disease progression in the Greek registry of IgAN.

Targeted proteomic analysis dataset of archival core human kidney biopsies to investigate the biology of hypertensive nephropathy.

Hypertensive nephropathy is the second most frequent cause of end-stage renal disease in western societies. In previous experiments in our laboratory with proteomic analysis of renal parenchyma of SHR hypertensive animals, we identified two molecules, namely SGLT2 and CLIC4, associated with the development of hypertension. Here, we apply the methodology of targeted proteomic analysis in kidney biopsies from patients with hypertensive nephropathy to study the role of SGLT2 and CLIC4 in the pathogenesis of the disease. Relative quantification data of SGLT2 and CLIC4 via means of targeted proteomic analysis in human kidney biopsies from hypertensive patients and normotensive controls are reported. In addition, validation data of the proteomic results via immunofluorescence are presented. Renal tissue biopsies (N = 17) from archival material of patients with hypertensive nephropathy and normotensive controls were used. Targeted proteomic analysis was performed using the method: ``Parallel Reaction Monitoring'' (PRM) in renal parenchyma of hypertensive and normotensive patients for the selective identification of SGLT2 and CLIC4 and the relative quantification of their expression using proteotypic peptides for each protein. The expression of SGLT2 molecule was also confirmed by immunofluorescence followed by quantification of fluorescence intensity. According to PRM, the SGLT2 protein was found with reduced and the CLIC4 protein with increased expression levels in hypertensive patients compared to normotensive controls. Comparison of representative immunofluorescence images confirmed a decrease in the expression of SGLT2 in the brush border of proximal tubular epithelial cells in hypertensive patients. Our data show changes in the tubular compartment of the kidney and especially in the proximal tubules associated with the hypertensive nephropathy. The clinical significance of these findings should be further explored for the discovery and/or confirmation of novel therapeutic approaches and biomarkers in the development of hypertensive kidney disease.

Immunohistochemical Study of Bladder Cancer Molecular Subtypes and Their Association with PD-L1 Expression.

The significant heterogeneity in clinical outcomes among patients with bladder cancer has highlighted the existence of different biological subtypes of muscle-invasive bladder cancer (MIBC) and non-muscle-invasive bladder cancer (NMIBC). Meanwhile, immune checkpoint proteins and their interference with tumor-related immune-evasive strategies has led to the development of several immunotherapeutic drugs targeting programmed death-1 (PD-1) or programmed death ligand-1 (PD-L1). However, the lack of any known biomarker that could predict responses to immunotherapy has led to a more agnostic therapeutic approach. Here, we present a study conducted in 77 bladder cancer (BC) patients (n = 77), ranging from stages pTa to pT2. Tumor specimens were resected via transurethral resection of bladder tumor (TURBT) and consistuted of 24 low-grade (LG) and 53 high-grade (HG) tumors. Patients' tumors were then categorized into molecular subtypes, via immunohistochemistry (CK5/6 and GATA3). Furthermore, all tumor specimens were stained with anti-PD-L1 and demonstrated significant correlations with basal immunophenotype, stage pT2 and HG tumors. As such, we attempted to stratify patients into groups of likely-responders and likely-not-responders to immunotherapy with anti-PD-L1, based on their molecular phenotype. Finally, in acknowledging the fact that there is a universal lack of biomarkers associated with predicting BC response to immunotherapeutic drugs, we tested all tumors for deficiency of mismatch repair proteins (MMR).

NETs decorated with bioactive IL-33 infiltrate inflamed tissues and induce IFN-α production in patients with SLE.

