Pulmonary involvement in juvenile dermatomyositis: a two-year longitudinal study.
OBJECTIVE
To investigate the prevalence and features of asymptomatic pulmonary involvement in juvenile dermatomyositis (JDM).


METHODS
Twelve JDM patients underwent pulmonary function tests at baseline, 12 and 24 months. Disease activity, duration, serum lactate dehydrogenase (LDH) values and antinuclear antibody (ANA) titres were also evaluated.


RESULTS
Five patients showed lung impairment at baseline and four at 12 and 24 months. Forced expiratory volume in 1s, forced vital capacity (FVC), carbon monoxide diffusing capacity (DLCO) and alveolar volume were the most frequently altered variables, indicating a restrictive pattern and impairment of diffusion. The prevalence and features of pulmonary alterations did not change during follow-up. FVC values were significantly lower in active JDM patients and were inversely related to LDH. DLCO values were significantly lower in ANA-positive patients. About half of the patients of this small case series of JDM had asymptomatic lung disease.


CONCLUSIONS
We suggest that lung function should be evaluated at disease onset and regularly during follow-up, as pulmonary function tests can detect otherwise unpredictable pulmonary involvement.
Department of Paediatrics, University of Florence, Italy.
S
S
Trapani
G
G
Camiciottoli
A
A
Vierucci
M
M
Pistolesi
F
F
Falcini
D000293:Adolescent; D002648:Child; D003882:Dermatomyositis / Q000150:complications*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008171:Lung Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D015995:Prevalence; D011446:Prospective Studies; D012129:Respiratory Function Tests; D013997:Time Factors