Interstitial Lung Disease In Non-Sicca Onset Primary Sjogren'S Syndrome: A Large-Scale Case-Control Study

AimThis study investigated the common initial clinical presentations of primary Sjogren's syndrome (pSS) with interstitial lung disease (ILD) and explored differences between sicca and non-sicca onset pSS-ILD patients.MethodA total of 1341 SS patients hospitalized between 2003 and 2012 were retrospectively reviewed. Of them, 102 were analyzed and recruited to examine the differences between non-sicca and sicca onset.ResultsFifty-one percent of pSS-ILD patients presented with non-sicca onset. Although the mean diagnosis time was equal, only 4% of non-sicca onset patients were diagnosed with pSS at onset versus 34% with sicca onset (P=0.000). Hyperglobulinemia, elevated rheumatoid factor (RF) titer, and anti-SSA and/or anti-SSB presence were less predominant in patients with non-sicca onset (immunoglobulin G, 16 [12-21] vs. 21 [15-28] g/L, P=0.032; RF, 22 [20-171] vs. 104 [20-237] IU/mL, P=0.048; anti-SSA and/or anti-SSB presence, 33% vs. 72%, P=0.000). The usual interstitial pneumonia pattern was more commonly seen in non-sicca onset patients (20.0% vs. 14.3%). The high-resolution computed tomography score was higher (12 [88-15] vs. 8 [5-13], P=0.070) and predicted total lung capacity and forced vital capacity were lower (8723% vs. 97 +/- 20%, P=0.050; 88 +/- 28% vs. 100 +/- 27%, P=0.089) in non-sicca patients.ConclusionNon-sicca is a common initial manifestation in pSS-ILD. Anti-SSA presence, elevated RF titer and hyperglobulinemia were less predominant, and pulmonary complications were more progressive and severe in non-sicca onset patients than sicca onset patients.