Master IgA Nephropathy (Berger's Disease) with Picmonic for Medicine

IgA nephropathy falls under nephritic syndrome, which means the kidneys are inflamed. You’ll mainly see blood in the urine (hematuria), sometimes red blood cell casts, and mild to moderate proteinuria instead of the heavy protein loss seen in nephrotic syndrome. Kidney function can dip too because that inflammation affects filtration.

This is the number one cause of primary glomerular disease worldwide, especially in younger patients. If an exam asks for the most common primary glomerulonephritis, it’s IgA nephropathy.

IgA nephropathy shows up more often and tends to be more severe in East Asian populations. It’s less common in Caucasians and is rare in people of African descent, which helps with epidemiology questions.

The classic presentation is hematuria that starts at the same time or shortly after a sore throat, cold, or GI infection. This timing is key. It helps you tell it apart from post-strep GN, which shows up weeks later, not days.

Of all the things to monitor, protein in the urine tells you how the disease will progress. The more proteinuria, the higher the risk of long-term kidney damage. Persistent proteinuria is a red flag that the disease isn’t staying mild.

The inflammation isn’t just from IgA itself. The alternative complement pathway, especially C3, gets activated and adds fuel to the fire. This complement involvement helps explain the kidney damage seen on biopsy.

The body makes more IgA during respiratory or GI infections, which contributes to IgA immune complex buildup in the kidneys. In patients with IgA nephropathy, levels of plasma IgA are increased, and there is prominent deposition of IgA immune complexes in the mesangium.

The immune complexes made of IgA end up depositing in the mesangium, which is the central support area inside the glomerulus. Their presence is one of the hallmark features of this disease.

ACE inhibitors or ARBs are the first treatment choice. They help lower proteinuria and protect kidney function. KDIGO guidelines recommend starting RAAS blockade early as part of supportive care.

If a patient still has more than 1 g/day of proteinuria after proper supportive care, systemic corticosteroids may be added. They’re not for everyone because of side effects, so they’re reserved for those with higher-risk or progressive disease.