Mycoplasma pneumoniae Antibodies (IgG, IgM)

Test Code

34127

CPT Codes
86738 (x2)

Preferred Specimen

1 mL serum

Minimum Volume

0.2 mL

Transport Container

Plastic screw-cap vial

Transport Temperature

Room temperature

Specimen Stability

Room temperature: 4 days
Refrigerated: 7 days
Frozen: 30 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Gross hemolysis • Grossly lipemic • Icteric

Methodology
Immunoassay (IA)

Setup Schedule

Set up: Tues-Sat; Report available: Next day

Limitations

IgM antibody testing is valuable for early diagnosis in children; in adults, paired sera for specific IgG and IgM are generally required together with PCR. Specific IgM antibodies are often absent in reinfections; specific IgA might be quite useful in this circumstance.

Reference Range

M. pneumoniae Ab (IgG)

≤0.90	Negative
0.91-1.09	Equivocal
≥1.10	Positive

M. pneumoniae Ab (IgM)

Negative	<770 U/mL
Low positive	770-950 U/mL
Positive	>950 U/mL

Clinical Significance

This test helps detect Mycoplasma pneumoniae infections. Respiratory tract infections including community-acquired pneumonia are common reasons for testing for M pneumoniae, especially in children [3,4].

Clinical presentations of M pneumoniae infection are generally mild, but can vary widely across individuals, and are most often characterized by tracheobronchitis with upper respiratory tract symptoms. Approximately one-third of people with M pneumoniae infection develop pneumonia that was previously considered "atypical." Extrapulmonary complications may include encephalitis, hemolytic anemia, renal dysfunction, gastrointestinal complaints, erythema multiforme, and Stevens-Johnson syndrome [1,2].

M pneumoniae infection is diagnosed by culture, serology, or nucleic acid amplification tests. Serologic tests may be useful when the possibility of Mycoplasma infection is high. A positive IgG result indicates previous or recent infection. Testing children who have suspected community-acquired pneumonia for M pneumoniae may help guide antibiotic selection [3,4].

Clinical false-negative results for IgG- and IgM-based serologic tests can occur due to compromised immunity, testing before an antibody response has started, or the presence of interfering substances in host serum.

Real-time polymerase chain reaction testing for M pneumoniae DNA is more sensitive than serology testing and can provide timely results to inform patient management [2]. IgA antibodies to M pneumoniae appear early; testing IgA antibodies may aid in identifying acute infection [1].

The results of this test should be interpreted in the context of pertinent clinical history and physical examination findings.

References
1. Waites KB, et al. Mycoplasma and Ureaplasma. In: Carroll KC, et al, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019. https://www.clinmicronow.org/doi/book/10.1128/9781683670438.MCM.ch64
2. Centers for Disease Control and Prevention. Mycoplasma pneumoniae Infections. Last reviewed June 5, 2020. Accessed January 27, 2022. https://www.cdc.gov/pneumonia/atypical/mycoplasma/hcp/index.html
3. Miller JM, et al. Clin Infect Dis. 2018;67(6):813-816.
4. Bradley JS, et al. Clin Infect Dis. 2011;53(7):617-630.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.