Renal Manifestations of IgG4-Related Disease: A Concise Review.

IgG4-related disease (IgG4-RD) is an immune-mediated disorder marked by fibro-inflammatory masses that can infiltrate multiple organ systems. Due to its relatively recent discovery and limited understanding of its pathophysiology, IgG4-related disease may be difficult to recognize and is consequently potentially underdiagnosed. Renal involvement is becoming regarded as one of the key features of this disease. To date, the most well-recognized renal complication of IgG4-related disease is tubulointerstitial nephritis, but membranous glomerulonephritis, renal masses, and retroperitoneal fibrosis have also been reported. This concise review has two objectives. First, it will briefly encapsulate the history, epidemiology, and presentation of IgG4-related disease. Second, it will examine the reported renal manifestations of IgG4-related disease, exploring the relevant histology, imaging, clinical features, and treatment considerations. This synthesis will be highly relevant for nephrologists, rheumatologists, general internists, and renal pathologists to raise awareness and help improve early recognition of IgG4-related kidney disease (IgG4-RKD).

Predictors of Hyperkalemia among Patients on Maintenance Hemodialysis Transported to the Emergency Department by Ambulance.

Background: Hyperkalemia is common among patients on maintenance hemodialysis (HD) and is associated with mortality. We hypothesized that clinical characteristics available at time of paramedic assessment before emergency department (ED) ambulance transport (ambulance-ED) would associate with severe hyperkalemia (K≥6 mmol/L). Rapid identification of patients who are at risk for hyperkalemia and thereby hyperkalemia-associated complications may allow paramedics to intervene in a timely fashion, including directing emergency transport to dialysis-capable facilities. Methods: Patients on maintenance HD from a single paramedic provider region, who had at least one ambulance-ED and subsequent ED potassium from 2014 to 2018, were examined using multivariable logistic regression to create risk prediction models inclusive of prehospital vital signs, days from last dialysis, and the presence of prehospital electrocardiogram (ECG) features of hyperkalemia. We used bootstrapping with replacement to validate each model internally, and performance was assessed by discrimination and calibration. Results: Among 704 ambulance-ED visits, severe hyperkalemia occurred in 75 (11%); 26 patients with ED hyperkalemia did not have a prehospital ECG. Younger age at transport, longer HD vintage, more days from last hemodialysis session (OR=49.84; 95% CI, 7.72 to 321.77 for ≥3 days versus HD the same day [before] ED transport), and prehospital ECG changes (OR=6.64; 95% CI, 2.31 to 19.12) were independently associated with severe ED hyperkalemia. A model incorporating these factors had good discrimination (c-statistic 0.82; 95% CI, 0.76 to 0.89) and, using a cutoff of 25% probability, correctly classified patients 89% of the time. Conclusions: Characteristics available at the time of ambulance-ED were associated with severe ED hyperkalemia. An awareness of these associations may allow health care providers to define novel care pathways to ensure timely diagnosis and management of hyperkalemia.

Evaluation of Sustained Virologic Response as a Relevant Surrogate Endpoint for Long-term Outcomes of Hepatitis C Virus Infection.

BACKGROUND: The causal link of sustained virologic response (SVR) with outcome has been challenged. With improved SVR rates with direct-acting antivirals (DAAs), the benefit of SVR would be expected to diminish if the association with outcome is not causal. METHODS: Data were collected for patients starting treatment with interferon (IFN) or DAAs between June 2006 and December 2016. To control for disease severity, criteria for the IDEAL (Individualized Dosing Efficacy vs. Flat Dosing to Assess Optimal Pegylated Interferon Therapy) trial determined IFN-eligibility. Clinical events were decompensation, hepatocellular carcinoma, liver transplantation, and all-cause mortality. RESULTS: In 1078 IDEAL-eligible patients, 1306 treatments occurred (52% IFN, 49% DAAs). Cirrhosis was present in 30% DAAs vs 21% IFN (P < .001). SVR was 97% with DAAs vs 52% with IFN (P < .0001). The 24-month cumulative event-free survival was 99% for IFN and 97% for DAAs with SVR (P = .08) and 96% and 75%, respectively, for non-SVR (P = .01). SVR was associated with improved event-free survival with an adjusted hazard ratio of 0.21 (95% confidence interval, .06-.71; P = .01). Using inverse probability of treatment weighting to match IFN nonresponders with DAA-treated patients, the 24-month event-rate was 1.1% with DAAs compared to 3.4% in IFN nonresponders (P = .005), highlighting the clinical benefit of maximizing SVR. CONCLUSIONS: In IFN-eligible patients, SVR is more commonly achieved with DAAs and confers a similar clinical benefit as in those treated with IFN. The reduced event-rate with DAAs compared to IFN, despite similar disease severity, confirm that SVR alters prognosis leading to improved clinical outcomes.

Maintained virological suppression and renal function with reduced dose tenofovir disoproxil fumarate in renally impaired chronic hepatitis B patients.

