The Expression Of IgG Subclasses In The Salivary Glands And The Clinical Analysis Of70Cases Of Sjogren’s Syndrome

【Objective】Since IgG subclasses are known to immediate different immuneresponses, we tried to clarify the distribution of IgG subclasses in the salivary glandsof Sjogren’s syndrome to explore the pathogenesis of Sjogren’s syndrome anddifferentiate it from Mikulicz’s disease.【Methods】We investigated the deposition of four IgG subclasses usingimmunohistochemistry in the salivary glands from70patients with Sjogren’ssyndrome and the differences were analyzed combined with the clinical information.【Results】All four IgG subclasses could be detected.IgG could be detected in36patients(51.4%）,with IgG1detected in32patients(45.7%),IgG2detected in2patients(2.9%),IgG3detected in5patients(7.2%),IgG4detected in6patients(8.6%).Weobserved no clinical associations between IgG1positive and negative groups in theaspects of clinical symptoms like sicca,tender joints,lack of strength,rash,but IgG1positive group appeared to have longer duration, lower WBC,more positiveANA,anti-SSA,anti-SSB and the immunologic injury was severer (P<0.05).There wasno significant difference in HB,PLT,globulin,complentments,IgA,IgG,IgM andsystemic involvements (P>0．05).【Conclusions】IgG1is the main IgG subclass in the salivary glands of Sjogren’ssyndrome,which is quite different from Mikulicz’s disease dominated by IgG4positive plasma cells.So it is of value to detect IgG subclasses to distinguish these twodiseases.And our data indicates that IgG1positive plasma cells is associated withlonger duration,the production of ANA,anti-SSA,anti-SSB and severity of pathologicinjury.Perhaps IgG1takes part in the local immunological injury of salivary glands todeteriorate SS.No significant difference of organ involvement has been found amongthese groups,which needs further study.