Risk factors for relapse and long-term outcome of idiopathic retroperitoneal fibrosis

Predictors of irreversible renal dysfunction in patients with idiopathic retroperitoneal fibrosis

OBJECTIVES

Idiopathic retroperitoneal fibrosis (iRPF) can lead to irreversible kidney damage. This study aimed to investigate predictors of irreversible renal dysfunction in patients with iRPF.

METHODS

Eighty-three patients with newly diagnosed iRPF were enrolled between January 2010 and September 2022 at Zhongshan Hospital of Fudan University, including 60 in the training set and 23 in the validation set. They were regularly contacted or followed up via outpatient examinations by specialist doctors, who documented their condition and treatment progress. Predictors of irreversible renal dysfunction were identified using univariate and multivariate regression, logistic model, and receiver operating curve analyses.

RESULTS

In the training set, over a median follow-up of 29 months, 16.7% of patients had an estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 at the last follow-up, and 25% had hydronephrosis or required prolonged double-J stents. A prognostic score was developed by assigning 1, 1, and 2 points for peripheral CD19+ B cells <9.3%, serum creatinine (sCr) ≥120 µmol/L, and no response at 6 months, respectively. A score of ≥2 for predicting irreversible renal dysfunction had sensitivity and specificity of 100% and 92%, respectively. In the validation set, 21.7% of patients suffered from irreversible renal dysfunction. The sensitivity and specificity for predicting irreversible renal dysfunction were 100% and 94.4%, respectively.

CONCLUSIONS

A prognostic score based on factors including CD19+ B cells <9.3% and sCr ≥120 µmol/L at baseline, and no response at 6 months, is suitable for predicting irreversible renal dysfunction in iRPF.

Multimodality imaging review of retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a rare fibroinflammatory disease with idiopathic and secondary causes. Idiopathic disease is more common and is believed to be immune mediated; associations with autoimmune diseases and/or inflammatory disorders such as IgG4 related disease are often present. Common complications include hydronephrosis and venous stenosis and/or thrombosis. Due to its nonspecific clinical presentation, imaging is vital for diagnosis; in addition, imaging may help distinguish idiopathic from secondary causes and can aid in distinguishing early/active disease from chronic/inactive disease. Magnetic resonance imaging is the preferred imaging modality to stage and monitor the disease, though CT and PET/CT imaging may also be of value. While the imaging findings can overlap with other diseases, there are some characteristic findings which can favor RPF. However, a biopsy is needed for a definitive diagnosis.The following article discusses the clinical features, imaging appearances across modalities, associated complications, potential diagnostic pitfalls, and treatment approaches for RPF. The role of advanced imaging techniques, such as diffuse weighted imaging and 18F-FDG PET/MRI, in the evaluation of RPF will also be included.

Idiopathic Retroperitoneal Fibrosis-Related Hydronephrosis: Evaluation of Comprehensive Management and Prediction of Inflammatory Markers for Stent-Free Outcomes

Objective

This study investigated the efficacy of comprehensive management and predictable inflammatory markers for idiopathic retroperitoneal fibrosis (iRPF)-related hydronephrosis outcomes.

Methods

Patients with iRPF-related hydronephrosis underwent surgical (ureteral stent and/or nephrostomy tube placement) and medical (corticosteroid-based multiple immunosuppressants) management were classified according to stent-indwelling outcomes. Univariate analysis of clinical profiles was conducted to screen possible predictors of hydronephrosis remission.

