Biomarker Reference · Bb IgM WB

What does the Borrelia burgdorferi IgM Antibody by Western Blot test measure?

Q: What is Borrelia burgdorferi IgM Antibody by Western Blot?

IgM antibodies to B. burgdorferi are the first immunoglobulin class generated following infection, typically appearing within 2–4 weeks of tick exposure and peaking at 3–6 weeks. The IgM response is directed primarily against the 23 kDa OspC surface protein and the 41 kDa flagellin protein. IgM levels typically decline after the acute phase but may persist for months or years in some individuals, which is a critical interpretive consideration — persistent IgM reactivity alone does not indicate ongoing or reactivated infection.

Q: Why is Borrelia burgdorferi IgM Antibody by Western Blot measured?

IgM Western Blot is the appropriate confirmatory marker for early Lyme disease (within the first 4 weeks of symptom onset), where IgG seroconversion may not yet have occurred. A positive IgM Western Blot following a positive or equivocal tier-one ELISA, in a patient presenting within 4 weeks of suspected tick exposure with compatible clinical features (erythema migrans, flu-like illness), supports a diagnosis of early Lyme disease. IgM Western Blot reactivity in patients with symptoms persisting beyond 4–6 weeks should be interpreted cautiously — isolated persistent IgM positivity without concurrent IgG in late presentations is more likely to represent non-specific reactivity, prior resolved infection, or laboratory cross-reactivity than ongoing active infection.

Q: What is the reference range for Borrelia burgdorferi IgM Antibody by Western Blot?

The standard reference range for Borrelia burgdorferi IgM Antibody by Western Blot is CDC/ASTPHLD positive criteria: ≥2 of 3 specific IgM bands reactive (23, 39, 41 kDa). Negative: <2 bands reactive. Indeterminate: 1 of 3 bands reactive. # REVIEWER FLAG: Confirm Immunosciences Lab, Inc. IgM Western Blot band panel and positivity criteria — some laboratories apply modified or expanded criteria. The 41 kDa flagellin band is not specific to B. burgdorferi and cross-reacts with other spirochaetes; confirm how Immunosciences Lab handles this in their positivity algorithm.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Q: Which tests measure Borrelia burgdorferi IgM Antibody by Western Blot?

Borrelia burgdorferi IgM Antibody by Western Blot is measured in 1 test on BiomarkersLabs.com, including Borrelia burgdorferi IgG, IgM Antibodies by Western Blot.

Borrelia burgdorferi IgM Antibody by Western Blot (Bb IgM WB) is a clinical biomarker used in infectious-disease assessment. IgM antibodies to B. It is measured in 1 laboratory test on BiomarkersLabs.com.

Reference Range: CDC/ASTPHLD positive criteria: ≥2 of 3 specific IgM bands reactive (23, 39, 41 kDa). Negative: <2 bands reactive. Indeterminate: 1 of 3 bands reactive. # REVIEWER FLAG: Confirm Immunosciences Lab, Inc. IgM Western Blot band panel and positivity criteria — some laboratories apply modified or expanded criteria. The 41 kDa flagellin band is not specific to B. burgdorferi and cross-reacts with other spirochaetes; confirm how Immunosciences Lab handles this in their positivity algorithm.
Units: Band reactivity (kDa)
Measured In: 1 test
Category: Infectious Disease

Functional medicine optimalNot applicable — confirmatory qualitative assay; no continuous value to optimise.

What is Borrelia burgdorferi IgM Antibody by Western Blot?

IgM antibodies to B. burgdorferi are the first immunoglobulin class generated following infection, typically appearing within 2–4 weeks of tick exposure and peaking at 3–6 weeks. The IgM response is directed primarily against the 23 kDa OspC surface protein and the 41 kDa flagellin protein. IgM levels typically decline after the acute phase but may persist for months or years in some individuals, which is a critical interpretive consideration — persistent IgM reactivity alone does not indicate ongoing or reactivated infection.

Why is Borrelia burgdorferi IgM Antibody by Western Blot measured?

IgM Western Blot is the appropriate confirmatory marker for early Lyme disease (within the first 4 weeks of symptom onset), where IgG seroconversion may not yet have occurred. A positive IgM Western Blot following a positive or equivocal tier-one ELISA, in a patient presenting within 4 weeks of suspected tick exposure with compatible clinical features (erythema migrans, flu-like illness), supports a diagnosis of early Lyme disease. IgM Western Blot reactivity in patients with symptoms persisting beyond 4–6 weeks should be interpreted cautiously — isolated persistent IgM positivity without concurrent IgG in late presentations is more likely to represent non-specific reactivity, prior resolved infection, or laboratory cross-reactivity than ongoing active infection.

Reference ranges

Standard reference: CDC/ASTPHLD positive criteria: ≥2 of 3 specific IgM bands reactive (23, 39, 41 kDa). Negative: <2 bands reactive. Indeterminate: 1 of 3 bands reactive. # REVIEWER FLAG: Confirm Immunosciences Lab, Inc. IgM Western Blot band panel and positivity criteria — some laboratories apply modified or expanded criteria. The 41 kDa flagellin band is not specific to B. burgdorferi and cross-reacts with other spirochaetes; confirm how Immunosciences Lab handles this in their positivity algorithm.
Functional medicine optimal: Not applicable — confirmatory qualitative assay; no continuous value to optimise.
Units: Band reactivity (kDa)

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.

Tests that measure Borrelia burgdorferi IgM Antibody by Western Blot

1 test on BiomarkersLabs.com include this biomarker.

BML-INF-002Comprehensive

Borrelia burgdorferi IgG, IgM Antibodies by Western Blot

Borrelia burgdorferi IgM Antibody by Western Blot reference range in this test: CDC/ASTPHLD positive criteria: ≥2 of 3 specific IgM bands reactive (23, 39, 41 kDa). Negative: <2 bands reactive. Indeterminate: 1 of 3 bands reactive. # REVIEWER FLAG: Confirm Immunosciences Lab, Inc. IgM Western Blot band panel and positivity criteria — some laboratories apply modified or expanded criteria. The 41 kDa flagellin band is not specific to B. burgdorferi and cross-reacts with other spirochaetes; confirm how Immunosciences Lab handles this in their positivity algorithm.

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Borrelia burgdorferi IgG Antibody by Western BlotBb IgG WB1 test

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