Evaluation of bone microarchitecture by trabecular bone score in patients with Gaucher disease

LARROUDE MS; AGUILAR G; ROSSI I; BRUN LR; DRELICHMAN G

Buenos Aires

Congreso; 20th PANLAR Meeting; 2018

PANLAR

Introduction: Gaucher disease is a secondary cause of osteoporosis (OP) vertebralfracture (VF) have been described. The measurement of bone mineral density(BMD) by dual-energy x-ray absorptiometry (DXA) is the "goldstandard" diagnostic study of OP. BMD is one of the major determinants ofbone strength and therefore the presence of OP is associated with increasedrisk to develop fractures. However some pathological fractures occur inpresence of osteopenia. The trabecular bone score (TBS) is a bone textureanalysis where a score is obtained with the acquisition of lumbar spine DXA. Itis also associated with increased risk to develop fractures. The TBS isstrongly correlated with trabecular number and connectivity and negatively withthe space between the trabeculae.  Theaim of this study was to evaluate the use of trabecular bone score (TBS) as acomplementary approach to dual-energy x-ray absorptiometry (DXA) in EG patientstreated with imiglucerase. We conducted a observational and descriptive studyin 148 GD adults patients receiving enzyme replacement therapy (imiglucerase,mean dose 52±14 U/kg [range: 11-90]) with a follow-up of 2 years. The lumbarspine BMD was measured by DXA (Lunar Prodigy) and the TBS was performed in asubgroup (n=54) of patients by TBS iNsight (Medimaps). Data are expressed asmean±SD and differences were considered significant if p<0.05. Results: 85women (57.6%) and 63 men (42.6%) were included, mean age 36±13 years (98% hadsplenomegaly, 49.2% hepatomegaly and 7.9% were splenectomized).The age at diagnosis was 198±169 months (range 8-702) and the mean age ofinitiation of treatment was 286±172 months (range 25-835). BMD was normal in80% and 20% showed osteopenia/OP. A significant increase in the lumbar spineBMD was found throughout the follow-up at the 1st year of treatment (percentageof change: +1.15) without differences in the 2nd year. A positive correlationwas found between BMD and TBS (Spearman, r=0.46, p= 0.0005). Patients with OP(1264±124) presented lower values of TBS than the group without OP (1376±101)(Mann Whitney test, p=0.002). 47% of patients without OP and 72% of those withOP showed altered bone quality assessed by TBS. In the whole group there was asignificant increase in TBS of 2.15% in the 1st year of treatment with imiglucerase(Wilcoxon signed rank test, p=0.02) and 1.57% after two years of treatment(p=0.04). This percentage of change was found to be even higher if only thosepatients with previous TBS alteration were considered (1st year: 3.7% and 2ndyear 3.4%). A tendency of lower TBS values in patients with Vertebral fracturewas found (with VF: 1292±99, without VF: 1349±132; Mann Whitney test p=0.20). Conclusion:The densitometry allowed us toevaluate the gain in the bone mass in the patients with treatment and the TBScould detect patients with alteration of the bone quality