Results

In a series of 38 patients, 52.6% achieved hydronephrosis remission and stent/tube removal (stent-free group). The median indwelling time in the stent-free group (12 months) was significantly lower than that in the treatment-failure group (37 months, p<0.05). Mean retroperitoneal mass diameters was significantly reduced (anteroposterior by 11.66 mm (95% CI 2.31-21.01), transverse by 15.41 mm (95% CI 3.37-27.46), suprainferior by 30.53 mm (95% CI 4.87-56.19); p<0.05) during the treatment course, in line with mean renal pelvis width (by 36.2%) and renal function parameters (serum creatinine by 16.9%, blood urea nitrogen by 12.9%). Renal function improved (36.9%) or remained stable (44.7%) in most patients, the mean estimated glomerular filtration rate increasing by 8.7% (from 55.4 mL/min/1.73 m2 to 60.2 mL/min/1.73 m2). At the initial diagnosis, median serum immunoglobulin IgG and CRP levels were significantly higher in the stent-free group than in the treatment-failure group (IgG 17.55 g/L vs. 13.50 g/L, CRP 19.60 mg/L vs. 3.15 mg/L; p<0.05). Decline in serum IgG (-5.80 g/L vs. -2.30 g/L), CRP (-18.93 mg/L vs. -1.72 mg/L) and erythrocyte sedimentation rate (-22.00 mm/h vs. -1.50 mm/h) levels in the stent-free group surpassed those in the treatment-failure group (p<0.05).

Conclusion

Comprehensive management benefits iRPF patients with hydronephrosis by preserving renal function. The 24-month scale might guide stent/tube removal. Elevated inflammatory markers (IgG and CRP) at the initial iRPF diagnosis and IgG, CRP, and erythrocyte sedimentationrate (ESR) variations associated with hydronephrosis outcomes.

Outcomes of retroperitoneal fibrosis-related hydronephrosis and its risk factors for poor prognosis: a multi-center retrospective cohort study in Chinese patients

Objective

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibroinflammatory tissue that surrounds the abdominal aorta and the iliac arteries and often entraps the ureters. Hydronephrosis is a common complication of RPF, however, its clinical features and outcomes have not been well elucidated.

Methods

A total of 115 RPF-related hydronephrosis patients have been recruited from 9 clinical centers in China since March 2010. They were followed up until death or September 2021, whichever came first.

Results

The mean age at diagnosis was 58.83 ± 12.13 years, and 80 patients (69.57%) were men. The median disease duration was 3.00 (1.00, 9.00) months. Renal impairment was observed in 88.35% of the patients, and 49.57% showed bilateral ureteral involvement. Elevated ESR and CRP were presented in 80.28 and 62.02% of the patients, respectively. Overall, 28.21% (11/39) of the patients had increased IgG4 levels, and 41.38% (12/29) showed positive pathological IgG4 staining (IgG4+/IgG+ ≥ 40% or IgG4+ ≥ 10/HPF). Among them, three patients were diagnosed as IgG4RD. After 60.43 ± 34.53 months of follow-up, 36 patients had poor prognosis, which was associated with severe kidney impairment, bilateral hydronephrosis and inflammation status (elevated ESR and IgG) at diagnosis by case-control study. eGFR and creatinine were independent risk factors after adjusting for all other significant associations (p = 0.002 and p = 0.067, respectively). Glucocorticoid-based therapy could reduce the time of stenting, decrease the need for long-term ureteral stenting/percutaneous nephrostomy (PNS)/ureterolysis, increase the rate of mass shrinkage, and reduce the new requirement of hemodialysis compared to surgery-only strategy for RPF-related hydronephrosis patients in need of renal drainage, but did not reduce new-onset renal atrophy.

Conclusion

Severity of kidney dysfunction and inflammation status were related to the poor prognosis of hydronephrosis induced by RPF. More efficient interventions and strategies are needed to further improve outcomes.

New insights into predictors of autoimmune pancreatitis relapse after steroid therapy

OBJECTIVES

While autoimmune pancreatitis (AIP) responds well to steroid therapy, the high relapse rate in type 1 AIP remains a critical problem. The present study examined predictors of relapse of type 1 AIP following steroid therapy.

MATERIALS AND METHODS

Nine factors potentially predictive of relapse were analyzed in 81 AIP patients receiving steroid therapy with follow-up ≥ 12 months. The rate of serum IgG4 decrease following steroid therapy was calculated by dividing the difference between serum IgG4 values before and at two months after the start of steroid by the IgG4 value before steroid.

