MANIFESTATIONS PLEURO-PULMONAIRES DE LA POLYARTHRITE RHUMATOIDE

: Sensitive investigations such as pulmonary function tests, broncho-alveolar lavage or computered tomography at high resolution enable pleuro-pulmonary disease to be detected in nearly 50% of those patients studied who had rheumatoid arthritis (PR). The prevalence of these manifestations is most usually elevated in male PR sufferers, those who are sero-positive or have associated extra-articular signs such as sub cutaneous nodules. More recently there has been evidence of genetic risk factors linked to HLA grouping or Pi phenotype. Amongst the usual manifestations, the pleurisies and above all necrobiotic nodules, which are most often asymptomatic, sometimes pose difficult problems in differential diagnosis, particularly when they precede the articular disease. The diffuse interstitial fibrosis remains the most worrying specific complication due to the fact of its potential seriousness. The pathophysiology of this form of fibrosis is better understood since the introduction of LBA. In the absence of any specific controlled studies its treatment remains impirical and is similar to that given for diffuse or idiopathic interstitial fibrosis. Pulmonary vascularity, the bronchiolitis obliterans with organising pneumonia and apical fibrosis, very similar to Hamilton's syndrome, are much rarer manifestations. On the other hand non specific respiratory infections are the cause of death in 10-20% of cases. Bronchiolitis obliterans induced by D Penicillamine is the most severe iatrogenic manifestation, since corticosteroid therapy associated with immunosuppressive drugs enables at best a stabilisation of the alveo bronchiolar lesions. More recently there have been twenty observations of hypersensitivity pneumonia to low dose methotrexate. The prevalence of these pulmonary disorders during the treatment of PR is around 5%. However the respiratory contraindications of these drugs which are being used more and more and the methods of pulmonary surveillance under treatment are not yet defined.