Retrospective analysis of rheumatologic evaluation results of the patient referred with i̇nterstitial lung disease

The aim of our study was in patients who were diagnosed with interstitial lung disease (ILD) and referred to rheumatology to investigate the etiology; To investigate and classify the prevalence of rheumatologic disease-associated interstitial lung disease (RD-ILD) and interstitial pneumonia with autoimmune features (IPAF), and to determine the parameters that can be used in clinical practice in differential diagnosis. In the study, demographic and clinical characteristics, laboratory and imaging tests, pathology reports, diagnosis and treatment of 226 patients who were diagnosed with ILD in Bursa Uludag University Faculty of Medicine Hospital pulmonology outpatient clinic and referred to the Rheumatology Department for etiology investigation between 2010 and 2020 were retrospectively analyzed. Patients included in the study; they were divided into 3 main groups as non-rheumatic ILD, IPAF, and rheumatological disease-associated ILD (RD-ILD). 49,1% (n=111) of the patients were evaluated as non-rheumatological ILD, 20,8% (n=47) as IPAF, and 30,1% (n=68) as RD-ILD. In patients in the RD-ILD group; Sjögren's syndrome (SjS) was the most common associated disease at a rate of 41,1% (n=28). The patients who included IPAF group 55% were detected female; however, median age was found 68,47±11,93 years. A typical pattern of usual interstitial pneumonia (UIP) was seen in 49% of patients. In addition to these, according to IPAF classification criteria, in the patients participating in the study, 25% joint involvement in the clinical area, 62% antinuclear antibody (ANA) positivity in the serological area, and nonspecific interstitial pneumonia (NSIP) pattern in the morphological area 21% were most common. Five independent factors were determined to distinguish the RD-ILD and IPAF group from the non-rheumatic ILD group. These independent factors that we detected in our study were comorbidity, skin lesion, joint involvement, presence of salivary gland biopsy pathology and ANA positivity. It is thought that these factors will contribute to our clinical practice in identifying patients who need rheumatological follow-up and who are candidates for immunosuppressive therapy.