Use of the trabecular bone score as a complementary to dual energy X ray absorciometry dxa in the follow-up to 2 years of patients with gaucher disease treated with imiglucerase

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

Quito

Congreso; 2019 PANLAR Meeting; 2019

PANLAR

Introduction:  Loss of bone mass occurs earlier and is moresevere in patients with GD and may cause pathological fractures (of long bones,vertebrae, etc.) Bone quantity is routinely measured by DXA as areal bonedensity, while bone quality includes less easily measurable features, such asbone microarchitecture, geometry and turnover. Bone microarchitecture can beassessed noninvasively by recently introduced DXA tools, namely trabecular bonescore (TBS) The TBS is stronglycorrelated with trabecular number and connectivity. The aim of this study wasto evaluate the bone mineral density and the use of TBS as a complementaryapproach to DXA in GD patients treated with imiglucerase. We conducted aobservational and descriptive study in 148 GD adults patients receiving enzymereplacement therapy (imiglucerase, mean dose 52±14 U/kg [range: 11-90]) with afollow-up of 2 years. The lumbar spine BMD was measured by DXA (Lunar Prodigy)and the TBS was performed by the software TBS iNsight (Medimaps). Thedistribution of the data was evaluated with the Shapiro-Wilk test andparametric or non-parametric tests were used as appropriate. Data are expressedas mean±SD and differences were considered significant if p<0.05. Results: 148 adultsGD patients, mean age: 36±13 years, were included: 85 women (57.6%) and 63 men(42.6%) of which 98% had splenomegaly, 49.2% hepatomegaly and 7.9% weresplenectomized. The age at diagnosis was 198±169 months (range 8-702) and themean age of initiation of treatment was 286±172 months (range 25-835). BMD wasnormal in 80% and 20% showed osteopenia/OP. A significant increase in thelumbar spine BMD was found throughout the follow-up at the 1st year oftreatment (percentage of change: +1.15) without additional increase in the 2ndyear of follow-up. A positive correlation was found between BMD and TBS(Spearman, r=0.19, p=0.033). Consistent with BMD, there was a significantincrease in TBS (+1.3%, p=0.0167) only in the 1st year of treatment withimiglucerase. Moreover, this percentage of change was found to be even higherif only those patients with previous TBS alteration were considered (1st year:3.2%, p=0.0004). Patients with OP (1287±130) presented lower values of TBS thanthe group without OP (1390±103) (Mann Whitney test, p=0.0001). 38.5% ofpatients without OP and 67.7% of those with OP showed altered bone qualityassessed by TBS (Fisher test, p=0.0064). However, no differences in TBS wasfound according to the presence of vertebral vertebral fracture (with VF:1336±120, without VF: 1367±114, Mann Whitney test p=0.27). Conclusion: Thedensitometry allowed us to evaluate the gain in the bone mass in the patientswith treatment and the TBS could detect patients with alteration of the bonequality.