Clinical evaluation of myeloma osteoclastic bone lesions: II. Induced hypocalcemia test using salmon calcitonin.

Acute effects of salmon calcitonin (SCT) were tested by an SCT induced hypocalcemia test (SCT delta Ca test) in 70 cases of multiple myeloma (MM) (including 52 untreated patients) with bone involvement. Response to SCT in terms of maximum induced hypocalcemia (M delta Ca) was compared to normal controls (NC) and correlated with the main presenting features and clinical status. Acute effects are significantly more marked in MM than in NC (p less than .001). There is a good correlation with the extent of lytic bone lesions (p less than .01), the presence of hypercalcemia (p less than .02) and the myeloma cell mass (p less than .05). After correction for bone involvement response to SCT (M delta Ca) was stronger in IgA lambda MM than in IgG kappa (p less than .01). It is of particular interest that acute effects are significantly more marked in cases of active disease than in non-active disease. We conclude that the SCT delta Ca test might be of practical value in the management of MM.