Immunoglobulin M (IgM), plasma or serum

Alternate test name

IgM

Lab area

Clinical Biochemistry - General

Method and equipment

Equipment : Roche Cobas Pro c503

Method : Immunoturbidimetric assay.
Anti‑IgM antibodies react with antigen in the sample to form an antigen/antibody complex. Following agglutination, this is measured turbidimetrically. Addition of PEG allows the reaction to progress rapidly to the end point, increases sensitivity, and reduces the risk of samples containing excess antigen producing false negative results.

Expected turn-around time

STAT/ Urgent: 4 Hours Routine: 24 Hours

Shipping information

Background and clinical significance

Immunoglobulin M (IgM) measurements performed with this assay in human serum and plasma are used as an aid in diagnosis of clinical conditions associated with increased IgM levels, such as infection and inflammation, and with decreased IgM levels, such as IgM deficiencies.

In serum, increased polyclonal IgM levels are found in viral, bacterial, and parasitic infections, in liver diseases (e.g. primary biliary cirrhosis), in rare
immunological disorders, such as hyper IgM (HIGM) syndromes, but also in autoimmune diseases.

Elevated monoclonal IgM levels are also found in B-cell lymphoproliferative disorders (LPD).

Decreased levels of IgM can be due to reduced synthesis, increased loss, hypercatabolism or a combination of causes. IgM deficiencies occur in congenital and acquired immunodeficiency syndromes, inherited deficiencies, hematologic malignancies.