Onconephrology: Core Curriculum 2023.

Onconephrology focuses on management of kidney disease in cancer, which manifests itself in a variety of clinical syndromes, including acute kidney injury, chronic kidney disease, hypertension, proteinuria, and electrolyte disorders. Many of these syndromes result from cancer treatments including chemotherapy, immunotherapy, chimeric antigen receptor T cells, and stem cell transplant. Others are due to kidney-specific effects of the cancer, as seen with monoclonal gammopathy or glomerular diseases associated with malignancy. Further, cancer risk itself is heightened in patients with kidney disease, particularly kidney transplant recipients, and their care requires specific considerations. In this installment of AJKD's Core Curriculum in Nephrology, we review these and other core concepts in onconephrology, using a case-based approach to highlight clinical decision making.

Onco-Nephrology: Kidney Disease in the Cancer Patient.

Patients with cancer may develop kidney disease with a variety of different clinical manifestations including acute kidney injury, chronic kidney disease, hypertension, proteinuria and electrolyte disturbances. Onco-nephrology is the subspecialty of nephrology that diagnoses and manages kidney disease in patients with cancer. In this article, we review major topics in Onco-Nephrology that may be encountered by the general internist.

Heavy Chain/Light Chain Antibody Immunofluorescence to Identify Monoclonal Plasma Cells in a Case of Plasma Cell-Rich Acute Interstitial Nephritis.

Heavy/light chain (HLC) antibodies can be used to quantify intact HLC pairs. In immunofluorescence studies, they allow differentiation of monoclonal versus polyclonal immunoglobulin deposits in kidney diseases that occur in the setting of monoclonal gammopathy. Here, we present a case of a patient with acute kidney injury with first kidney biopsy suggestive of acute interstitial nephritis with a polymorphous infiltrate of plasma cells. Routine immunofluorescence did not show a monotypic plasma cell infiltrate. Serum protein electrophoresis and immunofixation revealed monoclonal immunoglobulin A (IgA) lambda. She improved with steroid therapy, but kidney function worsened after steroids were stopped. She underwent a second kidney biopsy, which showed plasma cell-rich interstitial infiltrate with a population of IgA lambda-restricted plasma cells on routine immunofluorescence. In light of this finding, Hevylite HLC antibody was used to reassess the first biopsy, which confirmed the presence of a population of plasma cells with IgA lambda restriction. Because of the presence of monotypic plasma cells, anti-CD38 monoclonal antibody (daratumumab) was initiated.

Social Support, Caregivers, and Chronic Kidney Disease.

The morbidity and mortality associated with chronic kidney disease remains unacceptably high. Psychosocial issues in CKD patients are frequently overlooked yet are often modifiable risk factors for mortality. Addressing patient perception of social support can potentially improve patient outcomes.

The Resulting Variation in Nutrient Intake With the Inclusion of Walnuts in the Diets of Adults at Risk for Type 2 Diabetes: A Randomized, Controlled, Crossover Trial.

PURPOSE: We previously demonstrated that including walnuts in the diets of adults at risk for type 2 diabetes mellitus (T2DM) led to improved overall diet quality. This report examines the specific changes in their nutrient intake. DESIGN: This was a randomized, controlled, modified Latin square parallel design trial with 2 treatment arms. Participants were randomized to walnut intake with, or without, dietary advice to regulate caloric intake. Within each treatment arm, they were further randomized to one of 2 sequence permutations (walnut-included/walnut-excluded or walnut-excluded/walnut-included diet), with a 3-month washout between treatment phases. SETTING: Community hospital in Lower Naugatuck Valley in Connecticut. PARTICIPANTS: Cohort of 112 participants (31 men and 81 women) at risk for T2DM. INTERVENTION: Participants included 56 g (366 kcal) of walnuts in their daily diets for 6 months. MEASURES: Nutrient intake was assessed using web-based Automated Self-Administered 24-Hour Dietary Assessment. ANALYSIS: Data were analyzed using generalized linear models. RESULTS: Walnut inclusion led to increased intake of total fat, calcium, magnesium, thiamin, total saturated fatty acids, and monounsaturated and polyunsaturated fatty acids (379.0 ± 90.3 g vs -136.5 ± 92.7 g, P < .01; 230.7 ± 114.2 mg vs -95.2 ± 117.4 mg, P = .05; 111.0 ± 33.9 mg vs -32.3 ± 34.9 mg, P < .01; 0.28 ± 0.2 mg vs -0.47 ± 0.2 mg, P = .02; 8.6 ± 3.4 g vs -1.1 ± 3.5 g, P =.05; 6.3 ± 3.9 g vs -6.3 ± 4.0 g, P = .03; and 25.4 ± 4.0 vs -6.6 ± 4.2 g, P < .01, respectively). Vitamin C intake decreased (-65.3 ± 55.3 mg vs 98.9 ± 56.8 mg, P = .04). Protein intake increased from baseline with the inclusion of walnuts (20.0 ± 8.8 g, P < .05). Walnut inclusion led to an increase in total calories consumed when caloric intake is not regulated. CONCLUSION: Including walnuts in the diets of these adults led to increased dietary intake of some nutrients associated with lower risk of developing T2DM and other cardiometabolic risk factors.

