IgA nephropathy is the most common glomerular disease worldwide. Often asymptomatic, it is typically discovered incidentally during routine health check-ups. Today, we will discuss the causes, diagnosis, prognosis, and treatment of IgA nephropathy.
What is IgA Nephropathy?
IgA nephropathy is a kidney disease that occurs when IgA (Immunoglobulin A), a type of antibody, deposits in the kidneys, particularly in the glomeruli (the tiny filtering units of the kidney). While the exact cause is unknown, it is considered a type of autoimmune disorder where the immune system dysfunctions, leading to excessive production of IgA that accumulates in the kidneys.
Though it can affect individuals of all ages, it is most commonly diagnosed in teenagers and young adults.
What Are the Symptoms?
- Asymptomatic Detection
- Example: A 34-year-old woman undergoes a health check-up where multiple red blood cells and mild proteinuria (1+) are detected in her urine. Her blood pressure and kidney function are normal.
- In about 30% of cases, IgA nephropathy is discovered accidentally during a health check-up due to urinary abnormalities such as hematuria (blood in the urine) and proteinuria (protein in the urine). Microscopic hematuria is common, which means blood can be detected under a microscope but is not visible to the naked eye.
- Hematuria Following Upper Respiratory Infections
- Example: A 17-year-old male experiences cola-colored red urine two days after a cold. His condition resolves naturally within a week.
- Hematuria may appear within three days after an upper respiratory infection, such as a cold, and is common in young men and children under 25. Symptoms may include fatigue, muscle aches, and flank pain, but other serious signs are usually absent. Hematuria may persist for several days and can reoccur.
- Nephrotic Syndrome
- Example: A 23-year-old woman shows signs of swelling (edema), high blood pressure, and proteinuria with normal kidney function.
- Though rare, IgA nephropathy can manifest as nephrotic syndrome, characterized by swelling, high blood pressure, and significant proteinuria.
- Progression to Chronic Kidney Disease
- Example: A 45-year-old male presents with swelling, high blood pressure, anemia, and worsening kidney function, eventually preparing for dialysis.
- In advanced stages, IgA nephropathy can progress to chronic kidney disease (CKD), highlighting the importance of early detection.
How is IgA Nephropathy Diagnosed?
The gold standard for diagnosing IgA nephropathy is a kidney biopsy. Urine or blood tests alone cannot confirm the condition. A biopsy involves removing a small portion of kidney tissue to examine the deposits of IgA in the glomeruli.
Prognosis and Classification: The prognosis varies depending on the histological findings. The Oxford Classification is a commonly used system to evaluate IgA nephropathy and predict outcomes, with factors such as glomerular crescent formation, glomerulosclerosis, and interstitial fibrosis indicating poorer prognosis.
What is the Prognosis?
IgA nephropathy has a variable course. While many individuals experience a favorable outcome, some may progress to end-stage kidney failure. Studies show that 25-30% of people with IgA nephropathy may gradually develop end-stage renal disease (ESRD) over 20-25 years, requiring dialysis or kidney transplantation.
- Good Prognosis: Many patients exhibit a relatively stable condition with minor proteinuria and normal kidney function.
- Poor Prognosis: The risk of progressing to ESRD is higher in patients with:
- Reduced kidney function at diagnosis (elevated serum creatinine).
- Persistent proteinuria.
- Hypertension.
- Older age.
- Men are at a higher risk for poorer outcomes.
- Severe kidney biopsy findings (e.g., crescent formation, sclerosis).
Treatment Options for IgA Nephropathy
According to the 2020 KDIGO guidelines (Kidney Disease: Improving Global Outcomes), treatment for IgA nephropathy typically includes:
- Blood Pressure Control:
- The first line of treatment includes angiotensin-converting enzyme inhibitors (ACE inhibitors) or angiotensin receptor blockers (ARBs). These medications help control blood pressure and reduce proteinuria, which protects the kidneys.
- Proteinuria Management:
- For patients with proteinuria greater than 0.5 grams per day, ACE inhibitors or ARBs are also used to control protein levels in the urine.
- High-Dose Steroids:
- In patients with significant proteinuria (greater than 1 gram per day), high-dose steroid treatment may be indicated to reduce inflammation and prevent progression to CKD. However, steroids should be avoided in cases with low glomerular filtration rate (GFR), diabetes, obesity, recent infections, or active ulcers.
- Lifestyle Modifications:
- Recommendations include weight loss, regular exercise, smoking cessation, and a low-salt diet to support overall kidney health.
- Omega-3 Fatty Acids:
- Long-term use of omega-3 fatty acids may be beneficial as a supplement for reducing inflammation and supporting kidney function.
When Is Surgery or More Aggressive Treatment Necessary?
Surgery or more invasive treatments may be needed in the following situations:
- When distinguishing between benign and malignant cysts is difficult.
- If the cysts are large (greater than 6 cm).
- If the cysts cause significant symptoms such as flank pain, obstruction, or adjacent tissue atrophy.
- If infections or hypertension related to the cysts occur.
In such cases, biopsy, aspiration, or surgical removal may be necessary.
Conclusion
IgA nephropathy is the most common primary glomerular disease worldwide. Although it often presents without symptoms and is detected incidentally, early diagnosis is crucial for better management. The disease progresses at varying rates, but with appropriate treatment, the prognosis can be favorable for most people. If you experience any urinary abnormalities or have a family history of kidney disease, it’s important to seek medical attention early.