Background IgG4-related disease (IgG4-RD) is a recently recognized systemic condition characterized by unique pathological features that affect a wide variety of organs. Most available data come from descriptive series of patients with a unique organ involvement.
Objectives To describe clinical and biological characteristics of IgG4-RD patients from a large multicentric national registry.
Methods Cases were collected through a multicentric and multidisciplinary national registry between 2009 and 2014. Data were collected using a standardized form including clinical, biological, pathological and therapeutic findings.
Results From 120 collected cases, 90 cases fulfilled comprehensive diagnostic criteria for IgG4-RD . Patients presented with definite (44.5%), probable (24.4%) and possible (31.1%) IgG4-RD diagnosis. They were 64 males and 26 females (sex ratio 2.5:1) with a median age at onset of 56 years. Ninety-three percent of patients presented with symptoms at diagnosis, including constitutional symptoms (45%), abdominal pain (26%), cough or dyspnea (17%) and sicca syndrome (15%). Median number of organs involved was 3 and 80% of patients had multi-organ involvement, defined by ≥3 organs involved. Lymph nodes (58.9%), pancreas (44.4%), kidney (32.2%), salivary glands (32.2%), retroperitoneum (28.9%) and biliary ducts (27.8%) were the most frequent tissues involved. Inflammatory pseudotumors (IPT) were observed in 30% of patients (pulmonary, orbital, hepatic, meningeal or breast IPT). IgG4 serum concentration was >135 mg/dl in 84% of patients, with a mean of 989 mg/dl (ranging from 30 to 5380). Polyclonal hypergammaglobulinemia was noted in 79% of cases, and low complement in 34%. Elevated C reactive protein level was observed in 48% of patients. Mean follow-up was 17.6 months (ranging from 0 to 94). Only ten patients (11%) did not require systemic therapy. Seventy-seven patients (86%) received steroids in first line therapy. A second line therapy was required in 36 patients (40%), with 20 patients treated with 3 lines of treatment or more. Indications of second line treatments were essentially represented by relapse or corticodependance. Second line treatments were azathioprine in 14 patients, rituximab in 10, mycophenolate mofetil in 3, cyclophosphamide in 3 and methotrexate in 2. Six patients underwent surgery, essentially for histological diagnosis because cancer was suspected.
Conclusions As described in Asiatic populations, most IgG4-RD patients from our national registry present with multiple organ involvement. Localized disease is less frequent. Normal IgG4 levels are observed in 16% of patients. Steroids are usually effective, but almost half of patients require second line immunosuppressive therapy as steroid sparing agent or for relapse.
Umehara H, et al. Comprehensive diagnostic criteria for IgG4-related disease (IgG4-RD), 2011. Mod Rheumatol. 2012 Feb;22(1):21-30.
Disclosure of Interest None declared