Clinical utility of a wheat-germ precipitation assay for determination of bone alkaline phosphatase concentrations in patients with different metabolic bone diseases

Bone alkaline phosphatase was evaluated by wheat-germ lectin precipitation in several clinical conditions. The study included 33 premenopausal healthy women, 46 postmenopausal apparently healthy women, 19 growing children, 24 patients with Paget's disease, 31 patients with primary hyperparathyroidism and 66 patients with hepatobiliary diseases. In postmenopausal women the mean T score (i.e.: the number of SD below or above the mean for premenopausal women) was 2.6 +/- 1.3 (SD) for bone alkaline phosphatase and 1.61 +/- 1.21 for total alkaline phosphatase (p < 0.001). The T score for bone alkaline phosphatase provided a better discrimination from normals for both Paget's disease (22.1 +/- 27.8 versus 12.8 +/- 16 p < 0.001) and primary hyperparathyroidism (8.2 +/- 4.3 versus 4.6 +/- 3.7 p < 0.005 for bone alkaline phosphatase and total alkaline phosphatase respectively). After treatment with intravenous bisphosphonate the percent decrease of bone alkaline phosphatase was larger than that of total alkaline phosphatase both in patients with Paget's disease (-46% versus -72% p < 0.01) and in patients with primary hyperparathyroidism (-21% versus -47% p < 0.02) and an estimate of the precision (delta mean/SD of the delta mean) for bone alkaline phosphatase was 1.9-3.7 times higher than that of total alkaline phosphatase. In twelve osteoporotic patients treated for six months with oral alendronate the decrease in bone turnover was detected with significantly higher precision with bone alkaline phosphatase than with total alkaline phosphatase (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term effects of a treatment course with oral alendronate of postmenopausal osteoporosis

Several bisphosphonates are under investigation for the treatment and prevention of postmenopausal osteoporosis. Alendronate, one of these compounds, has been shown to inhibit bone turnover and induce substantial increases in bone mass, but little is known about the duration of its effects. This is considered important, keeping in mind the long half-life of bisphosphonate in bone. In this double-blind controlled study, two groups of 15 postmenopausal women with spinal bone mineral density (BMD) > 2 SD below adult mean peak without vertebral fractures were randomized to receive either alendronate, 20 mg/day, or placebo for 6 months. The treatment course with alendronate significantly suppressed all indices of bone turnover (hydroxyproline, collagen crosslinks, and alkaline phosphatase activity) within 3 months, and a further slight decrease was observed in the subsequent 3 months. After treatment withdrawal, all indices of bone turnover slowly increased, and they attained the pretreatment values within 6-9 months. Lumbar spine BMD rose by 3.7% (+/- 1.7 SD) after 6 months of alendronate therapy but did not change 6 and 12 months after treatment withdrawal (4.6 +/- 2.8 and 4.7 +/- 2.6% versus baseline, respectively). In control patients a slow decrease in lumbar spine BMD was observed, but this was significant only at month 18 of the study. Femoral BMD did not significantly change in the alendronate group, but it slowly decreased in the control group at all sites of evaluation. The fractional loss became statistically significant versus both baseline and the active group by the end of the study only at the level of the femoral neck.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of bisphosphonate therapy and parathyroidectomy on the urinary excretion of galactosylhydroxylysine in primary hyperparathyroidism

BACKGROUND

In patients with mild or asymptomatic primary hyperparathyroidism a reliable index of bone resorption might be useful for appropriate management. Hydroxyproline is the most commonly used marker of bone resorption but its low specificity and sensitivity are known. Galactosylhydroxylysine, an amino acid mainly represented in bone collagen, has been proposed as a more suitable index of bone resorption. In this study we evaluated the sensitivity of galactosylhydroxylysine and hydroxyproline assays in following the changes of their urinary levels in 12 patients with mild primary hyperparathyroidism before and after treatment with bisphosphonate and surgery.

METHODS

Serum and fasting urine specimens were obtained from 12 women with mild primary hyperparathyroidism before and after bisphosphonate treatment (2.5 mg daily for 5 days, intravenously) and after a further 25 days; in 7 patients biochemical tests were also performed 1 and 6 days after parathyroidectomy. Galactosylhydroxylysine was assayed by an HPLC method and hydroxyproline by a RIA commercial kit.

RESULTS

Baseline galactosylhydroxylysine urinary levels were far above the normal range in all the patients whilst in 8 of them baseline hydroxyproline levels were normal. Bisphosphonate treatment significantly decreased bone turnover as shown by a significant fall in serum calcium (from 2.9 to 2.6 mmol/l; P < 0.001) and in galactosylhydroxylysine and hydroxyproline (-55 and -31% respectively). Twenty-five days after the end of treatment, resorption increased again and serum calcium and galactosylhydroxylysine, but not hydroxyproline, rose significantly towards basal levels. One day after parathyroidectomy serum calcium, galactosylhydroxylysine and PTH showed reduction below normal ranges. PTH and galactosylhydroxylysine returned to normal values at day 6 after parathyroidectomy. No changes in hydroxyproline levels were seen. Galactosylhydroxylysine, but not hydroxyproline, correlated significantly with serum calcium and PTH.

CONCLUSION

Galactosylhydroxylysine appears to be a sensitive index of bone resorption, useful in the clinical assessment of bone involvement and in the management of patients with mild primary hyperparathyroidism.

