G. Rolla et al., INCREASED NITRIC-OXIDE IN EXHALED AIR OF PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS, Journal of rheumatology, 24(6), 1997, pp. 1066-1071
Objective, In experimental animals, elevated nitric oxide (NO) product
ion has been implicated in the pathogenesis of a lupus-like syndrome.
Abnormalities of lung function tests are reported in a high proportion
of patients with systemic lupus erythematosus (SLE). We investigated
whether NO output in exhaled air might be increased in patients with S
LE and whether it is related to disease activity and to respiratory fu
nction abnormalities. Methods. Lung volume, maximal expiratory flow at
50 and 25% of viral capacity (MEF50 MEF25), diffusion coefficient for
carbon monoxide (K-CO), and NO in the exhaled air were measured in 27
outpatients with SLE (23 women, age 39.2 +/- 16.3). NO in exhaled air
was also measured in 30 healthy control subjects. Disease activity wa
s assessed by the European Consensus Lupus Activity Measurement (ECLAM
) scoring system. Results. Mean values of peak concentrations of NO ex
haled air were 64.8 +/- 27.9 parts per billion (ppb) in patients and 3
1.6 +/- 7.7 ppb in controls, p < 0.001. Peak NO concentration was dire
ctly related to ECLAM activity score (p < 0.05) and inversely related
to MEF25 (p < 0.05). Conclusion, NO in exhaled air is significantly in
creased and correlated with disease activity in patients with SLE. Whe
ther increased NO output depends on respiratory tract inflammation, as
the relationship with MEF25 may suggest, or on circulating cytokines
produced elsewhere remains to be investigated.