Effects of prolonged thyrocalcitonin administration on Paget's disease of bone

Advances in osteoporosis from 1970 to 2018

In 1970, there were no drugs under study for osteoporosis. Estrogen was used, but little was known about the correct dose for preventing bone loss. At that time, fractures were not even recognized as a disease, but regarded as part of normal aging. From 1970 to this year (2018), there have been extensive advances in the osteoporosis field ranging from fracture epidemiology to the remarkable invention of bone density measurements. There have been major advances in therapeutic options available for patients for prevention and treatment of osteoporosis. In parallel, the advances in the laboratory helped elucidate the process of bone remodeling, not only at the macroscopic level but also at the cellular level. This led to rapid advances in translational research from cellular biology to new therapies exemplified by the development of monoclonal antibodies for osteoporosis. Further understanding of the signaling pathways in bone cells will lead to new small molecules made for osteoporosis treatment, perhaps causing less adverse events. University-based research throughout the world has been a leader in most of these advances, and Pharma support for phase 1 to 4 studies helped bring these discoveries to patients. In the osteoporosis field alone, one sees the tremendous value of grant support for university research by National funding agencies such as the National Institute of Health in this country and similar agencies in other countries. There are clinical challenges that have to be solved with long-term compliance with osteoporosis medication if we want to reduce fracture incidence in the long term.

A 5-year controlled randomized study of prevention of postmenopausal trabecular bone loss with nasal salmon calcitonin and calcium

The aim of this paper was to evaluate the long-term (5 years) efficacy of nasal salmon calcitonin in prevention of trabecular postmenopausal bone loss, which was a follow-up of a previously published study (3 years); a randomized, controlled group comparison. One hundred healthy postmenopausal women were randomly chosen from those (186) having completed the 3 year protocol. The 100 women were allocated to an additional 2 year period (total of 5 years) of treatment with either 500 mg d-1, 5 days week-1 of calcium or the same amount of calcium plus 50 IU d-1, 5 days per week of nasal salmon calcitonin, 87 (87%) women complied with the protocol throughout. The main outcome measures were the bone mineral density of the lumbar spine (1-BMD) (DPA) and biochemical parameters reflecting bone turnover (serum alkaline phosphatases, urinary calcium/creatinine and hydroxyproline/creatinine ratios). The women receiving calcium alone presented a significant decrease in 1-BMD after 6 months [-1.6 (0.5)%] [mean(SEM)] (P < 0.01) and this decrease remained significant after 36 months [-6.1(0.8)%] (P < 0.01) and until the end of the trial [-6.6(1.0)% at t60] (P < 0.01). In women receiving calcium and calcitonin, 1-BMD significantly increased after 36 months [+2(0.7%] (P < 0.01) and 42 months [+2.5(0.7)%] (P < 0.01 and was unchanged at the other times of investigation [+1.1 (1.1)% at t60] (NS). The evolution of BMD in the two groups was highly significantly different (P < 0.001) since the sixth month of the study and remained so until the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Prevention of osteoporosis with nasal salmon calcitonin: effect of anti-salmon calcitonin antibody formation

The amino acid sequence of salmon calcitonin (SCT) differs considerably from that of the human hormone and specific antibodies (Ab) develop in a significant proportion of patients after parenteral or nasal administration of SCT. Controversy remains regarding the functional importance of these Ab. We report on the development of specific anti-SCT Ab in a population of postmenopausal women receiving nasal SCT for prevention of postmenopausal bone loss, and compare the effects of nasal SCT in women with or without Ab. Thirty-nine per cent of women developed Ab after 6 months of treatment with SCT, 52% after 12 months, and 61% after 18 and 24 months. After 24 months the AB titre was 3.47-17.7 x 10(-9) M/l (mean +/- SD: 13.3 +/- 3.1 x 10(-9) M/l). No significant differences appeared between the changes in lumbar bone mineral density (BMD) measured in the whole population (n = 44) (mean +/- SD: +1.06 +/- 3.9%), the patients without Ab (n = 17) (+0.05 +/- 3.7%) or in those with Ab (n = 27) (+1.7 +/- 4.6%). During the same period, a control population randomly assigned to a 500 mg/day calcium intake showed a significant loss of lumbar BMD (-4.57 +/- 4.9%) (p < 0.01). In conclusion, in healthy postmenopausal women nasal SCT seems to maintain the same preventive effect against bone loss whether or not Ab are present.

