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At least 235 records · Page 13Linked to original sources
PubMed2002

Dyspnea scales as a measure of health-related quality of life in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is the most common interstitial lung disease and is usually associated with a poor prognosis. IPF patients have a significant impairment in health-related quality of life (HRQL), both in terms of physical and psychological functioning. A substantial number of dyspnea scales are available to clinicians for clinical and research use. The objective of the present study was to investigate how some commonly used dyspnea scales correlate with measurements of HRQL in IPF patients. MATERIAL/METHODS: A group of 30 patients with IPF who attended a specialized outpatient respiratory clinic were interviewed during a stable period of the disease. HRQL was assessed by the SF-36 questionnaire. Dyspnea was measured by the baseline dyspnea index (BDI), Modified Medical Research Council Scale (MRC), Oxygen Cost Diagram (OCD), clinical element of the Clinical, Roentgenographic and Physiologic score (CRP), and a new dyspnea scale (NS) based on estimates of required oxygen consumption for usual activities. RESULTS: Patients showed impairments in all HRQL domains except the Pain Index. All dyspnea scales showed significant correlations with both physical and mental HRQL domains. The highest Spearman's coefficients between dyspnea ratings and SF-36 components were obtained using the BDI. CONCLUSIONS: Dyspnea ratings correlate with HRQL measurements in IPF patients. Dyspnea scales can be used as a measure of HRQL in special circumstances.

Dyspnea↗
PubMed2006

Serum levels of oxidative stress as a marker of disease severity in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal illness characterized by progressive fibrosis resulting in severe dyspnea and impairment of lung function. Although the mechanisms by which lung fibrosis develops are not fully ascertained, recent findings suggest that oxidative stress may play an important role in the pathogenesis of tissue fibrosis. AIM: To evaluate the oxidative stress in the serum of patients with IPF and to explore the relationship between oxidative stress levels, dyspnea and impairment of lung function. MATERIAL AND METHODS: Blood samples from 21 untreated patients with IPF, sequentially recruited over a period of 2 years, and 12 controls were analyzed. The level of oxidative stress in the blood was determined through a spectrophotometric procedure (D-ROMs test). FVC and DLCO were measured in all patients. The level of dyspnea was assessed by the Medical Research Council (MRC) chronic dyspnea scale. RESULTS: Serum levels of oxidative stress were significantly increased in patients with IPF compared to controls (mean+/-SEM: 356.8+/-14 and 201+/-10 Carratelli units respectively, p<0.001). Oxidative stress was negatively associated with FVC (p<0.01, r=-0.79) and with DLCO (p<0.01, r=-0.75). Furthermore, oxidative stress was significantly correlated with MRC dyspnea score (p<0.01, r=0.87). Oxidative stress measurements were highly reproducible on two consecutive measurements in the same patients. CONCLUSION: The levels of systemic oxidative stress are enhanced in patients with IPF and could provide useful information about the classification of IPF severity. Strategies to reduce the oxidant burden in IPF may be beneficial in reducing the progressive deterioration of these patients.

Adult↗
PubMed2005

Cytokine levels in the sera of patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fibroproliferative disorder. Cytokines contribute an important but yet undefined role to its pathogenesis. OBJECTIVES: The present study aims to compare serum levels of cytokines involved in Th-1 and Th-2 immunity, such as interleukins (IL) IL-2, IL-4, IL-8, IL-10, interferon-gamma (IFN-gamma) and IL-12 (p40) in patients with IPF and healthy volunteers. Twenty patients with IPF and 40 healthy controls (HC) participated. METHODS: Cytokines were assessed by enzyme-linked immunoabsorbent assay (ELISA). RESULTS: Median values of serum IL-2, IL-8, IL-10, IL-12 (p40) were higher in the IPF than the control group: IPF group: 1.05 U/ml, 12.55, 10.13, 44.17 pg/ml; control group: 0.05 U/ml, 6.91, 0.75, 4.51 pg/ml, respectively (P<0.05). IFN-gamma serum levels were lower in the IPF (0.19 pg/ml) than in the control group (0.49 pg/ml). IL-4 values did not differ in a statistically significant way among the groups: 8.40 pg/ml in the IPF group, and 7.46 pg/ml in the control group (P>0.05). IL-4 positively correlated to fast expiratory volume in 1s (FEV1%) and forced vital capacity (FVC%), while IL-8 negatively correlated to the respective values (P<0.005). CONCLUSIONS: IL-2, IL-8, IL-10 and IL-12 (p40) were found to be elevated in the sera of patients with IPF. IFN-gamma was found to be decreased in the sera of patients with IPF.

