Comparison of the effects of intravenous pamidronate and oral clodronate on symptoms and bone resorption in patients with metastatic bone disease

BACKGROUND

There is considerable debate as to the optimum schedule of bisphosphonate treatment in advanced malignancy. Short term studies using symptomatic response and biochemical markers of bone resorption may provide useful insight into differences between agents.

PATIENTS AND METHODS

Fifty-one patients with metastatic bone disease were randomly allocated to either oral clodronate 1,600 mg daily (group 1), intravenous clodronate followed by the same schedule of oral clodronate (group 2). or intravenous pamidronate 90 mg monthly (group 3). No radiotherapy was delivered or other systemic anticancer treatments were allowed except for long term endocrine therapy. Bone resorption was assessed by measurement of urinary collagen crosslinks. At each visit a pain score was recorded.

RESULTS

Symptomatic response was more frequent in the pamidronate group than in patients receiving clodronate. Nine of sixteen patients experienced a sustained improvement in pain score in the pamidronate-treated group, in contrast to only 4 of 16 and 2 of 11 patients in groups 1 and 2, respectively. There was a significant improvement in pain scores in the pamidronate arm compared with the clodronate treated patients after both three months of treatment (P <0.01) and at the last measurement (P <0.05). Biochemical changes correlated with changes in the pain score (P = 0.01).

CONCLUSION

Intravenous pamidronate appears to be more effective than oral clodronate in both controlling symptoms and suppressing bone resorption.

Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides

The Serum CrossLaps One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a beta-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen alpha1-chain. Our objective was to assess the clinical value of the Serum CrossLaps assay for monitoring antiresorptive therapy in osteoporosis treatment. Samples obtained from postmenopausal women treated with different doses of cyclic or continuous hormone replacement therapy (HRT) with an estrogen analog (tibolone) or with a bisphosphonate (ibandronate) were measured in the Serum CrossLaps One Step ELISA at baseline and at various time points during therapy. The corresponding urine samples were measured in the urine CrossLaps ELISA and corrected for creatinine excretion. The serum CrossLaps measurements and corresponding urinary CrossLaps measurements were highly correlated (r >0.8 for all studies). The serum and urine CrossLaps measurements showed a significant decrease among the women treated with clinically relevant doses of either of the antiresorptive agents. Furthermore, the annual percentage change in bone mineral density (BMD) correlated with the measured changes in CrossLaps concentration. The serum CrossLaps assay showed a specificity of 83-100% and a sensitivity of 59-83% for assessing BMD changes. The corresponding values for the creatinine-corrected urinary measurements were 83-92% specificity and 68-79% sensitivity. We conclude that performance of the convenient Serum CrossLaps One Step ELISA is at least equivalent to that of the urine text for follow up of antiresorptive treatment in osteoporosis. Further studies are needed to optimize its use in this and other clinical applications.

Identification of important allergenic proteins in extracts of the granary weevil (Sitophilus granarius)

This paper describes the identification of important allergens from the granary weevil (Sitophilus granarius) (Sg). Sera from Danish bakers whose skin prick tests were positive to extracts of Sg were screened for IgE against Sg extracts. We found that 54% (n = 66) had elevated levels of IgE (RAST classes 1-3, by luminescent immunoassay) against whole-body extracts of Sg. The specificity of patient IgE was investigated in an inhibition-dot immunoblotting assay. IgE binding was inhibited in all sera but two, thus indicating that the patients' IgE was indeed specific for the Sg extract. In crossed immunoelectrophoresis, 23 different proteins were identified. All RAST-positive sera were investigated in crossed radioimmuno-electrophoresis. At least 11 proteins in the Sg extract were capable of binding IgE. All individual sera reacted with at least four different proteins. The two most prominent allergens bound IgE from 88% and 100%, respectively, of the patients. These two are considered to be the most important allergens from Sg, and will be useful as markers in environmental immunochemical assays to detect allergens in samples from bakeries, grain stores, etc.

[Biological availability of glycerol trinitrate after sublingual administration]

The relative bioavailability of a glyceryl trinitrate (GTN) spray (Nitro-Corangin Spray) compared to that of another GTN Spray was evaluated in 12 healthy male volunteers using an open, randomized cross-over design with two treatment phases. The parameters Cmax, tmax and AUC0-1 showed no statistically significant differences between the two treatments. It is concluded that the two GTN-Sprays may be considered bioequivalent.