The Clinicopathologic Study Of Retroperitoneal Fibrosis

Part Ⅰ:A cross-sectional study of 142 patients with retroperitoneal fibrosisObjective:To investigate the epidemiological,clinicolaboratory,imaging,and therapeutic characteristics of retroperitoneal fibrosis(RPF)in China.Method:All patients presenting to the Chinese People’s Liberation Army General Hospital from October 1996 to July 2016 diagnosed with RPF were included.Data were collected from medical records and the smoking index was calculated.Scheel radiological classification was used to assess the extent of soft-tissue density.Results:The study included 142 patients(120 men,22 women).The mean age was 54.3 years.Disease duration ranged from 0.23 to 109.5 months(median 2.7).Current smoking rate was 53.5%.Flank pain was more common in males(p = 0.041)and in the high smoking index group(p = 0.03).C-reactive protein level ranged from 0.08 to 8.9 mg/dL(median 1.9).Serum immunoglobulin G4(IgG4)was elevated in 31/63 patients(49.2%),and males had higher IgG4 concentrations(p = 0.017)at presentation.Respectively,44.4%,5.6%,and 22.5%of cases were classified into Scheel classes Ⅰ,Ⅱ,and Ⅲ.Eight patients(5.6%)had atypical RPF localization and 103(72.5%)presented with hydronephrosis,which was more common in class Ⅲ patients(p = 0.04).Nine patients(6.3%)received no treatment;the others received medical(34.5%)or surgical treatment(14.8%),or both(44.4%).Conclusions:There was a higher rate in males and younger age at disease onset in these Chinese RPF patients than in other populations.Acute-phase reactants and serum IgG4 were elevated in some patients.Tobacco use may be a risk factor for RPF in Chinese populations.Part Ⅱ:Comparison of two subsets of Chinese retroperitoneal fibrosis patients with respect to IgG4 immunohistochemical stainingObjective:To identify clinical and pathological differences between IgG4-RPF and iRPF in China,and analyze the pathogenesis in two different groups.Method:Clinical and pathological data of 50 RPF patients from 2006 to 2016 were retrospectively analyzed.At least one characteristic histopathologic feature,IgG4+plasma cells that number more than 30 per high power filed(HPF),and an IgG4+/IgG+plasma cells ratio cutoff greater than 40%were used to define IgG4-RPF.Results:Thirty-four(68%)cases were identified as IgG4-RPF with a mean onset age of 51.4 years,and 29 were male.In comparison with iRPF,patients with IgG4-RPF were significantly more likely to suffer from pain(p=0.048),and present with high IgE concentration(p=0.029).Only 5/16 cases of IgG4-RPF group had elevated serum IgG4 concentration,and they were all male.The remarkable histopathologic feature of IgG4-RPF patients was tissue eosinophilia.Patients with tissue eosinophilia were predominantly female(p=0.031),and were more likely to have retroperitoneal biopsies showing infiltration of IgG4+ plasma cells(p=0.008).Among 50 RPF patients,average number of IgG4+ plasma cells was positively correlated with eosinophils counts within tissue(r=0.37,p=0.009).Moreover,serum IgG4 concentration was positively correlated with serum IgE concentration(r=0.834,p=0.000).Conclusion:The distinct features of Chinese IgG4-RPF patients were high serum IgE concentration and tissue eosinophilia.Serum IgG4 concentration may not be elevated in patients with IgG4-RPF,especially in female patients.Serum IgE concentration might become a useful marker for diagnosing and monitoring the disease,especially for patients with normal serum IgG4 concentration.