Citations

Abstract Pulmonary eosinophilic granuloma is characterized by infiltration of the lungs with fibronodular lesions containing specialized Langerhans' cells. In some patients, progressive pulmonary fibrosis leads to significant respiratory impairment. Transforming growth factor-beta1 (TGF-beta1) promotes fibrosis by enhancing the synthesis of extracellular matrix components. The role of TGF-beta1 in promoting fibrosis in the setting of pulmonary eosinophilic granuloma is currently unknown. We used immunohistochemistry to evaluate the extent and distribution of TGF-beta1 and the extracellular matrix components type I collagen and decorin, a TGF-beta1-binding proteoglycan. Lung biopsies from 11 patients with pulmonary eosinophilic granuloma were evaluated. In biopsies with active inflammatory lesions containing Langerhans' cells, hyperplastic type 2 pneumocytes and alveolar macrophages within and surrounding the fibronodular lesions contained abundant TGF-beta1. Langerhans' cells were consistently devoid of immunoreactive TGF-beta1. Active inflammatory lesions also exhibited staining for decorin, in a loosely organized distribution. Advanced fibrotic lesions of eosinophilic granuloma, containing minimal inflammatory cells and few or no Langerhans' cells, exhibited weak or absent staining for TGF-beta1 within either hyperplastic type 2 pneumocytes or alveolar macrophages. The fibroconnective tissues of these advanced fibrotic lesions consistently revealed dense staining for decorin. Through their actions on extracellular matrix protein accumulation, TGF-beta1 and the TGF-beta1-binding proteoglycan decorin may modulate fibrotic repair accompanying pulmonary eosinophilic granuloma.

Abstract Acute eosinophilic pneumonia is characterized by acute respiratory insufficiency, hypoxemia, fever, diffuse radiographic infiltrates, and eosinophilia in bronchoalveolar lavage fluid (BALF) or lung biopsies in the absence of infection, atopy, or asthma. A rapid response to corticosteroids is characteristic. We reviewed our experience with nine cases of acute lung disease with histologic features of acute and organizing diffuse alveolar damage and prominent interstitial and alveolar eosinophils in order to determine whether this pathology was characteristic of acute eosinophilic pneumonia. The mean age of the patients (four men and five women) was 53 yr (range: 33 to 71 yr). They presented with 2 to 21 d of dyspnea, cough, myalgias, and fever. All were hypoxic and had bilateral infiltrates on chest radiographs. Peripheral blood eosinophilia was present in four of eight patients (peripheral blood count unavailable for one patient). All patients were treated with high-dose corticosteroids with a mean time to symptomatic and radiographic improvement of 4 d. Seven of the nine patients enrolled in the study are alive without relapse; one patient has a mild deficit in diffusing capacity, and one patient died of a myocardial infarct while improving on therapy. The presence of eosinophils in cases of acute respiratory insufficiency due to diffuse alveolar damage (DAD) should suggest the diagnostic possibility of acute eosinophilic pneumonia. Acute eosinophilic pneumonia should be distinguished from other causes of DAD because of important differences in natural history.

Abstract Cyclophosphamide-induced lung toxicity may be difficult to recognize because of the presence of confounding variables such as concomitant use of other cytotoxic drugs, opportunistic infections, diffuse pulmonary malignancy, radiation pneumonitis, and oxygen toxicity. The purpose of this retrospective analysis was to identify the clinical spectrum of pulmonary toxicity of cyclophosphamide. In our review of case records, we sought to identify patients in whom cyclophosphamide was the only identifiable etiologic factor for lung toxicity. In a 20-yr period six patients were identified with cyclophosphamide-induced lung disease, including five men and one woman ranging in age from 42 to 78 yr. Clinical features of toxicity include dyspnea, fever, cough, new parenchymal infiltrates, gas exchange abnormalities on pulmonary function tests, and pleural thickening on chest roentgenogram. Two patterns of cyclophosphamide-induced lung toxicity were identified. A single patient presented with early-onset pneumonitis and responded to discontinuation of the drug. Five patients with late-onset pneumonitis developed progressive pulmonary fibrosis associated with bilateral pleural thickening. Patients with late-onset pneumonitis showed no response to cessation of cyclophosphamide and institution of corticosteroid therapy. Three of these patients died of respiratory failure. Careful review of the individual cases reported in the literature as cyclophosphamide lung toxicity revealed only 12 cases in whom none of the additional confounding factors could be identified. These could easily be divided in the same two categories. Early-onset pneumonitis is reversible and may respond to corticosteroid therapy. Late-onset pneumonitis, frequently associated with pleural thickening, is clinically distinct from idiopathic pulmonary fibrosis but has a chronically progressive course. It appears unresponsive to corticosteroid therapy.