Studies suggest that high IgA can be a marker of chronic infections and low-grade inflammation. Read on to learn about the causes of high IgA levels and how they may impact health.
What Do High IgA Levels Mean?
A Signal of Chronic Inflammation/Infection
High IgA can indicate chronic inflammation or an infection.
Most labs consider values above 400 mg/dL in adults high. The upper limit varies by age and is lower in children and adolescents.
IgA is also elevated in people with:
- Liver damage [1, 2]
- IBD (can also be decreased) 
- After heart attacks 
- Diabetes and diabetic complications (mixed results — elderly diabetics may have lower levels) [5, 6]
- Fatty liver, liver damage and inflammation (NASH) 
- Hepatitis B and liver injury 
- Obesity 
- Metabolic syndrome (a term used to describe a group of conditions including high blood sugar levels, high blood pressure, high triglycerides, low HDL cholesterol, and excess fat around the stomach) 
- Alcoholism [7, 8]
- IgA nephropathy or Berger’s disease 
- Multiple myeloma (cancer of a specific type of white blood cells called plasma cells) 
There are no symptoms associated with high IgA levels. Instead, people with high IgA may only show symptoms from infections or inflammatory disorders. Your doctor will discuss your results with you. He or she may run additional tests to pinpoint the underlying cause of your high levels.
IgA Vasculitis & Nephropathy
IgA vasculitis occurs when IgA accumulates in the blood vessels; IgA nephropathy occurs when IgA accumulates in the kidneys.
In IgA vasculitis, IgA deposits in small blood vessels where it causes inflammation. Common symptoms are skin rash, joint pain, and swelling.
IgA vasculitis is more common among children, where the disease usually resolves within several weeks and requires no treatment. In adults, it can be more complicated and longer-lasting, with more severe kidney disease .
In IgA nephropathy, IgA complexes are deposited in kidneys. About 20 to 50% of patients develop progressive kidney failure .
High IgA usually points to chronic infections or inflammation, though diverse disorders can raise its levels. In adults, values above 300 mg/dL are considered high by most labs. High levels do not cause any symptoms. Symptoms depend on the underlying cause and health status, which should be evaluated by a physician.