IL-33, a nuclear alarmin released during cell death, exerts context-specific effects on adaptive and innate immune cells, eliciting potent inflammatory responses. We screened blood, skin, and kidney tissues from patients with systemic lupus erythematosus (SLE), a systemic autoimmune disease driven by unabated type I IFN production, and found increased amounts of extracellular IL-33 complexed with neutrophil extracellular traps (NETs), correlating with severe, active disease. Using a combination of molecular, imaging, and proteomic approaches, we show that SLE neutrophils, activated by disease immunocomplexes, release IL-33-decorated NETs that stimulate robust IFN-α synthesis by plasmacytoid DCs in a manner dependent on the IL-33 receptor ST2L. IL33-silenced neutrophil-like cells cultured under lupus-inducing conditions generated NETs with diminished interferogenic effect. Importantly, NETs derived from patients with SLE are enriched in mature bioactive isoforms of IL-33 processed by the neutrophil proteases elastase and cathepsin G. Pharmacological inhibition of these proteases neutralized IL-33-dependent IFN-α production elicited by NETs. We believe these data demonstrate a novel role for cleaved IL-33 alarmin decorating NETs in human SLE, linking neutrophil activation, type I IFN production, and end-organ inflammation, with skin pathology mirroring that observed in the kidneys.

Replication Protein A (RPA1, RPA2 and RPA3) expression in gastric cancer: correlation with clinicopathologic parameters and patients' survival.

PURPOSE: Replication Protein A (RPA) consists of three subunits (RPA1, RPA2 and RPA3) essential for all major DNA metabolic pathways. Although RPA seems to be a promising therapeutic target, its role in human cancers has not been fully elucidated. This is the first study investigating the expression of all the three RPA subunits in a series of 74 resected gastric carcinomas and analyzing the possible correlations with clinicopathologic parameters (histological type, grade, lymphovascular invasion, lymph node status and disease stage), Ki-67 proliferative index, Topoisomerase IIa expression and patients' survival. METHODS: Immunohistochemistry using monoclonal antibodies. Univariate and multivariate statistical analysis. RESULTS: All the three subunits showed widespread nuclear expressions in gastric carcinomas with significant associations among their expressions. RPA2 demonstrated higher expression levels in low grade carcinomas and a gradual significant decrease from N0 to N3 and from stage I to stage IV carcinomas. All the three subunits were statistical significantly more abundant in lymph node negative and earlier stage (stage I & II) gastric carcinomas. No associations were established among RPAs and the proliferative marker Ki-67. In patients with positive lymph nodes and advanced tumor stage, RPA1 expression seemed to predict a better overall survival implying a probable predictive role. CONCLUSIONS: The widespread expression of RPA(1-3) suggests one or more roles in gastric cancer. Their presence in earlier stage tumors probably offers an opportunity for early targeted therapy. Their probable predictive value in node positive and advanced stage tumors needs further investigation with respect to specific chemotherapeutic treatments.

Podocyte-targeted Heme Oxygenase (HO)-1 overexpression exacerbates age-related pathology in the rat kidney.

Although Heme Oxygenase-1 (HO-1) induction in various forms of kidney injury is protective, its role in age-related renal pathology is unknown. In the ageing kidney there is nephron loss and lesions of focal glomerulosclerosis, interstitial fibrosis, tubular atrophy and arteriolosclerosis. Underlying mechanisms include podocyte (visceral glomerular epithelial cell/GEC) injury. To assess whether HO-1 can attenuate ageing - related lesions, rats with GEC-targeted HO-1 overexpression (GECHO-1 rats) were generated using a Sleeping Beauty (SB) transposon system and extent of lesions over a 12-month period were assessed and compared to those in age-matched wild-type (WT) controls. GECHO-1 rats older than 6 months developed albuminuria that was detectable at 6 months and became significantly higher compared to age-matched WT controls at 12 months. In GECHO-1 rats, lesions of focal segmental and global glomerulosclerosis as well as tubulointerstitial lesions were prominent while podocytes were edematous with areas of foot process effacement and glomerular basement membrane thickening and wrinkling. GECHO-1 rats also developed hemoglobinuria and hemosiderinuria associated with marked tubular hemosiderin deposition and HO-1 induction, while there was depletion of splenic iron stores. Kidney injury was of sufficient magnitude to increase serum lactate dehydrogenase (LDH) and was oxidative in nature as shown by increased expression of 8-hydroxydeoxyguanosine (8-OHdg, a byproduct of oxidative DNA damage) in podocytes and tubular epithelial cells. These observations highlight a detrimental effect of podocyte-targeted HO-1 overexpression on ageing-related renal pathology and point to increased renal iron deposition as a putative underlying mechanism.

