Background/Purpose:

To assess presence of persistent serological activity and its association with clinical outcomes in a cohort of patients with primary Sjögren’s syndrome (pSS).

Methods:

We retrospectively reviewed the clinical charts of 275 patients with pSS according to the AECG criteria, attending a tertiary referral center. We defined persistent serological activity as increase IgG≥ 1.6 g or globulins>3.7 gr or diminished C3 <52 mg/dL or C4 <12 mg/dL at least during two consecutive visits during a year period (index period). We selected whenever possible, the closest period to the diagnosis of SS. We defined clinical activity, as the presence of at least 1 point in the clinESSDAI at the index period. We also scored the cumulative clinESSDAI as well as the SSDDI at the last medical appointment. We excluded patients with incomplete serological data or with <1 year of follow-up after the index period. We registered demographics, glandular and extraglandular features, anti-Ro/SSA, anti-La/SSB and RF determinations. We used descriptive statistics and used regression logistic analysis.

Results:

We excluded 115 patients due to incomplete data. Thus we included 160 patients with available serological data and follow-up: most females (95%), 94% with ocular symptoms, 91.2% oral symptoms, 46.9% parotid enlargement, 90% anti-Ro/SSA and 58% anti-La/SSB antibodies and median disease duration of 10.2 years. We identified persistent activity in 85 patients (53.1%): 57 due to hyperglobulinemia, 5 due to low C3 or C4, and 23 patients due to both. In only 13 patients, the serological status changed during the follow-up from active to inactive.

At the moment of the assessment (index period) we identified 58 patients with both clinical and serological activity, 49 with only clinical activity, 27 with only serological activity and 27 without clinical or serological activity. When we compared patients with (n=85) vs. without serological activity (n=74), the first group had a higher prevalence of impaired whole non-stimulated salivary flow (94% vs. 79.2%, p=0.01), anti-La/SSB antibody (70.6% vs. 44.6%, p=0.001) and RF (84.5% vs. 51%, p=0.0001). In addition, the persistent active serological group had a higher cumulative clinESSDAI at the last medical appointment (11 vs. 6 points 0.0001), being the main affected domains the constitutional (30.6% vs. 13.5%, p=0.02), glandular (52.9% vs. 32%, p=0.01), cutaneous (21.2% vs. 5.4%, p=0.005), renal (17.6% vs. 2.75, p=0.002) and hematological (42.4% vs. 17.6%, p=0.001). The SSDDI score was similar among groups (3 vs. 2 points, p=0.18), however the active serological group had more damage at the oral (92.5% vs 80%, p=0.03) and renal domain (12.6% vs. 2.7%, p=0.02). At the logistic regression analysis, the variables that remained associated were renal involvement (OR 12.8, 95% CI 1.7-92, p=0.01), hematological involvement (OR 4.7, 95% CI 1.6-13.4, p=0.004) and RF (OR 6.4, 95% CI 1.8-22, p=0.003).

Conclusion:

Half of the patients with pSS had persistent serological activity, being this status constant during the follow-up. Persistent serological activity was associated with renal and hematological features, as well as with the presence of RF.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/persistent-serological-activity-in-primary-sjogrens-syndrome/