Which foods are displaced in the diets of adults with type 2 diabetes with the inclusion of eggs in their diets? A randomized, controlled, crossover trial.

BACKGROUND: The inclusion or exclusion of specific foods from the overall diet inevitably affects other food choices, and this matter is routinely neglected in dietary guidance and nutritional epidemiology. We examined how the inclusion of eggs in the diets of type 2 diabetics affected dietary pattern. METHODS: Randomized, controlled, single-blind, crossover trial of 34 adults (mean age 64.5 years; 14 women, 20 men) with type 2 diabetes assigned to one of two possible sequence permutations of two different 12-week treatments (two eggs/day or egg exclusion), with 6-week washout periods. For the egg inclusion phase, participants received advice from a dietitian on how to preserve an isocaloric condition relative to the egg exclusion phase. To assess changes in dietary pattern in the diets of our study participants, we analyzed the 12 components of the 2010 Healthy Eating Index. RESULTS: The inclusion of eggs was associated with reduced consumption of refined grains nearing statistical significance (-0.7±3.4 vs 0.7±2.2; p=0.0530). The consumption of total protein foods significantly increased from baseline (0.3±0.7; p=0.0153) with the inclusion of eggs for 12 weeks, while the consumption of dairy products significantly decreased with the exclusion of eggs from their diets (-1.3±2.9; p=0.0188). CONCLUSIONS: Eggs in the diets of type 2 diabetics may lead to increased consumption of some healthful foods and reduced consumption of some less healthful foods. TRIAL REGISTRATION NUMBER: NCT02052037; Post-results.

Inclusion of walnut in the diets of adults at risk for type 2 diabetes and their dietary pattern changes: a randomized, controlled, cross-over trial.

BACKGROUND: In our recently published study, including walnuts in the diets of adults with prediabetes led to overall improvement in diet quality. This report adds to those study findings by examining the food groups displaced during walnut inclusion in the diets of those adults with prediabetes. METHODS: Randomized, controlled, modified Latin square parallel design with 2 treatment arms. The 112 participants (31 men, 81 women) were randomly assigned to a diet with or without dietary counseling to regulate calorie intake in a 1:1 ratio. Within each treatment arm, participants were further randomized to 1 of 2 sequence permutations to receive a walnut-included diet with 56 g (366 kcal) of walnuts per day and a walnut-excluded diet. Participants in the calorie-regulated arm received advice from a dietitian to preserve an isocaloric condition while including walnuts. We analyzed the 12 components of the 2010 Healthy Eating Index to examine dietary pattern changes of study participants. RESULTS: Seafood and plant protein foods intake significantly increased with walnut inclusion, compared with their exclusion (2.14±2.06 vs -0.49±2.33; p=0.003). The ingestion of healthful fatty acids also significantly increased with walnut inclusion, compared with their exclusion (1.43±4.53 vs -1.76±4.80; p=0.02). Dairy ingestion increased with walnut inclusion in the calorie-regulated phase, compared with walnut inclusion without calorie regulation (1.06±4.42 vs -2.15±3.64; p=0.02). CONCLUSIONS: Our data suggest that walnut inclusion in the diets of adults at risk for diabetes led to an increase in intake of other healthful foods. TRIAL REGISTRATION NUMBER: NCT02330848.