Aged↗
PubMed2003

Neutrophilic inflammation in induced sputum of patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology. Biopsy and bronchoalveolar lavage studies have shown, that accumulation of inflammatory cells, particularily neutrophils, in the alveolar space is a relevant feature of the pathogenesis of IPF. This paper adresses the issue of whether the safe and non-invasive method of sputum induction is a suitable tool to study respiratory tract inflammation in IPF. METHODS: In a cross-sectional analysis, 15 IPF patients and 14 healthy, non-smoking subjects underwent sputum induction. Total sputum cell counts, differentials, and the amount of interleukin (IL)-8, granulocyte-macrophage-colony stimulating factor (GM-CSF), and soluble ICAM-1 (sICAM) in sputum supernatant were analyzed. RESULTS: IPF patients had increased sputum neutrophils (60 +/- 6 vs 22 +/- 3%, p = 0.0003), and supernatant concentrations of IL-8 (19 +/- 3 vs. 7 +/- 1 ng/ml, p = 0.0002), GM-CSF (205 +/- 43 vs. 122 +/- 36 pg/ml, p = 0.08) and sICAM (12 +/- 3 vs. 5 +/- 3 ng/ml, p = 0.01), when compared with healthy controls. Sputum IL-8 was correlated with sputum neutrophils (rho = 0.61, p = 0.0006) in all patients. The extent of sputum neutrophilia was also correlated with lung function impairment (vital capacity, % of predicted) in IPF patients (rho = -0.68, p = 0.007). CONCLUSION: These data confirm the established role of neutrophilic inflammation in the pathogenesis of IPF, and show the potential of induced sputum to directly study inflammatory processes and surrogate markers in interstitial lung diseases like IPF.

Adult↗
PubMed2005

Analyses of efficacy end points in a controlled trial of interferon-gamma1b for idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a devastating disease, yet validated, reliable criteria for evaluating patient response to therapies in clinical trials are lacking. METHODS: To optimize selection of end point criteria for the study of interferon (IFN)-gamma1b in patients with IPF, we retrospectively analyzed the components of the primary efficacy end point used in a large, controlled study of 330 patients for reliability, validity, and sensitivity to treatment effect. The primary end point components were death, disease progression defined as a > or = 5 mm Hg increase in resting alveolar-arterial oxygen pressure gradient (P[A-a]O2), and disease progression defined as a > or = 10% decrease in percentage of predicted FVC. RESULTS: We found that the P(A-a)O2 criterion was not reliable and was not associated with mortality. In contrast, the FVC criterion was reliable and was associated with a 2.4-fold increase in the risk of death. Of the three measures, only mortality was sensitive to a treatment effect of IFN-gamma1b. Additionally, the tendency for mortality benefit was observed in nearly all patient subgroups defined by baseline physiology. The effect of IFN-gamma1b on mortality was strongest in patients with baseline percentage of predicted FVC > or = 55% (p = 0.004) or percentage of predicted diffusing capacity of the lung for carbon monoxide > or = 30% (p = 0.008). CONCLUSION: We conclude that mortality is the most inclusive end point for future trials of IFN- gamma1b in patients with IPF, and that a > 10% decrement in the percentage of predicted FVC represents a valid measure of disease progression.

