Diagnostic accuracy of salivary gland ultrasound in Sjögren's syndrome: A systematic review and meta-analysis

BACKGROUND

To systematically review the diagnostic accuracy of salivary gland ultrasound in primary Sjögren's syndrome (pSS).

METHODS

PubMed, Embase, CINAHL, Cochrane Central and Scopus and ClinicalTrials.gov were searched to identify diagnostic or validation studies in patients with pSS meeting the diagnostic criteria. A diagnostic test meta-analysis was performed using a bivariate model to calculate the pooled sensitivity, specificity, positive/negative likelihood ratios, and the diagnostic odds ratio. Meta-regression analyses were done for several pSS covariates.

RESULTS

Sixty-five studies met our criteria for the qualitative review. Fifty-four studies with a total of 6087 patients were included in the meta-analysis. Pooled sensitivity for salivary gland ultrasound was 80% [95% confidence interval (CI): 77-83%; I 2 = 78%], and specificity was 90% (95% CI: 87-92%; I 2 = 76%). The pooled positive and negative likelihood ratios were 8 (95% CI: 6.4-10) and 0.22 (95% CI: 0.19-0.25), respectively. The corresponding pooled diagnostic odds ratio (DOR) was 37 (95% CI: 28-48). Separate meta-regression models resulted in similar diagnostic estimates: (a) adjusted for mean age: sensitivity 81% (95% CI:77-84%; I 2 = 99%) and specificity 90% (95% CI: 87-93%; I2 = 99%); (b) adjusted for mean disease duration, sensitivity 79% (95% CI:72-84%; I 2 = 99%), and specificity 90% (89-94%; I 2 = 99%). The diagnostic estimates were robust to sensitivity analyses by quality criteria, pSS diagnostic criteria and ultrasound scoring systems.

CONCLUSION

Salivary gland ultrasound is a valuable modality for the diagnosis of Sjögren's syndrome. It is plausible that salivary gland ultrasound can be used as an important criterion for the diagnosis of pSS.

Biomarkers in systemic juvenile idiopathic arthritis: a comparison with biomarkers in cryopyrin-associated periodic syndromes

PURPOSE OF REVIEW

This review summarizes biomarkers in systemic juvenile idiopathic arthritis (sJIA). Broadly, the markers are classified under protein, cellular, gene expression and genetic markers. We also compare the biomarkers in sJIA to biomarkers in cryopyrin-associated periodic syndrome (CAPS).

RECENT FINDINGS

Recent publications showing the similarity of clinical response of sJIA and CAPS to anti-interleukin 1 therapies prompted a comparison at the biomarker level.

SUMMARY

sJIA traditionally is classified under the umbrella of juvenile idiopathic arthritis. At the clinical phenotypic level, sJIA has several features that are more similar to those seen in CAPS. In this review, we summarize biomarkers in sJIA and CAPS and draw upon the various similarities and differences between the two families of diseases. The main differences between sJIA and CAPS biomarkers are genetic markers, with CAPS being a family of monogenic diseases with mutations in NLRP3. There have been a small number of publications describing cellular biomarkers in sJIA with no such studies described for CAPS. Many of the protein marker's characteristics of sJIA are also seen to characterize CAPS. The gene expression data in both sJIA and CAPS show a strong upregulation of innate immunity pathways. In addition, we describe a strong similarity between sJIA and CAPS at the gene expression level in which several genes that form a part of the erythropoiesis signature are upregulated in both sJIA and CAPS.