In the Literature Retroperitoneal Fibrosis and Asbestosis–A Plausible Association? Commentary on Goldini M, Bonini S, Urban M, et al. Asbestos and smoking as risk factors for idiopathic retroperitoneal fibrosis. Ann Intern Med. 2014;161:181-188.
R
etroperitoneal fibrosis (RPF) is an unusual condition highlighted recently in the Annals of Internal Medicine by Goldini et al,1 who report the possibility that asbestos exposure and smoking may play a role in the fibroinflammatory activation underlying RPF. RPF is familiar to nephrologists (and urologists) because of its association with obstructive uropathy and kidney failure. RPF usually is described as rare, but increasingly is being recognized, with the increased use of cross-sectional imaging in the evaluation of various abdominal and back symptoms.2-4 Presently, we understand RPF to be an inflammatory condition of the perivascular connective tissues surrounding the lower aorta. Though historically it was described in association with ergotamine-related medications and more recently has been recognized as an unusual manifestation of immune-inflammatory conditions such as vasculitis and lupus or as a nonspecific concomitant of retroperitoneal malignancy, RPF most often is an idiopathic condition.3-6 Inflammation in idiopathic RPF responds well to anti-inflammatory therapy using corticosteroids along with steroidsparing immunomodulation, and long-term outcomes generally are favorable, with cessation of inflammatory activity occurring after 1 to 2 years.3-10 Extrinsic ureteral compression is a common occurrence, but disease activity also can appear in other sites as an inflammatory mass in the pelvis, hepatobiliary and pancreatic region, eye, thyroid, or peridiaphragmatic area. All these complications usually respond to medical treatment combined with stent placement or surgery when local disease so indicates.3-5 It is unclear why the perivascular region of the abdominal aorta is involved in RPF or what triggers the process. As a result, there are few, if any, specific immunologic, serologic, or histologic markers for RPF, leaving only acute-phase markers (eg, sedimentation rate and C-reactive protein) as nonspecific indicators of disease activity.3,4,9-11 Suggestions that RPF might be a reaction to components of the atherosclerotic process12 are not consistent with the Originally published online November 13, 2014. Address correspondence to Richard D. Swartz, MD, University of Michigan, 3914 Taubman Center, Box 0364, Ann Arbor, MI 48109. E-mail: [email protected] Published by Elsevier Inc. on behalf of the National Kidney Foundation, Inc. 0272-6386 http://dx.doi.org/10.1053/j.ajkd.2014.09.009 378
variety of patients now observed who have RPF, but do not have notable atherosclerotic disease. A particular HLA-DRB1 histocompatibility factor, recognized as a risk factor in inflammatory diseases such as rheumatoid arthritis, also has been reported in some patients with RPF,13 but is not identified often in most case series. There is additional interest in immunoglobulin G4 (IgG4)-related disease as a possible umbrella that might include RPF along with autoimmune pancreatitis,14,15 but the general experience is that in many cases of RPF, IgG4 markers are not prominent.
WHAT DOES THIS IMPORTANT STUDY SHOW? The report by Goldini et al1 revisits a previously reported notion that asbestos exposure might have a pathogenic role in the development of RPF. This new report has a robust case-control design that compares 90 patients having what appears to be well-defined idiopathic RPF with 270 matched controls in Italy. The data identifying asbestos exposure are based on clinical history and a previously published questionnaire exploring the degree of direct or indirect exposure. The results suggest that only 38% of RPF cases have no exposure to asbestos compared with 69% of controls, that only 16% of RPF cases have no smoking history compared with 35% of controls, and that there is a strong statistical relation among reported asbestos exposure, smoking, and the diagnosis of idiopathic RPF. The individual case information included in the report outlines many clinical characteristics of the patients but does not report any concomitant occurrence of pleuropulmonary asbestosis or specific identification of asbestos material when biopsy is performed in the diagnostic evaluation of the RPF cases.
