APMIS 100: 894-900, 1992
Serum levels of fetal antigen 2 in hyperthyroidism and primary hyperparathyroidism H. BOJE RASMUSSEN', B. TEISNER'.', J. GRAM3, K. BRIXEN4, E. YDE-ANDERSEN' and J. BOLLERSLEV, 'Department of Medical Microbiology, Institute of Medical Biology, Odense University, 2Division of Immunology, Statens Seruminstitut, Copenhagen, 'Department of Medical Endocrinology, Institute of Clinical Research, Odense University Hospital, Odense, and 4Department of Medical Endocrinology, Arhus County Hospital, Arhus, Denmark
Boje Rasmussen, H., Teisner, B., Gram, J., Brixen, K., Yde-Andersen, E. & Bollerslev, J. Serum levels of fetal antigen 2 in hyperthyroidism and primary hyperparathyroidism. APMIS ZOO: 894900, 1992. Serum concentration of fetal antigen 2 (FA2) in patients with hyperthyroidism (n= 18) (median: 12.9 mAU/1; range: 3.2-22.4 mAU/l) was significantly (p < 0.002) higher than in age- and sex-matched healthy controls (median: 4.1 mAU FA2/1; range: 2.4-10.0 mAU FA2/1). Serum FA2 was positively correlated with thyroxine (T4) (R,= 0.51; p < 0.05), triiodothyronine (T,) (R,=0.64; p < 0.01), boneGla protein (BGP) (R,=0.70; p < 0.01), total alkaline phosphatase (total-AP) (R,=0.62; p < 0.01), bone isoenzyme alkaline phosphatase (bone-AP) (R, = 0.63; p < 0.01), N-terminal procollagen type 111 (PTIINP) (R, = 0.65; p < 0.01) and urine OH-proline (OHP) (R, = 0.79; p i0.01). In patients with hyperparathyroidism the pretreatment levels of FA2 (n = 8) (median: 17.6 mAU/I; range: 5.2-35.0 mAU/l) were significantly (p < 0.001) higher than those of age- and sex-matched controls (median: 3.7 mAU FA2/1; range: 3.49.0 mAU/I). The pretreatment level of FA2 was positively correlated with the parathyroid hormone (PTH) (R, = 0.80; p < 0.05). Following surgical treatment the serum concentrations of FA2, PTH, and BGP decreased compared to pretreatment levels and the fall in these three parameters revealed parallelism. These data indicate that serum FA2 can be used as a marker in the evaluation of metabolic bone diseases. Key words: Fetal antigen 2; serum levels; hyperthyroidism; primary hyperparathyroidism. H. Boje Rasmussen, Department of Medical Microbiology, Institute of Medical Biology, Odense University, J. B. Winslerws Vej 19, DK-5000 Odense C, Denmark.
Fetal antigen (FA2) is an extracellular matrix protein, with a molecular weight (MW) of 27 kDa, initially isolated from second trimester human amniotic fluid (6, 18). FA2 is present diffusely in fetal mesenchymal tissues with a condensation along the basement membranes, whereas in normal adult human skin FA2 is found exclusively at the dermo-epidermal junction and around adnexal structures (18, 27). FA2 is found diffusely in the granulation tissue and within the cytoplasm of proliferating fibro-
Received March 9, 1992. Accepted May 18, 1992.
894
blasts during wound healing in skin, and the MW of FA2 isolated from human skin fibroblasts is 27 kDa (19). Furthermore, FA2 is present diffusely in tumor-induced stroma of e.g. basal cell carcinomas of the skin, breast carcinomas, and metastatic brain tumors (20-22). FA2 has been demonstrated in the cytoplasm of osteoblasts in fetal bone specimens (28), and detected in supernatants of osteoblasts cultured under serum-free conditions (23). In bone specimens with morphological changes of renal osteodystrophy FA2 is found within the cytoplasm of osteoblasts and in osteoid material; the osteoclasts are FA2 negative (23). The development of an ELISA technique for
SERUM LEVELS OF FETAL ANTIGEN 2
FA2 quantification has made it possible to measure FA2 in serum from normal healthy individuals. Application of the ELISA technique on serum samples from patients with chronic renal failure complicated by secondary hyperparathyroidism revealed increased FA2 concentration positively correlated with parathyroid hormone (PTH) and total alkaline phosphatase (total-AP) (23). Based on these results FA2 is regarded as a new matrix protein, related to bone and connective tissue metabolism. The function and the metabolism of FA2 remain unknown. The functions of fibroblasts and osteoblasts are regulated by several local growth factors and hormones, e.g. 1,25 dihydroxy-vitamin D3, growth hormone, calcitonin, glucocorticoids, thyroid- and parathyroid hormones (1 7, 26). The aim of this study was to investigate the serum FA2 levels in clinical conditions with increased bone and connective tissue turnover, i.e. hyperthyroidism and hyperparathyroidism, and to correlate FA2 with established bone and connective tissue markers.
