KL-6 in adult polymyositis and dermatomyositis patients and its correlation with interstitial lung disease.

Background: Pulmonary involvement is still regarded as a common cause of morbidity in Polymyositis/Dermatomyositis. Interstitial lung disease can result in potentially fatal consequences such as ventilatory failure, secondary pulmonary arterial hypertension, or cor pulmonale. Early diagnosis of interstitial lung disease is hence a top priority in Polymyositis/Dermatomyositis patients. Krebs von den Lungen-6 is a transmembrane mucoprotein that has recently been identified as a promising marker for interstitial lung disease diagnosis and progression. As a result, it is regarded as a powerful predictor of interstitial lung disease severity. Thirty polymyositis/dermatomyocitis patients were enrolled in this study. Thirty age and sex matched healthy individuals were selected as control group. Cutaneous Dermatomyositis Disease Area Severity index(CDASI) was used for evaluation of skin severity, KL6 was measured using Elisa kit, High-resolution computed tomography, pulmonary function tests were made. Results: Sixteen female and 14 male patients had a mean age of 41.64–8.02 and amedian of the disease duration of 4 years. Fifteen patients (50%) had normal readings on High-resolution computed tomography of the chest HRCT chest, while the other half had significant HRCT chest findings. KL-6 concentrations were seen to be higher in Polymyositis/Dermatomyositis patients mainly those with ILD (mean ± SD 38.66 ± 22.98), compared to the control group (Mean ± S 589.04 ± 409) and in patients without ILD (Mean ± SD 86.70 ± 8.99), (p < 0.001). KL-6 serum concentrations were shown to have a significant connection with the HRCT score (r = 0.803, P < 0.001). Forced vital capacity (FVC%) (r = − 0.910, P < 0.001), forced expiratory volume in 1 s (FEV1%) (r = − 0.767, P < 0.001), and FEV1/FVC% (r = − 0.228, P = 0.112) were all inversely related to KL-6 concentrations. Conclusion: Individuals with PM and DM with concomitant ILD have increased KL-6 serum concentrations in comparison to myositis individuals without ILD, denoting its potential role in diagnosis and follow up of PM/DM with ILD. Further studies are needed to discuss the role of KL6 in large sample of the patient's population, and its correlation with other organ affection rather than ILD. Also to clarify the potentiality of adding the KL6 biomarker to the guidelines of treat to target for Rheumatic diseases with lung affection and to see the effect of treatment on KL6 serum level. [ABSTRACT FROM AUTHOR]