Idiopathic Pulmonary Fibrosis 

  • Author: Amanda Godfrey, MD; Chief Editor: Zab Mosenifar, MD   more...
 
Updated: Jan 18, 2012
 

Background

Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, primarily occurring in older adults, limited to the lungs, and associated with the histopathologic and/or radiologic pattern of usual interstitial pneumonia (UIP).[1]

Of the 7 listed idiopathic interstitial pneumonias in the American Thoracic Society/European Respiratory Society consensus statement (ie, idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis-associated interstitial pneumonia, lymphoid interstitial pneumonia), idiopathic pulmonary fibrosis is the most common.[2] Idiopathic pulmonary fibrosis portends a poor prognosis, and, to date, no proven effective therapies are available for the treatment of idiopathic pulmonary fibrosis beyond lung transplantation.[3]

Most patients with idiopathic pulmonary fibrosis present with a gradual onset, often greater than 6 months, of dyspnea and/or a nonproductive cough. The symptoms often precede the diagnosis by a median of 1-2 years.[4] A chest radiograph typically reveals diffuse reticular opacities; however, it lacks diagnostic specificity.[5] High-resolution computed tomography (HRCT) findings are significantly more sensitive and specific for the diagnosis of idiopathic pulmonary fibrosis. On HRCT images, usual interstitial pneumonia is characterized by the presence of reticular opacities often associated with traction bronchiectasis. As idiopathic pulmonary fibrosis progresses, honeycombing becomes more prominent.[6] Pulmonary function tests often reveal restrictive impairment and reduced diffusing capacity for carbon monoxide.[5]

Available data suggest that no single etiologic agent serves as a common inciting event in the pathogenesis of idiopathic pulmonary fibrosis. During the past 15 years, the pathogenesis theory of generalized inflammation progressing to widespread parenchymal fibrosis has become less popular.[5] Rather, it is now believed that epithelial injury and activation in fibroblast foci are crucial early events that trigger a cascade of changes leading to reorganization of pulmonary tissue compartments.[7]

As mentioned above, idiopathic pulmonary fibrosis is an idiopathic interstitial pneumonia characterized by usual interstitial pneumonia on histopathology. The hallmark pathologic feature of usual interstitial pneumonia is a heterogeneous, variegated appearance with alternating areas of healthy lung, interstitial inflammation, fibrosis, and honeycomb change. Fibrosis predominates over inflammation.[7]

The diagnosis of idiopathic pulmonary fibrosis relies on the clinician integrating the clinical, laboratory, radiologic, and/or pathologic data to make a clinical-radiologic-pathologic correlation that supports the diagnosis of idiopathic pulmonary fibrosis.[3]

Next

Pathophysiology

The previous theory regarding the pathogenesis of idiopathic pulmonary fibrosis (IPF) was that generalized inflammation progressed to widespread parenchymal fibrosis. However, anti-inflammatory agents and immune modulators have proved to be minimally effective in modifying the natural course of the disease. It is currently believed that idiopathic pulmonary fibrosis (IPF) is an epithelial-fibroblastic disease, in which unknown endogenous or environmental stimuli disrupt the homeostasis of alveolar epithelial cells, resulting in diffuse epithelial cell activation and aberrant epithelial cell repair.[8]

In the current hypothesis regarding the pathogenesis of idiopathic pulmonary fibrosis, exposure to an inciting agent (eg, smoke, environmental pollutants, environmental dust, viral infections, gastroesophageal reflux disease, chronic aspiration) in a susceptible host may lead to the initial alveolar epithelial damage.[9] Reestablishing an intact epithelium following injury is a key component of normal wound healing. In idiopathic pulmonary fibrosis, it is believed that after injury, aberrant activation of alveolar epithelial cells provokes the migration, proliferation, and activation of mesenchymal cells with the formation of fibroblastic/myofibroblastic foci, leading to the exaggerated accumulation of extracellular matrix with the irreversible destruction of the lung parenchyma.[9]

