Ree wee Oe OE
“Why redal benieoeas
U.S. normal
peep we
ae
4
No besives (Clink)
Wuosal
3
ath
tug. ol
Figure 41, Percentages of peopl: in various groups having
givenlevels of thyroylalaalia (by READ, 173.
and a highincidence of parasitic infections, A preliminary examination of North Americans with
abnonnal leukocyte counts, hawever, did not show
a correlation between leukocytosis and jodoprotein level. Further studies on this are indicated,
"Phe chemical nature of this iodopratein is also une
known. By analogy with findings in various thy:
roid discases,"* the iodaprotcis is likely ¢o be come
priscd inaindy of jodoallbumin arising from the
iodination of scrum protcins,
It is now recognized, however, that thyroglobulin (PG) is a minor component of normal plasma,
Ata reported concentration of 3,120.49 (S.EAL)
ng/ml (range <1.6 to 20.7) in normal North
Aniericans,! and assuming an iodine content of
0.5/4, this would be equivalent te an iodoprotcin
iodine bevel of 2.60.25 ng/dl, Atthough it seems
unlikely, a preore, Uhat circulating Uhnvroglobulia in
the Marshallese could be clevated enough to give
were ee ws
an todoproteny level of 3 to 4 pad (iw. > 300 pg
whe
24 hie bagead
Bai TSlt
Ble
Jtbe
Figure 42. Effect of TSHL adininisteation on thyroglobulin
levels, 1975. 0, Persons with thyroid lesions (Rongelap
plus Ctirik); @. without lesions (Kongelaps).
of cach group, including the U.S. normal group,
had TG values >30 ng/ml, but the significance of
this is uncertain. Of 24 sul(e. swith elevated serum
joduprotein, only | had .cam TG >30 ng/di.
A striking finding (Figure 41) was that in the
Rongelap plus Ctirik group with thyroid lesions
(36 people) almost 50% of the levels were <5
ng/ml, a much higher percentage thanin the other
groups, Most of these people had had prior thyroid surgery or were athyreotic, and itis presumed
that they had insufficient thyreid tissue for normal
TG production. Furthermore, Ty suppression therapy mayhave contributed to the low TG levels in
the Rongelap people.
TG was also measured before and after TSH
irjection in 10 Rongelap plus Utirik subjects with
thyroid lesions and in 20 Ronyclapese with none
(Figure 42). la every case, VSI] resuliedina rise
in VG tevel, and there was no apparent dillerence
between the two groups.
The unusually high level ot iodaprotein in the
TG/d)), the possibility was investigated by radioimMUNGMcasurements (MM. Lacs, J. Bactieu,
Manhallese people is intriguing, and further studies are in progress, with ?="1 used as the tracer, in
aa atlempt to identily the protein, *
>S ng/ml, levels > 40 ny, ml were not quantivied.
ln the Rongelap and Uticik groups without thy.
G. CORRELATION OF THYROID ABNORMALITIES
WITH RAOLATION EXPOSURE
AND J. Ronnins, unpublished observations, 1974;
see Figure 11). Vhe assay could detect VG levels
roid lesions (47 ard 25 subjects respectively), 2 00%
of the values were within the U.S. range, and no
correlation was scen between clevated serumjodoe
protein and abaornal PG levels. A few members
ae
SSN ray or em ie
Statistics on the incidence of thyroid abnonnalities in people living on the Marshall Islands are
Mie (OF, Straub, NT. is chetig the cheiicat analyses.
.
Af
e
No lesions (Rongelap)
yar
*
\
fe eeee oe eeee
A
1G by RUA (ng/ml)
|
-cse
14 (Resngrlop + Ciirik)