Adult↗
PubMed2006

Membrane type-matrix metalloproteinases in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterized by fibroblast expansion and extracellular matrix accumulation. Some secreted matrix metalloproteinases (MMPs) as MMP2 are highly upregulated in IPF lungs. Membrane-type (MT)-MMPs participate in the activation of pro-MMP2. However, they have not been examined in IPF. METHODS: Type I transmembrane MT-MMPs, MT1, MT2, MT3, and MT5-MMP were analyzed by real-time PCR and immunohistochemistry in IPF and normal lungs. MMP-2 was also immunolocalized and evaluated by gelatin zymography in BAL fluids. Additionally, the MT-MMPs were examined by real time PCR in lung fibroblasts stimulated with TGF-beta1 and IFN-gamma. RESULTS: MT1-MMP, was the most highly expressed followed by MT2- and MT5-MMP, and by a moderate expression of MT3-MMP. Regarding their localization, MT1- and MT2-MMPs were found in alveolar epithelial cells, MT3-MMP in fibroblasts from fibroblastic foci and alveolar epithelial cells and MT5-MMP in basal bronchiolar epithelial cells and in areas of squamous metaplasia. MMP2 was localized in alveolar and basal bronchiolar epithelial cells and fibroblasts, and increased active enzyme was observed in BAL fluids. In lung fibroblasts, TGF-beta1 induced a strong upregulation of MT3-MMP, both at the gene and protein level. This effect was blocked by genistein, a protein tyrosin kinase inhibitor and partially repressed by SB203580 a p38 MAP kinase inhibitor. IFN-gamma had no effect. CONCLUSIONS: MT-MMPs are expressed in IPF, in the same cell types as MMP2. Mostly by different types of epithelial cells a pivotal component in the aberrant remodeling of the lung microenvironment. Interestingly MT3-MMP that was found in fibroblastic foci was upregulated in vitro by TGF-beta1 a potent profibrotic mediator.

Bronchoalveolar Lavage Fluid↗
PubMed2006

RhoA signaling modulates cyclin D1 expression in human lung fibroblasts; implications for idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) is a debilitating disease characterized by exaggerated extracellular matrix deposition and aggressive lung structural remodeling. Disease pathogenesis is driven by fibroblastic foci formation, consequent on growth factor overexpression and myofibroblast proliferation. We have previously shown that both CTGF overexpression and myofibroblast formation in IPF cell lines are dependent on RhoA signaling. As RhoA-mediated regulation is also involved in cell cycle progression, we hypothesise that this pathway is key to lung fibroblast turnover through modulation of cyclin D1 kinetic expression. METHODS: Cyclin D1 expression was compared in primary IPF patient-derived fibroblasts and equivalent normal control cells. Quantitative real time PCR was employed to examine relative expression levels of cyclin D1 mRNA; protein expression was confirmed by western blotting. Effects of Rho signaling were investigated using transient transfection of constitutively active and dominant negative RhoA constructs as well as pharmacological inhibitors. Cellular proliferation of lung fibroblasts was determined by BrdU incorporation ELISA. To further explore RhoA regulation of cyclin D1 in lung fibroblasts and associated cell cycle progression, an established Rho inhibitor, Simvastatin, was incorporated in our studies. RESULTS: Cyclin D1 expression was upregulated in IPF compared to normal lung fibroblasts under exponential growth conditions (p < 0.05). Serum deprivation inhibited cyclin D1 expression, which was restored following treatment with fibrogenic growth factors (TGF-beta1 and CTGF). RhoA inhibition, using a dominant negative mutant and a pharmacological inhibitor (C3 exotoxin), suppressed levels of cyclin D1 mRNA and protein in IPF fibroblasts, with significant abrogation of cell turnover (p < 0.05). Furthermore, Simvastatin dose-dependently inhibited fibroblast cyclin D1 gene and protein expression, inducing G1 cell cycle arrest. Similar trends were observed in control experiments using normal lung fibroblasts, though exhibited responses were lower in magnitude. CONCLUSION: These findings report for the first time that cyclin D1 expression is deregulated in IPF through a RhoA dependent mechanism that influences lung fibroblast proliferation. This potentially unravels new molecular targets for future anti-IPF strategies; accordingly, Simvastatin inhibition of Rho-mediated cyclin D1 expression in IPF fibroblasts merits further exploitation.

ADP Ribose Transferases↗
PubMed1993

Elevated serum superoxide dismutase levels correlate with disease severity and neutrophil degranulation in idiopathic pulmonary fibrosis.

