An Updated Review of Membranous Nephropathy.

Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The discovery of phospholipase A2 receptor (PLA2R) as a target antigen has led to a paradigm shift in the understanding and management of MN. At present, serum PLA2R antibodies are used for diagnosis, prognostication, and guiding treatment. Now, with the discovery of more than 20 novel target antigens, antigen mapping is almost complete. The clinical association of certain antigens provides clues for clinicians, such as the association of nerve epidermal growth factor-like 1 with malignancies and indigenous medicines. Serum antibodies are detected for most target antigens, except exostosin 1 and 2 and transforming growth factor-beta receptor 3, but their clinical utility is yet to be defined. Genome-wide association studies and studies investigating environmental factors, such as air pollution, shed more light on the underpinnings of MN. The standard therapy of MN diversified from cyclical cyclophosphamide and steroids to include rituximab and calcineurin inhibitors over the past decades. Here, we provide a cutting-edge review of MN, focusing on genetics, immune system and environmental factors, novel target antigens and their clinical characteristics, and currently available and emerging novel therapies in MN.

Recent Developments in the Evaluation and Management of Cardiorenal Syndrome: A Comprehensive Review.

Cardiorenal syndrome (CRS) is an increasingly recognized diagnostic entity associated with high morbidity and mortality among acutely ill heart failure (HF) patients with acute and/ or chronic kidney diseases (CKD). While traditionally viewed as a state of decline in glomerular filtration rate (GFR) due to decreased renal perfusion, mainly due to therapeutic interventions to relieve congestive in HF, recent insights into the underlying pathophysiologic mechanisms of CRS led to a broader definition and further classification of CRS into 5 distinct types. In this comprehensive review, we discuss the classification of CRS, highlighting the underlying common pathogenetic pathways of heart failure and kidney injury, including increased congestion, neurohormonal dysregulation, oxidative stress as well as inflammation, and cytokine storm that are particularly evident in COVID-19 patients with multiorgan failure and also in those with other disorders including sepsis, systemic lupus erythematosus and amyloidosis. In this review we also present the recent advances in the diagnostic strategies of CRS including cardiac and renal biomarkers as well as advanced cardiac and renal imaging techniques that are available to aid in the diagnosis as well as in the prognostication of this disorder. Finally, we discuss the various therapeutic options available to-date, including fluid optimization, hemofiltration, renal replacement therapy as well as the role of SGLT2 inhibitors in light of recent data from RCTs. It is important to note that, CRS population are either excluded or underrepresented, at best, in major RCTs and therefore, therapeutic recommendations are largely extrapolated from HF and CKD clinical trials.

A multi-center retrospective cohort study defines the spectrum of kidney pathology in Coronavirus 2019 Disease (COVID-19).

Kidney failure is common in patients with Coronavirus Disease-19 (COVID-19), resulting in increased morbidity and mortality. In an international collaboration, 284 kidney biopsies were evaluated to improve understanding of kidney disease in COVID-19. Diagnoses were compared to five years of 63,575 native biopsies prior to the pandemic and 13,955 allograft biopsies to identify diseases that have increased in patients with COVID-19. Genotyping for APOL1 G1 and G2 alleles was performed in 107 African American and Hispanic patients. Immunohistochemistry for SARS-CoV-2 was utilized to assess direct viral infection in 273 cases along with clinical information at the time of biopsy. The leading indication for native biopsy was acute kidney injury (45.4%), followed by proteinuria with or without concurrent acute kidney injury (42.6%). There were more African American patients (44.6%) than patients of other ethnicities. The most common diagnosis in native biopsies was collapsing glomerulopathy (25.8%), which was associated with high-risk APOL1 genotypes in 91.7% of cases. Compared to the five-year biopsy database, the frequency of myoglobin cast nephropathy and proliferative glomerulonephritis with monoclonal IgG deposits was also increased in patients with COVID-19 (3.3% and 1.7%, respectively), while there was a reduced frequency of chronic conditions (including diabetes mellitus, IgA nephropathy, and arterionephrosclerosis) as the primary diagnosis. In transplants, the leading indication was acute kidney injury (86.4%), for which rejection was the predominant diagnosis (61.4%). Direct SARS-CoV-2 viral infection was not identified. Thus, our multi-center large case series identified kidney diseases that disproportionately affect patients with COVID-19 and demonstrated a high frequency of APOL1 high-risk genotypes within this group, with no evidence of direct viral infection within the kidney.

Update and review of adult polycystic kidney disease.

Autosomal dominant polycystic kidney disease is a common cause of end stage kidney disease. It is a progressive and unfortunately incurable condition that can lead to significant morbidity and kidney failure. Many more patients are diagnosed with this disease without any symptoms as the population is increasingly undergoing imaging for other problems and diagnostic workup. Our understanding of the genetic variants has increased in recent years as research continues to improve. As well, therapeutic options have developed with the FDA approval of a new treatment medication, with many others underway. This review updates the clinician on the pathophysiology, clinical aspects, and therapeutic options for patients the is form of kidney disease.

