Chronic periaortitis and HLA-DRB1*03: another clue to an autoimmune origin

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.

Vascular Involvement of Immunoglobulin G4-Related Disease: A Case Report

Immunoglobulin-G4-related disease (IgG4-RD) is a fibro-inflammatory condition that can impact any organs/tissues, including the vascular systems, resulting in aortitis/periaortitis/periarteritis (PAO/PA). The complex nature of this disease and limited understanding have led to potential delays in identifying and managing irreversible organ damage. Herein, we report a 17-year-old female with hyper IgG4 disease, sclerosing mesenteritis, short stature, and insulin resistance who presented with symptoms of fever, epigastric pain, left flank pain, vomiting, dizziness, decreased urine output, and diarrhea. Imaging studies revealed an arterial wall thickening of the ascending aorta and aortic arch, splenic abscesses, and enlarged lymph nodes, consistent with IgG4-related aortitis. Treatment with steroids and antifungal agents was initiated. However, the patient developed septic shock and multi-organ failure requiring inotropes and mechanical ventilation. Ascending aortic aneurysm rupture, in this case, probably led to the patient's demise, but unfortunately, no autopsy was done to confirm it. This case highlights the importance of identifying and addressing vascular involvement in IgG4-RD to prevent irreversible organ damage and mortality.

Chronic periaortitis: A clinical approach

Chronic periaortitis (CP) is a rare disease characterised by the presence of a fibro-inflammatory tissue typically enveloping the abdominal aorta, the iliac arteries and, in some cases, the nearby structures, such as the ureters and the inferior vena cava. Imaging plays a key role in the diagnosis and follow-up: computed tomography and magnetic resonance imaging scans are used to define the extension of the pathological tissue, whereas fluorodeoxyglucose positron emission tomography is the gold standard to establish the degree of its metabolic activity. CP must be distinguished from secondary forms of periaortic infiltration, which include malignant, infectious, and drug-related aetiologies. This review focuses on the clinical aspects of CP and the differential diagnosis with secondary cases, and aims to provide the clinician with a guide through this challenging clinical approach.

Decreased absolute number of peripheral regulatory T cells in patients with idiopathic retroperitoneal fibrosis

Objective

In order to determine whether the immune balance of T helper 17(Th17)/regulatory T(Treg) is related to the pathogenesis of idiopathic retroperitoneal fibrosis (IRPF), we analyzed the differences in peripheral blood lymphocytes, CD4+T cell subsets and cytokines between patients with IRPF and healthy people to clarify the CD4+T cell subsets, especially Treg cell subsets, and the role of cytokines in the pathogenesis of IRPF.

Methods

This study included 22 patients with IRPF, 36 patients with IgG4-related diseases (IgG4-RD) without retroperitoneal fibrosis (RPF), and 28 healthy controls. The absolute numbers and percentage of peripheral blood lymphocyte subsets and CD4+T cell subsets in each group were detected by flow cytometry, and the serum cytokine level was detected by flow cytometric bead array (CBA).

Results

Compared with the healthy group, the absolute value of B cells in peripheral blood of IRPF patients was significantly decreased, and T, natural killer (NK), CD4+ and CD8+ were not significantly abnormal. The absolute numbers of Th2 cells were lower than healthy group(p=0.043). In particular, the absolute numbers of Treg cells were significantly lower than healthy group(p<0.001), while the absolute numbers of Th17 cells increased(p=0.682). Th17/Treg was significantly higher than healthy group (p< 0.001). Cytokine analysis showed that the level of interleukin (IL)-4 in IRPF patients was higher than healthy group(p=0.011), IL-6, IL-10, IL-17, TNF-α and IFN-γ were significantly higher than healthy group (all p<0.001). Receiver operating characteristic (ROC) curves showed that IL-10 and TNF-α could distinguish bilateral ureteral dilatation in IRPF patients, with areas under the ROC curve (AUCs) of 0.813 (95% CI:0.607-1.000, p=0.026) and 0.950 (95% CI:0.856-1.000, p=0.001), respectively. IL-6 could distinguish bilateral ureteral obstruction, with an AUC of 0.861 (95% CI: 0.682-1.000, p=0.015).

Conclusions

Our study showed that IRPF patients had reduced Treg cells and indeed had Th17/Treg imbalance, which may be related to the pathogenesis of the disease. The levels of IL-6, IL-10 and TNF-α appear to be associated with the progression of IRPF.

Ergotamine Induced Retroperitoneal Fibrosis

Retroperitoneal fibrosis (RPF) is an uncommon disease characterised by the presence of fibroinflammatory reaction which starts around the infrarenal portion of the abdominal aorta in the retroperitoneum and frequently entrap the ureter causing obstructive uropathy. Approximately, two thirds of the cases are idiopathic, where aetiopathogenesis is not known. Ergotamine-induced RPF, although rare, is considered under secondary group. The fibrogenic process here is thought to be due to serotonergic activity. We report a case of RPF in a young female with obstructive uropathy who had history of long-term ergotamine intake for migraine. Histopathological evaluation revealed different evolving stages of necrotising vasculitis. In addition, the patient has responded to withdrawal of offending drug along with immunosuppressive therapy. We believe, apart from serotonergic activity, ergotamine can lead to RPF through a vasculitic process which has not been reported earlier.

Bile Acids Elevated in Chronic Periaortitis Could Activate Farnesoid-X-Receptor to Suppress IL-6 Production by Macrophages

Chronic periaortitis (CP) is a rare autoimmune disease without effective treatment. By analyzing the serum bile acid spectrum in 28 CP patients with the ultra-performance liquid chromatography-tandem mass spectrometry, we found that the bile acids were significantly altered in CP patients, with significant increases in chenodeoxycholic acid (CDCA) and glycochenodeoxycholic acid (GCDCA) and decrease in deoxycholic acid (DCA). Signaling pathway enrichment analysis from the RNA sequencing results suggested that the altered gene sets in PBMC of CP patients were associated with bile acid metabolism. Furthermore, we found that pathological concentration of CDCA could significantly inhibited IL-6 expression in RAW 264.7 cells after LPS stimulation. Since CDCA is a well-known natural high-affinity ligand for the bile acid receptor farnesoid-x-receptor (FXR) while GW4064 is the synthetic specific agonist of this receptor, we then revealed that GW4064 significantly decreased IL-6 expression in RAW 264.7 cells and bone marrow-derived macrophages but not in FXR^-/- macrophages upon LPS stimulation. The western blot results with the anti-FXR antibody showed significantly increased expression in the nuclear proportion, suggesting that FXR agonist promoted the transportation of FXR into the nucleus but did not increase the FXR expression in macrophages. Dual-luciferase report assay and ChIP assay demonstrated that upon activation, FXR could directly bind to the promoter site of IL-6, leading to the decreased expression of IL-6. Thus, bile acids, especially CDCA, may operate to damp inflammation via FXR-mediated downregulation of IL-6 in mononuclear cells and provide a protective mechanism for CP patients.