Endogenous production of specific antibodies does not decrease hypocalcemic response to calcitonin in young rabbits

In order to evaluate the potential inhibition of the acute anti-osteoclastic activity of salmon calcitonin (SCT) by specific antibodies (Ab), we compared the SCT-induced hypocalcemic effect in young male rabbits with significant titers of high affinity Ab and in matched animals without Ab. Immunization of rabbits was performed by repetitive s.c. injections of SCT and Freund adjuvant. Ab were present in four-fifths of SCT-treated rabbits (Ab+). Their titer varied from 0.8 x 10(-9) to 30 x 10(-9) M/liter and their constant of affinity from 0.97 x 10(9) to 4.2 x 10(9) L/M. Intravenous injection of 1 IU/kg SCT to Ab+ rabbits induced a significant decrease (P less than 0.01) of ionized serum calcium (Ca2+) after 30 minutes (mean +/- SD: -9 +/- 0.6%) and until the 240th minute of the test (-16.7 +/- 4.7%), with a maximum after 120 minutes (-22.6 +/- 2%). This was not significantly different from the hypocalcemic effect measured after the same procedure performed in matched animals without Ab (Ab-): significant decrease in Ca2+ (P less than 0.01) after 30 minutes (-8.2 +/- 2.2%), maximal after 150 minutes (-23.2 +/- 4.9%), and lasting until 210 minutes (-14.5 +/- 3.7%). We conclude that, in the particular model of the male young rabbit, specific anti-SCT Ab do not block or reduce the acute anti-osteoclastic activity of SCT.

Bone turnover in postmenopausal osteoporosis. Effect of calcitonin treatment

To investigate the effectiveness of calcitonin treatment of postmenopausal osteoporosis in relation to bone turnover, we examined 53 postmenopausal osteoporotic women before and after one year of therapy with salmon calcitonin (sCT), at the dose of 50 IU every other day. Baseline evaluation revealed that 17 (32%) patients had high turnover (HTOP), and 36 (68%) normal turnover osteoporosis (NTOP) as assessed by measurement of whole body retention (WBR) of 99mTc-methylene diphosphonate. The two groups did not differ in terms of bone mineral content (BMC) measured by dual photon absorptiometry at both lumbar spine and femoral diaphysis. However, HTOP patients had higher levels of serum osteocalcin (OC) and urinary hydroxyproline excretion (HOP/Cr). Multivariate regression analysis showed no correlation between parameters of bone turnover (WBR, OC, HOP/Cr) and both femoral and vertebral bone density; the latter being negatively correlated only with the years elapsed since menopause (R2 = 0.406). Treatment with sCT resulted in a significant increase of vertebral BMC in the 53 patients taken as a whole group (+/- 7%, P less than 0.001). When the results obtained in HTOP and NTOP were analyzed separately, only those with HTOP showed a marked increment of spinal BMC (+22%, P less than 0.001), NTOP subjects neither gained nor lost bone mineral during the study. Femoral BMC decreased in the whole group after sCT therapy (-3%, P less than 0.003). However, HTOP patients maintained initial BMC values, whereas those with NTOP lost a significant amount of bone during the study period (-5%, P less than 0.001). The increase of vertebral bone mass was associated with a marked depression of bone turnover detectable in both subsets of patients and in the whole group.

IN CONCLUSION

(a) assessment of bone turnover cannot help predict the severity of bone loss in postmenopausal osteoporosis; (b) calcitonin therapy appears to be particularly indicated for patients with high-turnover osteoporosis, resulting in a net gain of bone mineral in the axial skeleton and a slowing of bone loss in the appendicular bones.

Paget's disease of bone

Paget's disease is a relatively common bone disease. This review aims to present reasonable treatment recommendations with enough background to understand them. To accomplish this end, some aspects of basic bone cell biology, biochemistry, and pathology are presented, as are speculations about possible causes of this disease. Treatment of Paget's disease will be considered in three sections. The first two sections will review treatment with calcitonin and diphosphonates, respectively. These sections briefly will consider the mechanism of action of the drugs, review in detail clinical studies of drug effectiveness, and summarize the advantages and disadvantages of each drug. The third section details specific treatment recommendations for each of the six clinical settings in which treatment of Paget's disease is justified.

Paget's disease of bone with particular reference to dentistry

Paget's disease of bone (osteitis deformans) is a relatively common disorder of uncertain aetiology. It is characterised by abnormal resorption and apposition of osseous tissue in one or more bones of the skeleton. This is a review of Paget's disease with particular reference to dentistry. The prevalence, aetiology, clinical features, radiography, histopathology, biochemistry, oral and dental manifestations, complications and treatment are discussed. One hundred and fifty-two reported cases of Paget's disease of the jaws have been analysed. The upper jaw was more frequently involved than the lower jaw in the ratio of more than 2:1. This survey shows a higher prevalence of Paget's disease in the mandible than previously recorded.

