Correlation between KL-6 value, GAP index and quality of life among pati̇ents di̇agnosed wi̇th idiopatic pulmonary fibrosis under treatment

Introduction - Aim: The purpose of this study is to compare the KL-6 value with the GAP index and the quality of life in patients diagnosed with IPF who are receiving treatment. Methods: Patients diagnosed with IPF and being treated in the outpatient clinic of Bursa Uludag University Faculty of Medicine Chest Diseases Department according to the ATS/ERS 2018 IPF guideline were included in this study. Patients' KL-6 levels were checked, pulmonary function tests were performed, GAP indexes were calculated, and the SGRQ questionnaire was used. Results: The study included 36 patients as participants. The patients in the study had an average age of 70,83 ±7,68. There were 83,3% (n: 30) males and 16,7% (n: 6) females among the 36 patients. While 25% (n: 9) of the patients were pathologically diagnosed with IPF, 75% (n: 27) were clinically and radiologically diagnosed. The patients were found to be 13,9% (n: 5) active smokers, 41,7% (n: 15) never smoked, and 44,4% (n: 16) former smokers. When the patients' HRCT findings were examined, a typical UIP pattern was found in 55,6% (n: 20) of them, and a possible UIP pattern was found in 44,4% (n: 16). The average KL-6 value of our patients was 187,37 ±167,13. The patients' mean GAP index was found to be 3,57 ±1,35. The KL-6 value had no statistical significance. The patients' total SGRQ score was 53.87 ± 15.00, their symptom score was 45,14 [15.15 - 74.32], their activity score was 78,50 ± 15,57, and their effect score was 41,92 ± 16,87. When the correlation between KL-6 value and SGRQ score was examined, a negative correlation was found between the symptom score and the activity score. Conclusions: Although the GAP index is used as a prognostic parameter in IPF patients and KL-6 is shown as a prognostic biomarker, no relationship was found between the two in our study. An important result of this study is the correlation with the parameters of the SGRQ questionnaire and KL-6 value. Patients with a high KL-6 value have a lower quality of life. Key words: Idiopathic Pulmonary Fibrosis, KL-6, SGRQ, GAP index