Pulmonary outcome in juvenile dermatomyositis

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Pulmonary outcome in juvenile dermatomyositis: a case-control study

Ann Rheum Dis doi:10.1136/ard.2010.131433

http://ard.bmj.com/content/early/2010/08/29/ard.2010.131433.short?rss=1

Correspondence to

Dr Helga Sanner, Department of Rheumatology, Oslo University Hospital,

Rikshospitalet, 0027 Oslo, Norway; helga.sanner@...

Abstract

Objectives To compare pulmonary function in patients with juvenile

dermatomyositis (JDM) with that of matched controls; and to examine

associations between pulmonary function impairment, high-resolution CT

(HRCT) abnormalities and other disease variables in patients with JDM.

Methods A total of 59 patients with JDM clinically examined a median 16.8

years (range 2-38 years) after disease onset were compared with 59

age-matched and sex-matched controls. Pulmonary function tests included

spirometry, diffusing capacity for carbon monoxide (DLCO) and body

plethysmography. In patients with JDM, HRCT scans were performed and

cumulative organ damage and patient-reported health status assessed.

Results Patients with JDM had lower total lung capacity (TLC) and DLCO

compared to controls (p=0.003 and <0.001, respectively). A low TLC was found

in 26% of patients versus 9% of controls (p=0.026), and a low DLCO in 49% of

patients versus 9% of controls (p<0.001). HRCT abnormalities were found in

37% of patients, and included interstitial lung disease (ILD) (14%), chest

wall calcinosis (14%) and airway disease (15%). Three patients were

diagnosed as having ILD prior to the follow-up visit. A low TLC was more

often found in patients with than without abnormal HRCT (50% vs 12%,

p=0.002). HRCT abnormality correlated with cumulative organ damage

(rs=0.346, p=0.008) and patient-reported health status at follow-up

(p<0.005).

Conclusions Patients with JDM had smaller lung volumes than controls; a

restrictive ventilatory defect was found in 26% and HRCT abnormality in 37%

of the patients, and these findings were associated. Although mostly

subclinical, the relatively high frequency of pulmonary involvement

highlights the systemic nature of JDM.