HOW DOES THIS STUDY COMPARE WITH PRIOR STUDIES? It is tempting to accept the hypothesis that some fibroinflammatory mechanism connects asbestos exposure to RPF, especially given the association of asbestosis with pleuropulmonary fibrosis, pleural malignancy, occasional parenchymal lung cancer, or even rarely nonpulmonary malignancy.16 The notion that RPF and asbestos are related is not new and is supported by the fact that asbestos exposure is still common and by a small handful of prior anecdotal cases of coincident RPF and asbestosis.17,18 A more recent case-controlled review from Finland by Uibi et al19 reports that 20% of patients with RPF have Am J Kidney Dis. 2015;65(3):378-380
In the Literature
asbestos exposure. In a subsequent study, Uibi et al20 compared chest tomography among asbestos-exposed patients with RPF with tomography among asbestosexposed controls, describing some asbestosis in both groups but more prominent pleural plaques and diffuse pleural thickening in the RPF cases. Goldini et al1 contend that these previous Finnish surveys were smaller and did not question as extensively for both occupational and nonoccupational asbestos exposure or for smoking history. However, the report from Goldini et al1 has its own notable shortcomings, including its dependence solely on data from clinical histories and questionnaires and its failure to include any evidence of typical clinical findings or histologic markers of asbestosis, despite the reportedly high prevalence of asbestos exposure in the study. Several other factors also temper outright acceptance of the hypothesized association. First, among any number of previous RPF case series that have been reported, there are few if any cases of identified asbestos exposure, let alone clinical manifestations of pleuropulmonary asbestosis.3-10,21 Admittedly, low sensitivity to the importance of asbestos exposure might bias the lack of notable prevalence in these previous reports. Second, biopsies commonly are performed in patients with RPF, and most series fail to find asbestos fibrils in the biopsy specimens. Third, RPF tends to respond well to corticosteroids and immunomodulation,3-10,21 therapies that are ineffective in treating asbestosis itself.16,19 It remains possible that inflammatory mechanisms instigated by asbestosis play a role in RPF, but a causal relation remains speculative for the present time. The association of RPF with smoking has been noted incidentally in previous reports,5,12 but the specific role of smoking in enhancing RPF inflammation, as it appears to do in patients with rheumatoid arthritis who are HLA-DRB1 carriers,22 remains suggestive but unproved.
WHAT SHOULD CLINICIANS AND RESEARCHERS DO? The appearance of this recent series by Goldini et al1 offers an opportunity to briefly review our present understanding of RPF. RPF usually presents as a chronic condition with back or abdominal pain and varying degrees of systemic fever and/or weight loss. The diagnosis most commonly is suggested by crosssectional imaging, for which typical criteria have been defined.2,3,9,12 The most prominent complications are urologic, with ureteral compression and obstructive renal failure.3-10,21 For many years, RPF has been treated by stent placement or nephrostomy, often with concomitant surgical management of entrapped ureters that sometimes is combined with corticosteroid administration.23,24 More recently, management has focused on nonsurgical relief of obstructive renal failure Am J Kidney Dis. 2015;65(3):378-380
and more aggressive medical therapy for what is thought to be a primary immune-mediated inflammatory disease. This medical therapy usually includes short-term treatment with corticosteroids along with longer term steroid-sparing agents such as cyclophosphamide, azathioprine, methotrexate, or mycophenolate; drugs with less-specific mechanisms of action such as tamoxifen or colchicine3-10,21; and newer agents such as rituximab25 or infliximab26 in more refractory cases. There presently is no consensus on the best therapy, and follow-up surveillance must rely on monitoring of clinical symptoms, imaging, and acute-phase markers, but it appears that long-term medical control of the inflammatory process usually can be achieved.4-10,21 For practitioners who evaluate these patients, it has become clear that some cases are not idiopathic RPF and that a number of other conditions may affect the retroperitoneum, including antineutrophil cytoplasmic antibody–associated vasculitis, systemic lupus erythematosus, IgG4-related disease with localized inflammatory masses, Erdheim-Chester disease, xanthogranulomatous pyelonephritis, or localized malignancy.2-4,6,15 As a result, it is necessary to evaluate whether imaging shows atypical features; whether serologic markers of vasculitis, collagen-vascular disease, or malignancy are present; whether biopsy of the affected area is needed because of unusual imaging and/or clinical presentation; and whether reevaluation is required when unexpected clinical changes develop during follow-up surveillance. The article by Goldini et al1 suggesting the possible association of RPF with asbestosis and smoking emphasizes the importance of caution in simply assuming that a given case of RPF is idiopathic. We recognize the hard work that Goldini et al1 have invested in their case-controlled study, but also emphasize that we are just beginning to understand the predispositions and pathogenesis of RPF (or asbestosis for that matter) well enough to foster the development of more specific diagnostic markers and directed treatments. In the meantime, cases that appear are optimally managed with concomitant multidisciplinary treatment and meticulous ongoing surveillance. Richard D. Swartz, MD University of Michigan Ann Arbor, MI
ACKNOWLEDGEMENTS Support: None. Financial Disclosure: The author declares that he has no relevant financial disclosures.