Bilateral Hydronephrosis From Retroperitoneal Fibrosis

Retroperitoneal fibrosis (RPF) is a rare condition characterized by fibroinflammatory tissue infiltrating and compressing retroperitoneal structures. While mostly idiopathic (idiopathic retroperitoneal fibrosis or IRF), RPF is frequently associated with certain drugs, infections, and malignancies. It is thought to be immune-mediated because of response to steroids and RPF is commonly seen with other autoimmune diseases, especially IgG4-related disease (IgG4-RD). IRF is also a part of the chronic aortitis syndromes and the presence of aortic aneurysms is another characteristic of this disease. A 63-year old woman presented with left-sided flank pain. Computed tomography (CT) scan showed left hydronephrosis from compression of the ureter by a retroperitoneal mass. A thoracoabdominal aneurysm was also noted. A [¹⁸F]- fluorodeoxyglucose positron emission tomography (FDG-PET) scan showed hypermetabolism in the mass, with no abnormally increased activity noted elsewhere. Within four months, the mass enlarged to involve the right ureter as well, leading to right hydronephrosis. She required bilateral ureteral stents and aneurysm repair. Biopsy of the mass showed dense fibrosis with a mononuclear cell infiltrate. The histology of the aneurysm specimen showed chronic periaortic inflammation. Laboratory investigations were significant for elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), with no evidence of monoclonal gammopathy. She was referred to the rheumatology clinic to receive steroid treatment for IRF. IRF commonly involves the ureters and is diagnosed on CT scans during a workup for obstructive uropathy. The treatment is high dose steroids, while in resistant cases, other immunosuppressants have been used. The presentation of a patient with IRF can commonly mimic that of urinary calculi and malignancy. While rare, IRF should not be forgotten when evaluating a patient for obstructive uropathy.

Overview of IgG4-related aortitis and periaortitis. A decade since their first description

Aortic involvement is relatively common in the context of IgG4-related disease (IgG4-RD). It includes IgG4-aortitis, and IgG4-(chronic) periaortitis (IgG4-CP). The latter overlaps with IgG4-retroperitoneal fibrosis (IgG4-RPF). Aortic wall thickening which characterizes these entities along with the presence of periaortic tissue in IgG4-CP, are often accompanied by aortic aneurysms, which belong to the group of the so-called inflammatory aneurysms. Both the thoracic and abdominal aorta can be affected. Aortitis appears to involve more often the former, while the opposite is the case for IgG4-CP. There is a lack of definitions and different classification criteria have been used to describe these entities. This report provides an overview on the current evidence of aortic involvement in IgG4-RD. It discusses the clinical, epidemiologic, serologic and histopathologic characteristics, as well as the imaging techniques used for their diagnosis and the therapeutic options and treatment outcomes. The differential diagnosis and underlying pathogenetic mechanisms are also discussed.

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.

Standardized approach to idiopathic retroperitoneal fibrosis: a comprehensive review of the literature

BACKGROUND

Idiopathic retroperitoneal fibrosis (iRPF) is a rare fibro-inflammatory disease, characterized by inflammation of the abdominal aorta and its surrounding structures. The exact pathophysiology remains unclear. Diagnosis is often troublesome due to the non-specific and highly variable clinical presentation. Standardized treatment protocols are lacking.

OBJECTIVE

This article presents a review on iRPF, addressing clinical and diagnostic modalities as well as its pathophysiology and the possible inclusion within the IgG4-related disease (IgG4-RD) spectrum. Finally, a diagnostic-therapeutic algorithm for a standardized approach to iRPF is proposed.

METHODS

The PubMed Internet database was searched. Articles were selected based on the relevance of abstract, article type and impact of the journal.

RESULTS

iRPF and IgG4-RD share a common autoimmune aetiology. Diagnostics are multimodal and based on imaging. Ruling out malignancy should be of primary concern. Complications are mostly of renal or vascular origin due to compression of retroperitoneal structures. Corticosteroids remain the first-line treatment regimen and are mostly successful, but evidence supporting alternative immunosuppressive and anti-inflammatory treatments is growing. Long-term therapy, as well as follow-up, is paramount in this chronic and often relapsing disease.

Vasculitis beyond aortitis in IgG4-related disease (IgG4-RD): case report and review of the literature

IgG4-related disease (IgG4-RD) can affect almost every tissue/organ. Vascular involvement in the setting of IgG4-RD is increasingly being recognized with most of the cases pertaining patients with aortitis and/or periaortitis with or without aneurysm formation. However, it is now evident that other vessels like iliac arteries, coronary arteries, carotids, and others can also be affected being often underdiagnosed. Vascular involvement is expressed as vessel wall thickening, while aneurysm formation is also occasionally seen. Although histopathological findings are the cornerstone in the diagnosis of IgG4-RD, imaging modalities like magnetic resonance imaging (MRI) and positron emission tomography (PET) are similarly important when vascular involvement occurs, helping in the mapping of the disease and in identifying other, more accessible to biopsy, affected organs. Inflammation markers like erythrocyte sedimentation rate and C-reactive protein have also been described in IgG4-RD patients with vascular involvement. Herein, we present a case of a middle-aged man with long-term high inflammation markers who eventually diagnosed with IgG4-RD after an ascending aorta aneurysm operation, while a subsequent comprehensive magnetic resonance angiography revealed also involvement of the abdominal aorta and the left subclavian and left common carotid. Moreover, we sought to review the current literature about medium- and large-vessel involvement, beyond the aorta, in patients with IgG4-RD.

