[Effect of clodronate in patients with multiple myeloma. Evaluation of specific markers of bone resorption]. / Ucinek klodronátu u pacientu s mnohocetným myelomem. Hodnocení specifickými markery osteoresorpce.

ABSTRACT

BACKGROUND: In adjuvant therapy of patients with multiple myeloma among others anti-absorption properties of bisphosphonates are used. The objective of the present investigation was to evaluate the effect of long-term oral treatment route clodronate on the bone metabolism in this condition. As markers of bone reabsorption, assessment of pyridinoline and deoxypyridinoline in urine was used. METHODS AND RESULTS: We investigated in an open clinical trial 22 patients with multiple myeloma with bone changes confirmed on X-ray who had a normal calcium and creatinine serum concentration the control group (A) comprised 13 patients (mean age 59 years, range 38-74 years), the experimental group (B) 9 patients (mean age 54 years, range 42-60 years). The patients in both groups were treated by chemotherapy, to group B concurrently clodronate 3 x 800 mg was administered by the oral route. No statistically significant differences were found between the two groups during the mean follow up period after assessment of the diagnosis (27 vs. 40 months) nor in the clinical stage of the disease. After intervals of 0, 3 and 12 months the excretion of pyridinoline and deoxypyridinoline in urine was assessed by liquid chromatography. At the same time also other parameters of osteoresorption were assessed (urinary calcium and hydroxyproline excretion). At the onset of the investigation the pyridinoline and deoxypyridinoline excretion in groups A and B did not differ statistically (pyr; 120.63 +/- 23.76 vs. 136.23 +/- 22.13 mumol/mmol creatinine. d-pyr 19.61 +/- 3.65 vs. 22.76 +/- 5.40 mumol/mmol creatinine). After three months in group B a statistically significant drop of excretion of both metabolites was recorded (pyr. to 84.11 +/- 38.67 mumol/mmol creatinine, d-pyr. to 15.23 +/- 6.10 mumol/mmol creatinine). Their significantly reduced excretion persisted also after one year (pyr. 85.52 +/- 60.96 mumol/mmol creatinine, d-pyr. 12.6 +/- 6.56 mumol/mmol creatinine). CONCLUSIONS: Using specific markers, pyridinoline and deoxypyridinoline, the authors proved the favourable effect of long-term administration of clodronate on the bone metabolism in patients with multiple myeloma.