REFERENCES 1. Goldini M, Bonini S, Urban M, et al. Asbestos and smoking as risk factors for idiopathic retroperitoneal fibrosis. Ann Intern Med. 2014;161:181-188. 379
Richard D. Swartz 2. Caiafa R, Vinuesa A, Izquierdo R, et al. Retroperitoneal fibrosis: role of imaging in diagnosis and follow-up. Radiographics. 2013;33:535-552. 3. Scheel P, Feeley N. Retroperitoneal fibrosis. Rheum Clin North Am. 2013;39:365-381. 4. Swartz R. Idiopathic retroperitoneal fibrosis: a review of the pathogenesis and approaches to treatment. Am J Kidney Dis. 2009;54:546-553. 5. Kermani T, Crowson C, Achenback S, Luthra H. Idiopathic retroperitoneal fibrosis: a retrospective review of clinical presentation, treatment and outcomes. Mayo Clin Proc. 2011;86: 297-303. 6. Mirault T, Lambert M, Puech P, et al. Malignant retroperitoneal fibrosis: MRI characteristics in 50 patients. Medicine. 2012;91:242-250. 7. Ha Y, Jung S, Lee K, et al. Retroperitoneal fibrosis in 27 Korean patients: single center experience. J Korean Med Sci. 2011;26:985-990. 8. Marcolongo R, Tavolini I, Laveder F, et al. Immunosuppressive therapy for idiopathic retroperitoneal fibrosis: a retrospective analysis of 26 cases. Am J Med. 2004;116:194-197. 9. Scheel P, Feeley N, Sozio S. Combined prednisone and mycophenolate treatment for retroperitoneal fibrosis. Ann Intern Med. 2011;154:31-36. 10. Swartz R, Lake A, Roberts W, et al. Idiopathic retroperitoneal fibrosis: a role for mycophenolate mofetil. Clin Nephrol. 2008;65:260-268. 11. Pelkmans L, Aarnoudse A, Hendriksz T, van Bommel E. Value of acute-phase reactants in monitoring disease activity and treatment response in idiopathic retroperitoneal fibrosis. Nephrol Dial Transplant. 2012;27:2819-2825. 12. Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis. Lancet. 2006;367:241-251. 13. Martorana D, Vaglio A, Greco P, et al. Chronic periaortitis and HLA-DRB1*03: another clue to an autoimmune origin. Arthritis Rheum. 2006;55:126-130.
