Clinicopathologic characteristics of IgG4-related retroperitoneal fibrosis among patients initially diagnosed as having idiopathic retroperitoneal fibrosis

Abstract

Objective. The purpose of our study was to determine the number of IgG4-related retroperitoneal fibrosis (RPF) cases that were initially diagnosed as idiopathic RPF and to investigate clinical characteristics of IgG4-related RPF. Methods. We retrospectively reviewed the medical records of 41 RPF patients who were treated at our tertiary care medical center in South Korea between January 2000 and January 2013. We identified cases of 19 patients in which a diagnosis was made based on percutaneous biopsy or surgery and selected these cases for further analysis. Immunostaining for IgG4 and histopathologic examinations were performed for pathology specimens. Results. In the 19 RPF patients, more than 30 IgG4-positive plasma cells per specimen were identified in 9 cases with dense lymphoplasmacytic infiltrates, storiform fibrosis, or obliterative phlebitis (IgG4-related RPF group). The recurrence rate of IgG4-related RPF was significantly higher than that of idiopathic RPF (67% vs. 10%, p = 0.015). Initial and cumulative steroid dosages were not different between the two groups. Conclusions. We found that 47% of the patients initially diagnosed with idiopathic RPF showed IgG4-related RPF evidence according to the pathology and IgG4-related RPF patients showed higher recurrence rate than idiopathic RPF patients. We suggest that maintenance immunosuppressive therapy is required in IgG4-related RPF patients.

Non-IgG4-related Multifocal Fibrosclerosis

“…As for RPF, Khosroshahi et al demonstrated that IgG4-related RPF was identified in 57% of the total cohort, and that the IgG4-related RPF patients had lymphoplasmacytic infiltrate, storiform fibrosis, or tissue eosinophilia in retroperitoneal biopsies at a significantly higher rate than observed in non-IgG4-related RPF patients (21). Koo et al also compared IgG4-related RPF with non-IgG4-related RPF, and reported the recurrence rate of IgG4-related RPF to be significantly higher than that of non-IgG4-related RPF (22). In this case, some histopathologic features, such as epithelioid granulomas and infiltration of neutrophils around the small vessels, were incompatible with IgG4-RD, possibly suggesting a difference in non-IgG4-related MFS from IgG4-RD.…”

Retroperitoneal fibrosis – the state-of-the-art

“…Immunohistochemical and histopathological examinations of retroperitoneal tissue showed lesions specific for IgG4-RD in about half (47–59%) of patients with IRF [2, 3, 32]. …”

“…However, 46–50% of cases of IgG4-related RPF show the involvement of organs located outside the retroperitoneal space; hence it is essential to distinguish these patients [2, 3]. Furthermore, the analysis of Koo et al [32] revealed that a group with IgG4-related RPF had a significantly higher recurrence rate compared to IRF; therefore the authors suggest the need for more aggressive immunosuppressive therapy and longer duration of maintenance treatment.…”

Fibrose rétropéritonéale : revue de littérature

“…12 Celle-ci a été identifiée dans 47-58 % des patients ayant déjà reçu un diagnostic de FPR idiopathique. 13,14 De même, environ 50 % des anévrismes inflammatoires de l'aorte abdominale sont liés aux IgG4. 15 Cependant, nous ne disposons que de peu d'informations sur la pathogenèse de cette maladie et la relation entre les formes de la FRP liée et non liée aux IgG4.…”

“…12 La maladie à IgG4 est responsable seulement d'une partie des cas de FRPI (50 %). 13,14 La possibilité d'un terrain prédisposé, voire de facteurs génétiques, a été envisagée. Des études génétiques ont montré une forte association entre FRPI et HLA-DRB1*03, allèle lié à de nombreuses MAI telles que le diabète de type 1, la myasthénie grave et la thyroïdite autoimmune.…”