Autosomal dominant polycystic kidney disease: updated perspectives.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited multisystem disorder, characterized by renal and extra-renal fluid-filled cyst formation and increased kidney volume that eventually leads to end-stage renal disease. ADPKD is considered the fourth leading cause of end-stage renal disease in the United States and globally. Care of patients with ADPKD was, for a long time, limited to supportive lifestyle measures, due to the lack of therapeutic strategies targeting the main pathways involved in the pathophysiology of ADPKD. As the first FDA approved treatment of ADPKD, Vasopressin (V2) receptor blocking agent, tolvaptan, is an urgently awaited advance for ADPKD patients. In our review, we also shed some lights on what is beyond Tolvaptan as there are other medications in the pipeline and many medications have been or are currently being studied in clinical trials such as Tesevatinib, Metformin and Pravastatin, with the goal of slowing the rate of progression of ADPKD by reducing the increase in total kidney volume or maintaining eGFR. Here, we review updates in the perspectives and management of ADPKD.

Class effects of SGLT2 inhibitors on cardiorenal outcomes.

BACKGROUND: To summarize the four recent sodium-glucose cotransporter 2 inhibitor (SGLT2i) trials: Dapagliflozin Effect on CardiovascuLAR Events (DECLARE-TIMI 58), CANagliflozin CardioVascular Assessment Study (CANVAS) Program, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients-Removing Excess Glucose (EMPA-REG OUTCOME), Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE), and explore the potential determinants for their cardiovascular, renal, and safety outcomes. RESULTS: The composite renal outcome event rates per 1000 patient-years for drug and placebo, as well as the corresponding relative risk reductions, were 3.7, 7.0, 47%; 5.5, 9.0, 40%; 6.3, 11.5, 46%; 43.2, 61.2, 30% for DECLARE-TIMI 58, CANVAS, EMPA-REG OUTCOME, and CREDENCE, respectively (event definitions varied across trials). The major adverse cardiovascular (CV) event rates per 1000 patient-years for drug and placebo, as well as the corresponding relative risk reductions, were 22.6, 24.2, 7%; 26.9, 31.5, 14%; 37.4, 43.9, 14%; 38.7, 48.7, 20% for DECLARE-TIMI 58, CANVAS, EMPA-REG OUTCOME, and CREDENCE, respectively. DECLARE-TIMI 58 had the fewest cardiorenal events and CREDENCE the most. These differences were presumably due to varying inclusion criteria resulting in DECLARE-TIMI 58 having the best baseline renal filtration function and CREDENCE the worst (mean estimated glomerular filtration rate 85.2, 76.5, 74, 56.2 mL/min/1.73 m2 for DECLARE-TIMI 58, CANVAS, EMPA-REG OUTCOME, and CREDENCE, respectively). Additionally, CREDENCE had considerably higher rates of albuminuria (median urinary albumin-creatinine ratios (UACR) were 927, 12.3, and 13.1 mg/g for CREDENCE, CANVAS, and DECLARE-TIMI 58, respectively; EMPA-REG OUTCOME had 59.4% UACR < 30, 28.6% UACR > 30-300, 11.0% UACR > 300 mg/g). CONCLUSIONS: Dapagliflozin, empagliflozin, and canagliflozin have internally and externally consistent and biologically plausible class effects on cardiorenal outcomes. Baseline renal filtration function and degree of albuminuria are the most significant indicators of risk for both CV and renal events. Thus, these two factors also anticipate the greatest clinical benefit for SGLT2i.

Kidney transplantation for the primary care provider.

Advancement in kidney transplantation has led to prolonged survival in our population with kidney disease. Newer agents of immunosuppression have made this possible with less rejections and lesser opportunistic infections and transplant related deaths. Preventative care like timely vaccines, cancer screenings, aggressive blood pressure, blood sugar, lipid control, timely referral to consultants is required in these patient population to provide quality care and to prolong their survival. Primary care physicians are the best advocate for our transplant populations. To care for these complex transplant patients, it is vital for primary care physicians to be familiar with the overall approach on our patients.

Approach to the patient with renal disease.

There are various ways by which a patient with renal disease can present as either an initial outpatient or an inpatient consultation. Some patients can present with incidental hematuria and/or proteinuria. Symptoms generally vary but are more commonly noted with advanced stages of chronic kidney disease. A systematic, well organized approach is of utmost necessity in arriving at the correct diagnosis. A multitude of laboratory and ancillary studies, including a percutaneous renal biopsy (performed when necessary), are available to arrive at the right diagnosis. An algorithmic approach to hematuria and proteinuria is also presented.