Association of ultrasonographic features with histologic findings in 71 dogs with protein-losing nephropathy (2008–2018)

OBJECTIVE To determine whether ultrasonographic features in dogs with protein-losing nephropathy (PLN) were associated with renal biopsy findings and compare corticomedullary ratios between dogs with PLN versus non-renal disease. ANIMALS 71 dogs with PLN and 33 dogs without renal disease. PROCEDURES Medical records and archived ultrasonographic images for dogs with PLN that underwent renal biopsy between 2008 and 2018 were reviewed. Corticomedullary ratios were measured. RESULTS In dogs with PLN, median serum creatinine and BUN concentrations and urine-protein-to-creatinine-ratio prior to renal biopsy were 3.4 mg/dL (interquartile range [IQR], 1.2 to 5.3 mg/dL), 80 mg/dL (IQR, 28 to 105 mg/dL), and 11.4 (IQR, 6.4 to 18.3), respectively. Histologic abnormalities within the tubulointerstitial space were associated with cortical echogenicity. Gastric wall thickness > 5 mm was associated with a histologic diagnosis of acute glomerular disease. Dogs with immune complex–mediated glomerular disease were more likely to have abnormal gastric mural architecture. Other ultrasonographic features of the kidneys, liver, and stomach and the presence of ascites did not help to differentiate immune complex–mediated from non-immune complex–mediated glomerular disease, acute from chronic disease, or amyloid from non-amyloid disease or distinguish whether tubulointerstitial disease was present or absent. Median left corticomedullary ratio for 66 dogs with PLN (1.2) was significantly higher than that for the 33 dogs without renal disease (1.0). Clinical Relevance Ultrasonographic features were poorly associated with specific pathological disorders in dogs with PLN. In this study, the corticomedullary ratio was higher in dogs with PLN, indicating the presence of cortical thickening, but the clinical relevance is unknown.

Ultrasound-Guided Lauromacrogol Injection for the Treatment of Active Bleeding After Renal Biopsy

Background: This study aimed to describe the technique and outcomes of hemostasis for ultrasound-guided lauromacrogol injection for active bleeding after renal biopsy.Methods: Data from patients with active bleeding after renal biopsy between January 2018 and December 2020 were retrospectively collected. Patients who still had active bleeding after 30 min of compression were then injected with lauromacrogol under ultrasound guidance. The patient’s symptoms before and after operation were collected to assess whether they had severe complications. Changes in hemoglobin and serum creatinine values were collected.Results: Data from a total of 15 patients with active bleeding after renal biopsy were collected, including data of 6 men and 9 women. After the operation, there were 11 cases of mild back pain; 1 case of chills, cold sweats, and back pain; 1 case of cold sweats and blood pressure reduction, and 2 cases with no obvious symptoms. No severe complications occurred in this study, and active bleeding was stopped in all patients. After the operation, compared with before the operation, there was no statistically significant difference in the hemoglobin value and serum creatinine value (p = 0.10 > 0.05, p = 0.78 > 0.05).Conclusion: Ultrasound-guided lauromacrogol injection is a relatively simple, safe and feasible method, which could be helpful in treating active bleeding in the immediate post-procedure period after renal biopsy.

Thrombotic microangiopathy and smoldering multiple myeloma after kidney transplant in a patient with MCP mutation

The most frequent cause of atypical hemolytic uremic syndrome (aHUS) is defective regulation of complement activation because of genetic anomalies. We present the case of 53-year-old man with a kidney transplant and stabilized kidney function (creatinine 2.5 mg/dL; proteinuria 0.4 g/24 h) with mycophenolate/tacrolimus/prednisone who was diagnosed of Thrombotic Microangiopathy (TMA). This diagnosis was associated with creatinine and proteinuria rise (3 mg/dL; 2.4 g/24 h) and a new monoclonal IgA/lambda component. Renal biopsy showed membranoproliferative glomerulonephritis; a pathogenic variant in the Membrane cofactor protein (MCP) gene with a polymorphism ggaac, typically associated to secondary aHUS, was identified. We suspected that immunoglobulin could be acting as a trigger for TMA in a genetically susceptible patient, so “clone-directed” therapy with bortezomib and dexamethasone was initiated.