RESULTS

A relapse occurred in 11 patients (13.5%) during a median of 38 months. Multivariate analysis revealed that the presence of IgG4-related retroperitoneal fibrosis (HR: 5.59; 95% CI: 1.42-22.0; p = 0.014) and the low rate of serum IgG4 decrease after steroid therapy (HR: 0.048; 95% CI: 0.005-0.46; p = 0.008) were significant, independent predictors of AIP relapse. The cut-off value based on receiver operating characteristic curve data for the rate of serum IgG4 decrease before and at two months after steroid therapy distinguishing patients with and without a relapse was 0.65. Using this cut-off value, the area under the curve, sensitivity, and specificity were found to be 0.63, 0.73, and 0.60, respectively.

CONCLUSION

The low rate of serum IgG4 decrease after the start of steroid therapy and the presence of IgG4-related retroperitoneal fibrosis were predictive of type 1 AIP relapse. Cautious, gradual tapering of steroid dosage and longer maintenance therapy are recommended for patients with these factors.

Combined therapy of prednisone and mTOR inhibitor sirolimus for treating retroperitoneal fibrosis

OBJECTIVES

Retroperitoneal fibrosis (RPF) is a rare autoimmune disease with fibrous tissue growth and inflammation in retroperitoneum. Its current treatments involve long-term uptake of glucocorticoids (e.g., prednisone) for controlling inflammation; however, side effects are common. We strived for an improved therapy for fibrosis remission while reducing side effects.

METHODS

We surveyed gene-disease-drug databases and discovered that mammalian target of rapamycin (mTOR) was a key signalling protein in RPF and the mTOR inhibitor compound sirolimus affected many RPF pathways. We designed a therapy combining a gradual reduction of prednisone with a long-term, stable dosage of sirolimus. We then implemented a single-arm clinical trial and assessed the effects in eight RPF patients at 0, 12 and 48 weeks of treatment by measuring fibrous tissue mass by CT, markers of inflammation and kidney functions by lab tests, immune cell profiles by flow cytometry and plasma inflammatory proteins by Olink proteomics.

RESULTS

With the combined therapy, fibrous tissue shrunk about by half, markers of acute inflammation reduced by 70% and most patients with abnormal kidney functions had them restored to normal range. Molecularly, fibrosis-related T cell subsets, including TH2, TH17 and circulating TFH cells, were reduced and tumour necrosis factor and related cytokines restored to healthy levels. No severe long-term side effects were observed.

CONCLUSIONS

Our combined therapy resulted in significant fibrosis remission and an overall regression of the immune system towards healthy states, while achieving good tolerance. We concluded that this new therapy had the potential to replace the steroid monotherapy for treating RPF.

Retroperitoneal fibrosis as a postoperative complication following renal transplantation in cats

OBJECTIVES

The aim of this report was to describe the clinical signs, diagnostic imaging findings, surgical management, histopathological findings, outcome and possible risk factors for cats that developed retroperitoneal fibrosis (RPF) following renal transplantation.

METHODS

Medical records of cats that underwent renal transplantation and developed clinically significant RPF between 1995 and 2019 were reviewed.

RESULTS

Eighty-one cats underwent 83 renal transplantations. Of these 81 cats, six developed clinically significant RPF. For all six cats, renal transplantation was performed using cold organ preservation solution and ureteral papilla implantation. Immunosuppression protocol included ciclosporin and prednisolone. All cats had at least one subtherapeutic trough ciclosporin level (<250 ng/ml) in the postoperative period. Cats presented with moderate-to-severe azotemia 39-210 days following renal transplantation. Abdominal ultrasonography and contrast pyelography revealed various degrees of hydroureter and hydronephrosis of the transplanted kidney. Surgical examination revealed a layer of dense fibrous tissue surrounding the transplanted kidney, ureter and bladder resulting in ureteral obstruction. Ureteral obstruction was managed by reimplantation of the proximal ureter or renal pelvis to the bladder. Histopathologic examination of the fibrous tissue and affected portion of the distal ureter revealed fibrous connective tissue with lymphoplasmacytic infiltration and perivascular inflammation suggestive of an autoimmune type reaction. Of the six cats, two died within 5 days after revision surgery, two developed signs consistent with recurrent partial ureteral obstruction (40 and 41 days after revision), one was euthanized 6 years later for an unrelated disease and one was lost to follow-up.

