Changes of the lung in rheumatoid arthritis--rheumatoid pneumonia. A clinicopathological study.

The frequency and patho-histological characteristics of pulmonary changes were studied on the autopsy material of 100 patients with rheumatoid arthritis (RA). The formal pathogenesis and different stages of vasculitis, rheumatoid nodule, interstitial pneumonia, rheumatoid pleuritis, obliterative bronchiolitis, amyloidosis and the so-called rheumatoid pneumonia in the lungs is discussed. The rheumatoid pneumonia is a disseminating inflammatory lobular-sublobular process, not described previously. The frequency of rheumatoid pneumonia was 4%. The rheumatoid pneumonia is characterized by the necrotic vasculitis, fibrinoid necrosis or thrombovasculitis of the pulmonary and bronchial arterioles, and of small arteries. Because of the diminished blood supply distal to the vascular changes inflammatory foci may develop, more or less respecting the anatomic borders of pulmonary tissue. The lobular-sublobular inflammation is basically of non haemorrhagic character. Because of the recurrent nature of vasculitis, foci of inflammation in different stages can be observed in the lungs simultaneously side by side. Clinically the rheumatoid pneumonia was accompanied by severe RA, according to the frequency and severity of acute exacerbations. In all 4 cases of rheumatoid pneumonia the pulmonary process had been proven clinically and radiologically. Rheumatoid pneumonia occurred subsequent to recurrent arthritis following steroid withdrawal, and it was resistant to antibiotics.