The Clinical Significance Of Thyroid Fine Needle Cytology, TGAb And TPOAb In Differential Diagnosis Of AITD

OBJECTIVE:To investigate the clinical significance of FNAC,TGAb and TPOAb in differential diagnosis of Grave's disease and Hashimoto thyroiditis through comparing the FNAC and TGAb,TPOAb in two groups.METHODS:All subjects was devided into two groups:The GD group,which including 41 cases,13 males and 28 females, aged 36.6±12.6,and the HT group, which including 44 cases,2 males and 42 females,aged 33.2±16.2.A11 cases were diagnosed in Qilu Hospital of Shandong University from Augest,2009 to Match,2010.The free serum triiodothyronine (FT3), free thyroxin (FT4),thyroid stimulating hormone(TSH), thyroglobulin antibody (TGAb), thyroid peroxidase antibody(TPOAb) and fine needle aspiration cytology(FNAC) were tested.The comparison of TGAb, TPOAb and FNAC between two groups and the correlation between thyroid cytology and autoantibodies were analyzed.RESULTS:l.The serum level of TGAb and TPOAb in HT group(TGAbl333.13±1250.33 IU/ml, TPOAb429.22±204.21 IU/ml) was significantly higher than that in GD group (387.43±689.19IU/ml,267.79±218.44 IU/ml) respectively. In GD group, the positive rates of TGAb and TPOAb were 51.2% and 87.8% respectively. In HT group, the positive rates of TGAb and TPOAb were 97.7% and 90.9%.The positive rate of TGAb in HT group was significantly higher than that in GD group(P<0.001),but the positive rate of TPOAb had no significantly difference between two groups (P=0.454)2.Fine needle aspiration cytology(1) The cytology of GD group:①There were many red cells in the background;②The distribution of thyroid follicular epithelial cells were clustering or dispersedly,the nucleus were round or oval and the size was uniform.③A few lymphocytic infiltration;④A few degenerative cells.The cytology of HT group:①The distribution of thyroid follicular epithelial cells were clustering or dispersedly, the nucleus were round or oval and the size was polymorphism.②Lots of lymphocytic infiltration;③The Hurthle cells could be found;④Lots of degenerative cells.(2)The patients with a few lymphocytic infiltration were most in GD group, and the percentage was 71.7%. While the patients with lots of lymphocytic infiltration were most in HT group, and the percentage was 63.6%.The percentage of the lymphocytic infiltration degrees was significantly different between two groups (P<0.001)(3) In GD group, no Hurthle cell was found. In contrast,81.8 percentage of HT patients found Hurthle cells.(4) 82.9 percentage of GD patients didn't find degenerative cell. In contrast,97.8 percentage of HT patients found degenerative cells. The percentage of the degenerative cell degrees was significantly different between two groups (P<0.001)3.There was no linear correlation between the lymphocytic infiltration and the autoantibodies (P=0.103,P=0.189)CONCLUSIONS:1. The test of thyroid autoantibodies can serve as a differential diagnosis of GD and HT, TGAb or TPOAb strong positive.can highly suspected HT, and TGAb is more significant than TPOAb.2. FNAC, which is a simple, safe, little injury and repeated inspection, is more sensitive than TGAb or TPOAb.3. There is no reference between the TGAb,TPOAb and lymphocyte infiltration.