Tenofovir disoproxil fumarate (TDF) effectively suppresses viral replication in chronic hepatitis B (CHB), but occasionally leads to renal impairment. We evaluated the prevalence of viral and biochemical breakthrough and renal function kinetics in renally impaired patients with CHB on reduced and on full-dose TDF. This clinic-based longitudinal cohort study included patients receiving full and reduced dose TDF (due to eGFR [Cockcroft-Gault] <60 mL/min/1.73 m2 ). Viral and biochemical breakthroughs were assessed 1 month after starting full and reduced TDF dose until the end-of-follow-up. Breakthroughs were studied in full and reduced dose TDF, and renal function (MDRD) longitudinally before and after dose reduction within patients starting on full-dose TDF. Of 750 patients on TDF, 78 (10%) had reduced dose and 672 (90%) full dose. At the time of dose reduction, 36 (46%) patients had chronic kidney disease stage G3B. A viral breakthrough occurred in one cirrhotic dialysis-dependent patient (dosed 300 mg weekly) which resolved without signs of decompensation, and in one patient on full dose which resolved spontaneously. One biochemical breakthrough occurred during dose reduction and resolved naturally without viral breakthrough. The MDRD improved within the first year of dose reduction (+3.0 [2.5] mL/min per year; P < .005) and remained stable thereafter. Fifty-three (79%) patients reached an MDRD >50 mL/min during dose reduction. Low dose TDF maintains renal function and viral suppression in most renally impaired patients with CHB, even in those with advanced liver disease. This useful, yet simple strategy could be particularly viable in resource-constrained settings.

Nonalcoholic Steatohepatitis Is Associated With Liver-Related Outcomes and All-Cause Mortality in Chronic Hepatitis B.

BACKGROUND AND AIMS: Chronic hepatitis B (CHB) and nonalcoholic fatty liver disease are increasingly observed together in clinical practice, and development of nonalcoholic steatohepatitis (NASH) represents another leading cause of liver-related morbidity and mortality. Our aims were to determine whether biopsy-proven NASH impacts clinical outcomes in CHB patients and assess prognostic risk factors. APPROACH AND RESULTS: CHB patients attending two tertiary centers in North America and Europe over 13 years with available clinical and biopsy data were included. Patients were categorized as no-NASH or probable/definite NASH based on standardized histological assessment. Clinical events (death, decompensation, transplant, and hepatoma) were evaluated, and Kaplan-Meier survival estimates and Cox proportional hazards regression were used to analyze the incidence of events. There were 1,089 CHB patients, classified as no-NASH (n = 904, 83%) or NASH (n = 185, 17%), with 52 (6%) versus 27 (15%) experiencing outcome events during follow-up, respectively. In the multivariable analysis adjusting for age, sex, hepatitis B e antigen serostatus, and diabetes, the presence of NASH and concomitant advanced fibrosis (AF) was significantly associated with clinical outcomes (hazard ratio [95% confidence interval], 4.8 [2.6-9.0], P < 0.01) when compared to absence of NASH and AF (reference). NASH and AF were associated with a greater risk of outcomes compared to AF (P = 0.01) or NASH alone (P < 0.01). Of the three histological determinants of NASH, ballooning and inflammation, but not steatosis, were independently associated with clinical outcomes (P < 0.05) in place of NASH. NASH was significantly associated with increased risk of hepatocellular carcinoma and death (P < 0.01) but not decompensation (P = 0.33). CONCLUSIONS: In our large combined tertiary center cohort, patients with concomitant NASH and CHB had more AF and shorter time to development of liver-related outcomes or death compared to patients with CHB alone. Among patients with AF, superimposed NASH predicted poorer clinical outcomes.

Prevalence and predictors of complementary and alternative medicine modalities in patients with chronic hepatitis B.

BACKGROUND & AIMS: The use of complementary and alternative medicine (CAM) in patients with chronic hepatitis B (CHB) can interact with antiviral treatment or influence health-seeking behaviour. We aimed to study the use of individual CAM modalities in CHB and explore determinants of use, particularly migration-related, socio-economic and clinical factors. METHODS: A total of 436 CHB outpatients who attended the Toronto Centre for Liver Disease in 2015-2016 were included in this cross-sectional study. Using the comprehensive I-CAM questionnaire and health records, data were collected on socio-demographic and clinical variables and on usage of 16 CAM modalities in the last year. RESULTS: Sixty percent of patients were male, 74% were Asian and 46% were using antiviral treatment. Three-hundred and nine (71%) patients used CAM. Vitamin/mineral preparations (45% of patients) were most commonly used. Overall CAM use and the specific use of potentially injurious CAM, such as green tea extract (9.2%) and St. John's wort (0.2%), were not associated with liver disease severity. Female sex, family history of CHB, lower serum HBV DNA, and higher socio-economic status were independently associated with bio-holistic CAM use, the clinically most-relevant CAM group (P < 0.05); ethnicity, antiviral therapy use and liver disease severity were not. CONCLUSIONS: CAM use among CHB patients was extensive, especially use of vitamin and mineral preparations, but without direct influence on liver disease severity. Bio-holistic CAM use appeared to be associated with socio-economic status rather than with ethnicity or liver disease severity. Despite the rare use of hepatotoxins, physicians should actively inquire about it.