Activated alveolar epithelial cells release potent fibrogenic cytokines and growth factors. These include, tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), platelet-derived growth factor, insulin-like growth factor-1, and endothelin-1 (ET-1).[7, 9] These cytokines and growth factors are involved in the migration and proliferation of fibroblasts and the transformation of fibroblasts into myofibroblasts. Fibroblasts and myofibroblasts are key effector cells in fibrogenesis, and myofibroblasts secrete extracellular matrix proteins.[9]

For normal wound healing to occur, wound myofibroblasts must undergo apoptosis. Failure of apoptosis leads to myofibroblast accumulation, exuberant extracellular matrix protein production, persistent tissue contraction, and pathologic scar formation.[9] TGF-β has been shown to promote an antiapoptotic phenotype in fibroblasts.[9] Additionally, myofibroblasts in fibroblastic foci of idiopathic pulmonary fibrosis have been reported to undergo less apoptotic activity in comparison to myofibroblasts in the fibromyxoid lesions of bronchiolitis obliterans organizing pneumonia.[10]

Excess alveolar epithelial cell apoptosis and fibroblast resistance to apoptosis are also believed to contribute to fibroproliferation in idiopathic pulmonary fibrosis. Research has demonstrated that prostaglandin E2 deficiency, in lung tissue of patients with pulmonary fibrosis, results in increased sensitivity of alveolar epithelial cells to FAS-ligand induced apoptosis but induces fibroblast resistance to Fas-ligand induced apoptosis.[11] Therefore, apoptosis resistance in the fibroblasts and myofibroblasts participating in the repair of the alveolar epithelium may contribute to the persistent and/or progressive fibrosis in idiopathic pulmonary fibrosis.

Evidence for a genetic basis for idiopathic pulmonary fibrosis is accumulating. It has been described that mutant telomerase is associated with familial idiopathic pulmonary fibrosis.[12] Telomerase is a specialized polymerase that adds telomere repeats to the ends of chromosomes. This helps to offset shortening that occurs during DNA replication. TGF-β negatively regulates telomerase activity.[9] It is proposed that pulmonary fibrosis in patients with short telomeres is provoked by a loss of alveolar epithelial cells. Telomere shortening also occurs with aging, and it can also be acquired. This telomere shortening could promote the loss of alveolar epithelial cells, resulting in aberrant epithelial cell repair, and therefore should be considered as another potential contributor to the pathogenesis of idiopathic pulmonary fibrosis.[12]

Additionally, a common variant in the putative promoter of the gene that encodes mucin 5B (MUC5B) has been associated with the development of both familial interstitial pneumonia and sporadic pulmonary fibrosis. MUC5B expression in the lung was reported to be 14.1 times as high in subjects who had idiopathic pulmonary fibrosis as in those who did not. Therefore, dysregulated MUC5B expression in the lung may be involved in the pathogenesis of pulmonary fibrosis.[13]

Finally, caveolin-1 has been proposed as a protective regulator of pulmonary fibrosis. Caveolin-1 limits TGF-β–induced production of extracellular matrix proteins and restores the alveolar epithelial-repair process.[9] It has been observed that the expression of caveolin-1 is reduced in lung tissue from patients with idiopathic pulmonary fibrosis and that fibroblasts, the key cellular component of fibrosis, have low levels of caveolin-1 expression in patients with idiopathic pulmonary fibrosis.[14]

The recognition of the above-mentioned factors as contributors to the pathogenesis of idiopathic pulmonary fibrosis has led to the development of novel approaches to treat idiopathic pulmonary fibrosis.

Previous
Next

Epidemiology

Frequency

United States

No large-scale studies of the incidence or prevalence of idiopathic pulmonary fibrosis are available on which to base formal estimates.

