Salivary gland ultrasonography for the early diagnosis of Sjögren’s syndrome

Here is a summary of the 2015 study into Salivary gland ultrasonography: a highly specific tool for the early diagnosis of primary Sjögren’s syndrome

 Image: The University of Iowa Health Centre

Introduction

Recently, a great interest has arisen for salivary gland ultrasonography (SGUS) as a valuable tool for the assessment of major salivary gland involvement in primary Sjögren’s syndrome (pSS). 

The aims of this study were to test the accuracy of SGUS for the early detection of pSS and to compare the diagnostic performance of SGUS with minor salivary gland biopsy (MSGB) and unstimulated salivary flow (USFR).

Method

Patients with suspected pSS and symptoms duration of 5 years or less, were enrolled in this study. 

The diagnosis of pSS was made according to the American European Consensus Group (AECG) criteria. 

SGUS was performed by two radiologists blinded to the diagnosis and a previously reported ultrasound scoring system was used to grade the echostructure alterations of the salivary glands. 

Statistical analysis was performed using SPSS v16.

Results

This study included 50 pSS patients and 57 controls with no-SS sicca symptoms. 

The mean age of the pSS group was lower than the non-SS group (47(13) vs 53(12)yrs, p = 0.006). 

No further differences between the two groups were observed. 

Patients with pSS showed a significantly higher SGUS score in comparison with controls.

The SGUS cut-off ≥ 1 showed a sensitivity of 66 %, a specificity of 98 %, a positive predictive value of 97 %, and a negative predictive value of 73 % for pSS diagnosis. 

The SGUS score correlated also with patients’ minor salivary gland biopsy focus score and unstimulated salivary flow.

Table 3

Diagnostic accuracy of salivary gland ultrasonography (cutoff score of 2), in comparison with anti-Ro/SSA antibodies, Schirmer’s test and minor salivary gland biopsy focus score

	Sensitivity	Specificity	Positive predictive value	Negative predictive value
SGUS ≥2	33/50 (66 %)	56/57 (98 %)	33/34 (97 %)	56 /73 (77 %)
Anti-Ro/SSA antibodies	30/50 (60 %)	56/57 (98 %)	30/31 (97 %)	56/67 (74 %)
Schirmer’s test	37/50 (74 %)	32/57 (56 %)	37/62 (60 %)	32/45 (71 %)
MSGB	46/50 (92 %)	56/57 (98 %)	46/47 (98 %)	56/60 (93 %)

SGUS salivary gland ultrasonography score, MSGB minor salivary gland biopsy

Conclusions

This study confirmed the good performance of SGUS for the early non-invasive diagnosis of pSS. 

Further research in a larger international cohort of patients is mandatory in order to assess the role of SGUS in the diagnostic algorithm of pSS.

FULL REPORT AT NIH