380
14. Zen Y, Onodera M, Inoue D, et al. Retroperitoneal fibrosis: a clinicopathological study with respect to immunoglobulin G4. Am J Surg Pathol. 2009;33:1833-1839. 15. Stone J, Zen Y, Deshpande V. IgG4-related disease. N Engl J Med. 2012;366:539-553. 16. Prazakova S, Thomas P, Sandrini A, Yates D. Asbestos and the lung in the 21st century: an update. Clin Respir J. 2014;8:1-10. 17. Maguire G, Meggs L, Addonizio J, Del Guercio L. Association of asbestos exposure, retroperitoneal fibrosis and acute renal failure. N Y State J Med. 1991;91:357-359. 18. Boulard J, Hanslik T, Doleris L, et al. Asbestos and idiopathic retroperitoneal fibrosis. Lancet. 1995;345:1379. 19. Uibi T, Oksa P, Auvinen A, et al. Asbestos as a risk factor for retroperitoneal fibrosis. Lancet. 2004;363:1422-1426. 20. Uibi T, Jarvenpaa R, Hakomaki J, et al. Asbestos-related pleural and lung fibrosis in patients with retroperitoneal fibrosis. Orphanet J Rare Dis. 2008;3:29-35. 21. van Bommel E. Retroperitoneal fibrosis. Neth J Med. 2002;60:231-242. 22. Linn-Rasker S, van der Vries R, van Gaalen F, et al. Smoking is a risk factor for anti-CCP antibodies only in rheumatoid arthritis patients who carry HLA-DRB1 shared alleles. Ann Rheum Dis. 2006;65:366-371. 23. Fry A, Singh S, Gunda S, et al. Successful use of steroids and ureteric stents in 24 patients with idiopathic retroperitoneal fibrosis: a retrospective study. Nephron Clin Pract. 2008;108: c213-c220. 24. Stifelman M, Shah O, Mufarrij P, Lipkin M. Minimally invasive management of retroperitoneal fibrosis. Urology. 2008;71:201-204. 25. Maturen K, Sundaram B, Marder W, Swartz R. Coronary artery involvement in idiopathic retroperitoneal fibrosis: computed tomographic findings. J Thorac Imaging. 2012;27:w35-w37. 26. Catanoso M, Spaggiari L, Magnani L, et al. Efficacy of infliximab in a patient with refractory idiopathic retroperitoneal fibrosis. Clin Exp Rheumatol. 2012;30:776-778.
Am J Kidney Dis. 2015;65(3):378-380
R
etroperitoneal fibrosis (RPF) is an unusual condition highlighted recently in the Annals of Internal Medicine by Goldini et al,1 who report the possibility that asbestos exposure and smoking may play a role in the fibroinflammatory activation underlying RPF. RPF is familiar to nephrologists (and urologists) because of its association with obstructive uropathy and kidney failure. RPF usually is described as rare, but increasingly is being recognized, with the increased use of cross-sectional imaging in the evaluation of various abdominal and back symptoms.2-4 Presently, we understand RPF to be an inflammatory condition of the perivascular connective tissues surrounding the lower aorta. Though historically it was described in association with ergotamine-related medications and more recently has been recognized as an unusual manifestation of immune-inflammatory conditions such as vasculitis and lupus or as a nonspecific concomitant of retroperitoneal malignancy, RPF most often is an idiopathic condition.3-6 Inflammation in idiopathic RPF responds well to anti-inflammatory therapy using corticosteroids along with steroidsparing immunomodulation, and long-term outcomes generally are favorable, with cessation of inflammatory activity occurring after 1 to 2 years.3-10 Extrinsic ureteral compression is a common occurrence, but disease activity also can appear in other sites as an inflammatory mass in the pelvis, hepatobiliary and pancreatic region, eye, thyroid, or peridiaphragmatic area. All these complications usually respond to medical treatment combined with stent placement or surgery when local disease so indicates.3-5 It is unclear why the perivascular region of the abdominal aorta is involved in RPF or what triggers the process. As a result, there are few, if any, specific immunologic, serologic, or histologic markers for RPF, leaving only acute-phase markers (eg, sedimentation rate and C-reactive protein) as nonspecific indicators of disease activity.3,4,9-11 Suggestions that RPF might be a reaction to components of the atherosclerotic process12 are not consistent with the Originally published online November 13, 2014. Address correspondence to Richard D. Swartz, MD, University of Michigan, 3914 Taubman Center, Box 0364, Ann Arbor, MI 48109. E-mail: [email protected] Published by Elsevier Inc. on behalf of the National Kidney Foundation, Inc. 0272-6386 http://dx.doi.org/10.1053/j.ajkd.2014.09.009 378
variety of patients now observed who have RPF, but do not have notable atherosclerotic disease. A particular HLA-DRB1 histocompatibility factor, recognized as a risk factor in inflammatory diseases such as rheumatoid arthritis, also has been reported in some patients with RPF,13 but is not identified often in most case series. There is additional interest in immunoglobulin G4 (IgG4)-related disease as a possible umbrella that might include RPF along with autoimmune pancreatitis,14,15 but the general experience is that in many cases of RPF, IgG4 markers are not prominent.
