An unusual form of kidney injury without glomerulonephritis in microscopic polyangiitis: a case report.

BACKGROUND: Microscopic polyangiitis (MPA), a kind of antineutrophil cytoplasmic autoantibody associated vasculitis (AAV), predominantly affects small-sized vessels. MPA is a significant cause of the pulmonary-renal syndrome. Pauci-immune necrotizing and crescentic glomerulonephritis is the typical renal histological feature of AAV. Tubulointerstitial lesions may occur and mostly form with inflammatory cell infiltration in the interstitium. However, a few cases reported only tubulointerstitial involvement without glomerular lesions in patients with MPA. CASE PRESENTATION: We present an MPA case, a 70-year-old male patient diagnosed with acute kidney injury accompanying the dialysis requirement. Only acute tubulointerstitial nephritis was revealed in kidney biopsy without evidence of glomerular injury. Also, interstitial pulmonary fibrosis was determined on computerized tomography, and myeloperoxidase antineutrophil cytoplasmic autoantibody was positive. Consequently, we have considered the main diagnosis as MPA. We did not prefer a standard tubulointerstitial nephritis treatment regimen due to the presence of life-threatening systemic vasculitis. Treatment was established like crescentic glomerulonephritis. Induction therapy consisted of pulse steroid, cyclophosphamide, and plasmapheresis. Unfortunately, severe SARS-CoV-2 infection caused death during induction therapy in this case. CONCLUSIONS: The lack of glomerular injury and solely interstitial inflammation is atypical regarding AAV involvement in the kidney. This diversity might be initially considered as only a simple histological elaboration. However, it is a significant entity for guiding the treatment of AAV.

Relationship between disease awareness and severity of kidney disease in autosomal dominant polycystic kidney disease patients.

INTRODUCTION: Polycystic kidney disease (PKD) is responsible for 5%-10% of end-stage renal disease. We examined the relationship between renal and extrarenal findings, disease severity, and the level of consciousness of PKD patients. METHODS: Patients were asked to answer the questionnaire about PKD. Disease severity was determined according to estimated glomerular filtration rate, and disease awareness was assessed by adapting the Disease Perception Scale to PKD. Awareness of patients was evaluated comparatively with chronic kidney disease stage, age, region, and symptoms. RESULTS: One out of five patients does not know that this disease is inherited. Mean awareness scores of the patients decreased significantly with increasing age. Awareness scores were significantly higher in patients with flank pain, hematuria, and urinary tract stones. CONCLUSION: Although PKD is the most common hereditary kidney disease, the rate of patients' knowledge on this subject is low. Increased awareness might lead to better treatment in those patients.

The effect of sodium exchange and dialytic biochemical parameters on blood pressure, arterial stiffness, and endothelial functions in patients with peritoneal dialysis.

OBJECTIVE: This study aimed to investigate the relationship between fluid and sodium excretion and blood pressure, echocardiographic parameters, and arterial stiffness in peritoneal dialysis (PD) patients and to evaluate the effect of sodium excretion on patients' survival. METHOD: This study was conducted as a single-centered, prospective study in the Department of Nephrology in Erciyes University. The patients included in the study were followed up for 3 years. Seventy PD patients were included in the study. We recorded demographic characteristics, biochemical parameters, urine and peritoneal ultrafiltration volumes, peritoneal equalization tests, ambulatory blood pressure measurements, and echocardiographic measurements. We measured the amount of total sodium excretion of the patients and arterial stiffness using pulse wave velocity (PWV). Patients were divided into two groups based on the amount of total sodium excretion: low group and high group. We compared these groups in terms of cardiac and biochemical parameters. RESULTS: When demographic data and biochemical values were compared, there was no significant difference between the two groups. NT-proBNP level, systolic blood pressure, and mean arterial pressure were significantly higher in the low group (p: 0.02, p: 0.031, p: 0.05, respectively). Net ultrafiltration was significantly higher in the high group (p: 0.03), was also found to be high in patients with high sodium excretion (p: 0.001). Negative correlations were found between sodium excretion and net ultrafiltration, NT-Pro BNP, and PWV. At the end of the 3-year follow-up, the survival rate was shorter and the mortality rate was higher in the low group (p: 0.042). DISCUSSION AND CONCLUSION: Fluid status in PD patients can affect arterial stiffness both directly and through hypertension. Correction of hypervolemia has the potential to not only prevent hypertension and left ventricular hypertrophy, but also to improve arterial stiffness, a well-known cardiovascular risk factor. The mortality rate was higher in PD patients with low total sodium excretion. Therefore, these patients should be followed more closely to ensure volume control.