Medical Challenge Posed by Retroperitoneal Fibrosis: Case Reports and Literature Review

Idiopathic retroperitoneal fibrosis (RPF) is a rare fibro-inflammatory disease, with a low incidence worldwide, which occurs around the abdominal aorta and the iliac arteries. It spreads through the retroperitoneum causing ureteral obstruction with associated renal failure and obstruction of other adjacent structures. RPF can be idiopathic or secondary to neoplastic processes, infections, or medications. RPF is considered part of the spectrum of the disease related to immunoglobulin G4 (IgG4) and other autoimmune disorders. Occupational exposure to asbestos and tobacco smoke are important risk factors for the development of idiopathic RPF. The clinical picture is nonspecific, from pain to symptoms due to ureteral compression, this being the main complication associated.

Imaging studies are essential in the diagnosis; computed tomography (CT) and magnetic resonance imaging (MRI) are the most reliable imaging modalities. The goal of treatment is to stop the progression of the fibroinflammatory reaction. The first line of treatment is usually with medical management. Biological agents, such as rituximab and infliximab, have also been used, even with scarce data in the literature. Surgery is usually performed to improve a ureteral obstruction and should always be accompanied by systemic steroid treatment. The conservative approach given by systemic therapy and ureteral stent placement or nephrostomies has been recommended, thus reserving surgical treatment for refractory cases.

We present two clinical cases of idiopathic RPF, one of them associated with IgG4.

Clinical and Prognostic Significance of Serum IgG4 in Chronic Periaortitis. An Analysis of 113 Patients

Objective: Chronic periaortitis (CP) is a rare fibro-inflammatory disorder that incorporates idiopathic retroperitoneal fibrosis, inflammatory abdominal aortic aneurysms, and perianeurysmal retroperitoneal fibrosis. CP is included in the spectrum of IgG4-related disease. Since CP patients rarely undergo diagnostic biopsies, serum IgG4 levels are often used to classify CP as IgG4-related. However, the clinical and prognostic significance of serum IgG4 in CP is unknown.

Methods: We measured serum IgG4 in active CP patients and compared the clinical characteristics, response to therapy and outcome of patients with high and normal levels. We also tested the diagnostic significance of IgG4 by comparing its levels in CP patients, healthy and disease controls (malignancies, Erdheim-Chester disease, large-, and small-vessel vasculitis).

Results: We studied 113 consecutive patients with active CP. Twenty-four (21.2%) had high serum IgG4 (>135 mg/dL). The demographic, laboratory, and clinical characteristics of patients with high and normal IgG4 were similar, and so were the rates of ureteral obstruction and the disease characteristics on CT, MRI, and ¹⁸F-FDG-PET. Patients with high IgG4 only had a higher frequency of extra-retroperitoneal fibro-inflammatory lesions (p = 0.005). There were no significant differences in response to therapy and relapses between the two groups. Serum IgG4 levels did not discriminate CP from controls.

Conclusions: Serum IgG4 levels are high in a minority of CP patients and do not identify specific clinical or prognostic subgroups; only a higher frequency of extra-retroperitoneal lesions is found in high-IgG4 patients. Serum IgG4 levels do not help in the differential diagnosis between CP and its mimics.

Retroperitoneal fibrosis-clinical presentation and outcome analysis from urological perspective

Purpose

To study clinical presentation, laboratory results, imaging findings and treatment options and outcomes of retroperitoneal fibrosis (RPF). To determine whether it follows the same natural course and response to treatment in the Asian population as in the Western world.

Materials and Methods

Medical records of patients diagnosed with RPF on imaging and histopathology between February 2010 and April 2016 were reviewed.

Results

Of the 21 patients analyzed, mean age at presentation was 50.81 years. The male to female ratio was 0.9:1. Pain was most common presenting complaint (95.23% cases), almost 85% cases were idiopathic and rests were postradiation induced. The median creatinine level was 1.8 mg/dL. The mean erythrocyte sedimentation rate (ESR) was 53.2 mm/h. Hydronephrosis was present in all patients and 47.6% had atrophic kidneys. Diffuse retroperitoneal mass was present in 61.1%. Ureterolysis with lateralization, omental wrapping or gonadal pedicle wrap was done in 17 cases. Two patients underwent uretero-ureterostomy. One patient underwent ileal replacement of ureter, and one ileal conduit. Eighteen patients received concurrent medical treatment, 11 were given tamoxifen, 2 steroids (Prednisolone), and five were given both. Of the 20 patients with follow-up, 70% had complete symptomatic relief; ESR improvement was seen in 77.8%. Follow-up ultrasound showed resolved and decreased hydronephrosis in 20% and 55% respectively. One patient had treatment failure and 17.65% had disease recurrence.

Conclusions

RPF is a rare disease with varied presentation and outcomes. The male to female ratio may be equal in Asians and smoking could be lesser contributing factor. More Asian cohort studies are required to support same.

Elevated serum IgG4 levels in diagnosis and treatment response in patients with idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis (iRPF) may be a manifestation of IgG4-related disease. Measuring serum IgG4 (sIgG4) may be of value in monitoring iRPF, but this has scarcely been evaluated. It is unknown if tamoxifen (TMX) affects sIgG4 levels. We performed a prospective inception cohort study of 59 patients with untreated (re)active iRPF stratified by elevated (>1.4 g/L) or normal sIgG4 level. Changes in sIgG4 levels following TMX initiation and, if treatment failed, during subsequent corticosteroid (CS) treatment were analyzed. The median sIgG4 level was 1.1 g/L (interquartile range (IQR) 0.4-2.2); 24 patients (40%) had elevated sIgG4 level. Patients with elevated sIgG4 tended to present with higher ESR (46 vs. 34 mm/h; P = 0.08) and more frequent locoregional lymphadenopathy adjacent to the mass (41.7 vs. 20.0%; P = 0.08). sIgG4 also correlated with ESR (ρ = 0.26; P = 0.05) and serum creatinine (SC) (ρ = 0.26; P = 0.04). Following TMX initiation, sIgG4 level decreased, particularly when achieving treatment success (P < 0.01). Odds ratio for TMX treatment success in patients with elevated sIgG4 level was 0.77 (95% CI 0.53-1.14; P = 0.19). After adjusting for age, sex, and SC, the odds ratio was 0.78 (95% CI 0.51-1.18; P = 0.24). ROC curve analyses of sIgG4 on a continuous scale and treatment success showed an AUC of 0.62. Treatment success and concurrent sIgG4 decrease (P < 0.01) were achieved in 78% of patients who converted to CS therapy. Patients with elevated sIgG4 level may be more inflammatory than patients with normal sIgG4 level, but this needs further study. TMX affects sIgG4 levels, but to a lesser extent than CSs. sIgG4 cannot be used as an outcome prediction tool, irrespective of which cutoff value was chosen.

