Nutcracker phenomenon in combination with glomerular nephritis in isolated hematuria patients

This study aims to analyze the relationship between nutcracker syndrome (NCS) and nutcracker phenomenon (NCP) in glomerular nephritis (GN) of patients with symptom of isolated hematuria. Our observations reveal that patients with combined GN and NCP/NCS have dysmorphic urine red blood cells or mixed-morphological urine red blood cells while patients with NCS only (without GN) contain isomorphic urine red blood cells.

Clinical and pathological data of 32 patients with NCP and complicating GN were analyzed. A different group of 17 patients with NCS served as the control. All patients underwent color Doppler ultrasonography. Routine urine examination, red blood cell counts, and phase observations of urinary sediments were performed both before and after exercise. twenty four hour urinary protein and albumin quantities were determined. Twenty-nine patients underwent renal needle biopsy.

All 32 patients were diagnosed with NCP. Results of urinary sediment examination of patients were either normal or showed isomorphic hematuria before exercise. Most patients exhibited mixed-morphological or dysmorphic hematuria at different degrees after exercise. Renal pathological findings in 29 patients included multiple types and showed no relevance to urinary examination results. All patients diagnosed with GN complicated by NCP were identified through clinical and laboratory examinations and renal biopsy.

NCP may coexist with a glomerular disease. NCS patients with urine red blood cells of mixed morphology or showing dysmorphism after exercise should be noted, with or without the coexistence of GN. Renal needle biopsy must be performed when necessary to avoid adverse effects on the patient's condition.