What are the next steps for an adult patient with a history of hypertension or diabetes, presenting with proteinuria (30g/l) and hematuria (25 erythrocytes/ul) on routine urinalysis?

Immediate Nephrology Referral Required

This patient requires urgent nephrology referral for consideration of renal biopsy, as the combination of severe proteinuria (30 g/L) and hematuria (25 RBCs/µL) strongly indicates glomerular disease that demands immediate evaluation. 1, 2

Critical Initial Steps

Confirm and Quantify the Findings

• Verify microscopic hematuria with ≥3 RBCs per high-power field on properly collected urine specimens, as dipstick alone has limited specificity (65-99%) 1, 2
• Quantify proteinuria immediately using spot urine protein-to-creatinine ratio or 24-hour urine collection—30 g/L represents massive nephrotic-range proteinuria that is highly abnormal 2, 3
• Examine urinary sediment specifically for dysmorphic RBCs (>80% indicates glomerular origin) and red cell casts (pathognomonic for glomerular disease) 1, 2

Essential Laboratory Workup Before Nephrology Referral

• Complete metabolic panel including serum creatinine, BUN, albumin, and total protein to assess renal function and degree of hypoalbuminemia 1, 3
• Complement levels (C3, C4) to evaluate for post-infectious glomerulonephritis or lupus nephritis 1, 3
• Antinuclear antibody (ANA) and ANCA testing if vasculitis is suspected based on systemic symptoms 1
• Hepatitis B and C serologies if risk factors are present, as these can cause membranous nephropathy 3
• Complete blood count with platelets to evaluate for underlying systemic disease 1

Why This Patient Needs Urgent Nephrology Referral

The combination of findings makes glomerular disease virtually certain:

• Severe proteinuria (30 g/L) far exceeds the threshold of >1,000 mg/24 hours (or protein-to-creatinine ratio >1.0) that mandates urgent nephrology referral 3
• Concurrent hematuria with massive proteinuria significantly increases likelihood of glomerular disease requiring biopsy 2, 3
• Patients with hypertension or diabetes presenting with this degree of proteinuria may have diabetic nephropathy, hypertensive nephrosclerosis, or superimposed glomerulonephritis 4

Specific Nephrology Referral Indications Met

• Proteinuria >1,000 mg/24 hours with abnormal renal function 3
• Persistent significant proteinuria (protein-to-creatinine ratio >0.2 for three specimens) 1
• Presence of red cell casts or >80% dysmorphic RBCs if found 1, 2
• Hypertension with hematuria and proteinuria 1

Concurrent Urologic Evaluation Considerations

Do not delay nephrology referral to complete urologic workup first, but recognize that urologic causes must still be excluded:

• Age and risk factors matter: If patient is >40 years with smoking history or occupational chemical exposure, urologic malignancy remains in differential despite glomerular features 1, 2
• Malignancy can coexist with medical renal disease—both evaluations should ultimately be completed, though nephrology takes priority given severity of proteinuria 1
• Multiphasic CT urography and cystoscopy can be coordinated after nephrology evaluation if urologic risk factors are present 1, 2

Management Pending Nephrology Evaluation

Blood Pressure Control

• Target BP <130/80 mmHg if proteinuria <1 g/day, or **<125/75 mmHg** when proteinuria >1 g/day 4
• Initiate ACE inhibitor or ARB immediately for antiproteinuric effect, uptitrating as tolerated to achieve proteinuria reduction 4

IgA Nephropathy Considerations

Given the patient's history of hypertension or diabetes, IgA nephropathy is a leading diagnostic consideration:

• Proteinuria >1 g/day indicates higher-risk disease requiring aggressive BP control and renin-angiotensin-aldosterone system inhibition 4
• Oxford Classification features on biopsy (mesangial hypercellularity, endocapillary proliferation, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis) will guide prognosis 4
• Time-averaged proteinuria >1 g/day predicts progressive GFR loss 4

Critical Pitfalls to Avoid

• Never attribute this degree of proteinuria to diabetes or hypertension alone without excluding primary glomerular disease—renal biopsy is essential 4, 5
• Do not delay referral because "renal function is normal"—proteinuria of this magnitude indicates active glomerular injury regardless of current GFR 5
• Renal pathologic changes do not always coincide with clinical manifestations—patients with hematuria and proteinuria found on routine examination do not necessarily have favorable outcomes 5
• Never ignore this finding even if patient is asymptomatic—26% of similar patients have renal insufficiency and 48% have hypertension at time of biopsy 5

Expected Nephrology Workup

The nephrologist will likely proceed with:

• Renal biopsy to establish definitive diagnosis, as this degree of proteinuria with hematuria requires histologic confirmation 4, 5
• Immunosuppressive therapy consideration depending on biopsy findings (e.g., corticosteroids for FSGS with nephrotic syndrome, cyclophosphamide or MMF for lupus nephritis) 4
• Risk stratification using clinical features (proteinuria degree, hypertension, GFR) and pathological features (Oxford Classification for IgA nephropathy, ISN/RPS classification for lupus) 4

Bottom line: This patient needs nephrology referral within days, not weeks—30 g/L proteinuria with hematuria represents severe glomerular disease requiring urgent diagnostic evaluation and treatment to prevent irreversible kidney damage. 1, 2, 3