Definition

Macroamylasemia is the presence of an abnormal substance called macroamylase in the blood.

Causes

Macroamylase is a substance that consists of an enzyme, called amylase, attached to a protein. Because it is large, macroamylase is filtered very slowly from the blood by the kidneys.

Most people with macroamylasemia do not have a serious disease that is causing it, but the condition has been associated with:

• Celiac disease
• Lymphoma
• HIV infection
• Monoclonal gammopathy
• Rheumatoid arthritis
• Ulcerative colitis

Symptoms

Macroamylasemia does not cause symptoms.

Exams and Tests

A blood test will show high levels of amylase. However, macroamylasemia can cause test results similar to acute pancreatitis, which also causes high levels of amylase in the blood.

Measuring amylase levels in the urine can help tell macroamylasemia apart from acute pancreatitis. Urine levels of amylase are low in people with macroamylasemia, but high in people with acute pancreatitis. Other tests such as the polyethylene glycol (PEG) precipitation assay are sometimes done to confirm the diagnosis.

References

Forsmark CE. Pancreatitis. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 130.

Siddiqi HA, Rabinowitz S, Axiotis CA. Laboratory diagnosis of gastrointestinal and pancreatic disorders. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 23.

Vege SS. Acute pancreatitis. In: Feldman M, Friedman LS, Brandt LJ, eds. Sleisenger and Fordtran's Gastrointestinal and Liver Disease: Pathophysiology/Diagnosis/Management. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 58.