Methotrexate-induced pneumonitis in Crohn's disease. Case report and review of the literature

Abstract

Methotrexate (MTX) is a folate-antagonist used in several neoplastic and inflammatory diseases. Reports of pulmonary complications in patients given low-dose MTX therapy are increasing. Pulmonary toxicity from MTX has a variable frequency and can present with different forms. Most often MTX-induced pneumonia in patients affected by rheumatoid arthritis (RA) is reported.In this paper we describe a case of MTX-related pneumonitis in a relatively young woman affected by Crohn's disease who presented non-productive cough, fever and dyspnea on exercise. Chest X-ray demonstrated bilateral interstitial infiltrates and at computed tomography (CT) ground-glass opacities appeared in both lungs. At spirometry an obstructive defect was demonstrated. A rapid improvement of symptoms and the regression of radiographic and spirometric alterations was achieved through MTX withdrawal and the introduction of corticosteroid therapy.

Figure 1a

HRCT of lung during methotrexate therapy. Diffuse bilateral alveolar infiltrates and ground glass areas can be seen without distortion of pulmonary parenchyma. Definition of abbreviation: HRCT, high-resolution computed tomography.

Figure 1b

PFT at admission to hospital. Mild obstructive defect with severe reduction of DL_CO. Definition of abbreviations: DL_CO, diffusing lung capacity for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; PFT, pulmonary function test; TLC, total lung capacity; VC, vital capacity.

Figure 2a

HRCT of lung after discontinuation of methotrexate therapy. No lung abnormalities can be observed. Definition of abbreviation: HRCT, high-resolution computed tomography.

Figure 2b

PFT at outcome. Normalization of functional parameters. Definition of abbreviations: DL_CO, diffusing lung capacity for carbon monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; PFT, pulmonary function test; TLC, total lung capacity; VC, vital capacity.