Bone Health Assessment in Patients Undergoing Hematopoietic Cell Transplantation

INTRODUCTION: The increased survival of hematological patients has required to widen the care of these patients, with emphasis in factors related to quality of life and late mortality. Among them, osteoporosis (OP) is a fundamental problem. Patients undergoing hematopoietic cell transplantation (HCT) are at great risk of OP, mainly due to prolonged exposure to chemotherapy, immunosuppresants and the hypogonadism frequently associated to these treatments. Despite this, there is lack of strong evidence on this matter and HCT guidelines are not clear on this problem.

OBJECTIVES: To evaluate parameters related to bone health in patients undergoing HCT. To measure the frequency and severity of the alterations in this group of patients.

PATIENTS AND METHODS:  Observational and retrospective analysis of patients undergoing HCT at the Catholic University Hematology-Oncology Department. All patients undergoing HCT were recommended to have determination of 25-OH vitamin D, PTHi, Calcium, Phosphorus and bone densitometry (DXA). We included all patients with the evaluation before HCT (preHCT) and 1 year after HCT (postHCT). Statistical analysis was performed by SPSS v.21 software.

RESULTS: We obtained data from 20 patients preHCT and 22 patients postHCT. Main diagnosis were acute myeloid leukemia (n=13; 32%), multiple myeloma (n=11; 26%), acute lymphoblastic leukemia (n=9; 21%) and Hodgkin's Lymphoma (n=5; 12%). Mean age was 40 years (range: 17-67) and 67% were males. In the preHCT group, the median 25-OH vitamin D levels were 13,6 ng/ml (range: 4,9-26,7 ng/ml) and 100% of the patients were in the insuficiency range leveles (<30 ng/ml). Median PTHi levels were 62,6 pg/ml (range: 24,4-223,7 pg/ml), and 46% of the patients had secondary hyperparathyroidism. In the postHCT group, median 25-OH vitamina D levels were 11,4 ng/ml (range: 4-29,4 ng/ml) and 100% had insuficiency levels. Median PTHi levels were 68 pg/ml (range: 37,4-135,8 pg/ml), and 56% of the patients had secondary hyperparathyroidism. 12 patients had DXA before HCT and 3 (25%) of them had DXA lumbar Z score less than -2.0. In 19 patients postHCT, 4 (21%) had decreased DXA Z score < 2.0. No difference could be established between autologus or allogeneic HCT in any meassurement. Only the presence of chronic graft vs host disease (GVHD) was associated with higher PTH levels by ANOVA test. None of the other variables were aasociated with acute or chronic GVHD.

CONCLUSIONS: HCT patients represent a high risk group of developing severe vitamin D deficiency, secondary hyperparathyrodism and decreased DXA levels. These data are a warning that this population of patients requiere early intervention to prevent long term complications. This report is the initial evaluation for the development and treatment of bone health in a prospective matter in HCT patients in our center.