Hematuria: Diagnosis and Approach

• Approach to hematuria by Prof MY Chothia, Nephrology, Stellenbosch University

Case History

• 30-year-old male presents with "reddish-pink" urine and blood in the sputum

Further history: Absence of

• Trauma
• Dysuria
• Flank or suprapubic pain
• Recent strenuous exercise
• Use of anticoagulants or other drugs
• Lower urinary tract symptoms
• Recent surgery or lower urinary tract instrumentation

Urine Dipsticks

• Urine dipsticks are part of the clinical examination
• False positives on urine dipsticks can occur due to menstruation, urine pH > 8-9 or bacterial peroxidases
• False negatives on urine dipsticks can occur due to ascorbic acid

Selected Nonheme Causes of Pigmenturia, as Compared with Red Cells or Free Hemoglobin

• Variable urine color
  • Red to rusty with red cells
  • Pink to red with hemoglobin
  • Rusty with myoglobin
  • Turns black, brown, or red in sunlight with Porphyria
  • Brown with Bile Pigments
  • Turns dark in sunlight with Alkaptonuria
• Heme test results
  • Positive in red cells, hemoglobin, and myoglobin
  • Negative in Porphyria, Bile Pigments, and Alkaptonuria
• Usual microscopic findings
  • Red cells, casts with red cells
  • No cells with hemoglobin
  • No red cells; casts may be present with Myoglobin
  • Normal in Porphyria, Bile Pigments, and Alkaptonuria
• Plasma
  • Normal with red cells
  • Pink with hemoglobin
  • Normal with myoglobin, Porphyria, and Alkaptonuria
  • Icteric with Bile Pigments
• Table 1 shows the selected endogenous causes of pigmenturia
• A heme test for exogenous causes, including beets, rhubarb, azo dye, sulfonamides, and phenolphthalein, is negative

Urine Microscopy

• Urine microscopy is a method of examining urine samples under a microscope to identify various components, such as cells, casts, and crystals
• Dysmorphic RBCs are abnormally shaped red blood cells often associated with glomerular bleeding
• RBC casts are cylindrical structures composed of red blood cells, indicating kidney origin of hematuria

Types of Hematuria

• Glomerular hematuria
  • Micro- or macroscopic
  • Dysmorphic RBCs
  • RBC casts
  • Proteinuria >1g/d
  • Kidney dysfunction
• Non-glomerular
  • Micro- or macroscopic
  • Normal RBCs
  • No RBC casts
  • Proteinuria absent or < 0.5g/d
  • Other evidence of non-glomerular urinary tract pathology

Patient Results

• Urine microscopy revealed dysmorphic RBCs and RBC casts
• Laboratory results showed raised serum creatinine

Laboratory investigations for glomerular haematuria includes:

• MCGN, Anti-GBM disease, SLE, GPA/eGPA/microscopic PAN, Thrombotic microangiopathy, Alport disease, Fabry disease, Infection-related GN, PIGN AND Infective endocarditis
• C3/C4, HBV, HCV, SPEP, Cryoglobulins, ANA, CXR, anti-GBM Ab, C3/C4, ΑΝΑ, anti-dsDNA + anti-Sm Ab, PR3-ANCA, MPO-ANCA, eosinophil count, CXR, Anti-cardiolipin, LA Audiometry, Plasma alpha-galactosidase A activity, HIV, HBV, HCV, C3/C4, ASOT, Anti-DNAse B and Blood cultures, C3/C4, echocardiography, RF are also included

Definitive investigation for glomerular haematuria

• Involves a kidney biopsy

Pulmonary-renal syndrome

• Characterized by the combination of glomerulonephritis and alveolar hemorrhage
• Anti-GBM disease is linear, and Anti-GBM Ab +
• Immune-complex GN is granular
• ANCA vasculitis is pauci-immune