URINARY HYDROXYPROLINE IN MULTIPLE-MYELOMA - CORRELATION WITH CLINICAL STAGES AND BONE-DISEASE

Twenty-four-hour urinary hydroxyproline excretion (HOP) (normal values: 6-22 mg/day per m2) was measured by the Hypronosticon test in 50 untreated patients with plasma cell myeloma. At diagnosis, HOP was elevated in 36 of 50 patients (72%) with a mean value of 35.9 mg/day per m2. Extent of bone lesions and clinical stage were accurately assessed in all patients. Higher HOP values were found in patients with a higher degree of bone lesions (multiple lytic areas and/or destruction of skeletal segments). According to clinical stages, HOP was very elevated only in stage III (mean: 43.7); in stages I and II the mean value (25.2) was just above the normal range. HOP in multiple myeloma at diagnosis is closely related to the extension of skeletal lesions and during the clinical course it may be useful in the follow-up of bone disease.