Onconephrology: mitigation of renal injury in chemotherapy administration

PURPOSE OF REVIEW

Onconephrology was first coined as a name for the intersection of cancer medicine and nephrology in the early 2010s. It was recognized then that beyond and understanding of kidney physiology, a new generation of nephrologists skilled in both molecular biology and precision medicine were needed to deal with the challenges of emerging cancer therapies. Stem cell transplants, biologic agents, adjuvants blocking basic cellular signaling pathways, immunotherapy were found to promote novel anticancer outcomes, but also to pose new risks to the kidneys. The field rapidly overlapped with emerging expertise in vascular glomerular disease, glomerular disease, and the same biologic agents now applied to auto immune systemic and kidney diseases.

RECENT FINDINGS

Many categories of chemotherapeutic agents have been discovered to have adverse renal side effects. In this review, we address classic chemotherapeutic nephrotoxicity and oncologic clinical situations leading to acute kidney injury. We also review the frontiers of nephrotoxicity reported with cell cycle inhibitors, diverse classes of tyrosine kinase inhibitors, immune checkpoint inhibitors, chimeric antigen receptor T-cell therapy, anticancer vaccines, and thrombotic microangiopathies triggered by malignancy and chemotherapy. The aim will be to focus on published strategies to mitigate nephrotoxicity.

SUMMARY

As onconephrology expands into its own field, it gives birth to new subdisciplines. An understanding that patient populations want the benefits of chemotherapy without the renal (and other) systemic toxicities is emerging. A need to develop a new class of molecular and genetic experts in onconephrology to mitigate nephrotoxicity from chemotherapy is apparent and urgent.

Kidney function assessment in the geriatric population

PURPOSE OF REVIEW

Kidney function declines with normal aging. But it also declines with the progression of some diseases. This review calls for a more nuanced interpretation of kidney function in the geriatric population, who may have frailty and comorbidities.

RECENT FINDINGS

GFR declines with healthy aging kidneys. Aging kidney changes include decreased cortical volume, senescent global glomerulosclerosis, and reduced nephron numbers. Yet normal aging is not associated with increased glomerular volume or single-nephron GFR. The prevalence of GFR less than 60 ml/min/1.73 m 2 in the geriatric population is high. However, the decline in GFR with normal aging may not reflect true CKD without albuminuria. Although the risk of ESKD and mortality increases in all age groups when eGFR less than 45 ml/min/m 2 , there is no significant increased relative risk of ESKD and mortality in the geriatric population when eGFR 45-59 ml/min/m 2 in the absence of albuminuria. Innovative approaches are needed to better estimate GFR and define CKD in the geriatric population.

SUMMARY

The expected GFR decline in the geriatric population is consistent with normal aging kidney changes. To avoid CKD overdiagnosis and unnecessary referrals to nephrology for possible CKD, age-adapted definitions of CKD in the absence of albuminuria are needed.

Liver Disease Is a Risk Factor for Recurrent Hyperkalemia: A Retrospective Cohort Study

Liver disease is often associated with dysfunctional potassium homeostasis but is not a well-established risk factor for hyperkalemia. This retrospective cohort study examined the potential relationship between liver disease and recurrent hyperkalemia. Patients with ≥1 serum potassium measurement between January 2004 and December 2018 who experienced hyperkalemia (serum potassium >5.0 mmol/L) were identified from the United States Veterans Affairs database. A competing risk regression model was used to analyze the relationship between patient characteristics and recurrent hyperkalemia. Of 1,493,539 patients with incident hyperkalemia, 71,790 (4.8%) had liver disease (one inpatient or two outpatient records) within 1 year before the index hyperkalemia event. Recurrent hyperkalemia within 1 year after the index event occurred in 234,807 patients (15.7%) overall, 19,518 (27.2%) with liver disease, and 215,289 (15.1%) without liver disease. The risk of recurrent hyperkalemia was significantly increased in patients with liver disease versus those without (subhazard ratio, 1.34; 95% confidence interval, 1.32-1.37; p < 0.0001). Aside from vasodilator therapy, the risk of recurrent hyperkalemia was not increased with concomitant medication. In this cohort study, liver disease was an independent risk factor strongly associated with recurrent hyperkalemia within 1 year, independent of concomitant renin-angiotensin-aldosterone system inhibitor or potassium-sparing diuretic use.

