Evolution of clinical, histological and serological features in a Primary Sjὄgren´s Syndrome cohort and the limitations of the current classification criteria.

Objective: The classification and/or diagnosis of Primary Sjögren's Syndrome (PSS) requires a multidimensional approach. Although age and the duration of sicca symptoms can affect the clinical, serological and histological features found at initial evaluation, these are not considered when using classification criteria as a guide for PSS diagnosis. Our study aimed to explore if there is any relationship between the duration of symptoms and clinical, histopathological and serological findings.

Methods: An observational, retrospective study was performed. All the evaluated subjects were part of the "sicca cohort". Patients' clinical, serological and histological characteristics were assessed according to the duration of symptoms. A Receiving Operator Characteristic (ROC) curve was performed to establish the duration of symptoms (months) that predicted a PSS diagnosis. Binary regression models and odds ratios were used to evaluate the association between the duration of symptoms and the clinical, serological, and histopathological profiles.

Results: One hundred and sixteen patients were included; 97(83.62%) fulfilled PSS criteria. Of the 116 patients, thirty-six (31.03%) had < 15 months presenting with sicca symptoms when receiving a diagnostic approach. A duration of symptoms >15 months was associated with an altered Schirmer test (OR 2.76; 95% CI 1.15-6.61, P=0.02), low salivary flow rate (OR 3.5; 95% CI 1.34-9.13, P=0.01), ≥1 foci score (OR 1.21; 95% CI 1-1.45, P=0.04), ocular (OR 7.8; 95% CI 1.49-40.81, P=0.02) and severe oral symptoms (OR 2.61; 95% CI 1.16-5.87, P=0.02).

Conclusion: The time of evolution of symptoms plays a fundamental role in the clinical, histological and serological profiles in PSS.