Fibrose rétropéritonéale: revue de littérature

La fibrose rétropéritonéale (FRP) est une maladie rare, caractérisée par la présence d’un tissu fibro-inflammatoire aberrant qui se forme souvent autour de la portion sous-rénale de l’aorte abdominale et des artères iliaques. Une obstruction urétérale est souvent observée. Récemment, la FPR idiopathique est rapportée parmi les manifestations de la maladie à IgG4. L’imagerie joue un rôle important dans le diagnostic de la FRP. Les glucocorticoïdes sont le traitement de référence, utilisés en monothérapie ou en association avec d’autres agents médicamenteux. En cas d’échec des mesures conservatrices, la chirurgie peut être proposée. Récemment, des techniques minimalement invasives ont été utilisées.

Retroperitoneal fibrosis - the state-of-the-art

Retroperitoneal fibrosis (RPF) is a rare disease, hallmarked by inflammation and deposition of fibrous tissue around the abdominal aorta. This process may spread contiguously and involve adjacent structures, leading to many complications, among which the most frequent and most severe is ureteral obstruction. The condition usually has idiopathic origin (idiopathic retroperitoneal fibrosis – IRF), but can also develop secondarily to a number of factors. The etiology of the disease remains unclear. Current research suggests that about half of the cases of IRF may be a symptom of a recently discovered, clinically heterogeneous immunoglobulin G4-related disease (IgG4-RD). Corticosteroids are the first-line treatment for IRF, but effective attempts to use immunosuppressants are also made. This paper presents the current state of knowledge on the etiopathogenesis, clinical presentation, diagnosis and therapeutic possibilities in different forms of RPF. Based on the latest research, an analysis of the relationship between IRF and IgG4-RD was performed.

Kidney involvement in medium- and large-vessel vasculitis

Medium- and large-vessel vasculitides (MVV and LVV, respectively) comprise a heterogeneous group of disorders whose common denominator is the inflammatory involvement of vessels of medium and large size. This disease spectrum includes giant-cell arteritis and Takayasu's arteritis, which typically affect the aorta and its main branches, and Kawasaki's disease and polyarteritis nodosa, which involve medium-sized arteries. Chronic periaortitis, characterized by a perivascular fibro-inflammatory reaction affecting the abdominal aorta and the periaortic tissue, frequently has a systemic distribution, involving other segments of the aorta and its major branches, and could thus be included in this group. Unlike small-vessel vasculitides, MVV and LVV do not cause glomerulonephritis, although glomerular immune-mediated lesions and tubulo-interstitial nephritis occur with varying frequency. However, MVV and LVV can often involve the renal artery and its branches, causing a wide array of lesions that range from renal artery stenosis to intra-renal vasculitis causing renal ischaemia/infarction, microaneurysms and haemorrhage. This review focuses on renal involvement in MVV and LVV and underlines why renal abnormalities in these syndromes should not be overlooked.

Idiopathic Retroperitoneal Fibrosis

Idiopathic retroperitoneal fibrosis (RPF), reviewed herein, is a rare fibro-inflammatory disease that develops around the abdominal aorta and the iliac arteries, and spreads into the adjacent retroperitoneum, where it frequently causes ureteral obstruction and renal failure. The clinical phenotype of RPF is complex, because it can be associated with fibro-inflammatory disorders involving other organs, is considered part of the spectrum of IgG4-related disease, and often arises in patients with other autoimmune conditions. Obstructive uropathy is the most common complication, although other types of renal involvement may occur, including stenosis of the renal arteries and veins, renal atrophy, and different types of associated GN. Environmental and genetic factors contribute to disease susceptibility, whereas the immunopathogenesis of RPF is mediated by different immune cell types that eventually promote fibroblast activation. The diagnosis is made on the basis of computed tomography or magnetic resonance imaging, and positron emission tomography is a useful tool in disease staging and follow-up. Treatment of idiopathic RPF aims at relieving ureteral obstruction and inducing disease regression, and includes the use of glucocorticoids, combined or not with other traditional immunosuppressants. However, biologic therapies such as the B cell-depleting agent rituximab are emerging as potentially efficacious agents in difficult-to-treat cases.

Idiopathic and secondary forms of retroperitoneal fibrosis: a diagnostic approach

Retroperitoneal fibrosis (RPF) is an uncommon disease characterized by a fibrous reaction that takes place in the peri-aortic retroperitoneum and often entraps the ureters causing obstructive uropathy. RPF is idiopathic in the majority of cases, but can also be secondary to malignancies, infections, drugs, radiotherapy, and rare histiocytic disorders such as Erdheim-Chester disease. Idiopathic RPF is an immune-mediated disease, which can either be isolated, associated with other autoimmune diseases, or arise in the context of a multifocal fibro-inflammatory disorder recently renamed as IgG4-related disease. The differential diagnosis between idiopathic, IgG4-related and secondary RPF is crucial, essentially because the therapeutic approaches - especially of idiopathic vs. secondary RPF - can be dramatically different. This review focuses on the clinical, laboratory and imaging features of the different RPF forms, and also provides an overview of the available treatment options.

Association between idiopathic retroperitoneal fibrosis and autoimmune thyroiditis: a case-control study

BACKGROUND

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease often associated with autoimmune disorders. Whether IRF is associated with Hashimoto's thyroiditis (HT) is poorly understood and only addressed by case-reports. We evaluated the prevalence of HT in a large IRF cohort and in matched controls.

METHODS

We studied 73 consecutive patients with new-onset IRF and 71 controls. The association between HT and IRF was cross-sectionally evaluated in a referral center. Longitudinally, thyroid function tests were also performed. Serum concentrations of FT4, TSH, and anti-thyroperoxidase antibodies (AbTPO) were evaluated together with thyroid ultrasound (US). Lymphocytic infiltrates were characterized in thyroid nodule fine needle aspirates (FNAB). In patients undergoing thyroidectomy, thyroid histology was also reviewed.