FA2 mAU/I
0 0
80 0 00 0 0
c T
ooo
+ 0 0
N
Fig. 1. FA2 concentrations in serum samples from 18 hyperthyroid patients (T) and 18 sex- and agematched controls (N), p < 0.002.
MATERIALS AND METHODS Serum and urine samples Two groups were studied: patients with hyperthyroidism and patients with primary hyperparathyroidism. The first group consisted of 18 hyperthyroid patients (16 females and two males, age range: 28-80 years). The diagnosis of hyperthyroidism was based on elevated serum levels of thyroxine (T4)and triiodothyronine (TJ, and low levels of thyroid-stimulating hormone (TSH) (Table 1). Serum and urine samples were obtained from the hyperthyroid patients before treatment. Serum and urine samples from age- and sex-matched controls were obtained from normal healthy individuals (age range: 27-78 years). The second group consisted of eight hyperparathyroid patients (three females and five males, age range: 32-83 years). The diagnosis of hyperparathyroidism was based on elevated serum levels for calcium (Ca) and intact immunoreactive parathyroid hormone (PTH) (Table 2). Serum samples from the TABLE 1. Biochemical parameters in 18 hyperthyroid patients and 18 age- and sex-matched healthy controls Hyperthyroid Controls T4 190b 88 nmol / 1 60-1 17 85-295 T, 3.84b 1.48 nmol / 1 1.87-12.24 1.15-1.96 TSH 0.01 lb 1.19 arb. units 0.01-0.03 0.02-2.18 16.5 10.9 Serum BGP ng/ml 4.4-100.0 5.7-23.7 158 140 Serum total-AP u/1 66278 93-207 Serum bone-AP 47 58 u/1 21-154 28-95 179.7” 127.2 Serum PICP ndml 89.6-448.0 77.8-296.0 Serum PIIINP 4.63‘ 1.94 1.34-1 1.79 1.00-5.63 ng/ml Serum Ca 2.45 mmol / 1 2.262.57 Urine Ca 0.33 0.29 mmol/mol creatinine 0.10-1.18 0.05-0.55 Urine P 1.90 1.98 0.13-3.46 0.684.33 mmol/mol creatinine OHP 45c 25 umol/mol creatinine 19-172 18-35 Values are median and range a p < 0.05 compared to controls p
Serum levels of fetal antigen 2 in hyperthyroidism and primary hyperparathyroidism H. BOJE RASMUSSEN', B. TEISNER'.', J. GRAM3, K. BRIXEN4, E. YDE-ANDERSEN' and J. BOLLERSLEV, 'Department of Medical Microbiology, Institute of Medical Biology, Odense University, 2Division of Immunology, Statens Seruminstitut, Copenhagen, 'Department of Medical Endocrinology, Institute of Clinical Research, Odense University Hospital, Odense, and 4Department of Medical Endocrinology, Arhus County Hospital, Arhus, Denmark
Boje Rasmussen, H., Teisner, B., Gram, J., Brixen, K., Yde-Andersen, E. & Bollerslev, J. Serum levels of fetal antigen 2 in hyperthyroidism and primary hyperparathyroidism. APMIS ZOO: 894900, 1992. Serum concentration of fetal antigen 2 (FA2) in patients with hyperthyroidism (n= 18) (median: 12.9 mAU/1; range: 3.2-22.4 mAU/l) was significantly (p < 0.002) higher than in age- and sex-matched healthy controls (median: 4.1 mAU FA2/1; range: 2.4-10.0 mAU FA2/1). Serum FA2 was positively correlated with thyroxine (T4) (R,= 0.51; p < 0.05), triiodothyronine (T,) (R,=0.64; p < 0.01), boneGla protein (BGP) (R,=0.70; p < 0.01), total alkaline phosphatase (total-AP) (R,=0.62; p < 0.01), bone isoenzyme alkaline phosphatase (bone-AP) (R, = 0.63; p < 0.01), N-terminal procollagen type 111 (PTIINP) (R, = 0.65; p < 0.01) and urine OH-proline (OHP) (R, = 0.79; p i0.01). In patients with hyperparathyroidism the pretreatment levels of FA2 (n = 8) (median: 17.6 mAU/I; range: 5.2-35.0 mAU/l) were significantly (p < 0.001) higher than those of age- and sex-matched controls (median: 3.7 mAU FA2/1; range: 3.49.0 mAU/I). The pretreatment level of FA2 was positively correlated with the parathyroid hormone (PTH) (R, = 0.80; p < 0.05). Following surgical treatment the serum concentrations of FA2, PTH, and BGP decreased compared to pretreatment levels and the fall in these three parameters revealed parallelism. These data indicate that serum FA2 can be used as a marker in the evaluation of metabolic bone diseases. Key words: Fetal antigen 2; serum levels; hyperthyroidism; primary hyperparathyroidism. H. Boje Rasmussen, Department of Medical Microbiology, Institute of Medical Biology, Odense University, J. B. Winslerws Vej 19, DK-5000 Odense C, Denmark.
