The incidence of antithyroglobulin autoantibodies (ATA) was 17.7% in 9
63 patients (who attended the clinic from 1981 to 1990) with different
iated thyroid carcinoma (DTC). Another 12 patients developed ATA for a
transient period after the treatment with radioiodine. The prevalence
of ATA in females (21.5%, 123/572) was significantly higher (p < 0.00
1) than that seen in males (12.0%, 47/391). Age-dependent occurrence o
f ATA was not seen for the various age decades. The ATA was more preva
lent (p < 0.01) with the papillary type of tumor (118/564) as compared
to the follicular variety (51/398). ATA did not influence the metasta
tic spread of the tumor at the initial presentation (105/170 for the A
TA-positive group and 445/793 for the ATA-negative group). However, wi
thin the group with metastases, 82.9% (87/105) of patients had local s
pread into the neck in the presence of ATA, which was significantly hi
gher (p < 0.01) than that seen for patients without ATA (63.8%, 284/44
5). For assessment of the influence of ATA on the outcome of the disea
se, the data from 222 patients (46 positive and 176 negative for ATA),
with a minimum follow-up of 5 years (mean follow-up of 7.4 years), wa
s considered suitable for analysis. The outcome of the disease was com
parable in the presence and the absence of ATA (38/46 and 137/176 pati
ents became disease-free in ATA-positive and -negative groups, respect
ively). Of the 46 patients with circulating ATA, antibodies disappeare
d or decreased in all 38 patients who became disease-free as compared
to 8 patients (p < 0.001) with persistent disease; ATA disappeared in
5 but remained unchanged in 3 of these patients. From this study we co
nclude (a) ATA is more prevalent in females and in papillary type of t
umors, (b) the occurrence of ATA in patients with DTC is not age depen
dent, (c) the presence of ATA does not restrict or promote the metasta
tic spread of the tumor, (d) there is a tendency for local metastases
in the presence of ATA, (e) ATA does not protect or worsen the progres
s of the disease, and (f) the persistence of antibodies is indicative
of functioning thyroid tissue.