Clinical impact of repeat renal biopsies in patients with lupus nephritis: Renal biopsy is essential especially later in the course of the disease.

OBJECTIVE: The clinical impact of repeat renal biopsies in patients with lupus nephritis (LN) is still debatable. The aim of this retrospective analysis was to assess whether repeat renal biopsy is a reliable tool in guiding therapeutic decisions. METHODS: Laboratory and histological parameters and therapeutic changes in 35 patients with LN and repeat renal biopsies were retrospectively analyzed. Biopsies were performed in the presence of clinical evidence of an active glomerular disease. Biopsy specimens were retrospectively re-assessed by two renal pathologists and were compared according to the last International Society of Nephrology/ Renal Pathology Society classification. RESULTS: Thirty-five patients had two, 13 had three, 5 had four, 4 had five, and 1 had six renal biopsies. Fifty-eight comparisons of renal biopsies were made. Median times between the first and second, second and third, third and fourth, and fourth and fifth biopsies were 31, 27, 34, and 28 months, respectively. The mean activity indices from the first to the fifth biopsy were 8.7, 6.6, 7.8, 9.4, and 4.7, whereas the mean chronicity indices were 1.7, 2.3, 4.3, 5.2, and 7.7, respectively. Conversion was observed in 65.5% of cases with the most frequent (21%) being between classes III and IV. Conversion to a more severe type of nephritis occurred in 19% of cases. There was no correlation of laboratory parameters to the type of nephritis upon conversion. In 79% of cases, immunosuppressive therapy was modified after repeat biopsy. CONCLUSION: Repeat biopsy is a reliable tool for monitoring the activity and chronicity status of LN and for tailoring immunosuppressive therapy to the needs of the patient, especially late in the course of the disease.

PLA2R-Negative Membranous Nephropathy Presenting as a Prodrome of IgG4-Related Autoimmune Pancreatitis.

Membranous nephropathy (MN) with tubulointerstitial nephritis (TIN) is an established manifestation of immunoglobulin G4 (IgG4)-related disease (IgG4-RD). A pathological feature aiming to distinguish between primary and secondary MN is the presence or absence of glomerular staining for phospholipase A2 receptor (PLA2R), respectively. Isolated MN without TIN has been rarely reported in the context of IgG4-RD. This case report describes a patient with a history of MN successfully treated with steroids and cyclophosphamide, who, 3 years later, presented with unexplained exacerbation of diabetes mellitus due to IgG4-related autoimmune pancreatitis. Pancreatitis was treated, and diabetes improved after treatment with steroids. Based on the presence of isolated IgG4 glomerular capillary deposits along with negative staining for PLA2R and the metachronous appearance of autoimmune pancreatitis, MN was retrospectively classified as secondary to IgG4-RD. Isolated IgG4-positive/PLA2R-negative MN without TIN can be a prodrome of IgG4-RD, reminiscent of MN secondary to neoplasms.

The P274S Mutation of Lecithin-Cholesterol Acyltransferase (LCAT) and Its Clinical Manifestations in a Large Kindred.

