Endocrine Abstracts

Background: Our hospital is located 40 km from the nuclear power plants(Tokyo Electric Dai-ichi; NPP) exploded in northern east Japan disaster (2010.3). After the explosion, yearly radiation dose reached to 1-10 mSV in our city and 10-50 mSV in most poluted areas (next to our city). In former ESE congress, we reported cytological analysis of nodular goiter (NOD). In the present study, patients’ thyroid autoimmunity was analyzed whether there is any difference between pre- and post-NPP accidents. Patients and methods: 1.625 new patients (pts; 6.242 exams; 2007-2021). Ultra-sonogram (US) and hormonal assay for anti-thyroglobulin (aTg), thyroid peroxidase antibody (TPO), anti-TSH receptor antibody (TSH-R) and, in case of HY, thyroid stimulating antibody (TS), were performed at their visits. Fine needle aspiration cytology (FNA) was, if necessary, performed for NOD. Clinical diagnosis: Hyperthytroidism (HY), 420 pts (26%, 1.592 exams). chronic thyroiditis (HA), 160 (10%, 642), NOD 1.045 (65%:solid 27%, cyst 12%, multiple 15%). Data was compared between pre-NPP (A, 2007-2009) and post-NPP period(B1-B3, 2010- 2021). Significance was determined by Kai2 or student-t test (significance P<0.05).

Results: 1) Age: A, 55±18 years (n=1.295); B1(2010-2013), 55±16 (n=1.796); B2 (2014-2017) 59±16 (n=1.495); B3 (2018-2021) 57±17. (B2B3>A, P=0.01). 2) Gender: female(%), A 21.4%; B1 29.6%; B2 23.6%; B3 5.1%(B>A, P<0.0001).3)Autoimmunity(%) : a) All periods; TP(aTg+ TPO+) 10%, Tp(aTg+ TPO-) 3.9%, tP(aTg- TPO+) 3.8%, tp(aTg- TPO-) 25%.b) Period A-B (new pts): TP(aTg+ TPO+); A 18%; B1 18%;B2 29%;B3 25%. (A< B2B3:P=0.004).c) Period A-B (all pts): TP (aTg+ TPO+); A 20%(n=97), B 123%(n=147), B2 24%(n=153), B3 28%(n=253). (B>A, P=0.0001). 4) TSH-R positive(%): A 34%(n=206), B1 27%(n=232), B2 21%(n=151), B2 22% +21%(n=196). (A>B, <0.0001). 5) NOD: Antibody positive(%): Solid, 41%, cyst 52% a) aTg+: A 12%(n=162), B1 42%(n=246), B2 13%(n=230), B3 44%(n=298). (A<B1B3, P<0.0001). b)TSH-R+: A 5.5%(n=162), B1 4%(n=246), B2 14%(n=230), B3 9.1%(n=296). (A<B, P<0.0001).

Discussion: There was a slight increase of aTg+ TPO+ pts and decrease of TSH-R+ pts. This phenomenon is similar to the results of Chernobyl inhabitants’ analysis. However, there are various factors influencing autoimmunity, aging, gendar, residence or some others.

Conclusions: No apparent effect of NPP accidents was observed in thyroid immunity. To confirm the radiation effects, more elaborated environmental study is needed.