Disease-modifying antirheumatic drugs and organising pneumonia

Abstract

Organising pneumonia (OP) in rheumatoid arthritis (RA) may be part of pulmonary manifestation (disease related) or disease-modifying antirheumatic drugs (DMARDs) related. We report a case series of RA patients with DMARDs related OP. A 65-year-old woman developed OP 3 weeks after initiation of methotrexate (MTX). High-resolution CT (HRCT) scan of the thorax revealed bilateral consolidations in the lung bases. She had complete radiological resolution 6 months after corticosteroid therapy with cessation of MTX. The second case was of a 60-year-old woman on MTX with recent addition of leflunomide due to flare of RA. She developed worsening cough 4 months later and HRCT scan revealed consolidation in the left upper lobe with biopsy proven OP. She responded within 6 months of corticosteroid therapy with clinical and radiological resolution. This case series highlights that OP may developed with low-dose MTX (as early as 3 weeks) and leflunomide and the diagnosis requires a high index of suspicion.

Keywords: interstitial lung disease; respiratory medicine; rheumatoid arthritis; rheumatology.

Figure 1

(A, B) Pretreatment imaging. Chest radiograph (A) showed bilateral peripheral lower zone infiltrates. HRCT scan of the thorax (B) revealed bilateral symmetrical patchy consolidation along the subpleural regions (red arrow) of bilateral lower lobes. (C, D) Post-treatment imaging. Chest radiograph (C) showed resolving bilateral infiltrates with residual consolidation at the periphery of left lower zone. HRCT scan of the thorax (D) after 6 months of prednisolone (prior to discontinuation) revealed significant interval improvement with residual minimal fibrosis bilateral lower zones with complete resolution of the consolidations. HRCT, high-resolution CT.

Figure 2

(A, B) Pretreatment imaging. Chest radiograph (A) revealed left upper zone reticulo-nodular opacity. CT scan of the thorax (B) revealed consolidation at anterior segment of left upper lobe with air bronchogram within the lesion. (C, D) Post-treatment imaging. Chest radiograph (C) 3 months later showed resolving reticulo-nodular opacity of the left upper lobe. High-resolution CT scan of the thorax (D) on completion of steroids showed resolution of the consolidation with residual subpleural thickening.