Lymphogranuloma Venereum (LGV) Differentiation Antibody Panel, MIF

The Lymphogranuloma Venereum (LGV) Differentiation Antibody Panel, MIF test contains 1 test with 20 biomarkers .

Lymphogranuloma venereum (LGV) is a clinical syndrome caused by certain strains (serovars) of Chlamydia trachomatis—most commonly associated with genital infection, tender swollen lymph nodes (“buboes”), and, in some cases, rectal inflammation (proctitis). Because antibodies to Chlamydia can “cross-react” between different Chlamydia species (and sometimes rise from nonspecific immune stimulation), interpreting Chlamydia antibody results can be challenging.

This differentiation panel measures antibody titers against multiple Chlamydia targets to help distinguish immune response patterns more consistent with LGV-associated C. trachomatis (L1) versus non-LGV genital C. trachomatis(D–K), while also evaluating antibodies to other Chlamydia species (C. pneumoniae and C. psittaci) that may contribute to cross-reactivity.

What’s Included

This panel includes antibody testing (IgG, IgA, IgM) for:

• C. trachomatis L1 Ab (IgG, IgA, IgM)
• C. trachomatis D–K Ab (IgG, IgA, IgM)
• C. pneumoniae Ab (IgG, IgA, IgM)
• C. psittaci Ab (IgG, IgA, IgM)

Methodology

• Micro-Immunofluorescence (MIF)

MIF is a serologic method that detects antibodies by observing antigen–antibody binding using fluorescence. Results are typically reported as titers, reflecting how strongly antibodies are detected.

Clinical Significance

Serologic detection of C. trachomatis infection is complicated because:

• Antibodies can cross-react with other Chlamydia species (C. pneumoniae, C. psittaci).
• Antibodies can reflect past exposure rather than active infection.
• Some immune responses may be nonspecific.

By testing a targeted panel of Chlamydia antibodies and comparing patterns and titers across species/serovars, clinicians can gain additional context when LGV is being considered—especially when clinical symptoms, exposure history, and other test results do not provide a clear answer.

Who May Benefit From This Test

This panel may be helpful when a clinician is evaluating possible LGV or differentiating Chlamydia exposure patterns, such as in people with:

• Swollen, tender groin lymph nodes (buboes)
• Genital ulcers/lesions (early LGV can be subtle)
• Rectal pain, bleeding, discharge, or proctitis symptoms
• Persistent or complicated symptoms where the strain type may affect clinical thinking
• Concern for cross-reactivity due to possible respiratory Chlamydia exposure (C. pneumoniae) or animal/bird exposure (more relevant for C. psittaci)

How to Use Results (High-Level)

Antibodies are commonly interpreted by:

• Antibody class
  • IgM: can be associated with more recent immune response (not definitive)
  • IgA: sometimes associated with mucosal/ongoing response (context-dependent)
  • IgG: often reflects prior exposure or longer-term immune response
• Titer patterns across targets
  • Comparison of L1 vs D–K responses may offer clues when LGV vs non-LGV C. trachomatis is being considered.
  • Antibodies to C. pneumoniae or C. psittaci may suggest potential sources of cross-reactivity.

Important: Antibody testing alone usually does not confirm an active infection. Results should be interpreted alongside symptoms, exam findings, and other laboratory testing.

Important Notes & Limitations

• This is a serology test (antibodies), not a direct detection test. Antibodies can remain after an infection has resolved.
• Cross-reactivity is common among Chlamydia species, which is exactly why this differentiation panel includes multiple organisms.
• Direct detection tests (commonly nucleic acid amplification tests, NAAT) are often used to identify active Chlamydia infection from appropriate specimens. Your clinician may order additional testing depending on the clinical picture.
• If you have symptoms of a sexually transmitted infection or possible LGV, do not delay medical care—timely evaluation and treatment guidance matters.

Next Steps

If results suggest a pattern compatible with LGV or another Chlamydia exposure, consider discussing with your clinician:

• Whether confirmatory/direct detection testing is needed
• Whether partner evaluation and follow-up testing are appropriate
• Whether additional STI screening (as clinically indicated) should be performed