Waldron, James A.

Abstract The early stage of idiopathic pulmonary fibrosis (IPF) is thought to involve a smaller number of alveoli and to be characterized predominantly by cellularity and minimal fibrosis, whereas advanced disease involves a large number of alveoli and is characterized predominantly by fibrosis with minimal cellularity. In addition, correlative studies have indicated that prognosis and response to therapy is determined in part by the extent of fibrosis and cellularity. This study was undertaken to determine whether pulmonary function assessment would help distinguish between the cellular and fibrotic phases of this disorder, as determined by a semiquantitative pathology scoring system that comprised four factor scores: fibrosis, cellularity, granulation/connective tissue, and desquamation. Ninety-six untreated patients with biopsy-confirmed IPF (27 never smokers, 32 current smokers, and 37 ex-smokers) were evaluated. In the group as a whole, there was no significant relationship between the fibrosis or the connective/granulation tissue factor scores and any of the physiologic parameters. The Dl co correlated with the “desquamation” and the total pathology scores, whereas the TLC and FVC correlated with the cellularity factor score. In the current smokers, the coefficient of elastic retraction, Dl co/Va, and FEV1/FVC ratio were significantly lower than in never smokers and ex-smokers, and TLC and FVC were higher than in never smokers. Also, the mean cellularity and granulation/connective tissue factor scores were significantly lower, and the desquamation factor score was significantly higher than those in never smokers and ex-smokers. Both age and smoking status were significant for the cellularity factor score, whereas for the connective/granulation tissue factor score, age was not significant but smoking status was. For the desquamation factor score, age was significant but smoking status was not. There were significant differences between never smokers and ever smokers in the relationship between the pathology factors and measurements of respiratory function, and this may explain some of the difficulty in assessing structure-function correlation in patients with IPF. In the never smokers, the correlations between structure and function were likely the direct result of IPF per se. In the current smokers, bronchiolar and/or emphysematous changes associated with cigarette smoking may have complicated the pathologic alterations caused by IPF, as well as influencing the functional derangements.

Abstract We report two patients with systemic necrotizing vasculitis (microscopic polyarteritis) and associated recurrent pulmonary capillaritis, in whom progressive irreversible airway dysfunction began approximately 10 yr after disease onset. Their course was characterized by repeated episodes of diffuse alveolar hemorrhage, glomerulonephritis, palpable purpura, and splinter hemorrhages. The lung revealed intraalveolar hemorrhage, neutrophilic infiltration and cellular fragmentation, fibrinoid necrosis of the alveolar interstitium, and parenchymal hemosiderin deposits. No medium-sized vessel involvement, granulomatous inflammation, or bronchiolar obliteration were seen. Renal biopsies revealed focal segmental necrotizing glomerulonephritis, and a cutaneous biopsy in one case showed a leukocytoclastic vasculitis. Immunofluorescent studies of lung and kidney showed minimal or no immunoreactivity. The clinical course and serologic tests did not support another systemic vasculitis, connective tissue disease, or antiglomerular basement membrane antibody disease. The acute episodes responded to antiinflammatory and immunosuppressive therapy. Symptoms, serial pulmonary function tests, and chest imaging documented the development of a progressive irreversible obstructive airway disease. No other predisposing factors were identified. These cases demonstrate the unexpected appearance of an irreversible obstructive airway disease with lung parenchymal hyperinflation after systemic necrotizing vasculitis associated with recurrent pulmonary capillaritis and diffuse alveolar hemorrhage.

Abstract It is hypothesized that the extent and severity of fibrosis and cellularity found on lung biopsy determine the prognosis and response to therapy in idiopathic pulmonary fibrosis (IPF). The objective of this study was to determine which histopathologic features predict survival in IPF. We prospectively studied 87 patients with usual interstitial pneumonia (UIP) confirmed by surgical lung biopsy. Four pathologists independently graded the extent and severity of specific histopathologic features. We used Cox proportional-hazards models to assess the effect of histopathologic patterns on patients' survival. The effects of age, sex, and smoking were also included in the analysis. Sixty-three patients died during the 17-yr study period. Survival was longer in subjects with lesser degrees of granulation/connective tissue deposition (fibroblastic foci). The degree of alveolar space cellularity, alveolar wall fibrosis, and cellularity did not affect survival. A history of cigarette smoking, the level of dyspnea, and the degree of lung stiffness at presentation were also shown to be independent factors predicting survival. The extent of fibroblastic foci present on lung biopsy predicts survival in IPF. These findings support the hypothesis that the critical pathway to end-stage fibrosis is not “alveolitis” but rather the ongoing epithelial damage and repair process associated with persistent fibroblastic proliferation. Controlling these processes, rather than stopping inflammation, appears most important in preventing progressive disease and the fatal outcome common in IPF.

Abstract It is not known if a surgical lung biopsy is necessary in all patients for the diagnosis of idiopathic pulmonary fibrosis (IPF). We conducted a blinded, prospective study at eight referring centers. Initially, cases were evaluated by clinical history and examination, transbronchial biopsy, and high-resolution lung computed tomography scans. Pulmonologists at the referring centers then assessed their certainty of the diagnosis of IPF and provided an overall diagnosis, before surgical lung biopsy. The lung biopsies were reviewed by a pathology core and 54 of 91 patients received a pathologic diagnosis of IPF. The positive predictive value of a confident (certain) clinical diagnosis of IPF by the referring centers was 80%. The positive predictive value of a confident clinical diagnosis was higher, when the cases were reviewed by a core of pulmonologists (87%) or radiologists (96%). Lung biopsy was most important for diagnosis in those patients with an uncertain diagnosis and those thought unlikely to have IPF. These studies suggest that clinical and radiologic data that result in a confident diagnosis of IPF by an experienced pulmonologist or radiologist are sufficient to obviate the need for a lung biopsy. Lung biopsy is most helpful when clinical and radiologic data result in an uncertain diagnosis or when patients are thought not to have IPF.

Abstract Four women with a chronic respiratory illness characterized by chronic cough, dyspnea, mild to severe physiologic abnormalities, relatively normal chest radiographs, and lack of response to bronchodilators or prednisone were identified and prospectively evaluated. Constrictive bronchiolitis, defined as concentric narrowing of the bronchiolar lumen, mural scarring, smooth muscle hyperplasia, and mucus stasis, was the major histologic finding on open lung biopsy in all cases. Each presented with an illness clinically distinct from asthma, connective tissue disorders, occupational or environmental lung disease, bronchiectasis, diffuse panbronchiolitis, cystic fibrosis, and emphysema. None of the patients smoked cigarettes. None had clinical evidence of a recent viral lower respiratory tract infection. The physical examinations were normal except for rales heard on chest examination in two patients. Chest radiographs showed increased bronchovascular markings in three patients. Lung function was normal in one patient, two of the patients had a reduced diffusing capacity associated with moderate hypoxemia and an obstructive ventilatory defect, and one patient exhibited a mixture of restrictive and obstructive defects. None have experienced significant progression of their disease over 1 to 5 yr of follow-up. However, complete return to normal function did not occur. We hypothesize that patients with the constellation of findings described represent a distinct and definable clinicopathologic entity and further clarifies the spectrum of “small airways disease.” Establishing the diagnosis appears important for prognostic and possibly therapeutic reasons.