Background/Purpose: Sjogren’s syndrome (SS) overlaps with systemic lupus erythematosus (SLE) in up to 20% of patients. Attempts to identify the characteristics of the SLE patients in whom this overlap occurs have been done in prevalent patients with long disease duration. Aim:To identify clinical variables predicting the development of SS in SLE patients.

Methods: We included all patients from a prospective cohort of lupus of recent onset (<12 months) at enrolment. At entry, and every 3-6 months a standardized evaluation including clinical assessment and laboratory tests was done. For SS assessment,  patients undertook a sequential three phase evaluation for SS as follows: screening (six-item sicca-symptoms questionnaire, Schirmer-I and wafer tests), confirmatory (fluorescein staining test, non-stimulated whole salivary flow rate) and lip biopsy. Anti-SSA/SSB and RF (ELISA) were measured at enrollment and SS screening. SS was defined by American-European Consensus Group criteria. Statistical analysis: descriptive statistics, sensitivity (SN), specificity (SP), negative predictive value (NPV), likelihood ratio positive (LR+) and negative (LR-), logistic regression. P value <0.05.

Results: At screening for SS, the cohort comprised 105 patients. Two patients were excluded (death, hepatitis C); therefore, 93 females and 10 males were screened. Median age at lupus diagnosis and SS assessment were 25 and 30 years, respectively. Lupus duration (years) was 0.48 (0 – 1) at enrolment, and 4.94 years (0-6.7) at SS assessment. Although the SS status could not be defined in 14 patients, 19 patients met criteria for SS, minimum prevalence 18.5% (95% C.I.  11% – 23%). All SLE/SS+ patients were females, and were older at lupus diagnosis than SLE/SS-, 30 (15-49) vs. 22 (14-54) years, P=0.003. No difference between groups was observed in lupus duration, clinical manifestations, baseline and cumulative disease activity, and damage accrual. At enrollment the prevalence of anti-SSA or anti-SSB or RF was higher in SLE/SS+ (94% vs. 61%, P= 0.006); however, individually only anti-SSA was significantly different between groups [(84% vs. 55%, P=0.02), SN 0.84, SP 0.45, NPV 0.91, LR+ 1.53 (95% C.I. 1.23 – 1.90), LR- 0.35 (95% C.I. 0.12 – 1.02). Adjusting for gender, the logistic regression analyses identified age >25 at lupus diagnosis, OR 3.8 (95% C.I. 1.19 – 12.4, P=0.007) and anti-SSA at baseline, OR 4.4 (95% C.I. 1.04-18.27, P=0.04) as predictors for SLE/SS+. Also, the absence of anti-SSA, anti-SSB and RF at lupus diagnosis was protective, LR- 0.14 (95% C.I. 0.02-0.95).   

Conclusion: The overlap of SLE and SS occurs early during the course of lupus. Even among young patients, SLE/SS+ patients are significantly older. At lupus diagnosis, age >25 years and anti-SSA antibodies predict the overlap with SS, while the absence of anti-SSA, SSB and RF identify patients at lowest risk.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/predicting-sjogrens-syndrome-at-diagnosis-of-systemic-lupus-erythematosus/