A population-based cohort study was completed in Olmsted County, Minnesota, between 1997 and 2005, with the intention of updating and describing the incidence and prevalence of idiopathic pulmonary fibrosis. Narrow-criteria idiopathic pulmonary fibrosis was defined by usual interstitial pneumonia on a surgical lung biopsy specimen or a definite usual interstitial pneumonia pattern on an HRCT image. Broad-criteria idiopathic pulmonary fibrosis was defined by usual interstitial pneumonia on a surgical lung biopsy specimen or a definite or possible usual interstitial pneumonia pattern on an HRCT image.[15] These criteria were obtained from the 2002 American Thoracic Society/European Thoracic Society consensus statement.[2]

The age-adjusted and sex-adjusted incidence rate of idiopathic pulmonary fibrosis among residents aged 50 years or older ranges from 8.8 cases per 100,000 person-years (narrow-case criteria) to 17.4 cases per 100,000 person-years (broad-case criteria).[15]

The age-adjusted and sex-adjusted prevalence among residents aged 50 years or older ranges from 27.9 cases per 100,000 persons (narrow-case criteria) to 63 cases per 100,000 persons (broad-case criteria).[15]

Whether the incidence and prevalence of idiopathic pulmonary fibrosis are influenced by geographic, ethnic, cultural, or racial factors is unclear.[1]

International

Worldwide, the incidence of idiopathic pulmonary fibrosis is estimated to be 10.7 cases per 100,000 person-years for males and 7.4 cases per 100,000 person years for females. The prevalence of idiopathic pulmonary fibrosis is estimated to be 20 cases per 100,000 persons for males and 13 cases per 100,000 persons for females.[5]

Mortality/Morbidity

Idiopathic pulmonary fibrosis portends a poor prognosis, with an estimated mean survival of 2-5 years from the time of diagnosis.[3] Estimated mortality rates are 64.3 deaths per million in men and 58.4 deaths per million in women.[16]

Death rates in patients with idiopathic pulmonary fibrosis increase with increasing age, are consistently higher in men than women, and experience seasonal variation, with the highest death rates occurring in the winter, even when infectious causes are excluded.[4]

Estimates are that 60% of patients with idiopathic pulmonary fibrosis die from their idiopathic pulmonary fibrosis, as opposed to dying with their idiopathic pulmonary fibrosis. Of those patients who die with idiopathic pulmonary fibrosis, most commonly it is after an acute exacerbation of idiopathic pulmonary fibrosis. When an acute exacerbation of idiopathic pulmonary fibrosis is not the cause of death, an increased cardiovascular risk and an increased venous thromboembolic disease risk contribute to the cause of death. The most common causes of death in patients with idiopathic pulmonary fibrosis include acute exacerbations of idiopathic pulmonary fibrosis, acute coronary syndromes, congestive heart failure, lung cancer, infectious causes, and venous thromboembolic disease.[3]

Race

Epidemiologic data from large, geographically diverse populations are limited, and, therefore this data cannot be used to accurately determine the existence of a racial predilection for idiopathic pulmonary fibrosis.

Sex

Using data obtained from a large US healthcare claims database, the incidence and prevalence of idiopathic pulmonary fibrosis is higher in men aged 55 years or older, compared with women of the same age.[17]

Age

Idiopathic pulmonary fibrosis mainly affects persons aged 50 years or older. Approximately two thirds of persons diagnosed with idiopathic pulmonary fibrosis are aged 60 years or older at the time of diagnosis. Using data obtained from a large US healthcare claims database, the incidence of idiopathic pulmonary fibrosis was estimated to range from 0.4-1.2 cases per 100,000 person-years for persons aged 18-34 years. However, the estimated incidence of idiopathic pulmonary fibrosis in persons aged 75 years or older was significantly higher and ranged from 27.1-76.4 cases per 100,000 person-years.[17]

Previous
Proceed to Clinical Presentation
 
 
Contributor Information and Disclosures
Author

Amanda Godfrey, MD  Fellow, Pulmonary and Critical Care Medicine, Henry Ford Hospital

Amanda Godfrey, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Medical Association, American Thoracic Society, and Michigan State Medical Society

Disclosure: Nothing to disclose.

Coauthor(s)

Daniel R Ouellette, MD, FCCP  Associate Professor of Medicine, Wayne State University School of Medicine; Consulting Staff, Pulmonary Disease and Critical Care Medicine Service, Henry Ford Health System

Daniel R Ouellette, MD, FCCP is a member of the following medical societies: American College of Chest Physicians and American Thoracic Society

Disclosure: Nothing to disclose.

