Authors:	Lollert, André Stihl, Clemens Hötker, Andreas Mengel, Eugen König, Jochem Laudemann, Katharina Gökce, Seyfullah Düber, Christoph Staatz, Gundula
Title:	Quantification of intramuscular fat in patients with late-onset Pompe disease by conventional magnetic resonance imaging for the long-term follow-up of enzyme replacement therapy
Online publication date:	11-Jan-2018
Year of first publication:	2018
Language:	english
Abstract:	OBJECTIVE: The objective of this study was to evaluate a quantitative method based on conventional T1-weighted magnetic resonance (MR) imaging to assess fatty muscular degeneration in patients with late-onset Pompe disease and to compare it with semi-quantitative visual evaluation (the Mercuri score). In addition, a long-term retrospective data analysis was performed to evaluate treatment response to enzyme replacement therapy with alglucosidase alfa. METHODS: MR images of the lumbar spine were acquired in 41 patients diagnosed with late-onset Pompe disease from 2006 through 2015. Two independent readers retrospectively evaluated fatty degeneration of the psoas and paraspinal muscles by applying the Mercuri score. Quantitative semi-automated muscle and fat tissue separation was performed, and inter-observer agreement and correlations with clinical parameters were assessed. Follow-up examinations were performed in 13 patients treated with alglucosidase alfa after a median of 39 months; in 7/13 patients, an additional follow-up examination was completed after a median of 63 months. RESULTS: Inter-observer agreement was high. Measurements derived from the quantitative method correlated well with Medical Research Council scores of muscle strength, with moderate correlations found for the 6-minute walk test, the 4-step stair climb test, and spirometry in the supine position. A significant increase in the MR-derived fat fraction of the psoas muscle was found between baseline and follow-up 1 (P = 0.016), as was a significant decrease in the performance on the 6-minute walk test (P = 0.006) and 4-step stair climb test (P = 0.034), as well as plasma creatine kinase (P = 0.016). No statistically significant difference in clinical or MR-derived parameters was found between follow-up 1 and follow-up 2. CONCLUSIONS: Quantification of fatty muscle degeneration using the semi-automated method can provide a more detailed overview of disease progression than semi-quantitative Mercuri scoring. MR-derived data correlated with clinical symptoms and patient exercise capacity. After an initial worsening, the fat fraction of the psoas muscle and performance on the 6-minute walk test stayed constant during long-term follow-up under enzyme replacement therapy.
DDC:	610 Medizin 610 Medical sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 04 Medizin
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-490
URN:	urn:nbn:de:hebis:77-publ-577604
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	PLoS one 13 1
Pages or article number:	e0190784
Publisher:	PLoS
Publisher place:	Lawrence, Kan.
Issue date:	2018
ISSN:	1932-6203
Publisher URL:	http://dx.doi.org/10.1371/journal.pone.0190784
Publisher DOI:	10.1371/journal.pone.0190784
Appears in collections:	JGU-Publikationen