Immunoglobulin M for Acute Infection: True or False?

Area of Science:

• Clinical immunology
• Diagnostic pathology
• Infectious disease diagnostics

Background:

• Immunoglobulin M (IgM) tests are valuable diagnostic tools.
• These tests are prone to a high rate of false-positive results.
• This issue can result in misdiagnoses and inappropriate medical interventions.

Purpose of the Study:

• To highlight the problem of false-positive IgM test results.
• To emphasize the need for confirmatory testing in clinical practice.
• To review case examples illustrating diagnostic challenges with IgM testing.

Main Methods:

• Review of literature and case examples.
• Analysis of clinical scenarios involving IgM testing.
• Discussion of diagnostic implications and confirmatory strategies.

Main Results:

• False-positive IgM results can occur across various pathogens, not just in virology.
• Clinicians and laboratorians may underestimate the frequency of false positives.
• IgM testing alone is insufficient for critical diagnostic decisions.

Conclusions:

• IgM detection should not be used as a standalone diagnostic test.
• Confirmatory testing, including serial sample analysis and alternative methods, is crucial.
• Accurate diagnosis is essential for effective therapy, prognosis, and public health.