Spectrum of Kidney Diseases in Patients With Hepatitis C Virus Infection.

OBJECTIVES: To study the pathologic spectrum of kidney diseases in patients with hepatitis C virus infection (HCV+). METHODS: Native kidney biopsy specimens in HCV+ patients were reviewed. RESULTS: A total of 9,836 native kidney biopsy specimens were evaluated from January 2007 to December 2016, of which 273 (2.8%) were from HCV+ patients, and of these, 115 (42.1%) had diagnoses consistent with HCV-associated glomerulonephritis (GN). Non-HCV-associated kidney diseases comprised most diagnoses (158 cases, 57.9%) including non-immune complex-mediated kidney diseases (127 cases, 46.5%) and other immune complex-mediated glomerular diseases (31 cases, 11.4%). Forty-one (40.6%) patients had HCV-associated GN among 101 HCV+ patients from 2007 to 2011 vs 74 (43.0%) patients with HCV-associated GN among 172 HCV+ patients from 2012 to 2016. HCV-associated GN showed five morphologic patterns: focal proliferative (5.2%), diffuse mesangial proliferative (50.4%), diffuse membranoproliferative (28.7%), proliferative GN with crescentic lesions (7.8%), and membranous patterns (7.8%). CONCLUSIONS: We found a spectrum of pathologic changes in renal biopsy specimens of HCV+ patients, with most having diseases unrelated to HCV infection, HCV-associated GN showing five morphologic patterns, and availability of effective HCV antiviral therapy not yet resulting in major changes in the spectrum of kidney diseases in these patients.

Acute kidney injury: quoi de neuf?

BACKGROUND: Acute kidney injury (AKI) is frequently encountered in the nephrology practice. Serum creatinine, with its many shortcomings, is still the main biomarker used to detect AKI. METHODS: This review focuses on recent advances in definition, diagnosis, risk factors, and molecular mechanisms of AKI. In addition, specific AKI syndromes such as contrast-induced AKI, hepatorenal syndrome, and acute decompensated heart failure are discussed. The connection between AKI and subsequent chronic kidney disease and recent developments in renal replacement therapy are also covered. RESULTS: Novel biomarkers such as cystatin C and neutrophil gelatinase-associated lipocalin (NGAL) are being investigated to replace serum creatinine in the detection of AKI. Recent studies suggest that intravenous (IV) fluid use is beneficial for the prevention of contrast-induced AKI, while N-acetylcysteine use is not as well established. Diuretics are clearly beneficial in the treatment of acute decompensated heart failure. Ultrafiltration is less promising and can lead to adverse side effects. Although terlipressin use in hepatorenal syndrome is associated with reduced mortality, it is not available in the United States; combination therapy with midodrine, octreotide, and albumin provides an alternative. Fluid resuscitation is frequently used in critically ill patients with AKI; however, overly aggressive fluid resuscitation is frequently associated with an increased risk of mortality. A 3-step approach that combines guided fluid resuscitation, establishment of an even fluid balance, and an appropriate rate of fluid removal may be beneficial. If fluid resuscitation is needed, crystalloid solutions are preferred over hetastarch solutions. Renal replacement therapy is the last resort in AKI treatment, and timing, modality, and dosing are discussed. Research suggests that AKI leads to an increased incidence of subsequent chronic kidney disease. However, this relationship has not been fully established and additional studies are needed for clarification. CONCLUSION: Despite major advances in AKI research, serum creatinine remains the major biomarker for the detection of AKI. The following interventions have shown to be beneficial: IV fluids for contrast-induced AKI; diuretics for acute decompensated heart failure/cardiorenal syndrome; and combination therapy with midodrine, octreotide, and albumin for hepatorenal syndrome. Fluid resuscitation in a patient with AKI should be used with caution because too liberal use of fluids can be associated with increased mortality. AKI appears to be related to increased rates of subsequent chronic kidney disease, and patients with AKI should therefore be monitored closely. Recent studies on renal replacement therapy have neither revealed an optimal timing for initiation of dialysis nor a clear advantage for a specific dialysis modality.