1. Tissue damage in idiopathic pulmonary fibrosis is due in part to oxidant-antioxidant imbalance. 2. We evaluated the serum levels of the antioxidant enzyme Cu/Zn superoxide dismutase (EC 1.15.1.1) in 25 patients with idiopathic pulmonary fibrosis, 34 patients with sarcoidosis and 40 healthy control subjects by an enzyme immunometric assay. 3. We found that patients with idiopathic pulmonary fibrosis have higher serum Cu/Zn superoxide dismutase levels than control subjects and patients with sarcoidosis. In addition, serum Cu/Zn superoxide dismutase levels correlate with disease severity indexes in patients with idiopathic pulmonary fibrosis. 4. The increase in serum Cu/Zn superoxide dismutase level in idiopathic pulmonary fibrosis could depend on degranulation of activated neutrophils or release from damaged cells. To elucidate the contribution of neutrophil degranulation we determined the polymorphonuclear cell elastase level in the same specimens. We found a strong correlation between serum Cu/Zn superoxide dismutase and polymorphonuclear cell elastase activities, and, in patients with idiopathic pulmonary fibrosis, we observed higher levels of polymorphonuclear cell elastase than in control subjects and patients with sarcoidosis, which correlated positively with disease severity indexes. 5. Cu/Zn superoxide dismutase can catalyse the dismutation of O2 into H2O2 and generate OH.. These oxygen radicals are probably the major factors responsible for tissue damage (in particular, alveolar and endothelial cells) and fibrosis in experimental lung injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed2006

Idiopathic pulmonary fibrosis: is it a familial disease?

PURPOSE OF REVIEW: Idiopathic pulmonary fibrosis is a progressively fatal interstitial lung disease associated with pathological findings of usual interstitial pneumonia. Its pathogenesis is unknown, and there are no proven effective therapies. Familial cases account for 0.5-2% of idiopathic pulmonary fibrosis. Familial idiopathic pulmonary fibrosis occurs as an autosomal dominant disorder with variable penetrance. The clinical characteristics of familial idiopathic pulmonary fibrosis are indistinguishable from sporadic idiopathic pulmonary fibrosis. These marked similarities support the hypothesis there may, in part, be a genetic basis for idiopathic pulmonary fibrosis. RECENT FINDINGS: Many investigations have evaluated genetic polymorphisms and idiopathic pulmonary fibrosis. Candidate genes include cytokines and surfactant protein genes. To date, no gene has been consistently identified to be associated with idiopathic pulmonary fibrosis. Recent studies in familial idiopathic pulmonary fibrosis have demonstrated a strong association with surfactant protein C gene mutations in one large kindred. SUMMARY: The pathogenesis of both idiopathic pulmonary fibrosis and familial idiopathic pulmonary fibrosis remains unclear. A consistent genetic basis has not yet been demonstrated in all cases. Other factors, including variable gene expression, co-carriage of other modifying genes and environmental stimuli, particularly cigarette smoke, significantly contribute to disease expression.

Humans↗
PubMed1995

Intravenous N-acetylcysteine and lung glutathione of patients with pulmonary fibrosis and normals.

Idiopathic pulmonary fibrosis (IPF) is characterized by a huge alveolar oxidant burden and a deficiency of glutathione, a major antioxidant, in the pulmonary epithelial lining fluid (ELF). Therefore, a rational therapeutic strategy is to increase lung glutathione to augment the pulmonary antioxidant protective screen. To evaluate this concept, different doses of N-acetylcysteine (NAC), a glutathione precursor, were administered intravenously to eight patients with pulmonary fibrosis and six control subjects. In patients, bronchoalveolar lavage fluid (BALF) total glutathione increased significantly from 0.99 +/- 0.25 microM to 1.79 +/- 0.37 microM within 3 h following 1.8 g NAC, whereas 4.8 g NAC had no additional effect (1.47 +/- 0.34 microM). In the control subjects, NAC did not significantly alter BALF total glutathione (baseline: 0.79 +/- 0.17 microM, 600 mg NAC: 0.92 +/- 0.33 microM, 1.8 g NAC: 1.39 +/- 0.41 microM, 4.8 g NAC: 1.33 +/- 0.46 microM). The same was true in ELF, 1.8 g NAC significantly raised ELF total glutathione in patients from 186 +/- 47 microM to near normal levels (373 +/- 103 microM), with no further increase following 4.8 g NAC (293 +/- 62 microM). In the control subjects, ELF total glutathione remained unchanged independent of the NAC dose (baseline: 342 +/- 91 microM, 600 mg NAC: 385 +/- 135 microM, 1.8 g NAC: 633 +/- 220 microM, 4.8 g NAC: 646 +/- 263 microM). The increases in total glutathione were almost entirely due to increased levels of reduced glutathione, the form functional as an antioxidant. No adverse effects were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcysteine↗
PubMed1990

[Unilateral lung transplantation--a new perspective in the treatment of pulmonary fibrosis].