Control of osteitis deformans using glucagon, calcitonin, and mithramycin

Glucagon, porcine calcitonin, and mithramycin were given to patients with Paget's disease of bone. There was rapid complete relief of bone pain accompanied by biochemical improvement or normalization in all cases. Calcitonin and glucagon appear to have additive properties in Paget's disease and the use of the 3 drugs in combination may reduce the incidence of side effects and the development of "drug resistance". The cost of treatment might also be reduced if periodic treatment as demonstrated in Case 1 is used.

Calcitonin therapy in Paget's sarcoma

A 68-year-old white male patient suffering from Paget's disease of bone developed a sarcoma in the sacroiliac region during treatment with calcitonin. There was no evidence of its presence before treatment. Progression of the sarcoma did not appear to be influenced by calcitonin therapy.

A quantitative study of the effects of prolonged calcitonin treatment on alveolar bone remodelling in the golden hamster

This study was carried out on adult golden hamsters, to correlate the effects of porcine calcitonin on serum Ca and P concentrations with changes in osteoclastic resorption of bone. After 1 month of treatment with 5 MRC units/kg/day, there was little effect on these parameters. On the other hand, the hormone appears to have an effect on the remodelling sequence, as indicated by a large and very significant decrease in the extent of resorption lacunae unoccupied by osteoclasts. It is suggested that the duration of the reversal phase, separating the end of active resorption from the beginning of active bone formation in each remodelling focus, is greatly decreased. This shortening is associated with a prolongation of the bone formation phase, and the extent of osteoid tissue is markedly and proportionally increased in the treated animals. After a prolonged administration, calcitonin does not seem to impede the formation of new osteoclasts, their number being only slightly diminished, but it remains possible that it does continue to inactivate these cells. The effect on the bone remodelling sequence could be either due to direct action on the osteoblasts or their percursor cells, or an indirect action via the osteoclasts.

Clinical, biochemical and histological observations on the effect of porcine calcitonin in Paget's disease of bone

The response to porcine calcitonin has been assessed in 38 patients with Paget's disease, observed during 44 treatment periods of from three to 42 months. In 36 of the treatment courses significant relief of pain was achieved but the contribution of placebo effect could not be determined. Serum alkaline phosphatase and urinary hydroxyproline levels reached normal in a few patients, but the grouped data indicated a plateau effect above the range of normal. The acute hypocalcaemic response to calcitonin was lost only in those patients whose bone turnover was restored to normal. Quantitative histology on iliac crest bone biopsy samples showed no statisically significant lowering of osteoclast counts. No antibody-based clinical resistance occurred and the incidence of side effects was low. The results indicate that porcine calcitonin is a useful treatment of Paget's disease, and the experience of the study helps in arriving at patient selection and treatment schedules. Treatment is recommended for bone pain and for active disease in the relatively young, using intermittent therapy with course of at least six months duration. Resumption of therapy is based on clinical and biochemical indications.

The scintigraphic findings in Paget's disease of bone

Bone scans and radiographic skeletal surveys have been done in 41 patients who had Paget's disease. The scintigraphic findings are consistent with what is known of the pathophysiology of Paget's disease. Diseased bone demonstrates increased vascularity, an increased degree of uptake of bone-seeking radiotracers and, in appropriate bones, evidence of marrow replacement. The bone scintiscan is a more sensitive indicator of the extent of polyostotic Paget's disease than conventional radiograph, demonstrating 34% more lesions. Because it reflects shorter term changes in osteoblastic activity the bone scan is of some value in providing immediate objective evidence of the therapeutic effectiveness of Mithramycin which has been used in this study in the treatment of the minority of patients with pain in Pagetoid bone. A technique for documenting alterations in uptake by diseased bone numerically is presented. Upon treatment with Mithramycin the ratio of abnormal uptake in relation to normal bone fell from 8.7 to 3.9.

Effect of calcitonin on carrageenan foot oedema

The effect of salmon calcitonin (SCT) on acute inflammation was tested in carrageenan induced foot oedema of the rat. A considerable inhibition of the oedema was obtained with 20 MRC U/kg of SCT. The injection of SCT is followed by decrease of calcemia. A hypothesis of possible inhibition of prostaglandin (PG) synthesis and/or release, caused by decrease of calcemia, is advanced.

Calcitonin: a general survey

Since the initial discovery of calcitonin, a considerable amount of information has been obtained concerning structure, function, secretion, and effects of the hormone from a number of species. The purpose of the present report is to review the studies of structure and function, the factors that influence secretion and synthesis, and the effects and mechanism of action of calcitonin. The clinical uses of the hormone and syndromes of calcitonin excess are discu,sed.