RATIONALE & OBJECTIVE: Lecithin-cholesterol acyltransferase (LCAT) catalyzes the maturation of high-density lipoprotein. Homozygosity for loss-of-function mutations causes familial LCAT deficiency (FLD), characterized by corneal opacities, anemia, and renal involvement. This study sought to characterize kidney biopsy findings and clinical outcomes in a family with FLD. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 2 (related) index patients with clinically apparent FLD were initially identified. 110 of 122 family members who consented to genetic analysis were also studied. PREDICTORS: Demographic and laboratory parameters (including lipid profiles and LCAT activity) and full sequence analysis of the LCAT gene. Kidney histologic examination was performed with samples from 6 participants. OUTCOMES: Cardiovascular and renal events during a median follow-up of 12 years. Estimation of annual rate of decline in glomerular filtration rate. ANALYTICAL APPROACH: Analysis of variance, linear regression analysis, and Fine-Gray competing-risk survival analysis. RESULTS: 9 homozygous, 57 heterozygous, and 44 unaffected family members were identified. In all affected individuals, full sequence analysis of the LCAT gene revealed a mutation (c.820C>T) predicted to cause a proline to serine substitution at amino acid 274 (P274S). Homozygosity caused a complete loss of LCAT activity. Kidney biopsy findings demonstrated lipid deposition causing glomerular basement membrane thickening, mesangial expansion, and "foam-cell" infiltration of kidney tissue. Tubular atrophy, glomerular sclerosis, and complement fixation were associated with worse kidney outcomes. Estimated glomerular filtration rate deteriorated among homozygous family members at an average annual rate of 3.56 mL/min/1.73 m2. The incidence of cardiovascular and renal complications was higher among homozygous family members compared with heterozygous and unaffected members. Mild thrombocytopenia was a common finding among homozygous participants. LIMITATIONS: The presence of cardiovascular disease was mainly based on medical history. CONCLUSIONS: The P274S LCAT mutation was found to cause FLD with renal involvement. Tubular atrophy, glomerular sclerosis, and complement fixation were associated with a worse renal prognosis.

Reproducibility of the Oxford classification of immunoglobulin A nephropathy, impact of biopsy scoring on treatment allocation and clinical relevance of disagreements: evidence from the VALidation of IGA study cohort.

BACKGROUND: The VALidation of IGA (VALIGA) study investigated the utility of the Oxford Classification of immunoglobulin A nephropathy (IgAN) in 1147 patients from 13 European countries. Methods. Biopsies were scored by local pathologists followed by central review in Oxford. We had two distinct objectives: to assess how closely pathology findings were associated with the decision to give corticosteroid/immunosuppressive (CS/IS) treatments, and to determine the impact of differences in MEST-C scoring between central and local pathologists on the clinical value of the Oxford Classification. We tested for each lesion the associations between the type of agreement (local and central pathologists scoring absent, local present and central absent, local absent and central present, both scoring present) with the initial clinical assessment, as well as long-term outcomes in those patients who did not receive CS/IS. RESULTS: All glomerular lesions (M, E, C and S) assessed by local pathologists were independently associated with the decision to administer CS/IS therapy, while the severity of tubulointerstitial lesions was not. Reproducibility between local and central pathologists was moderate for S (segmental sclerosis) and T (tubular atrophy/interstitial fibrosis), and poor for M (mesangial hypercellularity), E (endocapillary hypercellularity) and C (crescents). Local pathologists found statistically more of each lesion, except for the S lesion, which was more frequent with central review. Disagreements were more likely to occur when the proportion of glomeruli affected was low. The M lesion, assessed by central pathologists, correlated better with the severity of the disease at presentation and discriminated better with outcomes. In contrast, the E lesion, evaluated by local pathologists, correlated better with the clinical presentation and outcomes when compared with central review. Both C and S lesions, when discordant between local and central pathologists, had a clinical phenotype intermediate to double absent lesions (milder disease) and double present (more severe). CONCLUSION: We conclude that differences in the scoring of MEST-C criteria between local pathologists and a central reviewer have a significant impact on the prognostic value of the Oxford Classification. Since the decision to offer immunosuppressive therapy in this cohort was intimately associated with the MEST-C score, this study indicates a need for a more detailed guidance for pathologists in the scoring of IgAN biopsies.

REDD1/autophagy pathway promotes thromboinflammation and fibrosis in human systemic lupus erythematosus (SLE) through NETs decorated with tissue factor (TF) and interleukin-17A (IL-17A).