In patients with pulmonary fibrosis and progressive respiratory failure despite conservative treatment, unilateral lung transplantation offers a new therapeutic alternative. At the Medical School in Hannover, five patients--the first to be thus treated in Central Europe--with terminal pulmonary fibrosis of the lung have so far been successfully treated with unilateral lung transplantation. All five patients are still alive, and all experienced a marked improvement in their pulmonary function parameters, such that they have been enabled to lead a normal life again.

Adult↗
PubMed2000

[Spontaneous pneumomediastinum and idiopathic pulmonary fibrosis].

The association between pulmonary fibrosis and pneumomediastinum is infrequent. Computed tomography is the suited method for the detection of small pneumomediastinum, which is difficult to detect by chest radiography. A case of idiopathic pulmonary fibrosis, with frequent and violent cough, with pneumomediastinum and cervical subcutaneous emphysema, without pneumothorax, probably caused by rupture of bullae is presented. The outcome was favourable with symptomatic treatment.

Female↗
PubMed2002

The myofibroblast in pulmonary fibrosis.

The pathogenesis of pulmonary fibrosis remains incompletely understood. Studies of associated inflammation have led to the discovery of a number of cytokines and chemokines that are found to be important either directly or indirectly for the fibrotic process. However, the importance of inflammation in pulmonary fibrosis is unclear, and at the time of diagnosis the inflammatory component is variable and usually not responsive to anti-inflammatory therapeutic agents. Patients usually exhibit evidence of active fibrosis with increased numbers of activated fibroblasts, many of which have the phenotypic characteristics of myofibroblasts. At these sites, increased amounts of extracellular matrix deposition are evident with effacement of the normal alveolar architecture. Animal model studies show the myofibroblast to be the primary source of type I collagen gene expression in active fibrotic sites. In vitro studies show differentiation of these cells from fibroblasts under the influence of certain cytokines but indicate their susceptibility to nitric oxide-mediated apoptosis. In addition to promoting myofibroblast differentiation, transforming growth factor-beta1 provides protection against apoptosis. Thus, this well-known fibrogenic cytokine is important both for the emergence of the myofibroblast and its survival against apoptotic stimuli. This is consistent with the critical importance of this cytokine in diverse models of fibrosis in various tissues. In view of these properties, the persistence or prolonged survival of the myofibroblast may be key to understanding why certain forms of lung injury may result in progressive disease, terminating in end-stage disease.

Apoptosis↗
PubMed1990

Pulmonary fibrosis as an unusual clinical manifestation of a pulmonary-renal vasculitis in elderly patients.

Between 1978 and 1988, three patients at our institution had an initial diagnosis of idiopathic pulmonary fibrosis but later were correctly diagnosed as having pulmonary-renal syndrome and microscopic polyarteritis. These cases involved elderly patients with progressive dyspnea and nonproductive cough, bilateral dry crackling rales, bilateral interstitial infiltrates evident on a chest roentgenogram, and restrictive findings on pulmonary function testing. In two patients, lung biopsy specimens were obtained, and an initial diagnosis of nonspecific pulmonary fibrosis was made. All three patients eventually had microhematuria and renal insufficiency. A revised diagnosis of small-vessel pulmonary-renal vasculitis was based on the demonstration of segmental necrotizing glomerulonephritis in renal biopsy specimens in two patients, thrombotic microangiopathy consistent with healed vasculitis on postmortem examination of the kidney in one patient, and subsequent detection of small-vessel vasculitis on review of the two lung biopsy specimens. Anti-neutrophil cytoplasmic antibodies with perinuclear staining on indirect immunofluorescence microscopy were positive in the two patients in whom determinations were performed. The clinical manifestations of vasculitis were notably scarce--no involvement of the skin, nervous system, or gastrointestinal tract; no episodes of fever; and minimal or absent musculoskeletal symptoms. These cases illustrate the importance of a high index of suspicion for the diagnosis of systemic vasculitis in elderly patients and the need to consider a vasculitis in the differential diagnosis of idiopathic pulmonary fibrosis, especially if an active urinary sediment is present.

