Usefulness of Biochemical Markers of Bone Turnover in the Evaluation of Venezuelan Patients with Multiple Myeloma
Authors: Ionescu Eugenio , Martinez Edmundo , Cardenas Leonor , Zoghbi Dalal 
Published: October 2019

Abstract
Abstract 5003
Multiple Myeloma is a neoplastic disease of B-lymphocyte that invariably mature into plasma cells, synthesizing abnormal amounts of immunoglobulin or their fragments. Bone destruction is a relevant clinical finding and is responsible for the major signs of the disease. Since the osteolytic lesions of Multiple Myeloma do not heal rapidly, imaging studies and changes in the levels of monoclonal proteins cannot reflect the progress or regression of the bone disease during the anti-myeloma treatment. The purpose of this study is to establish the Profile of Biochemical Markers of Bone Turnover present in Venezuelan patients with Multiple Myeloma. The study was carried out in patients diagnosed with Multiple Myeloma that attended, during the year 2009, the Hematology Service of the “Dr. Miguel Pérez Carreño” General Hospital in Caracas, Venezuela.

Methods:
A descriptive, transversal, unicentric study was carried out in a single auto-comparable group. Urinary NTx osteoclastic activity biomarkers (Reticulated Collagen-type I N-telopeptides) and serum CTx (C-terminal telopeptide of type I collagen) were processed, as well as the osteoblastic activity biomarkers osteocalcin and bone specific alkaline phosphatase.

Results:
A total of 34 patients were included: 68% males and 32% females. By the International Staging System (ISS) 45% were stage I; 23 % stage II, 32% stage III. The average value of osteocalcine was the following: 15. 1 ± 9. 5 in stage I; 20. 9 ± 14. 5 in stage II and 25. 2 ± 23. 3 in stage III. The average value of bone specific alkaline-phosphatase was: 19. 1 ± 7. 7 in stage I; 20. 9 ± 8. 4 in stage II and 18. 4 ± 5 in stage III. The average value of CTx was: 2 ± 0. 6 in stage I; 2. 5 ± 0. 7 in stage II and 3. 3 ± 2. 5 in stage III. The average value of urinary NTx was: 48. 3 ± 21. 7 in stage I; 56 ± 22. 9 in stage II and 58. 7 ± 19. 2 in stage III.

Discussion:
It can be seen that the average value of serum CTx was elevated in all the states of the disease, regardless of the classification used to study the patients. It was also found that this value increases as the disease becomes more severe; that is to say, the more advanced the stage of the patient's disease. This is more significant when using the ISS to study the patients. The value of the urinary NTx osteoclastic activity was never high or outside its reference range. The osteoblastic activity markers osteocalcin and bone specific alkaline-phosphatase never appeared outside their average reference value.

Conclusion:
Serum CTX osteoclastic activity biomarker is useful to establish the severity of the bone disease in patients with Multiple Myeloma. The urinary NTX osteoclastic activity biomarker and the osteoblastic activity markers osteocalcin and bone specific alkaline-phosphatase do not appear to be useful to establish the severity of the bone disease in patients with Multiple Myeloma.

Disclosures:
No relevant conflicts of interest to declare.