OBJECTIVES: The release of neutrophil extracellular traps (NETs) represents a novel neutrophil effector function in systemic lupus erythematosus (SLE) pathogenesis. However, the molecular mechanism underlying NET release and how NETs mediate end-organ injury in SLE remain elusive. METHODS: NET formation and NET-related proteins were assessed in the peripheral blood and biopsies from discoid lupus and proliferative nephritis, using immunofluorescence, immunoblotting, quantitative PCR and ELISA. Autophagy was assessed by immunofluorescence and immunoblotting. The functional effects of NETs in vitro were assessed in a primary fibroblast culture. RESULTS: Neutrophils from patients with active SLE exhibited increased basal autophagy levels leading to enhanced NET release, which was inhibited in vitro by hydroxychloroquine. NETosis in SLE neutrophils correlated with increased expression of the stress-response protein REDD1. Endothelin-1 (ET-1) and hypoxia-inducible factor-1α (HIF-1α) were key mediators of REDD1-driven NETs as demonstrated by their inhibition with bosentan and L-ascorbic acid, respectively. SLE NETs were decorated with tissue factor (TF) and interleukin-17A (IL-17A), which promoted thrombin generation and the fibrotic potential of cultured skin fibroblasts. Notably, TF-bearing and IL-17A-bearing NETs were abundant in discoid skin lesions and in the glomerular and tubulointerstitial compartment of proliferative nephritis biopsy specimens. CONCLUSIONS: Our data suggest the involvement of REDD1/autophagy/NET axis in end-organ injury and fibrosis in SLE, a likely candidate for repositioning of existing drugs for SLE therapy. Autophagy-mediated release of TF-bearing and IL-17A-bearing NETs provides a link between thromboinflammation and fibrosis in SLE and may account for the salutary effects of hydroxychloroquine.

Membranoproliferative glomerulonephritis in a patient with chronic brucellosis.

Brucellosis is the most common zoonotic disease in Greece, with an endemic distribution and can affect any organ. Infiltration of the renal parenchyma causes acute and chronic interstitial nephritis with granulomas, whereas renal glomeruli are rarely affected. The disease has been sporadically reported, and it causes various histopathologic patterns. Herein, we describe the case of a 39-year-old stock breeder with a history of recurrent episodes of bacteremia caused by Brucella melitensis over a period of 3 years. Two months after the last episode of bacteremia, he presented with mild renal insufficiency, nephrotic range proteinuria, and microscopic hematuria. A renal biopsy revealed membranoproliferative glomerulonephritis with a pattern of focal-segmental nodular sclerosis and moderate tubulointerstitial fibrosis. The patient received antimicrobial and corticosteroid therapy with partial remission of the nephrotic syndrome.

Chloride Intracellular Channel 4 Overexpression in the Proximal Tubules of Kidneys from the Spontaneously Hypertensive Rat: Insight from Proteomic Analysis.

BACKGROUND: Hypertensive nephropathy, a leading cause of declining kidney function, is a multifactorial process not well understood. In order to elucidate biological processes and identify novel macromolecular components crucially involved in the process of kidney damage, the application of system biology approaches, like proteomics, is required. METHODS: Proteomic studies were performed using the renal parenchyma of spontaneously hypertensive rats (SHR) and their normotensive Wistar Kyoto controls. Animals were sacrificed at early time intervals (6, 13, and 20 weeks after birth), the renal tissue extract was subjected to two-dimensional gel electrophoresis, differential expressed proteins were identified, and altered pathways were evaluated. One specific protein, chloride intracellular channel 4 (CLIC4), not implicated so far in the development of hypertension and nephrosclerosis, was further studied by Western blotting, immunohistochemistry and immunofluorescence. RESULTS: Proteomic analysis identified several pathways/processes and organelles (mitochondria) as being affected from the early stages of hypertension. CLIC4 was overexpressed in SHR at all 3 time intervals examined. This finding was confirmed by Western blotting and by immunohistochemistry and immunofluorescence; these morphological techniques demonstrated that CLIC4 was almost exclusively localized at the apical surface of the proximal tubular epithelial cells. CONCLUSIONS: Our studies provide evidence that major changes occur in the renal parenchyma from early stages of the development of hypertension. The overexpression of CLIC4 suggests that alterations in the proximal tubular compartment during hypertension should be further examined and that CLIC4 may be a useful early marker of renal tubular alterations due to elevated blood pressure.