Lung function in children with juvenile idiopathic arthritis: A cross‐sectional analysis

Abstract

Aim We measured respiratory parameters in children with juvenile idiopathic arthritis (JIA) without clinical signs of respiratory involvement and assessed the influence of methotrexate (MTX) treatment and disease activity on lung function. Methods In 49 JIA children and 70 controls lung volumes by spirometry and body plethysmography, and lung diffusion for carbon monoxide (DLCO) with single‐breath technique were evaluated. Results DLCO was significantly different between JIA children and controls (P = .01), whereas no differences were found in flow expiratory volume in 1 second (FEV 1), forced vital capacity (FVC), forced expiratory flow at 25% to 75% of FVC (FEF 25‐75), peak expiratory flow, total lung capacity, and residual volume. After dividing study JIA patients according to MTX treatment, a significant difference in DLCO was found among JIA patients treated with MTX and those treated with other drugs and controls (P < .001). A significant difference in DLCO was also found among JIA patients with active disease and those with inactive disease and controls (P = .003). Analysis of covariance showed a weak independent effect of MTX therapy on DLCO after adjusting for sex and height (P = .04). Furthermore, a negative correlation of DLCO with MTX cumulative dose and MTX treatment duration (r = −.58, P = .006; r = −.68, P = .001, respectively) was found, whereas there was no correlation between DLCO and disease activity (r = −.10; P = .51). Conclusions In JIA children MTX treatment seems to have a dose‐dependent effect on lung function. For this reason in these patients, a regular assessment of lung function, especially with DLCO evaluation, is recommended.

Lung involvement in children with newly diagnosed rheumatic diseases: characteristics and associations

“…Many disease-modifying antirheumatic drugs have been reported to cause pulmonary toxicity, such as drug-induced ILD, in many case reports and retrospective studies [ 26 ]. Attanasi et al found a negative correlation of DL CO with cumulative methotrexate (MTX) dosage and the duration of MTX treatment in one study on JIA [ 8 ]. All patients in our study were treatment-naive and newly diagnosed.…”

“…DL CO is the most sensitive test for predicting the presence of ILD [ 32 ], and a reduction in DL CO suggests abnormalities of the alveolar–capillary interface, compatible with diffuse vascular and/or parenchymal lung disease [ 8 ]. The significant increase in FEV1/FVC and respiratory rate compared with that of controls may reflect volume loss associated with fibrosis, although FVC and FEV1 remained within the normal range after the decline.…”

“…However, PAH is uncommon, occurring in up to 14% of patients with JSLE [ 7 ]. In patients with JIA, the prevalence of lung disease is estimated to be 4–8% [ 8 ]. Although this remains low, children with systemic JIA are being increasingly found to have more severe and life-threatening lung diseases such as PAH, ILD, and pulmonary alveolar proteinosis [ 9 ].…”

Lung Involvement in Systemic Juvenile Idiopathic Arthritis: A Narrative Review

“…Therefore, screening techniques for subclinical disease are required. Indeed, lung function assessment could be useful in patients with JIA to improve patient management and to detect early pulmonary involvement [ 52 ]. Moreover, sJIA-LD may have been present since a patient was 2 years of age as children are unable to perform the recommended screening tests for sJIA-LD, including the 6-minute walk test, the lung function tests or an unsedated HRCT.…”

Pediatric pulmonology 2019 year in review: rare and diffuse lung disease

“…Although lung involvement is well-described among adults with rheumatoid arthritis, 42 data describing pulmonary manifestations of juvenile idiopathic arthritis (JIA) are sparse. [43][44][45] Attanasi et al 46 studied spirometry, body plethysmography, and diffusion capacity results in 49 children with JIA and compared them to the same from 70 unaffected controls. Only D L CO was lower in the JIA patients, and it was correlated with active disease.…”