IgA nephropathy—also called Berger’s disease—is a kidney disorder where deposits of immunoglobulin A (IgA) accumulate in the glomeruli, the blood-filtering structures within the kidneys. These deposits trigger inflammation, impair filtration, and can progress to chronic kidney disease over many years. While this condition can present with mild symptoms in some individuals, others may experience significant kidney damage. Effective management depends on early detection, careful monitoring, and treatment tailored to disease severity.
Causes and Risk Factors
IgA nephropathy results from the accumulation of abnormal IgA antibodies in kidney glomeruli, which initiates inflammatory reactions. Factors influencing this process include:
- Immune dysregulation: Altered IgA structure and clearance mechanisms lead to immune complexes depositing in the kidneys.
- Genetic predisposition: Family history of kidney or autoimmune disorders raises risk.
- Environmental factors: Recurrent respiratory or gastrointestinal infections often precede episodes of blood in the urine.
- Coexisting conditions: Hypertension, obesity, and metabolic syndrome may exacerbate disease progression.
Symptoms and Clinical Features
The presentation of IgA nephropathy varies greatly among patients:
- Hematuria: Blood in the urine is the hallmark—either visible (dark or red) during infection-triggered episodes or detected microscopically during routine examinations.
- Proteinuria: Elevated urinary protein may appear as foamy urine and often signals advancing kidney injury.
- High blood pressure: Often develops over time and contributes to kidney damage if not controlled.
- Edema: Swelling around the eyes, hands, or feet may result from protein loss and fluid imbalance.
- Declining kidney function: Indicated by elevated serum creatinine or decreasing eGFR over time.
Diagnosis
Diagnosis involves clinical evaluation and laboratory tests:
- Urinalysis: Confirms red blood cells, protein, and casts in urine samples.
- Blood tests: Measure kidney function via serum creatinine, estimate eGFR, and assess proteinuria.
- Imaging: Ultrasound may assess kidney size and rule out obstruction.
- Kidney biopsy: The definitive test revealing IgA deposits in glomeruli via immunofluorescence microscopy.
Clinical Course and Progression
IgA nephropathy follows a variable course. Some individuals maintain stable kidney function for years, while others experience gradual progression toward chronic kidney disease (CKD):
- Early phase: Often includes occasional hematuria and mild proteinuria with minimal impact on kidney function.
- Intermediate phase: Rising proteinuria (over 1 g/day), persistent microscopic hematuria, and earlyhypertension may appear.
- Late phase: Continued proteinuria, reduced eGFR, significant hypertension, and possible edema. Up to 40% may reach CKD over decades if untreated.
The rate of progression varies and depends on factors such as amount of proteinuria, sustained hypertension, initial decline in eGFR, and active inflammation on biopsy.
Treatment Strategies
Although there is no cure, treatments aim to reduce proteinuria, control blood pressure, minimize inflammation, and slow progression:
Supportive and Standard Care
- Blood pressure control: ACE inhibitors or ARBs are first-line treatments, reducing proteinuria and protecting kidney function.
- Proteinuria reduction: Optimal control of blood pressure often leads to reduced protein leakage.
- Lifestyle modifications: Adopt a balanced diet, maintain healthy weight, exercise, limit salt, and avoid smoking.
Immunosuppressive Therapy
- Corticosteroids: Considered when proteinuria exceeds 1 g/day despite supportive care and kidney function remains adequate.
- Other agents: Immunosuppressants like mycophenolate or cyclophosphamide may be used in selected cases but require careful monitoring for side effects.
Nephroprotective Adjuncts
- SGLT2 inhibitors: Originally developed for diabetes, these drugs have shown benefit in reducing progression of proteinuric kidney diseases.
- Dietary protein restriction: May be advised for patients with persistent high proteinuria.
Monitoring and Follow-Up
Effective management requires ongoing surveillance:
- Routine urinalysis: Every 3–6 months to track hematuria and proteinuria trends.
- eGFR and creatinine: Monitored every 3–6 months or more frequently with declining kidney function.
- Blood pressure: Regular checks and home monitoring to maintain targets below 130/80 mmHg.
- Specialist input: Referral to nephrology may be indicated if proteinuria remains elevated or eGFR continues to decline.
Long-Term Outlook
Long-term outcomes vary. Up to 30–40% of patients progress to CKD within 10–20 years. However, early diagnosis and intervention can slow this progression significantly:
- Positive indicators: Low proteinuria, well-controlled blood pressure, and stable eGFR.
- Negative indicators: High proteinuria, uncontrolled hypertension, histological evidence of inflammation, and descending eGFR curve.
Conclusion
IgA nephropathy is a complex and variable condition affecting kidney filtering units. With proper monitoring, early intervention, and a personalized treatment plan, it is possible to slow disease progression and preserve kidney function. Patients with persistent proteinuria, declining eGFR, or high blood pressure should collaborate closely with healthcare providers to optimize care and improve long-term outcomes.