Aylin Ozgen Alpaydın

Main Points • The Turkish version of the Test of Adherence to Inhalers (TAI) demonstrated strong psychometric validity, as evidenced by confirmatory factor analysis and good agreement with an established adherence measure (İUBÖ). • TAI effectively discriminated between patient groups with different adherence profiles, including those using multiple inhaler devices. • Internal consistency was high for both the 10-item and 12-item TAI, indicating reliable assessment across both domains.

INTRODUCTION Immunoglobulin G4 (IgG4) is the lowest among the IgG subfractions. IgG4 is believed to be different from other antibodies and its level in serum is between 0.35 and 0.51 mg/mL.1 IgG4 does not have an activating effect on complement pathways and binds to Fcγ receptors at a lower percentage than other IgG subclasses.1, 2 The biggest problem in diagnosis is IgG4-related disease can often present with findings that mimic malignancy both clinically and radiologically.