Related Experiment Video
Updated: Nov 16, 2025

Author Spotlight: A Focus on Standardized Salivary Gland Ultrasound Protocol in Connective Tissue Disease Research
Published on: October 13, 2023
Utility of lymphocyte phenotype profile to differentiate primary Sjögren's syndrome from sicca syndrome
José Loureiro-Amigo1,2, Carlos Palacio-García3, Mónica Martínez-Gallo4
1Internal Medicine Department, Autoimmune Systemic Diseases Unit, Hospital Universitari Vall d'Hebron.
Objective:
To assess the potential diagnostic utility of advanced lymphocyte profiling to differentiate between primary Sjögren's Syndrome (pSS) and non-Sjögren Sicca syndrome.
Methods:
Distribution of peripheral lymphocyte subpopulations was analysed by flow cytometry in 68 patients with pSS, 26 patients with sicca syndrome and 23 healthy controls. The ability to discriminate between pSS and sicca syndrome was analysed using the area under the curve (AUC) of the receiver operating characteristic curve of the different lymphocyte subsets.
Results:
The ratio between naïve/memory B cell proportions showed an AUC of 0.742 to differentiate pSS and sicca syndrome, with a sensitivity of 76.6% and a specificity of 72% for a cut-off value of 3.4. The ratio of non-switched memory B cells to activated CD4+ T cells percentage (BNSM/CD4ACT) presented the highest AUC (0.840) with a sensitivity of 83.3% and specificity of 81.7% for a cut-off value <4.1. To differentiate seronegative pSS patients from sicca patients, the BNSM/CD4ACT ratio exhibited an AUC of 0.742 (sensitivity 75%, specificity 66.7%, cut-off value <4.4), and the number of naïve CD4 T cells had an AUC of 0.821 (sensitivity 76.9%, specificity 88.9%, cut-off value <312/mm3).
Conclusion:
Patients with pSS show a profound imbalance in the distribution of circulating T and B lymphocyte subsets. The ratio BNSM/CD4ACT is useful to discriminate between pSS and sicca syndrome.

