An observational study in Cardiac Amyloidosis, sponsored by University Hospital Center of Martinique. Terminated at 1 site in Martinique. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2023-08-28.
Sponsored by University Hospital Center of Martinique · Observational
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Hereditary (familial) amyloidosis arising from the misfolding of a mutated or variant transthyretin, is the most frequent form of amyloid cardiomyopathy in the Caribbean basin. Affected organs invariably harbor extracellular amyloid deposits in the myocardium. Circulating or pre-fibrillar amyloidogenic proteins are implicated in the disruption of cell function. The investigators aim is to demonstrate that transthyretin mediated amyloid disease alter the mitochondrial function of cardiac cells.
Systemic amyloidosis are a family of diseases induced by misfolded and/or misassembled proteins. Extracellular deposits of these proteins disrupt vital organ function. Two types of amyloid commonly infiltrate the heart: immunoglobulin light-chain amyloid and transthyretin (TTR) amyloid. Among the TTR variants that predominantly target the heart, the valine to isoleucine substitution at position 122 (V122I or Ile122) is the most common. This TTR variant is responsible for the most frequent form of amyloid cardiomyopathy in the Caribbean basin. Increasingly study data supports a central role for circulating or pre-fibrillar amyloidogenic proteins in the disruption of cardiac function in TTR mediated amyloid disease. In vivo exposure of cultured cardiomyocytes to pre-fibrillar an amyloidogenic proteins stimulate the production of reactive oxygen species and disrupts calcium fluxes. (Recent studies indicate that pre-fibrillar amyloidogenic proteins may also induce apoptosis through the mitochondrial pathway, eventually leading to cardiac cell injury). Hence, growing evidence suggests that end-organ damage by pre-fibrillar TTR amyloid may be related to mitochondrial dysfunction. Diagnosis of cardiac amyloidosis can be based on invasive heart biopsies or a non-invasive approach including identification of amyloid tissue deposits from abdominal fat biopsies. The investigators aim is to demonstrate that transthyretin mediated amyloid disease alters the mitochondrial function of subcutaneous abdominal adipocytes.
The investigators objective is to study mitochondrial respiration assessed by oxygraphy in fragments of subcutaneous abdominal fat biopsies performed for diagnosis of TTR amyloidosis. Mitochondrial respiration will be evaluated in the absence and in the presence of ADP.
Follow the evaluation of mitochondrial respiration. So, no patient follow-up will be performed.
188 studies on the registry are indexed under Amyloid Neuropathies, Familial; 94 are open to participants now.
This study's enrollment of 12 is below the median of 233 across 92 observational studies indexed under Amyloid Neuropathies, Familial.
Browse Amyloid Neuropathies, Familial studies →University Hospital Center of Martinique is the lead sponsor of 79 studies on the registry; 21 are open to participants now.
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The selection of patients is done during the amyloidosis consultation of the cardiology department.
Patients are referred to this consultation following the discovery of characteristic abnormalities during echocardiography.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Biopsy and archival tissue
A biopsy takes a small piece of tissue to examine. “Archival tissue” is a sample already taken, for example at diagnosis, and kept by the hospital.
Whether a stored sample will do depends on when it was taken, how much there is and what the study needs. Ask whether the study accepts your stored sample or needs a new biopsy.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Oxygen consumption measure in subcutaneous abdominal fat biopsies
The mitochondrial respiration of the cells is measured by polarography with a "Clark" type oxygen electrode. The Clark electrode consists of a platinium cathode and a silver anode. When a potential difference of -0.6 volts is applied, the platinium electrode is negatively charged with respect to that of silver and each oxygen molecule dissolved in the medium diffuses through the gas-permeable Teflon membrane, and is reduced at the cathode according to the following reaction: O 2 + 4H + + 4e → 2H 2 O. The current thus generated is proportional to the concentration of dissolved oxygen. The oxygen saturation constant (406 nmol / ml) makes it possible to convert these results into oxygen consumption / minute.
Time frame: Three months
Rates of oxygen consumption
Rates of oxygen consumption (expressed as pmol O2.s-1.mg of fat tissue) will be recorded in-vivo in different conditions, which include routine respiration and after ADP addition. Carbonyl cyanide-4-(trifluoromethoxy) phenylhydrazone (FCCP), tetra methyl-p-phenylenediaminedihydrochloride (TMPD)-ascorbate and oligomycin will be tested in vitro to monitor uncoupled respiration, cytochrome c oxidase activity and leak state respiration by inhibition of ATP synthase, respectively.
Time frame: Three months
Plan to share: Yes — All collected IPD, all IPD that underlie results in a publication.
Supporting information: Study protocol, Statistical analysis plan, Clinical study report
Time frame: After the main publication of the results, for not limited time.
Access criteria: The conditions for the transfer of all or part of the database of the research are decided by the investigator coordinator / sponsor of the research and are the subject of a written contract.
Ran from Jul 2018 to primary completion in Sep 2019, 14 months.
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This study is terminated, as verified in Aug 2023. You cannot join it, but the record below documents what was studied.
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Amyloid Neuropathies, Familial →
University Hospital Center of Martinique