Patient Selection
Medical records of the patients in the SSc cohort of the Rheumatology
Department of Kocaeli University School of Medicine were reviewed. Among
164 patients who fulfilled the 2013 American College of
Rheumatology/European League Against Rheumatism (ACR/ EULAR) SSc
classification criteria between 2007 and 2019 [10], 135 patients
with a baseline HRCT evaluation were included in the study. Thirty-eight
gender- and age-matched healthy subjects, scanned for different
indications from various outpatient clinics were enrolled. Demographic,
clinical, and laboratory data were retrieved from medical records,
including organ involvements due to SSc, autoantibody status, forced
vital capacity (FVC), and carbon monoxide diffusing capacity (DLCO). The
patients were classified into limited cutaneous SSc (lcSSc, n=85) or
diffuse cutaneous SSc (dcSSc, n=50) according to LeRoy’s criteria
[11].
PF was defined based on a range of morphological HRCT findings,
including any one of the following: evident ground glass; honey combing;
interlobular septal thickening; or traction bronchiectasis. The
restrictive pulmonary disease pattern was characterized by a pulmonary
function test showing a normal FEV1/FVC value (≥70%) and at least one
of the following: FVC of <70% of predicted normal or DLCO of
<70% of predicted normal [12]. In case of doubt about the
findings (pneumonia, etc.), pulmonary involvement was confirmed with
supportive findings in follow-up HRCTs. Patients with a diagnosis of
other respiratory disorders such as asthma or chronic obstructive
pulmonary disease, malignancy and significant pulmonary hypertension
defined by previous clinical or echocardiographic evidence of
significant right heart failure, low cardiac index (≤2 L/min/m² with
right heart catheterization) or requiring parenteral therapy with
epoprostenol were excluded.
The study was approved by Kocaeli University School of Medicine Ethics
Committee, Kocaeli, Turkey, study number GOKAEK-2020/7.24.2020/118.