Aged↗
PubMed1995

Cellular localization of transforming growth factor-beta expression in bleomycin-induced pulmonary fibrosis.

Bleomycin-induced pulmonary fibrosis is associated with increased lung transforming growth factor-beta (TGF-beta) gene expression, but cellular localization of the source of this expression has not been unequivocally established. In this study, lung fibrosis was induced in rats by endotracheal bleomycin injection on day 0 and, on selected days afterwards, lungs were harvested for in situ hybridization, immunohistochemical and histochemical analyses for TGF-beta 1 mRNA and protein expression, and cell identification. The results show that control lungs express essentially no detectable TGF-beta 1 mRNA or protein in the parenchyma. Before day 3 after bleomycin treatment, scattered bronchiolar epithelial cells, mononuclear cells, and eosinophils expressed elevated levels of TGF-beta 1. Between days 3 and 14, there was a major increase in the number of eosinophils, myofibroblasts, and fibroblasts strongly expressing TGF-beta 1 mRNA and protein. TGF-beta 1-producing cells were predominantly localized within areas of injury and active fibrosis. After day 14, the intensity and number of TGF-beta 1-expressing cells significantly declined and were predominantly found in fibroblasts in fibrotic areas. The expression of TGF-beta 1 protein was generally coincident with that for mRNA with the exception of bronchiolar epithelial cells in which strong protein expression was unaccompanied by a commensurate increase in mRNA. The study demonstrates that myofibroblasts, fibroblasts, and eosinophils represent the major sources of increased lung TGF-beta 1 expression in this model of pulmonary fibrosis.

Animals↗
PubMed1997

Idiopathic pulmonary fibrosis in infants.

Idiopathic pulmonary fibrosis is a poorly characterized disease in infants. In the present report, we reviewed our experience with 10 infants during a 10-year period. In 9 patients, onset of symptoms occurred before the age of 2 months and included tachypnea, cough, and inadequate weight gain. However, despite the presence of these symptoms, diagnosis was delayed for 3 months at which time the infants were referred to the pediatric pulmonary department, when the diagnosis was confirmed by open lung biopsy. At the time of admission, bronchoscopy with alveolar lavage was performed in 9 children and showed severe alveolitis with an increase in the neutrophil count. Nine infants were treated with prednisone alone or in combination with chloroquine, colchicine, or cyclophosphamide; all these patients died despite treatment. One infant was treated with pulses of methylprednisolone because of a failure in response to oral prednisone. This girl who displayed similar clinical, radiological, and histological abnormalities as the other children at the time of diagnosis is the only child still alive after 3 years of follow-up. She is now free of respiratory symptoms and has a normal growth curve. The present report raised two important points: (1) a thorough evaluation of characteristic symptoms should lead to an early diagnosis of pulmonary fibrosis in infants; and (2) administration of pulse therapy using corticosteroids has been helpful and needs to be evaluated further.

Biopsy↗
PubMed1998

Idiopathic pulmonary fibrosis: current concepts.

Idiopathic pulmonary fibrosis (IPF) is generally defined as a progressive, fibrosing inflammatory disease of the lung parenchyma of unknown cause. It is characterized by slowly increasing dyspnea, diffuse interstitial lung infiltrates, restrictive lung dysfunction, and impaired gas exchange. Ultimately, it is fatal in most patients, and treatment options remain unsatisfactory. The advent of high-resolution computed tomography of the chest and modifications in the histopathologic classification of interstitial pneumonias have reshaped the concept of IPF. Although initially thought to be a relatively specific clinicopathologic entity, it seems likely that IPF as previously defined is a heterogeneous disorder consisting of several clinicopathologic entities with differing histopathologic patterns, clinical course, response to therapy, and prognosis. The most common histologic pattern in cases previously defined as IPF is usual interstitial pneumonia, which is associated with a median survival of less than 3 years. For accurate prognosis and optimal management of patients, the clinician should attempt to be as precise as possible in distinguishing various clinicopathologic entities that have been included under the clinical heading of IPF. In the future, we recommend that the use of the term "idiopathic pulmonary fibrosis" be restricted to patients with usual interstitial pneumonia and that clinicians recognize the fact that other idiopathic interstitial pneumonias do not have the same prognostic effect traditionally ascribed to IPF.

Diagnosis, Differential↗