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Test Code MYCOM Mycoplasma pneumoniae Antibodies, IgM, Serum


Specimen Required


Only orderable as part of a profile. For more information see MYCO / Mycoplasma pneumoniae Antibodies, IgG and IgM, Serum.

 

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Secondary ID

48318

Useful For

Screening for IgM antibodies in the indication of recent or past exposure to Mycoplasma pneumoniae

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
MMYCO M. pneumoniae Ab, IgM, S by IFA No No

Method Name

Only orderable as part of a profile. For more information see MYCO / Mycoplasma pneumoniae Antibodies, IgG and IgM, Serum.

 

Enzyme Immunoassay (EIA)

Reporting Name

M. pneumoniae Ab, IgM, S

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Rejected
Heat inactivated specimen Reject

Clinical Information

Mycoplasma pneumoniae is a small bacterium transmitted via organism-containing droplets. It is a cause of upper respiratory infection, pharyngitis, and tracheobronchitis, particularly in children, and has been associated with approximately 20% of cases of community-acquired pneumonia. Central nervous system and cardiac manifestations are probably the most frequent extrapulmonary complications of infections due to M pneumoniae. The disease is usually self-limited, although severe disease has been reported in immunocompromised patients.

 

Identification of M pneumoniae by culture-based methods is time consuming and insensitive. Serology-based assays for M pneumoniae have several drawbacks. The development of IgM antibodies takes approximately 1 week, and the IgM response may be variable in adults or decreased in immunosuppressed individuals. Confirmation of the disease is dependent on the observation of a 4-fold rise in IgG antibody titers between acute and convalescent specimens, several weeks following the initial onset of illness, providing clinical utility only for retrospective testing. Real-time polymerase chain reaction offers a rapid and sensitive option for detection of M pneumoniae DNA from clinical specimens for diagnosis of acute or current infection.

Reference Values

Only orderable as part of a profile. For more information see MYCO / Mycoplasma pneumoniae Antibodies, IgG and IgM, Serum.

 

Negative

Interpretation

IgG ELISA Result

IgM ELISA Result

Interpretation

Positive

Negative

Results suggest past exposure.

Positive

 

Reactive

Prior exposure to Mycoplasma pneumoniae detected. Confirmatory testing for IgM to M pneumonia will be performed by an immunofluorescence assay.

Equivocal

Negative

Negative

No antibodies to M pneumoniae detected. Acute infection cannot be ruled out as antibody levels may be below the limit of detection.  If clinically indicated, a second serum should be submitted in 14 to 21 days.

Negative

Reactive

No prior exposure to Mycoplasma pneumoniae. Confirmatory testing for IgM to M pneumonia will be performed by an immunofluorescence assay.

Equivocal

Equivocal

Negative

Recommend follow-up testing in 10 to 14 days if clinically indicated.

Reactive

Confirmatory testing for IgM to M pneumonia will be performed by an immunofluorescence assay.

Equivocal

 

ELISA = Enzyme-linked immunosorbent assay

Method Description

IgM Enzyme Immunoassay:

Test sera are diluted with the sample diluent provided. The sample diluent contains antihuman IgG that precipitates and removes IgG and rheumatoid factor from the sample, leaving IgM free to react with immobilized antigen. Diluted sera are incubated in antigen-coated microwells. Any antigen-specific antibody in the samples will bind to the immobilized antigen. The plate is washed to remove unbound antibody and other serum components. Peroxidase-conjugated goat-antihuman IgM (chain specific) is added to the wells and incubated. The conjugate will react with the IgM antibody/antigen on the solid phase. The wells are washed to remove unbound conjugate. The microwells containing immobilized conjugate are incubated with peroxidase substrate solution. Hydrolysis of the substrate by peroxidase produces a color change. After a period of time the reaction is stopped by the addition of diluted acid, and the color changes are measured photometrically. The color intensity of the solution depends on the antibody concentration in the serum sample.(Package insert: M pneumoniae IgM Test System. Zeus Scientific, Inc; Revision Date 9/22/2016)

 

IgM Immunofluorescence Assay:

Mycoplasma pneumoniae antigenic substrate is fixed onto microscope slide wells. Serum that has been pretreated to remove IgG antibodies is incubated with the substrate. If IgM antibody to M pneumoniae is present, it will bind to the substrate. Fluorescein-labeled antihuman-IgM conjugate is added to the slide wells, and the slide is incubated. If antibody is present, it can be observed as a characteristic positive, bright, apple-green fluorescent reaction when the slide is read on a fluorescence microscope.(Package insert: Mycoplasma pneumoniae IgM IFA Antibody Test System. Zeus Scientific, Inc; 09/2019)

Day(s) Performed

Monday through Friday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

86738

LOINC Code Information

Test ID Test Order Name Order LOINC Value
MYCOM M. pneumoniae Ab, IgM, S 5257-1

 

Result ID Test Result Name Result LOINC Value
MYCOM M. pneumoniae Ab, IgM, S 5257-1