Sjögren syndrome, also known as Sjögren’s Disease or Sjögren’s, often co-occurs with other autoimmune diseases, particularly when the same disease mechanisms are shared. Previous research has found that that systemic Lupus erythematosus (SLE) or Lupus is estimated to occur in 14 to 18% of Sjögren’s patients, approximately 1 in 6. Interestingly, 1 in 3 people with Lupus also have Sjögren’s disease. Like Sjögren’s, Lupus is caused by antibodies or the body’s defence system attacking healthy tissues causing inflammation, joint pain and stiffness, fatigue, and skin related conditions.
Researchers in Korea examined data from 1,082 people with Sjögren’s and no other autoimmune disease who visited Seoul St. Mary’s Hospital between January 2012 and March 2021. The patients were followed for a median of three years. The results showed that Forty-nine patients (4.5%) developed Lupus after an average of two years. Those that were diagnosed with Lupus were significantly younger (43 years) relative to those who didn’t develop Lupus (52 years). Further, individuals who developed Lupus lived with Sjögren’s for a significantly shorter time (15.2 months), compared to those who did not receive a diagnosis of Lupus (33.3 months).
A significantly greater proportion of patients who developed Lupus versus those that did not, had lymph node swelling (18.4% vs. 7.7%) and kidney involvement (8.2% vs. 1.8%) at the time of their first hospital visit. At baseline, these individuals also scored significantly higher on the EULAR Sjögren’s disease activity index (ESSDAI), a standardized measure where higher scores indicate more active disease. A lower white blood cell count, and the presence of antibodies were also more common among those who developed Lupus.
Upon further analysis, the researchers determined that having Sjögren’s for less than three years at baseline was linked to a more than twofold risk of developing Lupus. Higher disease activity (ESSDAI score of > 14) at baseline was associated with an eight times higher risk of developing Lupus. A lower white blood cell count (leukopenia) increased the risk for Lupus by three to four times. Testing positive for antibodies increased Lupus risk by up to nearly 14 times. The strongest risk factor of all was hypocomplementemia — or deficient levels of vital proteins in the immune system — which increased the risk of someone with Sjögren’s developing Lupus by 29 times.
The findings suggest that in the presence of any of these potential risk factors warrant close monitoring during the follow-up period due to the possibility of developing Lupus in future.
Reference
Lee B-W, Kwon E-J, Park Y, et al. Predictors for future development of systemic lupus erythematosus in Korean Sjögren’s syndrome patients. Lupus. 2023;32(12):1359-1368. doi:10.1177/09612033231204067
