Study population
Participants of our case control study were collected randomly from the
electronic medical record database between October 2019 and April 2020
from Rheumatology and Rehabilitation Department, and Pediatric
Department; Pulmonology, Immunology and Allergy Unit, children hospital.
All experimental procedures were approved and formed in accordance with
the guidelines of Institutional Review Board (IRB) of Faculty of
Medicine, Zagazig University, Egypt (Approval No.: ZU-IRB
#544459/14-7-2019).
Totally, the study include the connective tissue diseased children aged
5-15 years at primary diagnosis, according to the following
classification criteria: the 2010 European League Against Rheumatism
(EULAR) criteria for rheumatoid arthritis (RA)24 , the 2019 European League against
Rheumatism (EULAR) criteria for systemic lupus erythematosus (SLE)25 , the 2017 European League against
Rheumatism (EULAR) criteria for dermatomyositis (DM)26, The 2007 Pediatric Rheumatology
European Society/American College of Rheumatology/European League
against Rheumatism provisional classification criteria for juvenile
systemic sclerosis (SSc) 27, and The
2019 Diagnostic criteria for mixed connective tissue disease (MCTD):
From the Japan research committee of the ministry of health, labor, and
welfare for systemic autoimmune diseases28. While we exclude patients with
Active malignancy, and active acute infections.
The patients were examined for presence of ILD according to according to
American Thoracic Society clinical practice guideline: classification,
evaluation, and management of childhood interstitial lung disease and
European protocols for the diagnosis and initial treatment of
interstitial lung disease in children 29-32 .
The participants were divided into four groups, Group 1 (control group)
consisted of (20) healthy control volunteer children; Group 2 (CTD
group): included (20) connective tissue diseased children without
interstitial lung disease; Group 3 (CTD+ILD group): which
consisted of (20) connective tissue diseased children with interstitial
lung disease, 16 of the were already diagnosed and 4 patients were newly
diagnosed at time of study. Group 3 were subdivided according to
severity of interstitial lung disease (according to the pulmonary
function tests) 20 as follow: Group 3a
(mildILD subgroup): which consisted of connective tissue diseased
children with mild interstitial lung disease. Group 3b (severeILD
subgroup): which consisted of connective tissue diseased children with
severe interstitial lung disease.