Shrinking lung syndrome in systemic lupus erythematosus patients with dyspnea

ABSTRACT

To identify the frequency of shrinking lung syndrome [SLS] in systemic lupus erythematosus [SLE] with dyspnea and study the clinical characteristics and differences in disease activity and damage. The study included 47 SLE patients complaining of dyspnea. SLS was considered in those with exertional dyspnea, restrictive pulmonary function tests [PFTs] and elevated copula of the diaphragm. Full history taking, thorough clinical examination, laboratory and relevant radiological investigations were performed for all the patients. Systemic Lupus Erythematosus Disease Activity Index [SLEDAI] and Systemic Lupus International Collaborating Clinics [SLICC] indices were compared. High resolution CT chest was performed for patients with radiological findings consistent with SLS. The mean age of the patients was 29.43 +/- 7.45 years, mean disease duration 5.18 +/- 3.62 years. The SLS was present in 8 patients [17.02%]. There was bilateral elevation of the diaphragm copulae in 25% of SLS patients and two had associated basal atelectatic bands. The serum uric acid was significantly higher in those with SLS while the 24 h urine protein was significantly lower and C4 normalized. The levels of SLEDAI and SLICC tended to be lower in those with SLS, yet there was no significant difference from those without. The demographic features, clinical and laboratory manifestations, disease activity and damage scores, PFTs and radiological findings of the SLE patients are presented. In SLE patients with dyspnea, SLS should be looked for as it is present in a high proportion of cases