August forum- Disease activity and cryoglobulins in Sjogren's syndrome
Welcome to the August edition of #chatJRheum.
This month we discuss the article by Quartucio et al. who present cryoglobulins as independent markers of disease activity and complications in Sjogren’s syndrome.
In the study, data from 825 patients with primary Sjogren’s syndrome (pSS) was examined and disease activity at diagnosis was measured by the European Sjogren’s Disease Activity Index (ESSDAI) and clinical ESSDAI (ClinESSDAI). Among the 8.8% of patients with positive cryoglobulins, ESSDAI scores were significantly elevated as compared to cryoglobulin-negative patients (mean ESSDAI 12 vs 5, p<0.0001). They also found cryoglobulin-positive patients had significantly higher focus scores on minor salivary gland biopsy, higher rates of positive anti-SSB/La antibodies, ANA and RF, and lower C3 and C4.
The authors argue that cryoglobulinemia is an independent marker that can help clinicians identify patients with pSS at risk for extraglandular manifestations and lymphoma. Therefore, this subset of patients requires closer follow up.
You might be wondering, as I did, how they jump to this conclusion when lymphoma was not actually measured in their patient cohort… After a closer look at the ESSDAI and ClinESSDAI score, and a little background reading, I think like me, you too will come to see the connection.
The ESSDAI and ClinESSDAI were developed by consensus of worldwide experts as an international Sjögren’s syndrome disease activity index. The ESSDAI is a lengthy measure that includes 12 domains: constitutional, cutaneous, respiratory, renal, articular, muscular, peripheral nervous system, central nervous system, hematological, glandular, lymphadenopathy, and biological. The ClinESSDAI excludes the biological measures of hypocomplementemia, hypergammaglobulinemia, cryoglobulinemia and/or recent onset hypogammaglobulinemia.
What perhaps the authors of this paper might have presented, was that these clinical scores were previously shown to be correlated with developing lymphoma. A cohort of 1202 patients were followed over 118 months, and 61 (4.7%) developed a hematological neoplasia, the most frequent neoplasia being lymphoma.1 Systemic activity was significantly higher in patients who developed hematological neoplasia as measured by both ESSDAI (mean 10.4 vs 5.7, p<0.001) and ClinESSDAI (mean 10.3 vs 5.7, p<0.001) scores.1
With this knowledge, do you also see the simplified value of measuring cryoglobulins in patients with primary Sjogren’s syndrome? Let's discuss.
- Dr. Sarah Troster, Forum Editor
1 Retamozo, S et al. 2016. ESSDAI, ClinESSDAI and DAS Scoring at Diagnosis of Primary Sjogren’s Syndrome: Association with the Development of Hematologic and Solid Neoplasias in 1301 Patients. Presented as an abstract at the American College of Rheumatology (Abstract Number 2675): Washington, DC.