Primary Sjögren's syndrome (pSS) is a prototypical systemic autoimmune disease that manifests with various signs and symptoms. Although some studies have examined these manifestations over the long-term course of the disease, the association between initial clinical and immunological factors and subsequent long-term manifestations has not been fully elucidated. The aim of this study is to identify initial clinical and immunological factors associated with subsequent manifestations in patients with pSS.
A retrospective review was performed in pSS patients who were followed up over a 10-year period in our department. Clinical and immunological data, including serum immunoglobulin (Ig) and autoantibody levels, were collected and statistically analyzed.
We analyzed 91 patients who were followed up in our department. The proportion of patients with extraglandular involvement decreased from 90% to 73%, while eight patients developed extraglandular organ involvement. Extraglandular involvement at 10 years more frequently occurred in patients with hyper-IgG than those without hyper-IgG at initial testing (P < 0.01). Extraglandular organ involvement at 10 years more frequently occurred in rheumatoid factor (RF)-positive patients at the time of SS diagnosis (P < 0.05). Malignancy occurred in 9% of patients. Age, lower CH50 and thrombocytopenia were significantly associated with malignancy. Extraglandular organ involvement was associated with the presence of hyper-IgG and RF positivity (P < 0.01 and P < 0.05).
Our study identified important initial clinical and immunological factors associated with subsequent manifestations in patients with pSS over a long follow-up period. pSS patients with RF and hyper-IgG at diagnosis may have a higher risk of subsequent extraglandular involvement.