Ordering Recommendation

A combined IgG and IgM antibody panel is available (refer to Chlamydia Antibody Panel, IgG & IgM by IFA (0065100)). Differentiate between Chlamydophila species (C. psittaci, C. pneumoniae). Because of cross-reactivity, a C. pneumoniae-specific reaction will exhibit titers two-fold or greater than C. trachomatis or C. psittaci serology. Limited value in the diagnosis of most oculogenital (eg, eyes, genitalia) chlamydial infections.




Semi-Quantitative Indirect Fluorescent Antibody




1-3 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

Plain red or serum separator tube.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer1 mL serum to an ARUP Standard Transport Tube. (Min: 0.15 mL) Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as acute or convalescent.

Storage/Transport Temperature


Unacceptable Conditions

Contaminated, hemolyzed, or hyperlipemic sera.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval

 < 1:64  C. trachomatis IgG. 
< 1:64  C. pneumoniae IgG.
1:64  C. psittaci IgG.

Interpretive Data

The Chlamydia antibody test contains both species- and genus-specific antigens, and serological cross-reactions may be seen in both acute and convalescent samples (less than 1:128).  A C. pneumoniae-specific reaction will exhibit titers twofold or greater than titers observed with C. trachomatis or C. psittaci serology.  Any IgG titer may indicate past exposure to that particular species.  IgG titers in recently infected individuals are typically greater than or equal to 1:512.

The Chlamydia microimmunofluorescent assay slides utilize C. psittaci, C. pneumoniae, and nine serotypes of C. trachomatis. The LGV strains of C. trachomatis are not included in this assay.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Analyte Specific Reagent (ASR)


In adult populations, the prevalence of antibody titers indicative of exposure to the organism ranges from 50-78%.

Hotline History


CPT Codes

86631 x3


Component Test Code* Component Chart Name LOINC
0065104 C. pneumoniae IgG Titer 6913-8
0065106 C. trachomatis IgG Titer 6919-5
0065107 C. psittaci IgG Titer 6916-1
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • Chlamydia IgG Ab
  • CT IgG Ab
Chlamydia Antibody Panel, IgG by IFA