Specialty Editor Board

Stephen P Peters, MD, PhD, FACP, FAAAAI, FCCP, FCPP  Professor of Genomics and Personalized Medicine Research, Internal Medicine, and Pediatrics, Associate Director, Center for Genomics and Personalized Medicine Research, Director of Research, Section on Pulmonary, Critical Care, Allergy and Immunologic Diseases, Wake Forest University School of Medicine

Stephen P Peters, MD, PhD, FACP, FAAAAI, FCCP, FCPP is a member of the following medical societies: American Academy of Allergy Asthma and Immunology, American Association of Immunologists, American College of Chest Physicians, American College of Physicians, American Federation for Medical Research, American Thoracic Society, and Sigma Xi

Disclosure: See below for list of all activities None None

Francisco Talavera, PharmD, PhD  Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

Daniel R Ouellette, MD, FCCP  Associate Professor of Medicine, Wayne State University School of Medicine; Consulting Staff, Pulmonary Disease and Critical Care Medicine Service, Henry Ford Health System

Daniel R Ouellette, MD, FCCP is a member of the following medical societies: American College of Chest Physicians and American Thoracic Society

Disclosure: Nothing to disclose.

Timothy D Rice, MD  Associate Professor, Departments of Internal Medicine and Pediatrics and Adolescent Medicine, St Louis University School of Medicine

Timothy D Rice, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Physicians

Disclosure: Nothing to disclose.

Chief Editor

Zab Mosenifar, MD  Director, Division of Pulmonary and Critical Care Medicine, Director, Women's Guild Pulmonary Disease Institute, Professor and Executive Vice Chair, Department of Medicine, Cedars Sinai Medical Center, University of California, Los Angeles, David Geffen School of Medicine

Zab Mosenifar, MD is a member of the following medical societies: American College of Chest Physicians, American College of Physicians, American Federation for Medical Research, and American Thoracic Society

Disclosure: Nothing to disclose.

Additional Contributors

The authors and editors of eMedicine gratefully acknowledge the contributions of previous authors, Rajesh G. Patel, MD, and Javier I. Diaz, MD, to the development and writing of this article.

References

  1. Raghu G, Collard HR, Egan JJ, Martinez FJ, Behr J, Brown KK. An Official ATS/ERS/JRS/ALAT Statement: Idiopathic Pulmonary Fibrosis: Evidence-based Guidelines for Diagnosis and Management. Am J Respir Crit Care Med. Mar 15 2011;183(6):788-824. [Medline].

  2. American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001. Am J Respir Crit Care Med. Jan 15 2002;165(2):277-304. [Medline].

  3. Frankel SK, Schwarz MI. Update in idiopathic pulmonary fibrosis. Curr Opin Pulm Med. Sep 2009;15(5):463-9. [Medline].

  4. Ley B, Collard HR, King TE Jr. Clinical course and prediction of survival in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Feb 15 2011;183(4):431-40. [Medline].

  5. Kim DS, Collard HR, King TE Jr. Classification and natural history of the idiopathic interstitial pneumonias. Proc Am Thorac Soc. Jun 2006;3(4):285-92. [Medline]. [Full Text].

  6. Misumi S, Lynch DA. Idiopathic pulmonary fibrosis/usual interstitial pneumonia: imaging diagnosis, spectrum of abnormalities, and temporal progression. Proc Am Thorac Soc. Jun 2006;3(4):307-14. [Medline].

  7. Visscher DW, Myers JL. Histologic spectrum of idiopathic interstitial pneumonias. Proc Am Thorac Soc. Jun 2006;3(4):322-9. [Medline].

  8. Verma S, Slutsky AS. Idiopathic pulmonary fibrosis--new insights. N Engl J Med. Mar 29 2007;356(13):1370-2. [Medline].