Treatment of Paget's disease of bone with synthetic salmon calcitonin

Thirteen patients with painful Paget's disease of bone were treated as outpatients with low doses of synthetic salmon calcitonin 22.5-50 mug three times weekly. Treatment produced full remission of pain in a mean time of 5.5 weeks and a mean depression of serum alkaline phosphatase activity of 33%.The interval before symptomatic relief could not be predicted from the variables studied. The ultimate fall in serum alkaline phosphatase activity, however, could be predicted from the initial levels and from the early rate of decrease (P < 0.001). Biochemical resistance to treatment, which occurred in three cases, could be related to the dose and duration of treatment.Prolonged remissions of pain may occur which are not related to biochemical remission, to the dose of calcitonin, or to the duration of treatment. The side effects attributable to salmon calcitonin were transient nausea (in nine patients), transient flushing (in four), diarrhoea (in two), and rash (in one) though in only one patient did treatment have to be withdrawn prematurely because of these effects.

Calcitonin resistance: clinical and immunologic studies in subjects with Paget's disease of bone treated with porcine and salmon calcitonins

15 patients with Paget's bone disease were treated with varying schedules of porcine (3.8-157.5 MRCU/kg per wk) and/or salmon (1.5-210 MRCU/kg per wk) calcitonins over periods ranging from 4 to 24 months. All of the subjects experienced a striking decrease in serum alkaline phosphatase during the first 4 months of treatment. In six patients, however, resistance to these peptides was suggested by a subsequent elevation of alkaline phosphatase activity in spite of continued and augmented hormone administration. These rebounds in alkaline phosphatase levels correlated with the appearance of calcitonin-binding substances and neutralizing material in serum. Incubations of calcitonins-(125)I and sera from these six subjects resulted in the association of radioactivity with material whose behavior on chromatoelectrophoresis (6/6), sucrose density ultracentrifugation and immunoelectrophoresis (one subject) was identical with that of 7S immunoglobulin. Specific, reversible in vitro binding of salmon calcitonins-(125)I was observed in sera obtained from these patients 5 to 12 months after initiation of salmon calcitonin therapy. All six of these subjects' sera acquired the capacity to neutralize salmon calcitonin's hypocalcemic effect in rat bioassay. Neutralization titers correlated with maximal binding capacities, which ranged from 0.042 to 6.6 mg/liter of serum. Competitive displacement of calcitonins-(125)I from the sera of one patient treated with both porcine and salmon calcitonin indicated separate populations of antibodies to these hormones. In spite of return of disease activity comparable to baseline levels, 3/5 resistant subjects treated with salmon calcitonin failed to develop hypocalcemia after injection of 300-1000 MRCU of salmon calcitonin, but two of these patients developed hypocalcemia in response to the porcine hormone. The disappearance of total radioactivity from the circulation after intravenous administration of salmon calcitonin-(125)I was retarded and the amount of serum radioactivity precipitable in 50% (NH(4))(2)SO(4) greater in 3/3 resistant patients compared to control subjects. These observations on the incidence of significant titers of neutralizing antibodies to salmon (40%) and porcine (66%) calcitonins during their chronic (> 4 months) administration to man clearly indicate that an appraisal of this possibility be included in studies involving protracted use of these hormones.

The clinical and metabolic effects of porcine calcitonin on Paget's disease of bone

The clinical and metabolic effects of porcine calcitonin were assessed in six patients with Paget's disease and two patients with osteoporosis under metabolic balance conditions. The administration of calcitonin for 4-17 wk resulted in an amelioration of the clinical phenomena associated with Paget's disease, including bone pain, increased skeletal vascularity, congestive heart failure, and neurologic deficits secondary to skeletal impingement. The major metabolic effects of calcitonin in Paget's disease included the induction of positive calcium balance of +50 to +240 mg/day, reduction in hyperphosphatasia and hydroxyprolinuria of 15 to 60%, and a deceleration of radiocalcium turnover by 12 to 46%. Natriuresis, phosphaturia, and reduced urinary calcium excretion were observed, whereas sustained hypocalcemia and hypophosphatemia did not occur. The administration of porcine calcitonin was not associated with adverse objective or subjective reactions, toxic effects, or allergic phenomena. There was no evidence of antibody formation or loss of therapeutic potency. Although the response of individual patients with Paget's disease varied widely, the data indicate that calcitonin, presumably through its skeletal anti-resorptive action, is able to reduce skeletal turnover and volume in Paget's disease, and thereby improve the associated clinical and metabolic abnormalities. Long term therapeutic studies in progress suggest that prolonged periods of control of the generalized condition may be feasible. In osteoporosis, neither clinical improvement nor consistent metabolic changes indicative of amelioration of the skeletal disease were observed.