WHAT DOES THIS IMPORTANT STUDY SHOW? The report by Goldini et al1 revisits a previously reported notion that asbestos exposure might have a pathogenic role in the development of RPF. This new report has a robust case-control design that compares 90 patients having what appears to be well-defined idiopathic RPF with 270 matched controls in Italy. The data identifying asbestos exposure are based on clinical history and a previously published questionnaire exploring the degree of direct or indirect exposure. The results suggest that only 38% of RPF cases have no exposure to asbestos compared with 69% of controls, that only 16% of RPF cases have no smoking history compared with 35% of controls, and that there is a strong statistical relation among reported asbestos exposure, smoking, and the diagnosis of idiopathic RPF. The individual case information included in the report outlines many clinical characteristics of the patients but does not report any concomitant occurrence of pleuropulmonary asbestosis or specific identification of asbestos material when biopsy is performed in the diagnostic evaluation of the RPF cases.
HOW DOES THIS STUDY COMPARE WITH PRIOR STUDIES? It is tempting to accept the hypothesis that some fibroinflammatory mechanism connects asbestos exposure to RPF, especially given the association of asbestosis with pleuropulmonary fibrosis, pleural malignancy, occasional parenchymal lung cancer, or even rarely nonpulmonary malignancy.16 The notion that RPF and asbestos are related is not new and is supported by the fact that asbestos exposure is still common and by a small handful of prior anecdotal cases of coincident RPF and asbestosis.17,18 A more recent case-controlled review from Finland by Uibi et al19 reports that 20% of patients with RPF have Am J Kidney Dis. 2015;65(3):378-380
In the Literature
asbestos exposure. In a subsequent study, Uibi et al20 compared chest tomography among asbestos-exposed patients with RPF with tomography among asbestosexposed controls, describing some asbestosis in both groups but more prominent pleural plaques and diffuse pleural thickening in the RPF cases. Goldini et al1 contend that these previous Finnish surveys were smaller and did not question as extensively for both occupational and nonoccupational asbestos exposure or for smoking history. However, the report from Goldini et al1 has its own notable shortcomings, including its dependence solely on data from clinical histories and questionnaires and its failure to include any evidence of typical clinical findings or histologic markers of asbestosis, despite the reportedly high prevalence of asbestos exposure in the study. Several other factors also temper outright acceptance of the hypothesized association. First, among any number of previous RPF case series that have been reported, there are few if any cases of identified asbestos exposure, let alone clinical manifestations of pleuropulmonary asbestosis.3-10,21 Admittedly, low sensitivity to the importance of asbestos exposure might bias the lack of notable prevalence in these previous reports. Second, biopsies commonly are performed in patients with RPF, and most series fail to find asbestos fibrils in the biopsy specimens. Third, RPF tends to respond well to corticosteroids and immunomodulation,3-10,21 therapies that are ineffective in treating asbestosis itself.16,19 It remains possible that inflammatory mechanisms instigated by asbestosis play a role in RPF, but a causal relation remains speculative for the present time. The association of RPF with smoking has been noted incidentally in previous reports,5,12 but the specific role of smoking in enhancing RPF inflammation, as it appears to do in patients with rheumatoid arthritis who are HLA-DRB1 carriers,22 remains suggestive but unproved.