CONCLUSIONS AND RELEVANCE

The incidence of RPF in this population of cats was relatively low (7%), but still represents a significant cause of morbidity and mortality. The cause of RPF remains unknown, although investigation into suboptimal immunosuppression as a potential cause for local rejection reaction is warranted.

Idiopathic retroperitoneal fibrosis mimicking infiltrative malignancy: a case report

The treatment strategy for an idiopathic retroperitoneal mass has not yet been established. Additionally, differentiating between benign and malignant is a challenge. Herein, we report a case in which we performed partial resection of a mass in a symptomatic patient with idiopathic retroperitoneal fibrosis that mimicked malignancy. A 44-year-old woman with an unremarkable medical history other than gallstones presented with a 1-month history of abdominal pain and repetitive vomiting. Imaging studies identified a large, retroperitoneal mass compressing the duodenum that had grown acutely over the preceding 2 weeks. The possibility that the mass was malignant could not be excluded. Considering the invasiveness and potential curability, we performed partial resection of the mass, which involved partial colonic resection with reconstruction, to allow for pathological diagnosis and intestinal obstruction treatment. The final pathological findings revealed that the mass consisted of hemorrhagic and fibrotic tissue without a tumorous component. The patient's postoperative course was unremarkable. She is alive 8 years postoperatively with no recurrence. In conclusion, a surgical approach, including biopsies, to idiopathic retroperitoneal fibrosis that mimics malignancy should be actively considered in symptomatic patients. Decisions regarding the required degree of surgical intervention call for sufficient, case-specific discussion.

Renal Involvement in Retroperitoneal Fibrosis: Prevalence, Impact and Management Challenges

Retroperitoneal fibrosis (RPF) is a rare disorder consisting of idiopathic and various secondary forms and characterized by chronic inflammatory infiltrates and marked fibrosis in the retroperitoneal space. In idiopathic RPF (IRPF), 35–60% of cases have been reported to be IgG4-related RPF, the retroperitoneal lesions of IgG4-related disease (IgG4-RD). IRPF can frequently lead to renal insufficiency mediated by urinary tract obstruction and hydronephrosis irrespective of being IgG4-related or not. Clinical pictures, laboratory and imaging findings, and location of the urinary tract obstruction are generally similar in IgG4-related and non-IgG4-related IRPF although multiple organ involvement and serum IgG4 elevation may be characteristic of the IgG4-related forms. Periaortic/periarterial lesions are the most frequent cause of renal insufficiency. Although the response to glucocorticoids is generally good, relapse does occur in a considerable proportion of patients, and may require an additional immunosuppressive agent and/or urological intervention in cases with multiple relapses or refractory obstructive uropathy. In general, the prognosis of patients with IRPF is good, but careful attention needs to be paid to chronic kidney disease as a major complication and rupture of the affected aorta/artery as a life-threatening one. Further studies are necessary to better understand the pathogenesis of the disease and to establish the optimal diagnostic and therapeutic strategies for it.

Renal Involvement in IgG4-Related Disease: From Sunlight to Twilight

IgG4-Related Disease (IgG4-RD) is a fibroinflammatory condition characterized by a typical histopathological pattern (dense lymphoplasmacytic infiltrate with prevalent IgG4+ plasma cells and storiform fibrosis), which may involve the kidney both directly (IgG4-related kidney disease, IgG4-RKD) or indirectly, as a consequence of post-renal ureteral obstruction due to retroperitoneal fibrosis (IgG4-RD RF). The most frequent presentation of IgG4-RKD is IgG4-related tubulointerstitial nephritis (TIN), but a glomerular disease can be present, in most of the cases a membranous nephropathy. Albeit steroid-responsive, in some cases renal manifestations may lead to progressive and permanent organ damage. In this review we describe four clinical cases representative of typical and less typical renal manifestations of IgG4-RD, emphasizing a potential, subclinical, early involvement of the kidney in the disease.

