Total Immunoglobulin M (IgM)

Immunology

Normal Reference Ranges

Adult

40 - 230 mg/dL

Pediatric

Varies by age mg/dL

Clinical Significance

First antibody class produced in response to acute antigenic challenge. Elevation suggests recent primary infection or macroglobulinemia.

Causes of High

  • Acute infection
  • Waldenstrom macroglobulinemia
  • Hyper-IgM syndrome
  • Primary biliary cholangitis

Causes of Low

  • Common variable immunodeficiency (CVID)
  • Selective IgM deficiency
  • Protein loss / malnutrition