BackgroundPatients with Sjögren’s syndrome, like other patients with autoimmune disorders, display dysregulation in the function of their immune system. Fas and Fas Ligand (FasL) are among the dysregulated proteins.MethodsWe studied Fas and FasL on IL-2Rα+cells and in serum of patients with Sjögren’s syndrome (n= 16) and healthy individuals (n= 16); both from same ethnic and geographical background. We used flow cytometry and enzyme-linked immunosorbent for this purpose. We also measured the expression ofBcl-2andBaxby reverse transcription quantitative real-time PCR (RT-qPCR) and percentage of apoptotic and dead cells using Annexin V and 7-AAD staining in lymphocytes.ResultsFasL was increased in patients’ T and B cells while Fas was increased in patients’ monocytes, T and B cells. No signs of increased apoptosis were found. sFas and sFasL in patients’ serum were increased, although the increase in sFasL was not significant. We suspect an effect of non-steroidal anti-inflammatory therapy on B cells, explaining the decrease of the percentage Fas+B cells found within our samples. In healthy individuals, there was a noticeable pattern in the expression of FasL which mutually correlated to populations of mononuclear cells; this correlation was absent in the patients with Sjögren’s syndrome.ConclusionsMononuclear cells expressing IL-2Rα+had upregulated Fas in Sjögren’s syndrome. However, the rate of apoptosis based on Annexin V staining and theBcl-2/Baxexpression was not observed in mononuclear cells. We suspect a functional role of abnormal levels of Fas and FasL which has not been cleared yet.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12865-023-00544-5.