Learned cautions regarding antibody testing in mast cell activation syndrome

Area of Science:

• Immunology
• Clinical Medicine
• Chronic Inflammatory Disorders

Background:

• Mast cell activation syndrome (MCAS) is a prevalent, underrecognized chronic multisystem inflammatory disorder.
• MCAS presents with significant clinical heterogeneity.
• Accurate diagnosis is challenging due to overlapping symptoms and potential for misinterpretation of diagnostic markers.

Purpose of the Study:

• To analyze antibody titer trendlines in MCAS patients.
• To differentiate true pathogenic antibodies from clinically insignificant ones in MCAS.
• To provide clinical guidance on interpreting antibody tests in MCAS.

Main Methods:

• Retrospective review of medical records from 104 MCAS patients.
• Analysis of all available antibody tests and their titer trendlines.
• Comparison of observed trendlines with expected patterns for antibody-associated diseases (AADs).

Main Results:

• All patients exhibited positive/elevated antibodies at various points.
• Most positive antibodies were identified as clinically insignificant mimickers, not indicative of specific AADs.
• Two distinct antibody titer trendline patterns were observed: one for mimickers in MCAS and another for true AADs.

Conclusions:

• Positive antibody tests in MCAS patients frequently represent insignificant mimickers due to immune dysregulation.
• Caution is advised when interpreting positive antibody tests in MCAS to prevent misdiagnosis of AADs.
• Patience and careful assessment of antibody trendlines are recommended before diagnosing AADs in MCAS patients.