High levels can occur as a result of chronic or recurrent infections, haemoconcentration from dehydration, chronic inflammatory or autoimmune disorders such as RA or SLE, or malignancies such as Hodgkins Lymphoma or Multiple Myeloma.

Agammaglobulinaemia or hypogammaglobulinaemia occurs in patients with inadequate gamma globulin. The main causes are renal disease with protein loss as seen in nephrotic syndrome, liver dysfunction causing reduced globulin synthesis, malnutrition or malabsorption, protein-losing enteropathies or congenital immunodeficiency states.