From the Guidelines
Evaluation for glomerular diseases requires a comprehensive approach including clinical assessment, laboratory tests, and often kidney biopsy, as recommended by the most recent KDIGO 2021 clinical practice guideline for the management of glomerular diseases 1. The approach to evaluating glomerular diseases should begin with a thorough history and physical examination, focusing on symptoms like edema, hematuria, and hypertension.
- Essential laboratory tests include:
- Urinalysis to detect proteinuria and hematuria
- Quantitative protein measurements (spot urine protein-to-creatinine ratio or 24-hour urine collection)
- Serum creatinine to assess kidney function
- Complete blood count, serum albumin, and lipid panel should be ordered to evaluate for nephrotic syndrome features.
- Serological tests are crucial and should include:
- Complement levels (C3, C4)
- Antinuclear antibody (ANA)
- Anti-neutrophil cytoplasmic antibodies (ANCA)
- Anti-glomerular basement membrane antibodies
- Hepatitis B and C serologies
- HIV testing
- Serum and urine protein electrophoresis when appropriate Renal ultrasound helps assess kidney size and structure. A kidney biopsy remains the gold standard for definitive diagnosis, providing information on the specific glomerular pathology through light, immunofluorescence, and electron microscopy, and is typically indicated when there is significant proteinuria (>1g/day), unexplained acute kidney injury, or systemic disease with renal involvement 1. The comprehensive evaluation allows for accurate diagnosis and appropriate treatment planning for the specific glomerular disease identified, with consideration of the latest clinical practice guidelines and evidence-based recommendations 1.
From the Research
Approach to Evaluate Glomerular Diseases
The approach to evaluate glomerular diseases involves several steps and considerations, including:
- Laboratory tests to assess kidney function and damage, such as estimated glomerular filtration rate (eGFR) and urinary albumin excretion 2
- Urinalysis to provide information on localization and differentiation of kidney diseases 2
- Measurement of serum creatinine and blood urea nitrogen to diagnose kidney disease 3
- Kidney biopsies to determine the histologic diagnosis of patients with elevated serum creatinine and a concurrent normal urinalysis 3
Diagnostic Tests
Diagnostic tests for glomerular diseases include:
- Protein/creatinine ratio in urine samples to estimate 24-h proteinuria in patients with primary glomerulopathies 4
- New promising diagnostic tests, such as those for focal segmental glomerulosclerosis, membranous nephropathy, IgA nephropathy, and C3 glomerulopathies 5
- Urinary albumin excretion as a marker of kidney damage 2
Therapeutic Interventions
Therapeutic interventions for glomerular diseases include:
- Inhibition of the renin-angiotensin system (RAS) to retard chronic kidney disease (CKD) progression 6
- Statins and spironolactone to decrease the rate of CKD progression independently or in addition to RAS inhibition 6
- New therapeutic interventions, such as the pituitary hormone ACTH, the monoclonal antibody rituximab, and the monoclonal blocker of the fifth component of complement, eculizumab 5