Living Well With Kidney Disease and Effective Symptom Management: Consensus Conference Proceedings

Chronic kidney disease (CKD) confers a high burden of uremic symptoms that may be underrecognized, underdiagnosed, and undertreated. Unpleasant symptoms, such as CKD-associated pruritus and emotional/psychological distress, often occur within symptom clusters, and treating 1 symptom may potentially alleviate other symptoms in that cluster. The Living Well with Kidney Disease and Effective Symptom Management Consensus Conference convened health experts and leaders of kidney advocacy groups and kidney networks worldwide to discuss the effects of unpleasant symptoms related to CKD on the health and well-being of those affected, and to consider strategies for optimal symptom management. Optimizing symptom management is a cornerstone of conservative and preservative management which aim to prevent or delay dialysis initiation. In persons with kidney dysfunction requiring dialysis (KDRD), incremental transition to dialysis and home dialysis modalities offer personalized approaches. KDRD is proposed as the preferred term given the negative connotations of "failure" as a kidney descriptor, and the success stories in CKD journeys. Engaging persons with CKD to identify and prioritize their personal values and individual needs must be central to ensure their active participation in CKD management, including KDRD. Person-centered communication and care are required to ensure diversity, equity, and inclusion; education/awareness that considers the health literacy of persons with CKD; and shared decision-making among the person with CKD, care partners, and providers. By putting the needs of people with CKD, including effective symptom management, at the center of their treatment, CKD can be optimally treated in a way that aligns with their goals.

Novel approach to unpleasant symptom clusters surrounding pruritus in patients with chronic kidney disease and on dialysis therapy

PURPOSE OF REVIEW

Chronic kidney disease-associated-pruritus (CKD-aP) is a common symptom in patients with end-stage kidney disease (ESKD) undergoing dialysis. CKD-aP typically occurs alongside other debilitating symptoms and may comprise so-called 'symptom clusters' which have synergistic effects that adversely impact patient health-related quality of life (HRQoL). Importantly, symptoms in a cluster may share a common biological mechanism. Here we review the clinical impact of CKD-aP and its association with other symptoms reported by dialysis patients. The clinical benefits of treating pruritus and its potential impact on other symptoms are also addressed.

RECENT FINDINGS

Studies have shown CKD-aP significantly impairs HRQoL in patients with ESKD undergoing dialysis and is associated with adverse clinical outcomes, including increased risk of infections, hospitalizations, and mortality. Despite these negative effects, CKD-aP remains underrecognized and undertreated in clinical practice. CKD-aP is frequently associated with other symptoms, including disturbed sleep/poor sleep quality, anxiety, depression, and pain. Clinical studies of antipruritic therapies show that reduction of itch intensity may also alleviate other associated symptoms, such as poor sleep quality.

SUMMARY

CKD-aP and its associated symptoms are inadequately managed in clinical practice. Greater understanding and awareness of CKD-aP and its surrounding symptom clusters in dialysis patients may improve their overall symptom management and HRQoL.

Calcium Transport in the Kidney and Disease Processes

Calcium is a key ion involved in cardiac and skeletal muscle contractility, nerve function, and skeletal structure. Global calcium balance is affected by parathyroid hormone and vitamin D, and calcium is shuttled between the extracellular space and the bone matrix compartment dynamically. The kidney plays an important role in whole-body calcium balance. Abnormalities in the kidney transport proteins alter the renal excretion of calcium. Various hormonal and regulatory pathways have evolved that regulate the renal handling of calcium to maintain the serum calcium within defined limits despite dynamic changes in dietary calcium intake. Dysregulation of renal calcium transport can occur pharmacologically, hormonally, and via genetic mutations in key proteins in various nephron segments resulting in several disease processes. This review focuses on the regulation transport of calcium in the nephron. Genetic diseases affecting the renal handling of calcium that can potentially lead to changes in the serum calcium concentration are reviewed.