  9. Harari S, Caminati A. IPF: new insight on pathogenesis and treatment. Allergy. May 2010;65(5):537-53. [Medline].

  10. Thannickal VJ, Horowitz JC. Evolving concepts of apoptosis in idiopathic pulmonary fibrosis. Proc Am Thorac Soc. Jun 2006;3(4):350-6. [Medline]. [Full Text].

  11. Maher TM, Evans IC, Bottoms SE, Mercer PF, Thorley AJ, Nicholson AG. Diminished prostaglandin E2 contributes to the apoptosis paradox in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Jul 1 2010;182(1):73-82. [Medline].

  12. Armanios MY, Chen JJ, Cogan JD, et al. Telomerase mutations in families with idiopathic pulmonary fibrosis. N Engl J Med. Mar 29 2007;356(13):1317-26. [Medline].

  13. Seibold MA, Wise AL, Speer MC, Steele MP, Brown KK, Loyd JE. A common MUC5B promoter polymorphism and pulmonary fibrosis. N Engl J Med. Apr 21 2011;364(16):1503-12. [Medline].

  14. Wang XM, Zhang Y, Kim HP, et al. Caveolin-1: a critical regulator of lung fibrosis in idiopathic pulmonary fibrosis. J Exp Med. Dec 25 2006;203(13):2895-906. [Medline]. [Full Text].

  15. Fernandez Perez ER, Daniels CE, Schroeder DR, et al. Incidence, prevalence, and clinical course of idiopathic pulmonary fibrosis: a population-based study. Chest. Jan 2010;137(1):129-37. [Medline]. [Full Text].

  16. Olson AL, Swigris JJ, Lezotte DC, Norris JM, Wilson CG, Brown KK. Mortality from pulmonary fibrosis increased in the United States from 1992 to 2003. Am J Respir Crit Care Med. Aug 1 2007;176(3):277-84. [Medline].

  17. Raghu G, Weycker D, Edelsberg J, Bradford WZ, Oster G. Incidence and prevalence of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Oct 1 2006;174(7):810-6. [Medline].

  18. Antoniou KM, Hansell DM, Rubens MB, et al. Idiopathic pulmonary fibrosis: outcome in relation to smoking status. Am J Respir Crit Care Med. Jan 15 2008;177(2):190-4. [Medline].

  19. Lancaster LH, Mason WR, Parnell JA, et al. Obstructive sleep apnea is common in idiopathic pulmonary fibrosis. Chest. Sep 2009;136(3):772-8. [Medline]. [Full Text].

  20. Patel NM, Lederer DJ, Borczuk AC, Kawut SM. Pulmonary hypertension in idiopathic pulmonary fibrosis. Chest. Sep 2007;132(3):998-1006. [Medline].

  21. Fishman A, Elias J, Fishman J, Grippi M, Senior R, Pack A. Idiopathic Pulmonary Fibrosis. In: Fishman AP. Fishman's Pulmonary Diseases and Disorders. Vol 1. 4th ed. The McGraw-Hill Companies, Inc.; 2008:1143-60.

  22. Lawson WE, Loyd JE. The genetic approach in pulmonary fibrosis: can it provide clues to this complex disease?. Proc Am Thorac Soc. Jun 2006;3(4):345-9. [Medline]. [Full Text].

  23. Wootton SC, Kim DS, Kondoh Y, et al. Viral infection in acute exacerbation of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Jun 15 2011;183(12):1698-702. [Medline]. [Full Text].

  24. Flaherty KR, Thwaite EL, Kazerooni EA, et al. Radiological versus histological diagnosis in UIP and NSIP: survival implications. Thorax. Feb 2003;58(2):143-8. [Medline]. [Full Text].

  25. Martinez FJ, Flaherty K. Pulmonary function testing in idiopathic interstitial pneumonias. Proc Am Thorac Soc. Jun 2006;3(4):315-21. [Medline]. [Full Text].

  26. Tzilas V, Koti A, Papandrinopoulou D, Tsoukalas G. Prognostic factors in idiopathic pulmonary fibrosis. Am J Med Sci. Dec 2009;338(6):481-5. [Medline].

