Interpretation
Quantitative analysis does not distinguish between monoclonal or polyclonal immunoglobulin class elevation. Serum Protein Electrophoresis (SPE) and Immunofixation is usually required to interpret and characterise if any increase is due to the presence of a monoclonal band.
Note: Quantitative analysis may be unreliable if a cryoglobulin is suspected.
Elevations of IgG, IgA, or IgM may occur in gammopathies such as:
•Multiple myeloma or Waldenstroms macroglobulinaemia (IgM)
•Primary systemic amyloidosis
•Monoclonal gammopathy of uncertain significance (MGUS)
•Other related disorders.
Polyclonal elevation of immunoglobulins may arise from:
•Proliferative liver diseases (e.g. Hepatitis, cirrhosis)
•Connective tissue diseases
•Infections, acute and chronic.
Immunoglobulin levels may also be elevated if the blood is extracted from the umbilical cord of neonates where there has been an intrauterine or perinatal infection.
Immunoglobulin deficiencies may be due to:
•Immunosupression where a plasma cell dyscrasia exists
•Primary or secondary immune deficiencies
•Coeliac’s disease (IgA only)
Test Method
Nephelometric immunoassay on Siemens BNII.