FDG-PET is considered a reliable metabolic modality to assess the inflammatory activity of CP (22, 28C30); consequently, the related FDG uptake at demonstration in the two subgroups shows- together with the comparable levels of ESR and CRP- that the degree of swelling in CP individuals at presentation is not influenced from the IgG4 status. The only phenotypic difference we observed with respect to the IgG4 status lies in the more frequent occurrence of extra-retroperitoneal fibro-inflammatory lesions in the high IgG4subgroup, thus suggesting that patients with a more pronounced IgG4 response are more likely to have a systemic disease than those with normal levels, as previously demonstrated (10, 12, 14C16). We also evaluated response to treatment and relapses in the two subgroups. levels. We also tested the diagnostic significance of IgG4 by comparing its levels in CP individuals, healthy and disease settings (malignancies, Erdheim-Chester disease, large-, and small-vessel vasculitis). Results: We analyzed 113 consecutive individuals Rabbit Polyclonal to PPGB (Cleaved-Arg326) with active CP. Twenty-four (21.2%) had high serum IgG4 ( 135 mg/dL). The demographic, laboratory, and medical characteristics of individuals with high and normal IgG4 were related, and so were the rates of ureteral obstruction and the disease characteristics on CT, MRI, and 18F-FDG-PET. Individuals Epimedin A1 with high IgG4 only had a higher rate of recurrence of extra-retroperitoneal fibro-inflammatory lesions (= 0.005). There were no significant variations in response to therapy and relapses between the two organizations. Serum IgG4 levels did not discriminate CP from settings. Conclusions: Serum IgG4 levels are Epimedin A1 high in a minority of CP individuals and don’t identify specific medical or prognostic subgroups; only a higher rate of recurrence of extra-retroperitoneal lesions is found in high-IgG4 individuals. Serum IgG4 levels do not help in the differential analysis between CP and its mimics. (%). Variations between continuous variables were analyzed using the Mann Whitney test. Categorical variables were compared with Fisher’s exact test. Correlations were analyzed using Spearman’s rank correlation coefficient. All reported 0.05 were considered statistically significant. The statistical analysis was performed using GraphPad Prism 5. Results Serum IgG4 in the Differential Analysis of CP One hundred and thirteen CP individuals were included in the study. Twenty-four individuals (21.2%) had high serum IgG4 ( 135 mg/dL) and their median serum IgG4 level was 216 mg/dL (IQR 153C263.5). In addition to CP individuals, 51 healthy settings, 41 individuals with retroperitoneal malignancies or ECD, 22 individuals with aortitis (secondary to Takayasu or huge cell arteritis), and 18 with GPA were tested for serum IgG4; all individuals were tested at Epimedin A1 the time of analysis, before the start of treatment. Serum IgG4 levels were significantly higher in CP individuals than in healthy settings (= 0.01) and in CP individuals than in individuals with aortitis (= 0.02) (Number 1). No statistically significant variations were observed between CP individuals and individuals with neoplasms/ECD (= 0.21) or GPA (= 0.42). Receiver operating characteristic (ROC) analysis of the level of sensitivity and specificity of IgG4 in discriminating CP vs. healthy settings or aortitis individuals showed poor reliability of this marker (Number 1). Epimedin A1 Open in a separate windowpane Number 1 Serum IgG4 levels in chronic periaortitis individuals and settings. In the top figure, the storyline shows serum IgG4 levels in individuals with active chronic periaortitis, healthy controls, individuals with aortitis (secondary to Takayasu arteritis or giant-cell arteritis), granulomatosis with polyangiitis (GPA, Wegener’s) and retroperitoneal malignancies or Erdheim-Chester disease (ECD). The horizontal collection indicates the top limit of normal of serum IgG4 (135 mg/dL). In the lower figures, the receiver operating characteristic (ROC) curves display the level of sensitivity and specificity of serum IgG4 in discriminating chronic periaortitis individuals from healthy settings (remaining) and aortitis individuals (ideal). Baseline Characteristics The main demographic and medical characteristics of the individuals at disease onset are reported in Table 1. The proportion of males was higher in the group of individuals with high serum IgG4 compared to that with normal IgG4 (83 vs. 64%) but the difference was of borderline statistical significance (= 0.09). The two groups did not differ in terms of Epimedin A1 comorbidities (cardiovascular or autoimmune diseases) or showing signs or symptoms (Table 1); the rates of disease-related complications (e.g., hydronephrosis, acute renal failure, deep vein thrombosis) were also comparable between the two groups. The characteristics of CP on CT and MRI were also comparable: in particular, there were no statistically significant differences between the two groups in terms of proportion of aneurysmal forms, atypical localization (e.g., pelvic, isolated periureteral) and involvement of the thoracic vessels and/or mediastinum (i.e., thoracic periaortitis, fibrosing mediastinitis). A similar maximal CP thickness at baseline (on CT or MRI).
FDG-PET is considered a reliable metabolic modality to assess the inflammatory activity of CP (22, 28C30); consequently, the related FDG uptake at demonstration in the two subgroups shows- together with the comparable levels of ESR and CRP- that the degree of swelling in CP individuals at presentation is not influenced from the IgG4 status