Although pulmonary complications in pediatric patients may cause functional impairment and increase mortality, studies detecting lung involvement in children with treatment-naïve, newly diagnosed patients with rheumatic disease are scarce.
In pediatric patients with treatment-naïve, newly diagnosed rheumatic diseases, the odds of developing pulmonary issues are higher. Further, an increase in erythrocyte sedimentation rate (ESR) and both CD4 and CD8 were linked to elevated risk of lung involvement, according to a study published in Pediatric Rheumatology.1 Pulmonary evaluation in this patient population, particularly high-risk patients, is recommended once they are diagnosed with rheumatic disease.
“Pulmonary complications of rheumatic diseases may cause functional impairment and increase mortality,” investigators explained. “However, reports regarding detection of lung involvement in children with treatment-naive, newly diagnosed rheumatic diseases are scarce… We aimed to describe the characteristics of such patients and explore the association between lung involvement and rheumatic disease.”
The Department of Rheumatology and Immunology, Shanghai Children’s Medical Center, School of Medicine at Shanghai Jio Tong University identified 48 pediatric patients with treatment-naïve, newly diagnosed rheumatic diseases between January 2019 and June 2021. Patients with pulmonary function tests (PFTs) and high-resolution computed tomography (HRCT) were included and matched with 51 age-matched healthy controls. Age-matched controls were selected from children who underwent health check-ups at Shanghai Children’s Medical Center who had no medical history of rheumatic, heart, or lung diseases with no lung abnormalities. Both univariate and multivariable logistic regression analyses were used to evaluate the clinical characteristics and laboratory parameters previously associated with lung involvement.
Patients with rheumatic disease met classification criteria, which included the Systemic Lupus International Collaborating Clinics group classification criteria (2012), the American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus (SLE) (1982), and the International League of Association for Rheumatology Classification of Juvenile Idiopathic Arthritis (JIA). Data collection included age at diagnosis, height and weight, sex, and duration between disease onset and diagnosis. Investigators also noted a history of cigarette exposure.
The mean age of patients was 11.3 years, with 29 girls and 19 boys. Healthy controls consisted of 31 girls and 21 boys, with a mean age of 11. 3 years. Most patients were diagnosed with systemic lupus erythematosus (n = 16) and juvenile idiopathic arthritis (n = 11). Patients who were asymptomatic had a faster respiratory rate and a higher ratio of forced expiratory volume in 1 s/forced vital capacity when compared with controls (P < 0.05). Patients were also more likely to have a decreased lung diffusion for carbon monoxide (DLCO)below normal limits (18 of 45 [40.0%] vs. 6 of 36, respectively; P = 0.041). Of the 48 patients, 16.7% (n = 8) reported abnormal HRCT findings and 56.3% (n = 27) had abnormal PFT results. Most (64.6%, n = 31) experienced lung involvement.
The logistic regression showed that increased ESR and CD4/CD8 ratio were associated with an increased likelihood of lung involvement (1.037, 95% CI: 1.003–1.072; 9.875, 95% CI: 1.296–75.243, respectively). Female sex was also associated with an increase in lung involvement (OR = 3.492, 95% CI 1.012–12.051, P = 0.048).
The study was limited by the small sample size, as recruiting pediatric patients who were both treatment-naïve and newly diagnosed with a rheumatic disease was challenging. The study groups also showed significant heterogeneity and clinical entities were not evenly distributed. Additionally, a selection bias of illness may be different among children’s hospitals in Shanghai. Therefore, future multicenter longitudinal studies may be beneficial to identify lung involvement in other rheumatic diseases, future prognosis, and response to treatment. However, this is the largest study on pulmonary involvement in this patient population and the first to explore the factors linked to lung involvement in pediatric patients.
“Using PFTs and HRCT, we identified patients with asymptomatic lung involvement,” investigators concluded. “Patients at higher risk may be identified using ESR and CD4/CD8 ratios. Regular pulmonary appraisal as part of the routine assessment may help monitor these patients and optimize treatments and lung management from the initial stages to avert progression to advanced stages.”
Huang H, Hu Y, Wu Y, et al. Lung involvement in children with newly diagnosed rheumatic diseases: characteristics and associations. Pediatr Rheumatol Online J. 2022;20(1):71. Published 2022 Aug 20. doi:10.1186/s12969-022-00731-5