Thyroglobulin levels in serum and saliva of patients with differentiated thyroid carcinoma

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1 Pre, Indian Acad. Sci., Vl. 87 B (Experimental Bilgy-J), N.7, July pp. printed in India Thyrglbulin levels in serum and saliva f patients with differentiated thyrid carcinma D SHAH, S DANDEKAR and R D GANATRA Radiatin Medicine Centre, Bhabha Atmic Research Centre, C/ Tata Memrial Centre Annexe, Jerbai Wadia Rad, Parel, Bmbay MS received 17 Octber; revised 20 February 1978 Abstract. Serum thyrglbulin levels in 39 patients with differentiated thyrid carcinma and in 10 healthy vlunteers were studied by radiimmunassay. Sera frm tw f these patients were analysed preperatively. Bth f these sera shwed thyrglbulin levels higher than that btained frm nrmal individuals. Serum thyrglbulin levels f 10 nrmal subjects varied between1-0 t 20'0 ng/ml, Thirteen patients wh were in remissin shwed serum thyrglbulin levels between 0 1 t 18. ng/ml which is within the nrmal range. Patients with bne metastasis had elevated serum thyrglbulin levels while thse with lung metastasis had nrmal serum thyrglbulin levels. Salivary secretin frm nrmal subjects shwed thyrglbulin levels between 0'8 t 7 0 ng/ml., while that frm thyrid cancer patients ranged between 0.4 t 27. ngjml, It appears that salivary thyrglbulin is at pari passu with serum thyrglbulin levels. Keywrds. Serum thyrglbulin; salivary thyrglbulin; thyrid cancer. 1. Intrductin Thyrglbulin is a large mlecular weight prtein (660,000) prduced slely in the thyrid gland. Itis present in the serum f nrmal subjects and its levels are elevated in the serum f patients with varius thyrid disrders (Trrigiani et al 1969, Van Herle et al 1973; Van Herle and VIler 197; Gerf et a11977; Schneider et ai1977). The surce fthe high levels f serum thyrglbulin in patients wh had undergne ttal thyridectmy fr primary differentiated thyrid cancer culd be due t recurrence f primary cancer r metastasis lcated near the thyrid r remte frm it (Van Herle and VIler 197; Gerf et ai1977). We reprt serum thyrglbulin levels estimated by a radiimmunassay (RIA) in 39 patients with thyrid cancer. The serum thyrglbulin levels in patients with bne metastasis were high while in patients with lung metastasis and in remissin were within the nrmal range. Salivary thyrglbulin levels were in pari passu with the serum levels. 2. Materials and methds 2.1. Materials 12iI Nal (carrier free) was btained frm Amersham, England Nal was btained frm Bhabha Atmic Research Centre, Bmbay. Antibdies t puri- 169

2 170 D Shah, S Dandekar and R D Ganatra fied human thyrglbulin were raised in rabbits. Duble antibdy t rabbit y-glbulin in gat was btained frm Calbichem, Richmnd, CA, USA Methds Radiimmunassay: Serum thyrglbulin was determined by a duble antibdy radiimmunassay using the rabbit anti-human thyrglbulin at a final dilutin f 1 : 100,000. The prcedure used was that described by Van Herle et at (1973). Human thyrglbulin Was labelled with (1 2 1) by the methd f Hunter and Greenwd (1962). The sensitivity f the assay was 0 1 ng/ml. The variatin btained fr the intra and inter-assay was within the acceptable value fr radiimmunassay prcedure, namely, 7 % and 10 % respectively Criteria fr detectin fmetastasis: All the patients included in these studies except tw had undergne ttal thyridectmy. All patients were given a tracer dse f abut 0 mci f l31i NaI. The Whle bdy was then scanned after 48 t 72 h. The areas cncentrating radiidine ther than thyrid regin Were taken as metastatic regins and classifiedaccrdingly. Except fr ne case, the uptake in the thyrid regin f these 37 patients varied between 0 06%t 4 7%indicating very little functining residual thyrid mass Classificatin f subjects: Sera frm 10 healthy vlunteers were analysed fr nrmal thyrglbulin cncentratin. A ttal f 39 sera frm differentiated thyrid cancer patients were analysed fr thyrglbulin levels. Only in 2 cases with metastasis in the skull, the serum samples culd be btained befre thyridectmy, while the remaining 37 cases had ttal thyridectmy befre the studies. Thyrid cancer in all these patients was cnfirmed by histlgical methds. Thirty fur patients had predminantlyfllicular carcinma with a few areas f papillary type, While five patients had predminantly papillary Table 1. surgery. Number f patients studied in each grup at different intervals after Grups Intervals between surgery and investigatin 6 t 10 weeks 10 weeks t 3 years 3 t 13 years Number f patients Grup A (13) Grup B (11) Grup C (10)* Grup D ()* *1 patient each frm Grup C and Grup D was studied preperatively.. The figure in the parenthesis indicate the ttal number f patients investigated.