  27. du Bois RM, Weycker D, Albera C, Bradford WZ, Costabel U, Kartashov A, et al. Forced vital capacity in patients with idiopathic pulmonary fibrosis: test properties and minimal clinically important difference. Am J Respir Crit Care Med. Dec 15 2011;184(12):1382-9. [Medline].

  28. Flaherty KR, Andrei AC, Murray S, et al. Idiopathic pulmonary fibrosis: prognostic value of changes in physiology and six-minute-walk test. Am J Respir Crit Care Med. Oct 1 2006;174(7):803-9. [Medline]. [Full Text].

  29. Swigris JJ, Swick J, Wamboldt FS, et al. Heart rate recovery after 6-min walk test predicts survival in patients with idiopathic pulmonary fibrosis. Chest. Sep 2009;136(3):841-8. [Medline]. [Full Text].

  30. Bois RM, Weycker D, Albera C, et al. Six-minute-walk test in idiopathic pulmonary fibrosis: test validation and minimal clinically important difference. Am J Respir Crit Care Med. May 1 2011;183(9):1231-7. [Medline].

  31. Ohshimo S, Bonella F, Cui A, et al. Significance of bronchoalveolar lavage for the diagnosis of idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Jun 1 2009;179(11):1043-7. [Medline].

  32. Kinder BW, Brown KK, Schwarz MI, Ix JH, Kervitsky A, King TE Jr. Baseline BAL neutrophilia predicts early mortality in idiopathic pulmonary fibrosis. Chest. Jan 2008;133(1):226-32. [Medline].

  33. Lee JS, Ryu JH, Elicker BM, Lydell CP, Jones KD, Wolters PJ, et al. Gastroesophageal reflux therapy is associated with longer survival in patients with idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Dec 15 2011;184(12):1390-4. [Medline].

  34. Kozower BD, Meyers BF, Smith MA, et al. The impact of the lung allocation score on short-term transplantation outcomes: a multicenter study. J Thorac Cardiovasc Surg. Jan 2008;135(1):166-71. [Medline].

  35. Weiss ES, Allen JG, Merlo CA, Conte JV, Shah AS. Survival after single versus bilateral lung transplantation for high-risk patients with pulmonary fibrosis. Ann Thorac Surg. Nov 2009;88(5):1616-25; discussion 1625-6. [Medline].

  36. Orens JB, Estenne M, Arcasoy S, et al. International guidelines for the selection of lung transplant candidates: 2006 update--a consensus report from the Pulmonary Scientific Council of the International Society for Heart and Lung Transplantation. J Heart Lung Transplant. Jul 2006;25(7):745-55. [Medline].

  37. Behr J, Kolb M, Cox G. Treating IPF--all or nothing? A PRO-CON debate. Respirology. Nov 2009;14(8):1072-81. [Medline].

  38. Demedts M, Behr J, Buhl R, et al. High-dose acetylcysteine in idiopathic pulmonary fibrosis. N Engl J Med. Nov 24 2005;353(21):2229-42. [Medline].

  39. Raghu G, Brown KK, Bradford WZ, et al. A placebo-controlled trial of interferon gamma-1b in patients with idiopathic pulmonary fibrosis. N Engl J Med. Jan 8 2004;350(2):125-33. [Medline].

  40. Raghu G, Brown KK, Costabel U, et al. Treatment of idiopathic pulmonary fibrosis with etanercept: an exploratory, placebo-controlled trial. Am J Respir Crit Care Med. Nov 1 2008;178(9):948-55. [Medline].

  41. King TE Jr, Albera C, Bradford WZ, et al. Effect of interferon gamma-1b on survival in patients with idiopathic pulmonary fibrosis (INSPIRE): a multicentre, randomised, placebo-controlled trial. Lancet. Jul 18 2009;374(9685):222-8. [Medline].

  42. King TE Jr, Behr J, Brown KK, et al. BUILD-1: a randomized placebo-controlled trial of bosentan in idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Jan 1 2008;177(1):75-81. [Medline].

