Clinical characteristics of IgG4-related retroperitoneal fibrosis versus idiopathic retroperitoneal fibrosis: a retrospective study of 132 patients

Abstract

Backgroud Retroperitoneal fibrosis (RPF) is a condition characterized by the presence of inflammation and fibrosis in the retroperitoneal space. More than two-thirds of all cases of RPF are idiopathic retroperitoneal fibrosis (IRPF), while the remaining one-third stem from different secondary causes. Many studies suggest that IgG4-related RPF is a secondary form of RPF. We undertook this study to compare detailed demographic, clinical and laboratory characteristics of IgG4-related RPF and IRPF in a large China cohort.Methods We carried out a retrospective review of the medical records of 132 cases of RPF diagnosed at Peking University People’s Hospital between March 2010 and March 2018. We divided the patients into two groups, IgG4-related RPF group and IRPF group. A standardized case report form was used for data collection. All statistical analyses were performed by SPSS 24.0.Results Among the 132 patients, the mean age at disease onset was 54.8 years. IgG4-related RPF group showed greater male predominance compared to IRPF group. IgG4-related RPF patients showed a longer interval between symptom onset and diagnosis, and allergic diseases were more common in this group. Sixty-four patients (48.4%) had lower back pain, which was more common in IRPF group than that in IgG4-related RPF patients. In terms of organ involvement, although 42 of 47 patients (89.3%) with IgG4-related RPF had other organ involvement, there were no patients in the IRPF group with other organ involvement. In addition, the serum IgG4 level, elevated eosinophils counts and IgE level were significantly higher in IgG4-related RPF patients.Conclusions We have revealed demographic, clinical and laboratory differences between IgG4-related RPF and IRPF patients, which indicated potential differences in pathogenesis and important implications for the diagnosis and management of these two phenotypes.