Early onset primary Sjögren syndrome, clinical and laboratory characteristics

Primary Sjögren syndrome (pSS) is usually encountered between the fourth and sixth decades. It is known that the age of onset in autoimmune diseases may affect the clinical features. In this study, we aimed to investigate the clinical and laboratory characteristics of early onset pSS patients.

The data of 352 pSS patients were analyzed retrospectively. The patients were divided into two groups as those with the onset age of 35 or younger (early-onset) and those with the onset age of older than 35. The clinical, laboratory, and serological characteristics of the two groups were compared. p < 0.05 was considered statistically significant.

Forty patients in the group with an onset age of 35 or younger (11.4%) and 312 patients with an onset age of older than 35 (88.6%) were analyzed. The frequency of skin (22.5% vs 1.9%, p < 0.001) and renal involvement (10% vs 2.2%, p = 0.026) was significantly higher in the early-onset group than the late-onset group. There was no significant difference between the two groups in terms of xerostomia, eye dryness, arthritis, and other systemic involvement. Anti-Ro52 positivity (p = 0.04), elevated serum IgG levels (p = 0.004), and low C4 (p = 0.002) presence were more frequent in the early-onset group.

Consequently, it is seen that the clinical phenotype of early-onset pSS patients may be different to those with later onset. Especially the more frequent observation of poor prognostic factors at early-onset ages shows the necessity to monitor these patients more regularly.

• The clinical and laboratory features of patients with early-onset primary Sjogren syndrome may differ from late-onset patients.