To comprehend clinical features at onset of primary Sjogren's syndrome (pSS) in order to provide useful data for its clinical management.
In the study, 224 patients diagnosed with pSS in the Department of Rheumatology and Immunology of Peking University People's Hospital  from Jun. 1st, 2007 to Aug. 1st, 2008 were investigated, including gender, age of onset, time and site of first hospitalization and definite diagnosis, etc.
In this 224 pSS cohort (213 females and 11 males), the male/female ratio was 1:19.4, the mean age of onset was (53.5±11.7) years, and  median duration was 9.4 years (ranging from 0.2 to 40.0 years).The manifestations showed that up to 33% of the patients (74/224) had leukopenia, 25%  (56/224) polyarthralgia, 16.5% (37/224) raynaud phenomenon, 15.6% (35/224) hepatic injury, 12.1% (27/224) pulmonary interstitial fibrosis, 11.6% (26/224)  purpuras on lower extremities, 8.0% (18/224) hemogram abnormal, 5.8% (13/224) thrombopenia, and 3.6% (8/224) renal tubule acidosis. When the risk  factor of the systemic involvements, was analyzed, two factors were significantly associated with pulmonary interstitial fibrosis: age (OR=1.074, 95%  CI=1.031-1.118), and duration (OR=1.075, 95% CI=1.023-1.128). Liver involvement was associated with duration (OR=1.050, 95% CI=1.002-1.100). In addition,  8.0% of the pSS patients(18/224)showed family history of autoimmune diseases and 11.2%(25/224)had family history of tumor.
In this  cohort of the pSS patients, female is predominant and the incidence of extro-glandular manifestations, such as leukopenia, lung and liver involvements is  high, and pSS has inheritance intention.