The association between autoantibody types and salivary gland hypofunction in patients with primary Sjogren's syndrome

Background This study analyzed the association between autoantibody types and salivary gland hypofunction in patients with primary Sjogren's syndrome (pSS). Methods A retrospective analysis was performed on patients who visited the Department of Orofacial Pain and Oral Medicine at Yonsei University Dental Hospital from January 1, 2010 to May 31, 2021, and who were diagnosed with pSS. Out of 191 patients who fulfilled the 2016 American College of Rheumatology/European League Against Rheumatism classification criteria, 50 were positive for both anti-Ro/SSA and anti-La/SSB, whereas 97 had anti-Ro/SSA but not anti-La/SSB antibodies. Forty-four patients for whom neither anti-Ro/SSA nor anti-La/SSB antibodies were found were diagnosed with Sjogren's syndrome by minor salivary gland biopsy. Results The anti-Ro/SSA antibody-positive group showed higher rheumatoid factor (RF) levels than the anti-Ro/SSA antibody-negative group. The anti-La/SSB antibody-positive group showed lower unstimulated whole saliva (UWS), stimulated whole saliva (SWS), higher erythrocyte sedimentation rate and RF level than the anti-La/SSB antibody-negative group. In addition, the group with both anti-Ro/SSA and anti-La/SSB antibodies showed lower UWS than the group with only anti-Ro/SSA antibodies. However, there were no significant differences in UWS or SWS after taking pilocarpine, and C-reactive protein. Conclusions UWS and SWS were lower when a patient was positive for anti-La/SSB, showing that anti-La/SSB is more likely to be involved in salivary gland hypofunction than anti-Ro/SSA in patients with pSS. Therefore, performing laboratory tests, including anti-La/SSB, helps predict the prognosis of salivary gland function in patients with suspected pSS.