Characteristics of Adult Patients with Idiopathic Retroperitoneal Fibrosis and Assessment of Risk of Relapse at Diagnosis

OBJECTIVES

To compare adult patients' characteristics suffering from idiopathic retroperitoneal fibrosis between "relapse-free" and relapsing patients at the diagnosis and identify factors associated with relapse at initial presentation.

METHODS

We conducted a retrospective multicentric study in four hospitals in Eastern France, from 1993 to 2020, of adult patients suffering from idiopathic retroperitoneal fibrosis. We analyzed clinical, biological, and radiological features at diagnosis and during a forty-month follow-up.

RESULTS

Of 47 patients suffering from retroperitoneal fibrosis, 21 patients had idiopathic retroperitoneal fibrosis. Among them, 13 experienced one or more relapses during follow-up. At diagnosis, clinical characteristics, relevant comorbidities, biological and radiological features were similar between groups. Smoking cessation seems associated with decreased relapse risk (p: 0.0624). A total of 8 patients developed chronic renal failure during follow-up. Ureteral infiltration at diagnosis was associated with evolution to chronic renal failure (p: 0.0091).

CONCLUSION

No clinical, biological, or radiological features could predict relapse at retroperitoneal fibrosis diagnosis, but smoking cessation may prevent relapse.

Including Medical Management in the Urologic Approach to Idiopathic Retroperitoneal Fibrosis

OBJECTIVE

To characterize the timing and effectiveness of medical management in resolving stent-dependent ureteral compression secondary to idiopathic retroperitoneal fibrosis (RPF), the long-term relevant outcomes, and the side effects of treatment.

METHODS

A retrospective review of RPF patients diagnosed from 2002-2018 was performed. Patients with hydronephrosis due to ureteral involvement that were managed with medication and with temporary stenting as needed, but without initial ureterolysis, were included. Patient demographics and RPF management details were obtained, including the following subsequent events: ureterolysis, nephrectomy, recurrent upper tract obstruction, and medication side effects.

RESULTS

Fifty-two patients met inclusion criteria. Resolution of ureteral obstruction with medical management and temporary renal drainage as needed occurred in 36 (69%) patients with a median stent duration of 16 months, and median clinical and radiographic follow up of 4.2 and 3.3 years, respectively. Recurrent obstruction after a stent-free period occurred in 9 (18%) patients. Ureterolysis was performed in 8 (15%) patients at a median of 2.2 years for medication intolerance, lack of radiographic response to medication, or persisting pain. Potential medication side effects occurred in 6 (12%) patients.

CONCLUSIONS

Medical management supported successful resolution of ureteral obstruction in 69% of patients without the need for ureterolysis after temporary renal drainage using stents, with rare incidence of worsening renal dysfunction or medication side effect. To date, this is the largest reported series of systematically managed RPF patients with obstructive uropathy receiving initial medical therapy and serves to counsel patients and advise urologists and nephrologists of the expected course and advantages and disadvantages of medical versus surgical management.

Into Clinical Practice: Diagnosis and Therapy of Retroperitoneal Fibrosis

PURPOSE OF THE REVIEW

We aim to review the most relevant diagnostic features and treatment options of retroperitoneal fibrosis, in order to provide a useful guide for clinical practice.

RECENT FINDINGS

The recent literature highlights the role of imaging studies such as computed tomography, magnetic resonance imaging and positron emission tomography as useful tools for the diagnosis of retroperitoneal fibrosis, with retroperitoneal biopsy being reserved to atypical cases. The treatment approach is mainly conservative and is based on the use of medical therapies plus urological interventions. Medical therapies essentially comprise glucocorticoids and immunosuppressants-either traditional or biological agents such as rituximab. Surgical ureterolysis is only left for refractory cases. Recent findings in retroperitoneal fibrosis highlight the possibility of a non-invasive diagnostic approach and a conservative treatment strategy.

