From the Research
Introduction to Evaluating Hematuria and Subnephrotic Range Proteinuria
Evaluating hematuria and subnephrotic range proteinuria requires a comprehensive approach, considering the patient's age, medical history, family history, and physical examination findings, as well as basic laboratory test results 1.
Diagnostic Evaluation
The diagnostic evaluation should include:
- Routine urinalysis to detect proteinuria and hematuria
- Measurement of proteinuria, which can be glomerular and/or tubular in origin, and may be transient, orthostatic, or persistent 2
- Assessment of hematuria, which can be gross or microscopic, and may originate from the glomeruli or other sites of the urinary tract 2
- Consideration of the patient's symptoms, such as edema, hypertension, or flank pain
Referral to Specialists
Patients with:
- Drug-resistant proteinuria
- Persistent hematuria with concomitant proteinuria
- A renal biopsy being considered should be referred to a nephrology subspecialist 1. Patients with abnormal genitourinary anatomy, trauma, stones, tumors, nonglomerular gross hematuria, or persistent microscopic hematuria should be referred to a urology subspecialist 1.
Importance of Kidney Biopsy
Kidney biopsy is essential in determining the underlying cause of subnephrotic range proteinuria, as it can help identify primary glomerulopathies, which are associated with a substantial risk of end-stage kidney disease (ESKD) and death 3.
Treatment and Management
Treatment and management of patients with hematuria and subnephrotic range proteinuria should be personalized, based on the underlying cause and severity of the disease. This may include:
- Monitoring of proteinuria and hematuria
- Control of blood pressure and proteinuria using angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs)
- Consideration of immunosuppressive therapy in patients with primary glomerulopathies
Caveats and Differentials
It is essential to consider the differential diagnoses of hematuria and proteinuria, including:
- Orthostatic proteinuria
- Glomerulonephritis
- Nephrotic syndrome
- Urologic causes of hematuria, such as stones or tumors A thorough evaluation and careful monitoring are necessary to avoid missing a serious underlying condition 4.
Conclusion
Evaluating hematuria and subnephrotic range proteinuria requires a comprehensive approach, considering the patient's clinical presentation, laboratory results, and underlying cause of the disease. A kidney biopsy may be necessary to determine the underlying cause and guide personalized treatment, as supported by studies such as 3 and 5.