3 Thyrglbulin levels in thyrid carcinma 171 type f a carcinma with a few areas f fllicular type. Thirteen thyrid cancer patients were in remissin at the time f this investigatin (Grup A). The duratin f the disease in these patients ranged frm a few mnths t abut 13 years. At the time f the study, these patients had n evidence f a functining thyrid tissue in any part f the bdy ther than in the neck regin as shwn by whle bdy radiidine scanning. After a tracer dse f m.ci f radiidine the uptake in the neck regin in these 13 patients varied between %at 48 h. Of the remaining 26 cases with metastasis, I I had metastasis in lung (Grup B), loin the bnes (Grup C) and in bth lung and bnes (Grup D). As a large amunt f thyrglbulin is released during surgery, it is pssible that circulating thyrglbulin may vary with the time interval between surgery and investigatin. These patients are therefre further classified accrding t the pstperative perid as shwn in table 1. Salivary secretins frm seven f the abve thyrid cancer patients and eight nrmal subjects Were analysed fr thyrglbulin cntent Detectin fantithyrglbulin antibdies: All the sera studied were tested fr the presence f antithyrglbulin antibdies by tannic acid-cated red cell agglutinatin techinque using the prcedure f Ah et al (1971). The titres btained with nrmal sera ranged between 1 : 40 t I : 80 and hence all the sera with titres I : 40 and abve were excluded frm the present studies. Tw ut f the 41 patients analyzed had titres 1 : 40 and abve, and were therefre excluded frm the present studies. 3. Results 3.1. Serum thyrglbulin levels Circulating thyrglbulin levels in 10 nrmal subjects ranged between 1 0 t 20 ngjml (figure I). In 13 patients wh were in remissin at the time f the investigatin, serum thyrglbulin levels were between 0 1 t 18 ngjml which is within the nrmal range. Amng the 11 patients with metastasis in lung, 10 had thyrglbulin levels within the nrmal range (l'1 ng/ml t 22 0 ng/ml) while nly ne patient had a value f 0 ng/ml. Six patients with bne metastasis shwed serum thyrglbulin levels abve 1000 ngjrn! (ranging between 1000 t 6000 ngrrnl), Tw f these patients studied preperatively had serum levels f thyrglbulin as high as in perated patients. Three patients in grup C had thyrglbulin levels in the higher regin fthe nrmal range. One fthese patients, P had breast and thyrid cancer, and bne metastasis was suspected t riginate frm the breast cancer. Only ne patient, F f grup Chad thyrglbulin f 1 0 ng/ml. The bne metastasis in the pelvic regin in this case was nt cnclusively established and the results f radiidine scan f the pelvic regin were interpreted as suspicius but nt cnclusive. Of the five patients with bne and pulmnary metastasis, fur had serum thyrglbulin levels> 1000 ngjrnl while ne had thyrglbulin level f 30 ngjml (figure I). It is evident frm figure 1 that

4 172 D Shah, S Dandekar and R D Ganatra NORMAL > REMISSION LUNG BONE LUNG &. BONE c 2 10 I- Ql (/) I I,,.P <1 0 '--_&- --.!!~~ =:...:.. '..._..J (10) (13) (11) (10) 4) A A B C.F Figure 1. Serum thyrglbulin levels in nrmal and thyrid cancer patients. varius grups studied are indicated in table 1. The lung metastasis did nt shw significantly elevated thyrglbulin levels while bne metastasis exhibited very high thyrglbulin levels in the circulatin Salivary thyrglbulin levels Salivary thyrglbulin f eight nrmal vlunteers ranged between 0 8 t 7 0 ngjml (figure 2) while seven thyrid cancer patients had thyrglbulin levels between 0 4 t 27 ngjml (figure 2). Tw patientswith bne and pulmnarymetastasis had the salivary thyrglbulin values f 20 0 and 27 ngjml, respectively, which is significantly higher than that btained with nrmal subjects. These tw patients had serum thyrglbulin value abve 2000 ngjml, The salivary thyrglbulin cntent f a patient in remissin and f fur patients with lung metastasis was in the nrmal range. Thus, the salivary thyrglbulin levels shwed the same trend as that fthe serum thyrglbulin levels but were in the lwer range. 4. Discussin Our studies with 39 thyrid cancer patients indicated that serum thyrglbulin levels are nt elevated in all metastatic thyrid cancer patients. These results are in agreement with the findings f Schneider et 01 (1977). Gerf et al (1977) have reprted