RESULTS

A higher prevalence of AbTPO positivity (P<0.03) and US findings suggestive of autoimmune thyroiditis (US-AIT) (P<0.0001) were found in IRF patients compared to controls. In the logistic regression analysis, the risk of AbTPO-diagnosed HT and that of US-AIT was significantly higher in IRF patients than in controls (ORs, 3.56, 95% CI 1.48-8.59, P=0.004 and 4.74, 95% C.I., 2.34-9.61, P<0.0001 in AbTPO-diagnosed HT and US-AIT, respectively). Thyroid histology in IRF patients showed either classical or the fibrous variant of HT. At the end of the follow-up (median, 45 and 36 months in patients and controls, respectively), 25% of IRF patients and 3% of controls were receiving l-thyroxine.

CONCLUSIONS

IRF patients have a higher risk of HT compared to controls. Thyroid function should be monitored in patients with IRF.

Retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a rare disease that is marked by systemic inflammation and the development of a periaortic fibroinflammatory mass. The fibroinflammatory infiltration can encase the abdominal aorta, ureters, and other abdominal organs. The clinical presentation often includes constitutional symptoms, abdominal pain, and signs of renal insufficiency or renal failure related to ureteral obstruction. Less frequently, RPF may present with vascular complications, such as venous thrombosis or claudication. The idiopathic form of RPF is most common but secondary forms have been described and are associated with malignancy and a variety of different medications. The pathophysiology is uncertain, but RPF has been linked with periaortitis and IgG4-related disease. Treatment centers on the relief of symptoms and complications associated with mass effects. Corticosteroids and other immunosuppressant therapies can improve constitutional symptoms, reduce infiltrate mass, and achieve disease remission, but a chronic relapsing course is not uncommon.

[Subacute lower back pain and acute kidney failure in a 47-year old man]

A 47-year-old man presented with subacute, low back pain and increased creatinine levels. A CT scan showed an extrinsic, bilateral compression of the ureters by a retroperitoneal mass with pronounced uptake of 18F-fluorodeoxyglucose in positron emission tomography. Histological findings were consistent with the diagnosis of retroperitoneal fibrosis. Urological decompression was performed. The initiated corticosteroids led to a rapid clinical improvement and regression of the retroperitoneal mass. A relapse occurred after tapering of corticosteroids with a prompt response to increase of the dosage.

Chronic periaortitis (retroperitoneal fibrosis) concurrent with giant cell arteritis: a case report

INTRODUCTION

Giant cell arteritis is the most common form of large-vessel vasculitides. However, it is probable that extracranial involvement is underdiagnosed in patients with classical giant cell arteritis. In the recent literature most cases of giant cell arteritis have been described in conjunction with aortic aneurysms or dissections. Nonetheless the coexistence of giant cell arteritis and retroperitoneal fibrosis is extremely rare. Here, we describe a case of giant cell arteritis at a very early clinical stage, in a woman with coexistence of retroperitoneal fibrosis.

CASE PRESENTATION

We report a case of giant cell arteritis at a very early clinical stage, in a 47-year-old Greek woman with coexistence of retroperitoneal fibrosis who was admitted to our hospital with a history of high-grade fever and mild right periumbilical abdominal pain for the past 30 days. In the context of fever of unknown origin, an abdomen computed tomography was ordered. A temporal artery biopsy was also performed because during hospitalization she complained of a headache. Examination of eosin and hematoxylin slides from biopsy specimens of her temporal artery, showed lesions consisting of predominantly lymphocytes, few plasma cells and occasional polymorphonuclear leucocytes. In addition no giant cells were detected in examining biopsies at multiple levels. This was consistent with giant cell arteritis according to the American college of Rheumatology criteria. An abdomen computed tomography revealed the presence of a retroperitoneal soft-tissue mass located anteriorly to the upper infrarenal aorta at the site of the scintigraphic uptake. The computed tomography and magnetic resonance imaging characteristics of the mass were consistent with retroperitoneal fibrosis, and its morphology suggestive of benignity. Our patient started oral prednisolone and was afebrile from day one.

CONCLUSIONS

In our experience this is the first case of retroperitoneal fibrosis due to giant cell arteritis occurring at the same time. Involvement of the aorta (aortitis) and its branches has been also observed in a subset of patients with giant cell arteritis. In addition, giant cell arteritis has been associated with a markedly increased risk of aortic aneurysm particularly thoracic aortic aneurysm.

Multiple cerebral lesions as the unique complication of idiopathic retroperitoneal fibrosis

We present a case of idiopathic retroperitoneal fibrosis (IRF) complicated by severe renal failure and multiple intracranial lesions, which are probable results of cerebral vasculitis. IRF is an idiopathic hyperplasia of the retroperitoneal tissue that often entraps the ureters and causes post-renal failure. While the etiology of IRF is unclear, researchers consider IRF a systemic autoimmune disease complicated by immune-mediated vasculitides. The chief complaints of the patient were cognitive disorders, and brain MRI findings revealed multiple intracranial lesions with accompanying central degeneration. Given that vasogenic cerebral edemas derive from uremia, we speculated that the lesions in our case were related to more destructive changes such as aortic and periaortic inflammation. Details on this case manifesting rare cerebrovascular complications may help elucidate the pathogenesis of IRF.

TLR-4 and VEGF polymorphisms in chronic periaortitis

Objective

Chronic periaortitis (CP) is a rare disease that is characterised by fibro-inflammatory tissue surrounding the abdominal aorta and has both non-aneurysmal (idiopathic retroperitoneal fibrosis [IRF]) and aneurysmal forms (inflammatory abdominal aortic aneurysm [IAAA]). We investigated whether toll-like receptor 4 (TLR-4) and vascular endothelial growth factor (VEGF) polymorphisms were associated with susceptibility to, and the clinical features of CP.

Methods

One hundred and two CP patients and 200 healthy controls were molecularly genotyped for TLR-4 gene polymorphism (+896 A/G) (rs4986790), VEGF mutations +936 C/T (rs3025039) and −634 C/G (rs2010963), and an 18 base pair (bp) insertion/deletion (I/D) polymorphism at −2549 of the VEGF promoter region. The patients were grouped on the basis of the type of CP (IRF or IAAA), and the presence or absence of established atherosclerotic disease (ischemic heart disease, cerebrovascular disease, and peripheral arterial disease).