WHAT SHOULD CLINICIANS AND RESEARCHERS DO? The appearance of this recent series by Goldini et al1 offers an opportunity to briefly review our present understanding of RPF. RPF usually presents as a chronic condition with back or abdominal pain and varying degrees of systemic fever and/or weight loss. The diagnosis most commonly is suggested by crosssectional imaging, for which typical criteria have been defined.2,3,9,12 The most prominent complications are urologic, with ureteral compression and obstructive renal failure.3-10,21 For many years, RPF has been treated by stent placement or nephrostomy, often with concomitant surgical management of entrapped ureters that sometimes is combined with corticosteroid administration.23,24 More recently, management has focused on nonsurgical relief of obstructive renal failure Am J Kidney Dis. 2015;65(3):378-380
and more aggressive medical therapy for what is thought to be a primary immune-mediated inflammatory disease. This medical therapy usually includes short-term treatment with corticosteroids along with longer term steroid-sparing agents such as cyclophosphamide, azathioprine, methotrexate, or mycophenolate; drugs with less-specific mechanisms of action such as tamoxifen or colchicine3-10,21; and newer agents such as rituximab25 or infliximab26 in more refractory cases. There presently is no consensus on the best therapy, and follow-up surveillance must rely on monitoring of clinical symptoms, imaging, and acute-phase markers, but it appears that long-term medical control of the inflammatory process usually can be achieved.4-10,21 For practitioners who evaluate these patients, it has become clear that some cases are not idiopathic RPF and that a number of other conditions may affect the retroperitoneum, including antineutrophil cytoplasmic antibody–associated vasculitis, systemic lupus erythematosus, IgG4-related disease with localized inflammatory masses, Erdheim-Chester disease, xanthogranulomatous pyelonephritis, or localized malignancy.2-4,6,15 As a result, it is necessary to evaluate whether imaging shows atypical features; whether serologic markers of vasculitis, collagen-vascular disease, or malignancy are present; whether biopsy of the affected area is needed because of unusual imaging and/or clinical presentation; and whether reevaluation is required when unexpected clinical changes develop during follow-up surveillance. The article by Goldini et al1 suggesting the possible association of RPF with asbestosis and smoking emphasizes the importance of caution in simply assuming that a given case of RPF is idiopathic. We recognize the hard work that Goldini et al1 have invested in their case-controlled study, but also emphasize that we are just beginning to understand the predispositions and pathogenesis of RPF (or asbestosis for that matter) well enough to foster the development of more specific diagnostic markers and directed treatments. In the meantime, cases that appear are optimally managed with concomitant multidisciplinary treatment and meticulous ongoing surveillance. Richard D. Swartz, MD University of Michigan Ann Arbor, MI
ACKNOWLEDGEMENTS Support: None. Financial Disclosure: The author declares that he has no relevant financial disclosures.