5 Thyrglbulin levels in thyrid carcinma ~ 20 - NORMAL CANCER i s c ' 10 -.&I Jl CIt ~.. e~.. - (8) <1-0 L.- ~_ u--...j..lj- (7) Figure 2. Salivary thyrglbulin level in nrmal and thyrid cancer patients. Nrmal subjects 0 Patients in remissin frm thyrid cancer Patients with bth lung and bne metastasis 0 Patients with lung metastasis. mderately elevated thyrglbulin levels in tw patients f metastatic thyrid cancer. One f these patients had cervical lymphnde invlvement while the ther had pulmnary infiltrates frm metastatic thyrid tumur. They have als reprted markedly raised thyrglbulin levels in seven patients wh had diffuse active pulmnary invlvement. Our bservatins cntradict these findings and als thse f Van Herle and UlIer (197). In the latter study, the authrs have nt indicated the type f metastatic invlvement. Mre recently, Schneider et al (1977) have explred the pssibility f using serum thyrglbulin level as a screening prcedure in 904 persns expsed t radiatin in the neck regin t evaluate the risk f develping thyrid malignancy. A substantial number f thyrid carcinma patients in their study had nrmal serum thyrglbulin levels. The elevated thyrglbulin levels have been reprted in the inhabitants f the endemic gitre regin (Van Herle et ai1976). It is pssible that the thyrglbulin released prir t and during surgery culd persist fr a lng time in circulatin and thus result in false elevated thyrglbulin levels. Hwever, Trrigiani et al (1969) failed t detect circulating thyrglbulin in a patient f papillary carcinma f thyrid 10 days after thyridectmy. Mrever, Van Herle et al (197), have bserved a decrease in serum thyrglbulin levels frm 14'1 ± 66 7 ng/rnl t 6 4 ± 1 ngjrnl in seven thyrid cancer patients 3 3 mnths (mean) after surgery. Althugh the half-life f circulating thyrglbulin is nt knwn in the human, it can be inferred frm the abve mentined tw studies that the half-life f thyrglbulin may nt be mre than 3 3 mnths. Very high values fr circulating thyrglbulin was bserved in 3 cases (grups C and D), studied at 8 weeks after thyridectmy. The duratin f the disease

6 174 D Shah) S Dandekar and R D Ganatra in ten cases ranged between 1 t 11 years) and the surce f thyrglbulin culd nt pssibly be frm the pst-peratively circulating thyrglbulin. It therefre appears that metastatic tissue may be the surce f the circulating thyrglbulin. OUf results and thse f thers clearly indicate that lw levels f thyrglbulin are present in sera f nrmal subjects althugh the physilgical significance f this is still nt clear. The surce f circulating thyrglbulin in patients wh had n evidence f a functinal thyrid remains t be understd. Althugh a marginal increase in serum thyrglbulin levels in patients with lung metastasis was bserved, it was very large in the case f thyrid cancer patients with bne metastasis. It can be argued' that the absence f adequate cllid matrix in metastatic tissue where thyrglbulin can be stred may be respnsible fr the abnrmally high circulating levels fthis prtein. Hwever, this pstulate des nt explain the difference in the serum levels fthyrglbulin in bne and lung metastasis. Thyrglbulin is a large prtein mlecule with a number f heterantigenic determinants (abut 0) and a very few ( t 6) aut-antigenic determinants (Shulman 1971). Hence it is pssible that thyrglbulin secreted by the thyrid tissue and cancerus thyrid tissue are bichemically different but immunlgically identical (Beraud et al 1969; Valenta et al 1969). Fenzi et al (1976) have reprted ne case f pulmnary thyrid metastasis prducing abnrmal thyrglbulin which was immunlgically related t bvine) equine and vine but nt t human thyrglbulin. Further bichemical characterizatin f thyrglbulin f thyrid cancer patients is warranted. Van Herle and Uller (197) have estimated thyrglbulin levels in pleural fluid in patients with malignant effusin and shwed that a patient with mixed papillary and fllicular carcinma f thyrid had elevated thyrglbulin level f ng/ml in pleural fluid. Increase in thyrglbulin levels in saliva and serum as in pleural fluids may be f a cmmn phenmenn. The physilgical significance fthyrglbulin in circulatin needs t be carefully investigated. Acknwledgements We wish t express ur thanks t Shri K B Desai, Radiatin Medicine Centre, Bhabha Atmic Research Centre fr prviding human thyrglbulin and its antibdy. We are grateful t Dr S M Sharma, Radiatin Medicine Centre) Bhabha Atmic Research Centre fr the helpful discussin. References Ah K, Vikrla P and Heinnen Acta Bndcrinl, Fenzi G, RefetffS, Astcries G and Vassare G 1976 Acta Endcrinl.Suppl.l04 86 ab n. 63 p. 29 Gerf P L, Stillman T, Clacchi D and Feind C 1977Lancet (i) Hunter W M and Greenwd F C 1962 Nature (Lndn) Schneider A B, Favus M J, Statura M E, Arnld J B, Ry Y, Pinsky S, Clman M, Margaret J. Arnld R N and Frhman L A 1977 Ann. Intern. Med Shulman S 1971 Adv.Tmmunl, 148

7 Thyrglbulin levels in thyrid carcinma 17 Th, Leumarchand Beraud, Valenta Land Vanntti A 1969 in Thyrid Cancer (ed) C E Hedinger (New Yrk: Springer-Verlag) Trrigiani G, Dniach D and Ritt I M 1969J. Clin. Endcrinl. Metab Valenta L, Lissitzky S. Rques M and Rlland M 1969 J. Clin. Endcrinl. Metab Van Herle A J, Uller R P, Methews N L and Brwn J 1973J. Clin.Lnvest, Van Herle A J and Viler R P 197 J. en». Invest Van Herle A J. Chpra I J, Hershman J M and Hrnabrk R W 1976 J. cu«endcrinl. Metab. 4312