IgM (monoclonal)

Diagnostic paraprotein

Expression
Present (obligate)
Evidence level
established
Targeted by
Ibrutinib (reduces), Rituximab (reduces but ineffective on symptoms)

Role in pathogenesis

Obligate diagnostic criterion. Kappa light chain predominance (15:1). Relationship to inflammation is the central unsolved mystery.

Targeting drugs (2)

DrugMechanismResponseLine
IbrutinibBTK inhibitorComplete in case reportsAlternative
RituximabAnti-CD20 (B-cell depletion)Ineffective on inflammationNot recommended

Sources (3)

A2Lipsker D et al. (2001) Lipsker diagnostic criteria for Schnitzler syndrome · MedicineDOI ↗
J4Qiao J et al. (2022) Schnitzler and Schnitzler-like syndromes review · Clin RheumatolPubMed ↗
A3de Koning HD et al. (2007) Landmark systematic review (94 patients) · Semin Arthritis RheumDOI ↗
IgM (monoclonal) in Schnitzler Syndrome | Kipine