  43. The Idiopathic Pulmonary Fibrosis Clinical Research Network, Zisman DA, Schwarz M, Anstrom KJ, Collard HR, Flaherty KR. A controlled trial of sildenafil in advanced idiopathic pulmonary fibrosis. N Engl J Med. Aug 12 2010;363(7):620-8. [Medline].

  44. Daniels CE, Lasky JA, Limper AH, Mieras K, Gabor E, Schroeder DR. Imatinib treatment for idiopathic pulmonary fibrosis: Randomized placebo-controlled trial results. Am J Respir Crit Care Med. Mar 15 2010;181(6):604-10. [Medline].

  45. Richeldi L, Costabel U, Selman M, et al. Efficacy of a tyrosine kinase inhibitor in idiopathic pulmonary fibrosis. N Engl J Med. 365:1079-1087.

  46. Azuma A, Nukiwa T, Tsuboi E, et al. Double-blind, placebo-controlled trial of pirfenidone in patients with idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. May 1 2005;171(9):1040-7. [Medline].

  47. Taniguchi H, Ebina M, Kondoh Y, et al. Pirfenidone in idiopathic pulmonary fibrosis. Eur Respir J. Apr 2010;35(4):821-9. [Medline].

  48. Noble PW, Albera C, Bradford WZ, et al. Pirfenidone in patients with idiopathic pulmonary fibrosis (CAPACITY): two randomised trials. Lancet. May 21 2011;377(9779):1760-9. [Medline].

  49. Hyzy R, Huang S, Myers J, Flaherty K, Martinez F. Acute exacerbation of idiopathic pulmonary fibrosis. Chest. Nov 2007;132(5):1652-8. [Medline].

  50. Song JW, Hong SB, Lim CM, Koh Y, Kim DS. Acute exacerbation of idiopathic pulmonary fibrosis: incidence, risk factors and outcome. Eur Respir J. Feb 2011;37(2):356-63. [Medline].

  51. du Bois RM, Weycker D, Albera C, Bradford WZ, Costabel U, Kartashov A, et al. Ascertainment of individual risk of mortality for patients with idiopathic pulmonary fibrosis. Am J Respir Crit Care Med. Aug 15 2011;184(4):459-66. [Medline].

  52. Fang A, Studer S, Kawut SM, Ahya VN, Lee J, Wille K. Elevated Pulmonary Artery Pressure Is a Risk Factor for Primary Graft Dysfunction Following Lung Transplantation for Idiopathic Pulmonary Fibrosis. Chest. Apr 2011;139(4):782-787. [Medline].

  53. Kinder BW, Brown KK, McCormack FX, et al. Serum surfactant protein-A is a strong predictor of early mortality in idiopathic pulmonary fibrosis. Chest. Jun 2009;135(6):1557-63. [Medline]. [Full Text].

  54. [Medline].

  55. , Zisman DA, Schwarz M, Anstrom KJ, Collard HR, Flaherty KR. A controlled trial of sildenafil in advanced idiopathic pulmonary fibrosis. N Engl J Med. Aug 12 2010;363(7):620-8. [Medline].

  56. American Thoracic Society. Idiopathic pulmonary fibrosis: diagnosis and treatment. International consensus statement. American Thoracic Society (ATS), and the European Respiratory Society (ERS). Am J Respir Crit Care Med. Feb 2000;161(2 Pt 1):646-64. [Medline].

 
Previous
Next
 
Chest radiograph of a patient with idiopathic pulmonary fibrosis showing bilateral lower lobe reticular opacities (red circles).
Classic subpleural honeycombing (red circle) in a patient with a diagnosis of idiopathic pulmonary fibrosis.
A patient with IPF and a confirmed histologic diagnosis of usual interstitial pneumonia. Note the reticular opacities (red circle) distributed in both lung bases and the minimal ground-glass opacities (blue circle).
A patient with nonspecific interstitial pneumonia. Note the predominance of ground-glass opacities (blue circles) and a few reticular lines (red arrow).
Patchwork distribution of abnormalities in a classic example of usual interstitial pneumonia (low-magnification photomicrograph; hematoxylin and eosin stain; original magnification, X4). Courtesy of Chad Stone, MD.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2012 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.