Results

There were no significant differences in the distribution of the studied polymorphisms between the patients and controls. However, carriage of the +936 T allele was significantly more frequent in the patients with IRF than in those with IAAA (26.5% vs 5.3%; p = 0.046; OR 6.49 [95% CI 0.82–51.54]). There were significantly more carriers of the I allele among the patients with ureteral obstruction (83.8% vs 58.8%; p = 0.006; OR 3.63 [95% CI 1.42–9.28]) and those who received conservative treatment (48.5% vs 23.5%; p = 0.015; OR 3.06 [95% CI 1.22–7.721]) than among those without, and II homozygosity was significantly more frequent in the patients with deep vein thrombosis than in those without (30.4% vs 11.7%, p = 0.031; OR 3.31 [95% CI 1.07–10.21]).

Conclusion

The VEGF +936 C/T polymorphism may be associated with an increased risk of developing the non-aneurysmal IRF form of CP. Carriers of the I allele and II homozygosity are respectively at increased risk of developing ureteral obstruction and deep vein thrombosis.

Retroperitoneal fibrosis

Retroperitoneal fibrosis is a rare syndrome hallmarked by a fibrosclerotic tissue in the retroperitoneum, often leading to encasement of the ureters. About two-thirds of cases of retroperitoneal fibrosis are idiopathic, while the remaining cases are secondary to a variety of different causes, including drugs, tumors and infections. Idiopathic retroperitoneal fibrosis may be associated with abdominal aorta aneurysms, with vasculitis of the thoracic aorta and of epi-aortic vessels, or both. Most patients present with abdominal and/or low back pain. Serum markers of inflammation are usually, but not invariably, elevated. The diagnosis is secured by computed tomography or magnetic resonance imaging, which typically show an enhancing retroperitoneal mass medially dislodging the ureters. Positron emission tomography can be useful to document the extent and metabolic activity of the inflammatory process. Treatment rests on glucocorticoids with a tapering scheme variably combined with immunosuppressive agents. In cases of ureter obstruction, relief of obstruction by stenting or ureterolysis is required.

Retroperitoneal fibrosis

Retroperitoneal fibrosis (RPF) is a condition characterized by the presence of inflammation and fibrosis in the retroperitoneal space, for which no standard diagnostic criteria exist. Historically, treatment has focused on relieving the obstruction with percutaneous or cystoscopic assisted placement of ureteral stents followed by more definitive resolution of ureteric obstruction with open or laparoscopic ureterolysis. However, over the past several years management has shifted from primarily a surgical approach to an immunosuppressive-based therapy aimed at modulation of the immune system. This review focuses on the recent advances in the classification, epidemiology, pathophysiology, pathology, imaging, and treatment of RPF.

Eotaxin/CCL11 in idiopathic retroperitoneal fibrosis

BACKGROUND

Idiopathic retroperitoneal fibrosis (IRF) is a rare fibro-inflammatory disorder characterized by a periaortic tissue which often encases the ureters causing acute renal failure. IRF histology shows fibrosis and a chronic inflammatory infiltrate with frequent tissue eosinophilia. We assessed a panel of molecules promoting eosinophilia and fibrosis in IRF patients and performed an immunogenetic study.

METHODS

Serum levels of eotaxin/CCL11, regulated and normal T-cell expressed and secreted (RANTES), granulocyte colony-stimulating factor (G-CSF), interleukin (IL)-5, platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF) were measured using a multiplex assay in 24 newly diagnosed, untreated IRF patients and 14 healthy controls. Retroperitoneal biopsies (available in 8/24 patients) were histologically evaluated to assess eosinophil infiltration, whereas mast cells (MCs) were identified by immunohistochemical analysis for human tryptase. Immunohistochemistry for eotaxin/CCL11 and its receptor CCR3 was also performed. Six single nucleotide polymorphisms (SNPs) within the CCL11 gene (rs6505403, rs1860184, rs4795896, rs17735961, rs16969415 and rs17809012) were investigated in 142 IRF patients and 214 healthy controls.

RESULTS

Serum levels of eotaxin/CCL11 were higher in IRF patients than in controls (P = 0.009). Eotaxin/CCL11 drives tissue infiltration of eosinophils and MCs, which can promote fibrosis. Eosinophilic infiltration was prominent (>5 cells/hpf) in five (62.5%) cases, and abundant tryptase-positive MCs were found in all cases; notably, MCs were in a degranulating state. Immunohistochemistry showed that CCL11 was highly produced by infiltrating mononuclear cells and that its receptor CCR3 was expressed by infiltrating eosinophils, MCs, lymphocytes and fibroblasts. None of the tested CCL11 SNPs showed disease association, but the TTCCAT haplotype was significantly associated with IRF (P = 0.0005).

CONCLUSIONS

These findings suggest that the eotaxin/CCL11-CCR3 axis is active in IRF and may contribute to its pathogenesis; the TTCCAT haplotype within the CCL11 gene is significantly associated with IRF.

Malignant retroperitoneal fibrosis: MRI characteristics in 50 patients

We analyzed magnetic resonance imaging (MRI) morphologic patterns of retroperitoneal fibrosis (RF) to identify those able to distinguish malignant RF (mRF) from idiopathic RF (iRF). This retrospective study concerned 50 consecutive patients with MRI-based RF diagnoses, 35 of whom also had histologically proven RF. Previous radiotherapy, abdominal or pelvic surgery or infection during the preceding 6 months, vascular aneurysm (aorta or iliac artery), presence of retroperitoneal multiple nodular masses, or enlarged lymph nodes with a diameter >15 mm constituted exclusion criteria. Patients with mRF differed from those with iRF by age, smoking habits, and follow-up duration but not by clinical manifestations, inflammatory syndrome, or renal insufficiency. MRI-documented mRF extension along the aorta, from above the renal arteries to below the aortic bifurcation, was more frequent than iRF (47% vs. 0%; p = 0.001) but less frequent between the renal arteries and the aortic bifurcation (18% vs. 50%; p = 0.04); mRF extension behind the aorta was wider than iRF (5.0 vs. 2.5 mm; p = 0.03). Neither urinary tract nor vessel involvement differed. Medial ureteral attraction was significantly less frequent in mRF than iRF (24% vs. 83%; p < 0.001), according to univariate and multivariate analyses. An algorithm based on the most discriminant criteria (RF extending from above the renal arteries to below the aortic bifurcation and the absence of medial ureteral attraction) for mRF diagnosis had 82% sensitivity and 83% specificity. When applied to the 15 iRF patients without histologic data, specificity was 73%. This mRF decision tree, consisting of the 2 most discriminant MRI criteria, could be used as a supplementary argument to support RF biopsy.