[Therapeutic strategies in osteoporosis: whom and when to treat]

Postmenopausal bone loss can be efficiently prevented by compounds which inhibit bone resorption, but they can not induce a sustained and relevant bone gain. The initial increase in bone volume observed within the first year of treatment is due to a transient uncoupling between bone resorption and formation: the first is suddenly blocked whereas bone formation decreases slowly within several months; bone is gained until the previously resorbed cavities are refilled. This net increase in bone mass is completely lost as soon as treatment is withdrawn. Since these antiresorptive agents can only be used in order to prevent bone loss, they should be given for several years. Thus, the choice of the drug is also conditioned by its cost and long-term compliance. Estrogen replacement is very convenient, from these points of view in most patients immediately after the menopause. Afterwards, parenteral calcitonin has been, up to now, the sole available alternative with convincing evidence of effectiveness, at least in the medium term. Its cost and the scarce compliance to injections have strongly limited its extensive use. There is increasing evidence that oral bisphosphonates are very effective and therefore they might represent, in the near future, an effective and convenient alternative to estrogen replacement therapy.

Effects of the acute subcutaneous administration of synthetic salmon calcitonin in tumoral calcinosis

We examined the effects of the acute administration of salmon calcitonin on phosphate metabolism in tumoral calcinosis. On two different days, 200 MRC U of the synthetic hormone were administered sc to a 38-year-old patient, either as twice daily 100 MRC U injections, or as a continuous sc infusion via a portable pump. Both ways of calcitonin administration elicited a phosphaturic effect and a lowering of serum phosphate level comparable with that observed after an iv infusion of calcitonin. 1,25 dihydroxyvitamin D level, which was in the normal range during a control study, increased after calcitonin administration. In our patient, long term therapy with diet, a phosphate-binding agent and calcitonin prevented the occurrence of new ectopic calcifications. Owing to its phosphaturic activity, synthetic salmon calcitonin may be a useful adjunct to diet and aluminium-containing antacids in long-term management of tumoral calcinosis.

Intramuscular administration of salmon calcitonin impairs delayed cutaneous hypersensitivity

The delayed cutaneous hypersensitivity to seven ubiquitous antigens (Multitest CMI, Istitute Mĕrieux) was evaluated in normal healthy volunteers before and at the time of intramuscular administration of 50 (12 subjects) or 50 + 50 (nine subjects) units of salmon calcitonin or 2 ml of saline (eight subjects). The delayed cutaneous hypersensitivity, in terms of number of positive tests or sum of positive tests, significantly fell in both groups given salmon calcitonin, but no changes were observed in the control group. These results indicate that salmon calcitonin, as well as inhibiting osteoclastic bone resorption, has important immunological effects.

Extrarenal synthesis of 1,25-dihydroxyvitamin D: sensitivity to glucocorticoid treatment

The response of circulating 1,25-dihydroxyvitamin D [1,25-(OH)2D] to challenge with vitamin D treatment both before and after 7-10 days of prednisone therapy (25 mg/day) was investigated in five anephric subjects, six patients with chronic renal failure (CRF), two patients with vitamin D intoxication and four patients with hypoparathyroidism. In anephric subjects serum 25-hydroxyvitamin D [25-(OH)D] rose from 58 +/- 48 (SD) to 377 +/- 221 (SD) nmol/l after administration of 150 micrograms of 25-(OH)D3 for 1 month. Serum 1,25-(OH)2D, which was barely detectable in only two out of five patients under basal conditions, rose to 30 +/- 21 pmol/l after 2 weeks of therapy with 25-(OH)D3, but fell to 10 +/- 5 pmol/l during prednisone treatment. In CRF patients circulating 1,25-(OH)2D rose from 37 +/- 24 to 58 +/- 24 pmol/l during 25-(OH)D3 therapy, but fell to 41 +/- 31 pmol/l during prednisone treatment. In two patients with rheumatoid arthritis, hypercalcaemia due to vitamin D intoxication was associated with raised levels of 1,25-(OH)2D (288 and 317 pmol/l). Administration of prednisone resulted in suppression of 1,25-(OH)2D levels (132 and 96 pmol/l respectively) and reduction of serum calcium to within the normal range. In the hypoparathyroid patients prednisone therapy did not affect circulating 25-(OH)D levels but serum 1,25-(OH)2D fell from 192 +/- 42 to 117 +/- 23 pmol/l and serum calcium from 2.41 +/- 0.21 to 2.20 +/- 0.05 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)

[The action of the vaccinia virus upon placenta and fetus in revaccinated pregnants (author's transl)]

We studied 608 antivariolic revaccinated pregnants in spring 1972 at different ages of gestation. 60 presented spontaneous abortus; in 502 cases there has been performed therapeutical abortion, and 46 pregnants revaccinated after 2 1/2-3 months of gestation continued their pregnancy. Pregnancy and birth in revaccinated pregnants which did not abort, evolved without any difference against the witness-sample; the newborns presented in a higher percentage underweight. The absence of the vaccinia-virus and of Guarnieri-inclusions in the examined placentae and embryos as well as the moment of abortion, only after 20 days from the revaccination data, leads to the supposition that the placental lesions do not seem to be produced by the direct action of the virus by its replication, but probably by reactions of hypersensibility of the late type against the alergizin antigens of the antismallpox vaccine. The antivariolic revaccination of the sample of pregnants, showed that the vaccinia virus did not present a malformative action upon the embryo, but in change the abortive action was manifest in indirect proportion to the age of gestation.