What is the workup for Glomerulonephritis (GN)?

From the Guidelines

The workup for glomerulonephritis (GN) should include a comprehensive evaluation starting with a thorough history and physical examination, followed by laboratory tests including urinalysis with microscopy, complete blood count, comprehensive metabolic panel, and urine protein-to-creatinine ratio. Specific serologic tests should include complement levels (C3, C4), anti-nuclear antibody (ANA), anti-neutrophil cytoplasmic antibodies (ANCA), anti-glomerular basement membrane antibodies, hepatitis B and C serologies, HIV testing, and serum and urine protein electrophoresis 1. A 24-hour urine collection for protein and creatinine clearance provides valuable information about kidney function and degree of proteinuria. Imaging studies such as renal ultrasound should be performed to assess kidney size and structure. The definitive diagnosis often requires a kidney biopsy, which allows for histopathological examination, immunofluorescence, and electron microscopy to determine the specific type of glomerulonephritis. This comprehensive approach is necessary because different types of glomerulonephritis require different treatments, and early diagnosis and intervention can significantly improve outcomes by preventing progression to end-stage renal disease, as emphasized in the KDIGO 2021 guideline for the management of glomerular diseases 1. Management should be coordinated with a nephrologist who can guide appropriate therapy based on the specific diagnosis, with the goal of preventing disease progression and reducing proteinuria, as highlighted in the executive summary of the KDIGO 2021 guideline 1. Key considerations in the diagnostic strategy for rapidly progressive glomerulonephritis include evaluating for non-glomerular etiology of acute kidney injury, obtaining autoimmune serologies, and considering a kidney biopsy if feasible, as outlined in the KDIGO 2021 guideline 1. By following this comprehensive approach, clinicians can provide optimal care for patients with glomerulonephritis and improve their morbidity, mortality, and quality of life outcomes. Some key points to consider in the workup and management of glomerulonephritis include:

• The importance of a thorough history and physical examination in identifying potential causes and complications of glomerulonephritis
• The role of laboratory tests, such as urinalysis and serologic tests, in diagnosing and monitoring glomerulonephritis
• The need for imaging studies, such as renal ultrasound, to assess kidney size and structure
• The importance of kidney biopsy in determining the specific type of glomerulonephritis and guiding treatment
• The goal of preventing disease progression and reducing proteinuria in the management of glomerulonephritis, as emphasized in the KDIGO 2021 guideline 1.

From the Research

Workup for Glomerulonephritis (GN)

The workup for Glomerulonephritis (GN) involves a comprehensive approach to diagnose and manage the condition. The following steps are involved in the workup:

• A careful and complete examination of family history and medications used by the patient 2
• A thorough clinical examination, including skin, joints, and measurement of arterial blood pressure 2
• Laboratory analyses in blood, such as full blood screen, erythrocyte sedimentation rate, CRP, creatinine, urea, and glucose 2
• Urinalysis to look for hematuria, red cell casts, and proteinuria 2
• Quantification of proteinuria using a random urine sample, with proteinuria > 3g/d being diagnostic for glomerular damage 2
• Screening for infections, including search for HIV, hepatitis B or C, and various bacteria 2
• Screening for systemic inflammatory diseases, including tests for antibodies such as ANA, anti-dsDNA, ANCA, anti-GBM, and anti-CCP 2
• Radiological examinations, including an ultrasound of the kidney 2
• Renal biopsy to establish a firm diagnosis and define treatment options 2, 3, 4

Specialized Tests

Depending on the clinical circumstances and type of disease, specialized tests may be required, such as:

• Antibodies against phospholipase-A2-receptor in cases of membranous nephropathy 2
• Tumor screening, especially in cases of membranous and minimal-change nephropathy 2
• Complement system analysis in cases of C3 glomerulopathy 3, 4

Diagnosis and Treatment

The diagnosis and treatment of GN depend on the underlying cause and type of disease. The following are some of the key points to consider:

• C3 glomerulopathy (C3G) is a rare renal disease characterized by abnormal activation of the complement alternative pathway and abnormal deposition of C3 in the glomeruli 3
• Membranoproliferative glomerulonephritis (MPGN) is a heterogeneous group of diseases that can be idiopathic or secondary to other conditions 4
• Treatment of GN depends on the underlying cause and may involve immunosuppressive therapy, such as corticosteroids and antiproliferative drugs, as well as complement inhibitors and monoclonal antibodies 2, 3, 5, 4, 6