Clinical trial NCT02108392: Characterization of Pseudoxanthoma Elasticum
Official title: Characterization of Patients With Pseudoxanthoma Elasticum
Study type: OBSERVATIONAL
Overall status: UNKNOWN
Conditions: Pseudoxanthoma Elasticum
Keywords: PXE
phenotype
eye
biomarkers
Lead sponsor: University Hospital, Bonn
Sponsor class: OTHER
First posted: 2014-04-09
Enrollment: 100
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: OTHER
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Pseudoxanthoma elasticum

Brief summary: Pseudoxanthoma elasticum (PXE) is a rare multisystem disorder of autosomal recessive inheritance (OMIM# 264800) and an estimated prevalence between 1:25.000 and 1:100.000. PXE is characterized by calcification and fragmentation of connective tissue rich in elastic fibers. Due to its high content of elastic fibers, Bruch Membrane in eyes of patients affected by PXE becomes thickened and calcified. The ocular phenotype is characterized by angioid streaks and peau d'orange but also choroidal neovascularizations and chorioretinal atrophy thereby in part mimicking the phenotype of age-related macular degeneration. The disease is due to mutations of the ABCC6-gene coding for a transmembrane protein which is mainly expressed in the liver and kidney. It is hypothesized that ABCC6 is involved in the excretion of a yet unknown factor from the liver which inhibits systemic calcification. In animal models several candidates for this factor have been identified but direct evidence for such a factor in patients with PXE is still missing. The primary purpose of this study is to further investigate the ocular phenotype of patients with PXE using multimodal imaging and functional testing to delineate the impact of Bruch membrane pathology on the eye. Furthermore, possible systemic anti-calcification factors, as well as associations with the vascular alterations are investigated to gain more insights into the pathogenesis of PXE..


Eligibility criteria: Inclusion Criteria:

* Diagnosis of Pseudoxanthoma elastcium based on histopathologic and/or genetic testing

Primary outcomes:
measure: Ocular phenotype
timeFrame: patients will be followed longitudinally with an expected 1-year average interval between visits
Secondary outcomes:
measure: Biomarkers in PXE
timeFrame: 1 day (first visit)
Other outcomes:
Locations:
city: Bonn
country: Germany
facility: Department of Ophthalmology, University of Bonn
state: NRW
Study officials:
affiliation: Department of Ophthalmology, University of Bonn
name: Peter Charbel Issa, MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Gliem M, Zaeytijd JD, Finger RP, Holz FG, Leroy BP, Charbel Issa P. An update on the ocular phenotype in patients with pseudoxanthoma elasticum. Front Genet. 2013 Apr 4;4:14. doi: 10.3389/fgene.2013.00014. eCollection 2013.
citation: Finger RP, Fenwick E, Marella M, Charbel Issa P, Scholl HP, Holz FG, Lamoureux EL. The relative impact of vision impairment and cardiovascular disease on quality of life: the example of pseudoxanthoma elasticum. Health Qual Life Outcomes. 2011 Dec 12;9:113. doi: 10.1186/1477-7525-9-113.
citation: Charbel Issa P, Finger RP, Gotting C, Hendig D, Holz FG, Scholl HP. Centrifugal fundus abnormalities in pseudoxanthoma elasticum. Ophthalmology. 2010 Jul;117(7):1406-14. doi: 10.1016/j.ophtha.2009.11.008. Epub 2010 Mar 1.
citation: Finger RP, Charbel Issa P, Ladewig M, Gotting C, Holz FG, Scholl HP. Fundus autofluorescence in Pseudoxanthoma elasticum. Retina. 2009 Nov-Dec;29(10):1496-505. doi: 10.1097/IAE.0b013e3181aade47.
citation: Charbel Issa P, Finger RP, Holz FG, Scholl HP. Multimodal imaging including spectral domain OCT and confocal near infrared reflectance for characterization of outer retinal pathology in pseudoxanthoma elasticum. Invest Ophthalmol Vis Sci. 2009 Dec;50(12):5913-8. doi: 10.1167/iovs.09-3541. Epub 2009 Jun 24.
citation: Gliem M, Finger RP, Fimmers R, Brinkmann CK, Holz FG, Charbel Issa P. Treatment of choroidal neovascularization due to angioid streaks: a comprehensive review. Retina. 2013 Jul-Aug;33(7):1300-14. doi: 10.1097/IAE.0b013e3182914d2b.
citation: Gliem M, Fimmers R, Muller PL, Brinkmann CK, Finger RP, Hendig D, Holz FG, Charbel Issa P. Choroidal changes associated with Bruch membrane pathology in pseudoxanthoma elasticum. Am J Ophthalmol. 2014 Jul;158(1):198-207.e3. doi: 10.1016/j.ajo.2014.04.005. Epub 2014 Apr 13.
citation: Charbel Issa P, Gliem M, Holz FG, Knabbe C, Hendig D. [Pseudodominant inheritance of pseudoxanthoma elasticum]. Ophthalmologe. 2015 Aug;112(8):686-90. doi: 10.1007/s00347-014-3231-9. German.
citation: Gliem M, Hendig D, Finger RP, Holz FG, Charbel Issa P. Reticular pseudodrusen associated with a diseased bruch membrane in pseudoxanthoma elasticum. JAMA Ophthalmol. 2015 May;133(5):581-8. doi: 10.1001/jamaophthalmol.2015.117.
citation: Gliem M, Muller PL, Birtel J, Hendig D, Holz FG, Charbel Issa P. Frequency, Phenotypic Characteristics and Progression of Atrophy Associated With a Diseased Bruch's Membrane in Pseudoxanthoma Elasticum. Invest Ophthalmol Vis Sci. 2016 Jun 1;57(7):3323-30. doi: 10.1167/iovs.16-19388.
citation: Gliem M, Muller PL, Birtel J, McGuinness MB, Finger RP, Herrmann P, Hendig D, Holz FG, Charbel Issa P. Quantitative Fundus Autofluorescence in Pseudoxanthoma Elasticum. Invest Ophthalmol Vis Sci. 2017 Dec 1;58(14):6159-6165. doi: 10.1167/iovs.17-22007.