BRONCHOALVEOLAR LAVAGE CELL ANALYSIS AND LUNG-FUNCTION IMPAIRMENT IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE)

We examined the relationship between peripheral blood and bronchoalveo lar lavage (BAL) lymphocyte phenotypes and lung function in 19 patient s with SLE, and evaluated their association with disease activity. Lun g function assessment showed a mildly restrictive pattern with frequen t impairment of transfer factor for carbon monoxide (T1,CO) and diffus ing capacity of the alveolocapillary membrane (Dm), of late-expiratory airflow rates and with a high prevalence of increased airway resistan ce. T1,CO, K(CO) and Dm correlated inversely with the numbers of CD8cells and CD56+/CD16+/CD3- (NK) cells in BAL. Oxygen radical productio n, both by stimulated and unstimulated BAL cells and blood polymorphon uclear leucocytes (PMN) was significantly increased in SLE. In compari son with healthy controls, patients with SLE had a lower percentage of CD19+ B cells in the BAL versus an increased percentage of these cell s in peripheral blood. HLA-DR expression on CD4+ and CD8+ lung lymphoc ytes was markedly increased in SLE. Current SLE disease activity was n ot associated with changes in BAL or peripheral blood lymphocyte pheno types. Our data suggest that an ongoing cell-mediated immune response is present in the lungs in SLE, particularly involving activated CD8T cells and CD56+/CD16+/CD3- NK cells. It is associated with up-regula ted local production of oxygen radicals and with impaired pulmonary di ffusing capacity. This inflammatory process seems to be independent of general SLE disease activity.