Fabry Nephropathy in a Young Female Patient Presenting with Only Urinary Mulberry Bodies Treated with Chaperone Therapy

Fabry disease (FD) is an X-linked disorder of the sphingolipid metabolism, caused by deficiency or decreased activity of α-galactosidase A. We report a rare case of Fabry nephropathy (FN) in a 21-year-old Japanese female patient presenting with only urinary mulberry bodies; she was treated with pharmacological chaperone therapy (PCT) after renal biopsy. The patient underwent a detailed examination because her mother was diagnosed with FD in the Division of Community Medicine of our hospital. She did not have renal dysfunction or proteinuria, and only mulberry bodies were detected in the urine. The activity of α-galactosidase A was low, and genetic analysis revealed the R301Q mutation. A percutaneous renal biopsy was performed, and the findings revealed enlargement and vacuolation of glomerular podocytes by light microscopy, and myelin and zebra bodies were detected in podocytes by electron microscopy. She was diagnosed with FN by renal biopsy and gene analysis. PCT was selected as the treatment to prevent cardiac events and renal dysfunction. The present case suggests that renal biopsy may be necessary even for young women with only mulberry bodies for the diagnosis of FN. It could be useful to evaluate the effect of treatment using the counts of mulberry bodies in the urine. In addition, due to its oral administration, PCT may be suitable for patients who are unable to visit the hospital frequently.

Clinicopathological discordance in biopsy-proven nephrosclerosis: a nationwide cross-sectional study of the Japan Renal Biopsy Registry (J-RBR)

Background Patients with nephrosclerosis display heterogenous clinical phenotypes, often leading to a clinical diagnosis discordant with pathological nephrosclerosis diagnosis. However, little is known about clinical factors associated with clinicopathological discordance of biopsy-proven nephrosclerosis. Methods In a cross-sectional study of 891 patients with biopsy-proven nephrosclerosis registered in the Japan Renal Biopsy Registry (J-RBR) between July 2007 and June 2016, we examined clinical characteristics associated with a pre-biopsy clinical diagnosis discordant with pathological nephrosclerosis diagnosis using multivariable logistic regression with adjustment for relevant clinical characteristics. Results Overall, the mean (SD) age was 58.6 (13.7) years; 67.6% of patients were male; and 63.2% were on antihypertensive drugs. The median estimated glomerular filtration rate (eGFR) was 43.8 mL/min/1.73 m2 and the median proteinuria was 0.5 g/day. Of the 891 patients, 497 (55.8%) had a clinical diagnosis discordant with pathological nephrosclerosis diagnosis, with chronic nephritic syndrome being the most common (> 75%) discordant clinical diagnosis. After multivariable adjustment, age (odds ratio 1.34, [95% confidence interval, 1.16–1.55], per 10 years increase), eGFR (1.10 [1.00–1.21], per 10 mL/min/1.73 m2 increase), and proteinuria (1.20 [1.03–2.16], per 1 g/day decrease) were found to be significantly associated with the clinicopathological discordance. Conclusions Patients with older age, higher eGFR, and lower proteinuria had significantly higher likelihood of being clinically diagnosed with other glomerular disease in patients with biopsy-proven nephrosclerosis. Our findings highlight the heterogeneous clinical phenotypes of nephrosclerosis and suggest the need for continuous improvement of clinical diagnostic accuracy as well as for wider kidney biopsy indications for nephrosclerosis.

Central renal cell carcinoma: a diagnostic dilemma

Centrally Located renal tumor poses a diagnostic challenge to differentiate between renal cell carcinoma and transitional cell carcinoma. Imaging alone is not sufficient to make the diagnosis, some invasive diagnostic investigations are required to ascertain the diagnosis. We present a 60 years old gentleman, who presented dyspepsia and further investigation by contrasted CT kidney revealed a centrally located right renal tumor. Before making a management decision, we performed the right renal biopsy of the tumor which turns out to be a renal cell carcinoma. Henceforth, we performed a robotic-assisted laparoscopic right nephrectomy. A renal biopsy, in this case, assisted to decide only radical nephrectomy instead of radical nephroureterectomy which has higher associated morbidity. Thus, it is important to make confirm by tissue biopsy before deciding on surgery in case of the central renal tumor as this prevents subjecting a patient to under-or overtreatment.