Fetal antigen (FA2) is an extracellular matrix protein, with a molecular weight (MW) of 27 kDa, initially isolated from second trimester human amniotic fluid (6, 18). FA2 is present diffusely in fetal mesenchymal tissues with a condensation along the basement membranes, whereas in normal adult human skin FA2 is found exclusively at the dermo-epidermal junction and around adnexal structures (18, 27). FA2 is found diffusely in the granulation tissue and within the cytoplasm of proliferating fibro-
Received March 9, 1992. Accepted May 18, 1992.
894
blasts during wound healing in skin, and the MW of FA2 isolated from human skin fibroblasts is 27 kDa (19). Furthermore, FA2 is present diffusely in tumor-induced stroma of e.g. basal cell carcinomas of the skin, breast carcinomas, and metastatic brain tumors (20-22). FA2 has been demonstrated in the cytoplasm of osteoblasts in fetal bone specimens (28), and detected in supernatants of osteoblasts cultured under serum-free conditions (23). In bone specimens with morphological changes of renal osteodystrophy FA2 is found within the cytoplasm of osteoblasts and in osteoid material; the osteoclasts are FA2 negative (23). The development of an ELISA technique for
SERUM LEVELS OF FETAL ANTIGEN 2
FA2 quantification has made it possible to measure FA2 in serum from normal healthy individuals. Application of the ELISA technique on serum samples from patients with chronic renal failure complicated by secondary hyperparathyroidism revealed increased FA2 concentration positively correlated with parathyroid hormone (PTH) and total alkaline phosphatase (total-AP) (23). Based on these results FA2 is regarded as a new matrix protein, related to bone and connective tissue metabolism. The function and the metabolism of FA2 remain unknown. The functions of fibroblasts and osteoblasts are regulated by several local growth factors and hormones, e.g. 1,25 dihydroxy-vitamin D3, growth hormone, calcitonin, glucocorticoids, thyroid- and parathyroid hormones (1 7, 26). The aim of this study was to investigate the serum FA2 levels in clinical conditions with increased bone and connective tissue turnover, i.e. hyperthyroidism and hyperparathyroidism, and to correlate FA2 with established bone and connective tissue markers.
FA2 mAU/I
0 0
80 0 00 0 0
c T
ooo
+ 0 0
N
Fig. 1. FA2 concentrations in serum samples from 18 hyperthyroid patients (T) and 18 sex- and agematched controls (N), p < 0.002.
MATERIALS AND METHODS Serum and urine samples Two groups were studied: patients with hyperthyroidism and patients with primary hyperparathyroidism. The first group consisted of 18 hyperthyroid patients (16 females and two males, age range: 28-80 years). The diagnosis of hyperthyroidism was based on elevated serum levels of thyroxine (T4)and triiodothyronine (TJ, and low levels of thyroid-stimulating hormone (TSH) (Table 1). Serum and urine samples were obtained from the hyperthyroid patients before treatment. Serum and urine samples from age- and sex-matched controls were obtained from normal healthy individuals (age range: 27-78 years). The second group consisted of eight hyperparathyroid patients (three females and five males, age range: 32-83 years). The diagnosis of hyperparathyroidism was based on elevated serum levels for calcium (Ca) and intact immunoreactive parathyroid hormone (PTH) (Table 2). Serum samples from the TABLE 1. Biochemical parameters in 18 hyperthyroid patients and 18 age- and sex-matched healthy controls Hyperthyroid Controls T4 190b 88 nmol / 1 60-1 17 85-295 T, 3.84b 1.48 nmol / 1 1.87-12.24 1.15-1.96 TSH 0.01 lb 1.19 arb. units 0.01-0.03 0.02-2.18 16.5 10.9 Serum BGP ng/ml 4.4-100.0 5.7-23.7 158 140 Serum total-AP u/1 66278 93-207 Serum bone-AP 47 58 u/1 21-154 28-95 179.7” 127.2 Serum PICP ndml 89.6-448.0 77.8-296.0 Serum PIIINP 4.63‘ 1.94 1.34-1 1.79 1.00-5.63 ng/ml Serum Ca 2.45 mmol / 1 2.262.57 Urine Ca 0.33 0.29 mmol/mol creatinine 0.10-1.18 0.05-0.55 Urine P 1.90 1.98 0.13-3.46 0.684.33 mmol/mol creatinine OHP 45c 25 umol/mol creatinine 19-172 18-35 Values are median and range a p < 0.05 compared to controls p
