IgA Nephropathy (Berger's disease, IgAN)

IgA nephropathy affects the glomeruli, the tiny filters inside the kidneys. Current understanding describes a multi-step process in which the body produces a form of IgA1 antibody that is deficient in galactose, a sugar molecule normally attached to it. The immune system then appears to generate antibodies against this altered IgA1, and the resulting immune complexes settle in the glomerular mesangium, triggering inflammation, cell proliferation, and gradual damage to the filtering structures.

IgA nephropathy is considered the most common primary glomerulonephritis worldwide, though its frequency varies widely by region and is described as higher in parts of Asia and Europe and lower in populations of African descent. Research describes a wide range in long-term outcomes, and it is thought that a meaningful share of people with the condition eventually progress toward reduced kidney function, which is part of why early detection and specialist follow-up matter.

Common signs

Often there are no symptoms early on. When they appear, people may notice blood in the urine (sometimes visible, often during or just after a cold or sore throat), foamy urine from protein, swelling in the hands and feet, pain in the back below the ribs, high blood pressure, and tiredness.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.