IgA nephropathy, also known as Berger’s disease, is a kidney disorder marked by the deposition of immunoglobulin A (IgA) in the glomeruli—the kidney’s filtering units. This immune-mediated process often results in inflammation, progressive kidney damage, and diverse clinical outcomes. As one of the most common primary glomerular diseases globally, IgA nephropathy can range from isolated urinary abnormalities to chronic kidney disease (CKD).
Causes and Risk Factors
IgA nephropathy is thought to result from an abnormal immune response, where altered IgA molecules deposit in the glomeruli and trigger inflammation. Several factors contribute to its development:
Immune dysfunction: Aberrantly glycosylated IgA forms immune complexes that accumulate in the kidney.
Genetic predisposition: A family history increases susceptibility, indicating a possible inherited component.
Environmental triggers: Respiratory or gastrointestinal infections often coincide with disease flares.
Other factors: Hypertension, obesity, and metabolic conditions may accelerate kidney damage.
Clinical Presentation and Symptoms
Symptoms of IgA nephropathy vary significantly. Common features include:
Hematuria: Visible (gross) blood in the urine, often following infections, or microscopic hematuria detected on testing.
Proteinuria: Presence of protein in urine, which may appear foamy; persistent proteinuria suggests ongoing kidney damage.
Hypertension: Elevated blood pressure is common, especially in advanced stages.
Edema: Swelling in the hands, feet, or around the eyes due to significant protein loss.
Decline in kidney function: Indicated by rising serum creatinine and falling estimated glomerular filtration rate (eGFR).
Diagnosis
A diagnosis is established through clinical assessment and diagnostic testing:
Urinalysis: Detects red blood cells, protein, and urinary casts.
Blood tests: Evaluate kidney function (creatinine, eGFR) and quantify proteinuria.
Imaging: Renal ultrasound helps rule out structural abnormalities.
Kidney biopsy: Confirms the diagnosis by revealing IgA deposits in glomeruli under immunofluorescence.
Clinical Course and Prognosis
The progression of IgA nephropathy is unpredictable. Some individuals maintain stable kidney function with minimal abnormalities, while othersprogress to CKD over time. Risk factors for progression include:
Persistent proteinuria over 1 gram/day
Reduced eGFR at diagnosis
Frequent gross hematuria
Poorly controlled hypertension
Early detection and appropriate treatment can slow progression, though regular monitoring remains essential.
Treatment and Management Strategies
There is currently no cure, but treatment focuses on preserving kidney function and reducing inflammation.
Supportive Therapies
Blood pressure control: ACE inhibitors or ARBs are first-line options that reduce both blood pressure and proteinuria.
Proteinuria reduction: Treatment is titrated based on the protein/creatinine ratio.
Lifestyle interventions: Dietary sodium restriction, weight management, and regular exercise are beneficial.
Immunosuppressive Therapies
Corticosteroids: Used in patients with high-risk features or persistent proteinuria despite supportive care.
Other agents: Cyclophosphamide, mycophenolate mofetil, or calcineurin inhibitors may be considered in select cases.
Emerging and Adjunctive Options
SGLT2 inhibitors: Though originally for diabetes, they may help preserve kidney function in IgA nephropathy.
Targeted therapies: Investigational treatments, including complement inhibitors, are being studied to interrupt inflammatory pathways.
Monitoring and Follow-Up
Ongoing follow-up is key to managing IgA nephropathy:
Urine testing: Every 3–6 months to track hematuria and proteinuria.
Kidney function tests: eGFR and creatinine monitored regularly.
Blood pressure checks: Both at home and in clinic settings.
Specialist care: Referral to a nephrologist is important if kidney function worsens or proteinuria remains high.
Long-Term Outlook and Lifestyle Impact
With careful management, many patients retain kidney function long-term. However, a portion will eventually develop end-stage kidney disease requiring dialysis or transplantation. Supportive care, lifestyle changes, and patient education play crucial roles in long-term outcomes.
Conclusion
IgA nephropathy is a complex and often unpredictable kidney disease. While a cure remains elusive, early diagnosis, consistent monitoring, and tailored therapy—including blood pressure control, reduction of proteinuria, and emerging treatments—can help preserve kidney function and improve quality of life. Ongoing care and patient engagement are essential for managing the condition effectively.