Essential Diagnostic Tests for Chronic Glomerulonephritis: A Comprehensive Guide to Early Detection and Monitoring
Chronic glomerulonephritis (CGN) is a progressive, long-term kidney disorder that often develops silently—without obvious symptoms in its early stages. Timely and accurate diagnosis is critical to slow disease progression, prevent irreversible kidney damage, and reduce the risk of complications such as hypertension, fluid retention, and eventual kidney failure. A well-structured diagnostic workup combines non-invasive imaging, urinalysis, and comprehensive blood testing to assess kidney structure, filtration function, and underlying systemic contributors.
1. Urinalysis: The First-Line Window into Kidney Health
Urinalysis remains the cornerstone of CGN evaluation—not only for detection but also for ongoing monitoring. A microscopic urine sediment exam is especially valuable: the presence of dysmorphic red blood cells (RBCs) or RBC casts strongly suggests glomerular injury rather than lower urinary tract bleeding. This distinction helps clinicians determine whether hematuria originates from the kidneys themselves—a hallmark sign of glomerulonephritis.
Beyond hematuria, quantifying urinary protein excretion is essential. A 24-hour urine collection or, more conveniently, a spot urine albumin-to-creatinine ratio (UACR) provides reliable insight into glomerular permeability. Persistent proteinuria (>150 mg/day or UACR >30 mg/g) signals ongoing inflammation and podocyte damage—and correlates closely with long-term renal outcomes.
2. Comprehensive Blood Testing: Beyond Basic Renal Function
Serum creatinine and estimated glomerular filtration rate (eGFR) are standard markers of overall kidney filtration capacity—but they reflect late-stage changes. For early and holistic assessment, clinicians routinely order an expanded panel:
Key Blood Biomarkers Include:
- Kidney function markers: Cystatin C (a more sensitive eGFR estimator), blood urea nitrogen (BUN), and electrolytes (especially potassium and bicarbonate)
- Metabolic screening: Fasting glucose, HbA1c, lipid profile (LDL, HDL, triglycerides)—since metabolic syndrome accelerates CKD progression
- Liver and systemic health indicators: ALT, AST, total protein, albumin, and complete blood count (CBC) to rule out overlapping conditions like hepatitis-associated nephropathy or anemia of chronic disease
- Autoimmune and inflammatory workup: ANA, anti-dsDNA, ANCA (MPO/PR3), complement levels (C3, C4), and serum immunoglobulins—critical for identifying lupus nephritis, vasculitis, or IgA nephropathy
3. Renal Ultrasound: Assessing Anatomy, Structure, and Flow
Renal ultrasound is a safe, radiation-free imaging modality that delivers vital structural insights. In chronic glomerulonephritis, it typically reveals diffuse echogenicity changes, cortical thinning, and reduced kidney size—especially in advanced stages. Importantly, ultrasound helps differentiate primary glomerular disease from secondary causes like obstructive uropathy or polycystic kidney disease.
Modern Doppler ultrasound adds functional value by evaluating intrarenal blood flow resistance indices. Elevated resistive index (RI >0.7) may indicate microvascular injury and correlate with interstitial fibrosis—making it a useful prognostic tool alongside traditional lab values.
Why a Multimodal Approach Matters
No single test can definitively diagnose or stage chronic glomerulonephritis. Instead, integration across domains—urine findings, blood biomarkers, and imaging—is key. Emerging tools like urinary NGAL, KIM-1, or serum suPAR are gaining traction in research settings, but today's gold-standard clinical pathway still hinges on this triad. Early identification allows for timely intervention: blood pressure control (with ACE inhibitors or ARBs), sodium restriction, SGLT2 inhibitor therapy, and referral to nephrology when eGFR falls below 60 mL/min/1.73m² or proteinuria exceeds 1 g/day.
Regular follow-up—including repeat urinalysis, eGFR tracking, and annual renal ultrasound in high-risk patients—empowers proactive management and significantly improves long-term kidney survival.