Induction of late-onset spontaneous autoimmune thyroiditis by a single low-dose irradiation in thyroiditis-prone non-obese diabetic-H2h4 mice.
The previous data regarding the effect of irradiation on thyroid autoimmunity are controversial. We have recently reported the exacerbation of autoimmune thyroiditis by a single low dose (0.5 Gy) of whole body irradiation in thyroiditis-prone non-obese diabetic (NOD)-H2(h4) mice treated with iodine for 8 weeks. However, it is uncertain in that report whether the results obtained by the provision of iodine in a relatively short period of time (8 weeks) accurately reflects the long-term consequences of low-dose irradiation on thyroid autoimmunity. Therefore, we repeated these experiments with mice that were monitored after irradiation without iodine treatment for up to 15 months. We found that a single low-dose (0.5 Gy) irradiation increased the incidence and severity of thyroiditis and the incidence and titers of anti-thyroglobulin autoantibodies at 15 months of age. The numbers of splenocytes and percentages of various lymphocyte subsets were not affected by irradiation. Thus, we conclude that low-dose irradiation also exacerbates late-onset spontaneous thyroiditis in NOD-H2(h4) mice; one plausible explanation for this may be the acceleration of immunological aging by irradiation.
Nagayama
Yuji
Y
Department of Medical Gene Technology, Atomic Bomb Disease Institute, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. nagayama@nagasaki-u.ac.jp
Ichikawa
Tatsuki
T
Saitoh
Ohki
O
Abiru
Norio
N
D000818:Animals; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D051379:Mice; D016688:Mice, Inbred NOD; D009765:Obesity / Q000150:complications; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000209:etiology* / Q000276:immunology*; D013967:Thyroiditis, Autoimmune / Q000209:etiology* / Q000276:immunology*; D014916:Whole-Body Irradiation