[Clinical usefulness of Beta2microglobulin in patients with Primary Sjögren Syndrome]

The extraglandular manifestations and lymphoproliferative disorders are complications in pSS. There are few serological markers that they are useful in these conditions.

to evaluate the usefulness of the β2microglobulin level in patients with pSS and its relation to extra glands manifestations , lymphoproliferative disorders and the presence of Rheumatoid factor (RF), serum immunoglobulins (Igs), and C3 and C4 levels.

we retrospectively studied patients with pSS , OAD and healthy controls . Ig G, Ig A and Ig M levels, serum complement C3 and C4 and RF were performed by immunoturbidimetry, and β2microglobulin protein by the ELISA technique in all patients.

19 patients with pSS (Group SSp), 28 patients with other autoimme diseases diferent from pSS (Group PAD) and 24 healthy controls (Group C).There was an signifcant increase of β2m values in Groups SS and OAD vs Group C (6.19 mg/dl vs. 2.53 mg/dl p<0.001) and (4.38 mg/dl vs. 2.53 mg/dl p<0.01). On the other hand, mean β2m levels in Group SS were higher than in Group OAD (6.19 vs. 4.38 mg/dl p<0.01).There was not a relationship between β2m level and Ig G, A , M ,complement levels and the presence of RF.

β2m can discriminate patients with pSS from those with other autoimmune diseases and healthy subjects. Increased β2m level in pattients with pSS could reflect hyperactivation of B cells and it could be a potential marker associated with extraglandular manifestations and cell lymphoproliferative disorders.