CCL18 -- potential biomarker of fibroinflammatory activity in chronic periaortitis

OBJECTIVE

Promising therapeutic approaches have emerged in chronic periaortitis, whereas peripheral blood biomarkers are lacking. CC-chemokine ligand 18 (CCL18) is known as a marker of fibrotic activity and prognosis in pulmonary fibrosis. We investigated whether CCL18 levels are increased in patients with chronic periaortitis and are associated with clinical, laboratory, and imaging findings.

METHODS

In this retrospective study, serum concentrations of CCL18 were assessed in 30 patients with chronic periaortitis and related to clinical data, laboratory variables, and imaging studies. Serum levels were compared to 15 apparently healthy volunteers and 15 controls with aortic sclerosis.

RESULTS

Serum concentrations of CCL18 were increased in patients with chronic periaortitis (median 197.6 ng/ml, range 73.7-301.0) compared to healthy volunteers (median 34.6 ng/ml, range 22.6-70.4; p < 0.0001) and controls with aortic sclerosis (median 50.4 ng/ml, range 24.5-141.2; p < 0.0001). CCL18 levels correlated with (n = 30; r = 0.461, p = 0.01) and increased with the transversal diameter of the periaortic mantle < 5, 5-10, and ≥ 10 mm (p = 0.008). Contrast enhancement (p = 0.044), treatment naivety (p = 0.042), and the occurrence of systemic symptoms (p = 0.007) were associated with higher CCL18 levels. During followup, changes of CCL18 correlated with changes of the transverse diameter of the periaortic mantle (n = 17; r = 0.512, p = 0.033).

CONCLUSION

Serum concentration of CCL18 reflects fibroinflammatory activity and extent of disease in patients with chronic periaortitis.

Evidence for clonal fibroblast proliferation and autoimmune process in idiopathic retroperitoneal fibrosis

Idiopathic retroperitoneal fibrosis is an uncommon disease characterized by encasement of retroperitoneal structures by fibrosis and chronic inflammation. Multiple etiologies have been proposed. First, we investigated if idiopathic retroperitoneal fibrosis is a clonal fibroblast proliferation by performing X-chromosome inactivation analyses. Second, we sought to determine if idiopathic retroperitoneal fibrosis is an autoimmune or immunoglobulin G4-driven process. Thirty cases of idiopathic retroperitoneal fibrosis, in whom known causes of retroperitoneal fibrosis were excluded and those for which paraffin blocks were available, were included in this study. We performed clonality analysis in 16 female patients. Genomic DNA samples were prepared from formalin-fixed, paraffin-embedded tissue sections using laser capture microdissection. Of the 16 cases, 15 were informative. Of 15 informative cases, 8 (53%) showed nonrandom X-chromosome inactivation or a clonal process. Of the 26 patients for which immunoglobulin G4 analysis was performed, 14 (54%) were positive for immunoglobulin G4-positive plasma cells, and all were negative for anaplastic lymphoma kinase. Of cases positive for immunoglobulin G4, the immunoglobulin G4:immunoglobulin G ratio ranged from 0.30 to 1.00 (mean, 0.80). Of the 12 patients for which both clonality analysis and immunoglobulin G4 analysis were performed, 4 (33%) were clonal and immunoglobulin G4 negative; 2 (17%), clonal and immunoglobulin G4 positive; 2 (17%), nonclonal and immunoglobulin G4 positive; and 4 (33%), nonclonal and immunoglobulin G4 negative. Our data indicate that a significant proportion (53%) of idiopathic retroperitoneal fibrosis cases in women is associated with a clonal expansion of fibroblasts. In addition, a subset of idiopathic retroperitoneal fibrosis cases could be classified in the immunoglobulin G4-related sclerosing disease spectrum.

Inflammation aggravates disease severity in Marfan syndrome patients

Background

Marfan syndrome (MFS) is a pleiotropic genetic disorder with major features in cardiovascular, ocular and skeletal systems, associated with large clinical variability. Numerous studies reveal an involvement of TGF-β signaling. However, the contribution of tissue inflammation is not addressed so far.

Methodology/Principal Findings

Here we showed that both TGF-β and inflammation are up-regulated in patients with MFS. We analyzed transcriptome-wide gene expression in 55 MFS patients using Affymetrix Human Exon 1.0 ST Array and levels of TGF-β and various cytokines in their plasma. Within our MFS population, increased plasma levels of TGF-β were found especially in MFS patients with aortic root dilatation (124 pg/ml), when compared to MFS patients with normal aorta (10 pg/ml; p = 8×10⁻⁶, 95% CI: 70–159 pg/ml). Interestingly, our microarray data show that increased expression of inflammatory genes was associated with major clinical features within the MFS patients group; namely severity of the aortic root dilatation (HLA-DRB1 and HLA-DRB5 genes; r = 0.56 for both; False Discovery Rate(FDR) = 0%), ocular lens dislocation (RAET1L, CCL19 and HLA-DQB2; Fold Change (FC) = 1.8; 1.4; 1.5, FDR = 0%) and specific skeletal features (HLA-DRB1, HLA-DRB5, GZMK; FC = 8.8, 7.1, 1.3; FDR = 0%). Patients with progressive aortic disease had higher levels of Macrophage Colony Stimulating Factor (M-CSF) in blood. When comparing MFS aortic root vessel wall with non-MFS aortic root, increased numbers of CD4+ T-cells were found in the media (p = 0.02) and increased number of CD8+ T-cells (p = 0.003) in the adventitia of the MFS patients.

Conclusion/Significance

In conclusion, our results imply a modifying role of inflammation in MFS. Inflammation might be a novel therapeutic target in these patients.

Analysis of human leucocyte antigen genes in Caucasian patients with idiopathic moyamoya angiopathy

BACKGROUND

The etiology and genetic susceptibility of Moyamoya angiopathy (MMA) (Moyamoya disease, Moyamoya syndrome and unilateral type of MMA) still remain unclear. In Asian patient cohorts several HLA markers were described to be associated with MMA, but in Caucasians very little is known about genetic susceptibility of this angiopathy.

METHOD

We analysed DNA of 33 Caucasian patients with MMA for HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 markers, respectively. HLA frequencies of all 33 patients with MMA were compared with HLA-frequencies of Caucasian controls. Additionally, subgroup analysis of 22 patients with Moyamoya disease (MMD) and 11 patients with unilateral type of MMA was performed.