REFERENCES 1. Goldini M, Bonini S, Urban M, et al. Asbestos and smoking as risk factors for idiopathic retroperitoneal fibrosis. Ann Intern Med. 2014;161:181-188. 379
Richard D. Swartz 2. Caiafa R, Vinuesa A, Izquierdo R, et al. Retroperitoneal fibrosis: role of imaging in diagnosis and follow-up. Radiographics. 2013;33:535-552. 3. Scheel P, Feeley N. Retroperitoneal fibrosis. Rheum Clin North Am. 2013;39:365-381. 4. Swartz R. Idiopathic retroperitoneal fibrosis: a review of the pathogenesis and approaches to treatment. Am J Kidney Dis. 2009;54:546-553. 5. Kermani T, Crowson C, Achenback S, Luthra H. Idiopathic retroperitoneal fibrosis: a retrospective review of clinical presentation, treatment and outcomes. Mayo Clin Proc. 2011;86: 297-303. 6. Mirault T, Lambert M, Puech P, et al. Malignant retroperitoneal fibrosis: MRI characteristics in 50 patients. Medicine. 2012;91:242-250. 7. Ha Y, Jung S, Lee K, et al. Retroperitoneal fibrosis in 27 Korean patients: single center experience. J Korean Med Sci. 2011;26:985-990. 8. Marcolongo R, Tavolini I, Laveder F, et al. Immunosuppressive therapy for idiopathic retroperitoneal fibrosis: a retrospective analysis of 26 cases. Am J Med. 2004;116:194-197. 9. Scheel P, Feeley N, Sozio S. Combined prednisone and mycophenolate treatment for retroperitoneal fibrosis. Ann Intern Med. 2011;154:31-36. 10. Swartz R, Lake A, Roberts W, et al. Idiopathic retroperitoneal fibrosis: a role for mycophenolate mofetil. Clin Nephrol. 2008;65:260-268. 11. Pelkmans L, Aarnoudse A, Hendriksz T, van Bommel E. Value of acute-phase reactants in monitoring disease activity and treatment response in idiopathic retroperitoneal fibrosis. Nephrol Dial Transplant. 2012;27:2819-2825. 12. Vaglio A, Salvarani C, Buzio C. Retroperitoneal fibrosis. Lancet. 2006;367:241-251. 13. Martorana D, Vaglio A, Greco P, et al. Chronic periaortitis and HLA-DRB1*03: another clue to an autoimmune origin. Arthritis Rheum. 2006;55:126-130.
380
14. Zen Y, Onodera M, Inoue D, et al. Retroperitoneal fibrosis: a clinicopathological study with respect to immunoglobulin G4. Am J Surg Pathol. 2009;33:1833-1839. 15. Stone J, Zen Y, Deshpande V. IgG4-related disease. N Engl J Med. 2012;366:539-553. 16. Prazakova S, Thomas P, Sandrini A, Yates D. Asbestos and the lung in the 21st century: an update. Clin Respir J. 2014;8:1-10. 17. Maguire G, Meggs L, Addonizio J, Del Guercio L. Association of asbestos exposure, retroperitoneal fibrosis and acute renal failure. N Y State J Med. 1991;91:357-359. 18. Boulard J, Hanslik T, Doleris L, et al. Asbestos and idiopathic retroperitoneal fibrosis. Lancet. 1995;345:1379. 19. Uibi T, Oksa P, Auvinen A, et al. Asbestos as a risk factor for retroperitoneal fibrosis. Lancet. 2004;363:1422-1426. 20. Uibi T, Jarvenpaa R, Hakomaki J, et al. Asbestos-related pleural and lung fibrosis in patients with retroperitoneal fibrosis. Orphanet J Rare Dis. 2008;3:29-35. 21. van Bommel E. Retroperitoneal fibrosis. Neth J Med. 2002;60:231-242. 22. Linn-Rasker S, van der Vries R, van Gaalen F, et al. Smoking is a risk factor for anti-CCP antibodies only in rheumatoid arthritis patients who carry HLA-DRB1 shared alleles. Ann Rheum Dis. 2006;65:366-371. 23. Fry A, Singh S, Gunda S, et al. Successful use of steroids and ureteric stents in 24 patients with idiopathic retroperitoneal fibrosis: a retrospective study. Nephron Clin Pract. 2008;108: c213-c220. 24. Stifelman M, Shah O, Mufarrij P, Lipkin M. Minimally invasive management of retroperitoneal fibrosis. Urology. 2008;71:201-204. 25. Maturen K, Sundaram B, Marder W, Swartz R. Coronary artery involvement in idiopathic retroperitoneal fibrosis: computed tomographic findings. J Thorac Imaging. 2012;27:w35-w37. 26. Catanoso M, Spaggiari L, Magnani L, et al. Efficacy of infliximab in a patient with refractory idiopathic retroperitoneal fibrosis. Clin Exp Rheumatol. 2012;30:776-778.
Am J Kidney Dis. 2015;65(3):378-380
![[Retroperitoneal fibrosis].](/assets/img/hold.png)
