IgG4-Related Disease: Retrospective Analysis of One Hundred Sixty-Six Patients

Objective: To investigate clinical and pathologic aspects of IgG4-related disease (IgG4-RD) in non-Asian populations. Methods: We conducted a retrospective review of the medical records of patients with IgG4-RD who presented to an academic medical center from January 1994 to September 2012. Results: Among 166 patients identified, the median age at diagnosis was 61 years (interquartile range [IQR] 49–70 years), 75% were male, and 80% were white. The median number of organs involved was 2 (IQR 2–3). When organs were grouped according to anatomic system, the hepatopancreaticobiliary system was most commonly involved (77%). The median highest serum IgG4 level during the clinical course was 215 mg/dl (IQR 122–466). Forty-three patients (26%) had a normal serum IgG4 level. Seventy-nine pathology specimens were available for immunostaining. The median number of IgG4+ cells was 37 (IQR 25–82) per high-power field, with an IgG4+:IgG+ ratio of 0.50 (IQR 0.32–0.68). Among 151 patients who received medical therapy, 72 (48%) received steroid-sparing agents because of relapse, recurrence, or corticosteroid intolerance. Of the 66 patients who were newly diagnosed, started on corticosteroid monotherapy as the initial treatment, and followed up at our institution, 30 (45%) experienced relapse or recurrence despite an initial favorable response. The number of organs involved had a significant impact on time to relapse or recurrence, with a hazard ratio of 1.48 (95% confidence interval [95% CI] 1.12–1.93) (P < 0.01) in multivariate analysis. The standardized incidence ratio of malignancy was 4.5 (95% CI 1.5–7.5). Conclusion. IgG4-RD is a multisystem disorder that commonly affects older men and has a propensity for relapse, recurrence, and malignancy.