FINDINGS

Significant association was observed for HLA-DRB1*03 and HLA-DRB1*13 in all 33 patients (P (c) < 0.001 and P (c) < 0.001, respectively). Moreover, HLA-A*02 (P (c) = 0.009); HLA-B*08 (P (c) = 0.009), and HLA-DQB1*03 (P (c) = 0.003) frequencies were higher in all patients with MMA when compared with the controls. In addition, in 22 patients with MMD a higher frequency of HLA-DRB1*03 (P (c) < 0.001) was observed when compared with controls.

CONCLUSIONS

The results of this study indicate a putative association of HLA markers with MMA in Caucasian patients. Further studies are needed to elucidate the role of human MHC in the pathogenesis of this angiopathy.

Retroperitoneal fibrosis in 27 Korean patients: single center experience

Retroperitoneal fibrosis (RPF) is a rare disease with unclear etiology, which is characterized by chronic non-specific inflammation of the retroperitoneum. This study was performed to investigate the clinical characteristics, laboratory findings, radiologic findings, treatment and outcome in Korean patients with RPF. We retrospectively reviewed medical records of 27 RPF patients who were admitted to Yonsei University Medical Center between 1998 and 2009. Twenty-two patients (81%) were male. The mean age at diagnosis was 56 yr. Nine patients had identifiable risk factors of RPF and three patients had combined autoimmune diseases. Acute phase reactants were elevated in most patients. Rheumatoid factor was positive in 3 of 16 patients (19%) and antinuclear antibody in 4 of 17 (24%). Five of 6 patients who were taken positron-emission tomography showed positive uptake. Glucocorticoids were used in 16 patients (59%) and four of them received combination therapy with azathioprine. After immunosuppressive treatment, the levels of acute phase reactants dropped, and the size of mass also decreased in most patients. In conclusion, the clinical characteristics of RPF in Korean patients are similar with other series except for higher proportion of male. Some patients with RPF have autoimmune features. The effect of immunosuppressive treatment on RPF is good.

Prednisone versus tamoxifen in patients with idiopathic retroperitoneal fibrosis: an open-label randomised controlled trial

BACKGROUND

Glucocorticoids are the mainstay of treatment of idiopathic retroperitoneal fibrosis, but they often have substantial toxic effects. Several reports have suggested tamoxifen as an alternative to glucocorticoids. We compared the efficacy of prednisone with that of tamoxifen in maintainance of remission in patients with idiopathic retroperitoneal fibrosis.

METHODS

In this open-label, randomised controlled trial, we enrolled patients aged 18-85 years with newly diagnosed idiopathic retroperitoneal fibrosis at the Parma Hospital, Parma, Italy, between Oct 1, 2000, and June 30, 2006. After induction therapy with 1 mg/kg daily of prednisone for 1 month, the patients who achieved remission were randomly assigned to receive tapering prednisone (initial dose 0·5 mg/kg daily) for 8 months or tamoxifen (fixed dose 0·5 mg/kg daily) for 8 months. The sequence of randomisation (1:1), blocked in groups of two and four (with block size randomly selected), was generated by the trial statistician with a computer programme. After the end of treatment, the patients were followed up for an additional 18 months. Neither patients nor those giving interventions or analysing the data were masked to group assignment. The two radiologists who assessed CT and MRI scans were masked. The primary endpoint was the relapse rate by the end of treatment (month 8), which was analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00440349.

FINDINGS

After induction therapy, 36 of the 40 enrolled patients achieved remission and were randomly assigned to treatment (18 per group). One patient (6%) in the prednisone group and seven patients (39%) in the tamoxifen group relapsed by the end of treatment (difference -33% [95% CI -58 to -8, p=0·0408]. The difference in relapse rate between the groups was sustained after the additional 18-month follow-up: the 26-month estimated cumulative relapse probability was 17% with prednisone and 50% with tamoxifen (difference -33% [-62 to -3, p=0·0372]). Cushingoid changes and grade 2 hypercholesterolaemia were more common in the prednisone group than in the tamoxifen group (p=0·0116 and p=0·0408, respectively).

INTERPRETATION

Prednisone is more effective in prevention of relapses than is tamoxifen in patients with idiopathic retroperitoneal fibrosis. Therefore, prednisone should be considered as first-line treatment for patients with newly diagnosed idiopathic retroperitoneal fibrosis.

FUNDING

Parma University Hospital.

Idiopathic retroperitoneal fibrosis: a retrospective review of clinical presentation, treatment, and outcomes

OBJECTIVE

To describe the clinical manifestations, laboratory results, imaging findings, and treatments in patients with idiopathic retroperitoneal fibrosis (IRF) seen at Mayo Clinic in Rochester, MN.

PATIENTS AND METHODS

In this retrospective study, we used International Classification of Diseases, Ninth Revision codes to identify all patients evaluated for IRF between January 1, 1996, and December 31, 2006, at Mayo Clinic in Rochester, MN. Medical records were reviewed, and clinical information was abstracted. Idiopathic retroperitoneal fibrosis was diagnosed on the basis of compatible imaging findings. Patients were followed up until their last visit at Mayo Clinic, death, or December 31, 2008, whichever came first.

RESULTS

Of the 185 patients identified as having IRF, 113 (61%) were men and 72 (39%) were women. Mean ± SD age at diagnosis was 57.6 ± 11.8 years. Biopsy specimens were obtained in 142 cases (77%). The most common presenting symptoms were back pain (38%) and abdominal pain (40%). Baseline erythrocyte sedimentation rate and/or C-reactive protein levels were elevated in 88 (58%) of the 151 patients tested. The median creatinine level at diagnosis was 1.3 mg/dL (interquartile range, 1.1-2.1 mg/dL). Fifteen patients (8%) were treated with ureteral procedures only, 58 patients (31%) with medications only, and 105 patients (57%) with a combination of medical and surgical therapies. Seven patients (4%) were not treated. Corticosteroids were initiated in 116 patients (63%), and tamoxifen was used in 120 patients (65%). Follow-up was available for 151 patients (82%). Creatinine levels were normal at last visit in 102 (68%) of the 151 patients with follow-up. No patient developed end-stage renal disease. Relapses occurred in 18 (12%) of the 151 patients. Eleven patients died.

CONCLUSION

In this cohort, outcomes such as end-stage renal disease or death from renal failure were not observed. Relapses may occur, and patients with IRF warrant long-term follow-up.