What is the treatment for a patient with hematuria and significant proteinuria (30 mg of protein)?

Treatment for Hematuria and Proteinuria

For a patient with hematuria and proteinuria (30 mg), referral to nephrology is recommended for comprehensive evaluation and management, as this combination suggests possible glomerular disease requiring specialized assessment. 1

Initial Assessment

• The combination of hematuria and proteinuria, even at relatively low levels (30 mg), warrants careful evaluation as it may indicate underlying renal parenchymal disease 1
• Exclude benign causes of hematuria first, including menstruation, vigorous exercise, sexual activity, viral illness, trauma, and infection 1
• Assess for dysmorphic red blood cells or red cell casts, which are suggestive of glomerular bleeding and require evaluation for primary renal disease 1
• Evaluate for risk factors that may indicate more serious urologic disease, including smoking history, chemical exposure, age >40 years, history of gross hematuria, or recurrent UTIs 1

Diagnostic Approach

• Confirm proteinuria with a spot urine protein/creatinine ratio (PCR), as dipstick testing alone may yield false positives, especially in the presence of hematuria 1, 2
• A PCR ratio ≥30 mg/mmol (0.3 mg/mg) is considered abnormal 1
• Examine urinary sediment for red cell morphology - dysmorphic RBCs suggest glomerular origin, while normal "doughnut-shaped" RBCs suggest lower urinary tract bleeding 1
• High specific gravity and hematuria are strong predictors of false-positive proteinuria results on dipstick testing 2

Management Algorithm

For Isolated Proteinuria (30 mg) without Hematuria:

1. If proteinuria is between 0.5-1 g/day:

   • Initiate ACE inhibitor or ARB therapy 1
   • Losartan is specifically indicated for treatment of proteinuria in patients with type 2 diabetes and hypertension 3
   • Monitor blood pressure with target <130/80 mmHg 1

2. If proteinuria is <0.5 g/day:

   • Consider conservative management with periodic monitoring 1
   • ACE inhibitor or ARB may still be considered 1

For Combined Hematuria and Proteinuria (as in this case):

1. Primary recommendation: Refer to nephrology for evaluation 1

   • The combination suggests possible glomerular disease 1
   • Canadian Society of Nephrology recommends nephrology referral for persistent proteinuria >1 g/day, but the combination with hematuria warrants referral even at lower levels 1

2. While awaiting nephrology evaluation:

   • Initiate ACE inhibitor or ARB therapy if no contraindications exist 1
   • Monitor blood pressure with appropriate targets 1
   • Consider renal biopsy if glomerular disease is suspected 1

Special Considerations

• In patients with IgA nephropathy (a common cause of combined hematuria and proteinuria), ACE inhibitors or ARBs are recommended when proteinuria is between 0.5-1 g/day 1
• If proteinuria persists >1 g/day despite 3-6 months of optimized supportive care with ACE inhibitors/ARBs and blood pressure control, corticosteroid therapy may be considered if GFR >50 ml/min/1.73m² 1
• The presence of red cell casts is virtually pathognomonic for glomerular bleeding and should prompt immediate nephrology referral 1

Pitfalls to Avoid

• Do not dismiss low-grade proteinuria (30 mg) when combined with hematuria, as this combination increases the likelihood of significant renal disease 1
• Avoid relying solely on dipstick urinalysis in the presence of hematuria, as this can lead to false-positive proteinuria results 2
• Do not delay nephrology referral when both hematuria and proteinuria are present, even at relatively low levels 1
• Remember that benign causes of isolated proteinuria or hematuria are less likely when both findings are present simultaneously 4, 5