Background The presence of overlapping autoimmune diseases is not uncommon in patients who are being evaluated for Primary Sjogren's Syndrome (PSjS). The hallmark of PSjS is subjective and objective evidence of xerophthalmia or xerostomia, otherwise known as sicca. It is unknown whether the presence of Limited Scleroderma (CREST syndrome) impacts the presence or severity of sicca.
Objectives To determine if the presence of CREST syndrome affects the incidence or severity of sicca in patients being evaluated for PSjS.
Methods Patients were pre-screened for objective evidence of abnormal serology, dry eyes or dry mouth based on Schirmer's test and unstimulated salivary flow (USSF). 609 patients were assessed on protocol at the Sjogren's Clinic of the Toronto Western Hospital over 22 years. The evaluation included a visual analogue score (VAS) for severity of xerophthalmia and xerostomia, as well as Schirmer's test, Rose Bengal staining, USSF, minor salivary gland biopsy and serology. PSjS was classified according the American European Consensus Group (AECG) Criteria. Patients with anti-centromere antibody (ACA) were designated as CREST Syndrome whether or not they met criteria for PSjS. A 2-tailed student t-test with heterogenous variance was used to compare measures of severity.
Results Among 609 patients: average age was 53.4 years with 91% female. 446 met the AECG criteria for PSjS. 34 patients (5.6%) were ACA positive and were designated as CREST syndrome patients. All had sicca. Of these, 26 patients met the AECG criteria for PSjS. These patients were designated as CREST syndrome overlap patients. Whether or not the CREST patients met AECG criteria made no difference with respect to either the incidence or severity of sicca symptoms (data not shown). Of all 34 CREST patients: 91% had xerophthalmia; 100% had xerostomia; severity of xerophthalmia was 6.6 (out of 10); severity of xerostomia 8.5 (out of 10).
Conclusions CREST syndrome overlap patients had subjectively and objectively worse xerostomia than PSjS patients without overlap. CREST syndrome overlap patients had more severe objective xerophthalmia than PSjS patients. A significant difference in ocular symptoms could not be detected. CREST patients may meet AECG Criteria for PSjS despite a less frequent anti-Ro or –La positivity. These patients have a less frequent but more profound elevation of IgG levels.
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Acknowledgements This project was made possible with the support of the Sjogren's Society of Canada summer student research grant.
Disclosure of Interest None declared