Bone Abstracts

Low bone mass is common in thalassemia (Thal) and sickle cell disease (SCD). Bone pain is also reported, though its relationship to low bone mass has not been explored. The aims of this study were to determine the prevalence of vertebral height abnormalities (VHA) and evaluate the relationship between VHA, low bone mass and patient assessed pain in Thal and SCD. Data were collected from the Thalassemia Clinical Research Network Pain Survey study and CHRCO Clinical Bone Density database. The Pain study used a validated pain survey to collect data on patients from CHRCO at multiple time points. This was then analyzed with clinical bone mineral density (aBMD) scans if ±6 months. Full lateral spine scans conducted at the time of aBMD scan were re-analyzed by one observer using the Vertebral Fracture Analysis (VFA) Software (Hologic v12.6.1), and scored according to Genant for VHA (Grades 1 to 3). 232 VFA scans were re-analyzed from 91 patients with Thal (21.5±10.7 years, 55% F) and 46 SCD (38.1±12.7 years, 61% F). Of the patients with Thal who had VFA scans, 26.9% had at least one VHA, compared to 34.8% of those with SCD (P=NS). A similar percentage of Thal patients had substantial VHA deficits (Grade 2 or 3; 15.1%) compared to SCD (13.3%). The average number of vertebrae with abnormalities within a patient was lower in Thal (1.6±0.2) compared to SCD (2.8±0.4; P=0.003). Thal had wedge-type whereas SCD had biconcavity-type deformed vertebrae. The presence of a VHA was related to age in Thal (P=0.029) with a trend towards a relationship to low bone mass (P=0.12). In the patients for which both VFA scans and pain studies were performed (n=32), bodily pain was not related to VHA. A high percentage of both SCD and Thal patients had significant VHA. The etiology of the abnormal morphology is unclear but appears to be more developmental in SCD, but apparently a consequence of inherent bone fragility in Thal. Further research should focus on the clinical relevance of VHA and possible temporal relationship to bone pain in these at risk patient populations.