MONITORING OF MULTIPLE-MYELOMA PATIENTS BY SIMULTANEOUSLY MEASURING MARKER SUBSTANCES OF BONE-RESORPTION AND FORMATION

Fifteen patients (13 males and two females; mean age, 63 years; age ra nge, 46-84 years) with multiple myeloma were studied prospectively (ra nge of follow-up period, 2-6 months) to elucidate the diagnostic valid ity of biochemical markers of bone formation (bone alkaline phosphatas e and the C-terminal propeptide of type I procollagen) and bone resorp tion (urinary excretion of pyridinium cross-links) for monitoring thes e patients. Eleven of 15 patients received melphalan i.v. and predniso ne p.o. every 4 weeks. All patients were given pamidronate i.v. for in hibition of bone resorption. The mean values of the urinary excretion of pyridinium cross-links were significantly higher in the patients fu lfilling the criteria of 'progression' or 'relapse' than in those show ing 'response' and those in the 'plateau phase' (P<0.05). In contrast, neither bone alkaline phosphatase nor C-terminal propeptide serum val ues differed significantly between these two groups (P > 0.05). The co ncentrations of both bone formation markers were significantly lower i n the patients than in the samples obtained from apparently healthy pe rsons (P < 0.001). There was a significant inverse correlation between the number of pamidronate courses and the serum concentrations of bon e alkaline phosphatase (P<0.05). A lack of correlation was observed be tween the urinary excretion of pyridinium cross-links and all other la boratory parameters measured (serum concentrations of total protein, c alcium, creatinine and (beta(2)-microglobulin). In conclusion, the uri nary excretion of pyridinium cross-links might be a useful parameter f or monitoring multiple myeloma patients. Decreased values of bone form ation markers may be due to a suppressive effect of the bisphosphonate agents administered or reflect the severity of osteolytic lesions whi ch have been described as being associated with unbalanced bone remode lling. (C) 1998 Elsevier Science B.V.