Clinical characteristics and outcomes of Korean patients with sarcoidosis

Abstract

Sarcoidosis is a systemic granulomatous disorder of unknown cause involving multiple organs. Its clinical presentation and prognosis vary among races. We identified the clinical characteristics and outcomes of Korean patients with sarcoidosis. Clinical data of 367 Korean patients with biopsy-proven sarcoidosis diagnosed in 2001-2017 were retrospectively analyzed. Treatment responses included improvement, stability, or progression based on changes in pulmonary sarcoidosis on chest images. The mean age was 47.4 years, and 67.3% of patients were women. The median follow-up period was 80 months. The highest prevalence was observed in individuals aged 50-59 years (30-39 years in men, 50-59 years in women), and the number of diagnoses showed an increasing trend. Lung involvement was the most common (93.5%), followed by the skin, eyes, and extrathoracic lymph nodes. Among patients with lung involvement and a follow-up period of ≥ 3 months, 66.8%, 31.0%, and 2.2% showed improvement, stability, and progression, respectively. Eleven patients (2.9%) died, and the 5-year survival rate was 99%. The number of diagnosed cases showed an increasing trend, and the mean age at diagnosis was increased compared with that in previous reports. Organ involvement was similar to that of Westerners, although the prognosis appeared better.

Figure 1

Annual number of patients diagnosed with sarcoidosis in 2001–2017. The white bars represent total patients, and the black bars represent patients diagnosed by EBUS-TBNB. The black lines with dots represent the proportion of patients diagnosed with EBUS-TBNB. EBUS-TBNB, endobronchial ultrasound-guided transbronchial needle biopsy.

Figure 2

Age distribution and organ involvement of patients with sarcoidosis. (A) Age at diagnosis for the total population (white bars), male patients (grey bars), and female patients (black bars). (B) Pattern of organ involvement in South Korean patients with sarcoidosis. Each organ’s involvement was defined based on the updated WASOG assessment instrument. WASOG, World Association of Sarcoidosis and Other Granulomatous Diseases.

Figure 3

Clinical course of pulmonary sarcoidosis according to treatment status. The grey bars represent patients with pulmonary sarcoidosis treated with systemic steroids, while the black bars represent those without treatment.

Figure 4

Kaplan–Meier survival estimates of patients with sarcoidosis. The vertical axis represents survival rate, while the horizontal axis represents years after diagnosis.