Idiopathic retroperitoneal fibrosis: an update for nephrologists

Idiopathic retroperitoneal fibrosis (IRF) is a rare condition characterized by the development of a peri-aortic and peri-iliac tissue showing chronic inflammatory infiltrates and pronounced fibrosis. Ureteral entrapment with consequent obstructive uropathy is one of the most common complications of IRF, which can lead to acute renal failure and, in the long term, to varying degrees of chronic kidney disease. IRF may be isolated or develop in association with autoimmune diseases (e.g. Hashimoto's thyroiditis and psoriasis) and other fibro-inflammatory disorders (often within the spectrum of immunoglobulin G4-related disease), which suggests that it should be considered as a potentially systemic condition. IRF is an immune-mediated disease: genetic variants (e.g. human leukocyte antigen (HLA)-DRB1*03) and environmental agents (mainly exposure to asbestos and smoking) are strongly associated with an increased risk of developing the disease, while a complex network of chemokines (e.g. CXCL12 and C-C moti chemokine 11 (CCL11)) and cytokines [e.g. interleukin (IL)-6, IL-12 and IL-13] is likely to orchestrate the inflammatory response and simultaneously promote fibrosis. Glucocorticoids, alone or in combination with traditional immunosuppressants such as methotrexate and mycophenolate mofetil, are usually efficacious and promptly induce disease remission; however, up to 50% of patients relapse, thus requiring repeat immunosuppressive courses. Biologic drugs, namely rituximab, are being explored for the treatment of IRF. In addition to medical therapies, interventional procedures (mainly ureteral stenting) are required to relieve ureteral obstruction, whereas surgical ureterolysis is generally reserved to refractory cases. If appropriately treated, then the overall and renal prognosis of IRF are good, with <5% patients developing end-stage renal disease.

La fibrose rétropéritonéale idiopathique

Retroperitoneal fibrosis (RPF) is a rare disease characterized by the presence of fibro-inflammatory tissue around the aorta entrapping the adjacent structures. RPF can be idiopathic or secondary to many disorders. The physiopathology is unknown but can be part of the spectrum of IgG4 related diseases. Imaging studies and inflammatory markers are essential for initial evaluation and follow-up. Biopsy is usually not recommended. The first line of treatment is corticosteroids associated or not with immunosuppressive drugs. In case of ureteral obstruction with renal failure, ureteral stent placement or nephrostomies are recommended. Initial response to treatment is usually good but relapses are frequent.

Retroperitoneal Fibrosis and its Differential Diagnoses: The Role of Radiological Imaging

Background Retroperitoneal fibrosis is a rare disease with an incidence of 0–1/100 000 inhabitants per year and is associated with chronic inflammatory fibrosis of the retroperitoneum and the abdominal aorta. This article sheds light on the role of radiological imaging in retroperitoneal fibrosis, names various differential diagnoses and provides an overview of drug and surgical treatment options.

Methods A literature search for the keywords “retroperitoneal fibrosis” and “Ormond’s disease” was carried out in the PubMed database between January 1, 1995 and December 31, 2019 (n = 1806). Mainly original papers were selected, but also reviews, in English and German language, with a focus on publications in the last 10 years, without excluding older publications that the authors believe are relevant to the topic discussed in the review (n = 40).

Results and Conclusion Ormond’s disease is a rare but important differential diagnosis for nonspecific back and flank pain. Imaging diagnostics using CT or MRI show a retroperitoneal mass, which must be differentiated from lymphoma, sarcoma, multiple myeloma and Erdheim-Chester disease. Patients have an excellent prognosis under adequate therapy. FDG-PET/CT or FDG-PET/MRT should be considered as potential modalities, as hybrid imaging can evaluate both the morphological changes and the inflammation.

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