Background Pleuropulmonary involvement in Systemic Lupus Erythematosus (SLE) occurs in 60 to 80% of patients. Shrinking lung syndrome (SLS) is a non-exclusive, rare manifestation of SLE. The pathogenesis and treatment of SLS are not well established.
Objectives We describe the clinical, immunological and radiological features and the therapeutic management of a series of 8 cases of SLS.
Methods This study is a retrospective, descriptive study of a series of 8 cases of patients diagnosed with SLE in the Rheumatology Unit of Ramόn y Cajal Hospital and Severo Ochoa Hospital.
Results Of the 8 patients, 7 were women with a mean age at diagnosis of 40 years. Only 2 patients had severe visceral involvement. All patients had a history of serositis. All patients had positive ANA, 87.5% anti-DNA positive and 100% had low complement at some point in the evolution of the disease. 62.5% had anti-Ro and 50% had anti-RNP. 37.5% of patients were already in treated with low or intermediate doses of corticosteroids at the time of diagnosis, 37.5% received dolquine, 25% were treated with azathioprine and one patient had epratuzumab.In relation to diagnostic studies, 100% of patients had elevating one hemidiaphragm or both on chest radiography and basal atelactasis. The most common findings on the CT scan were: elevation of the diaphragm, pleural effusion and the presence of basal atelectasis. All cases had a restrictive pattern in PFT and in the cases in which the results were available, the carbon monoxide gas transfer capacity was reduced. Regarding the therapeutic management, 62.5% were treated initially with intermediate-high doses of oral corticosteroids (mean dose 17.5 mg/day), in 25% was added Chloroquine, in 25% of cases Azathioprine and MMF in one patient. Only one patient received treatment with Beta-2 agonists. The evolution was favorable only in the patient receiving MMF with clinical and radiological improvement of stabilization on clinical and radiological findings over the time. In 62.5% of patients the pleuritic chest pain persisted and 37.5% presented later infectious respiratory complications.
Conclusions SLS is a rare complication in patients with SLE. The pathogenesis of SLS is unknown. It was suggested the possible involvement of the anti-Ro antibody. In our series, 62.5% had anti-Ro positive and 50% anti-RNP positive. The SLS must be suspected when a SLE patient star with unexplained dyspnea and/or pleuritic chest pain and a loss of lung volume in the imaging studies and development of a restrictive pattern in PFT. The treatment is not well established. In most published series, as in our case, the initial treatment is represented by the oral corticosteroid (30–60 mg/day). In several studies it has been proposed the use of Beta-2 adrenergic agonists and Theophylline, although their effectiveness has not been well demonstrated. In refractory cases the use of other immunosuppressive has been successfully reported. In our series, the addition of Chloroquine or Azathioprine was not associated with radiological improvement but with clinical stabilization in time. The MMF was associated with clinical and radiological improvement but a conclusion cannot be taken. The clinical outcome in most of the series is usually favorable, with subjective improvement in pain and dyspnea and with progressive improvement in lung function tests.
Disclosure of Interest None declared