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International Journal of Molecular... Apr 2021Transthyretin (TTR) is an essential transporter of a thyroid hormone and a holo-retinol binding protein, found abundantly in human plasma and cerebrospinal fluid. In... (Review)
Review
Transthyretin (TTR) is an essential transporter of a thyroid hormone and a holo-retinol binding protein, found abundantly in human plasma and cerebrospinal fluid. In addition, this protein is infamous for its amyloidogenic propensity, causing various amyloidoses in humans, such as senile systemic amyloidosis, familial amyloid polyneuropathy, and familial amyloid cardiomyopathy. It has been known for over two decades that decreased stability of the native tetrameric conformation of TTR is the main cause of these diseases. Yet, mechanistic details on the amyloidogenic transformation of TTR were not clear until recent multidisciplinary investigations on various structural states of TTR. In this review, we discuss recent advancements in the structural understanding of TTR misfolding and amyloidosis processes. Special emphasis has been laid on the observations of novel structural features in various amyloidogenic species of TTR. In addition, proteolysis-induced fragmentation of TTR, a recently proposed mechanism facilitating TTR amyloidosis, has been discussed in light of its structural consequences and relevance to acknowledge the amyloidogenicity of TTR.
Topics: Amyloid; Amyloid Neuropathies, Familial; Animals; Humans; Prealbumin; Protein Folding
PubMed: 33922648
DOI: 10.3390/ijms22094429 -
International Journal of Molecular... Dec 2022The care of systemic amyloidosis has improved dramatically due to improved awareness, accurate diagnostic tools, the development of powerful prognostic and companion... (Review)
Review
The care of systemic amyloidosis has improved dramatically due to improved awareness, accurate diagnostic tools, the development of powerful prognostic and companion biomarkers, and a continuous flow of innovative drugs, which translated into the blooming of phase 2/3 interventional studies for light chain (AL) and transthyretin (ATTR) amyloidosis. The unprecedented availability of effective drugs ignited great interest across various medical specialties, particularly among cardiologists who are now recognizing cardiac amyloidosis at an extraordinary pace. In all amyloidosis referral centers, we are observing a substantial increase in the prevalence of wild-type transthyretin (ATTRwt) cardiomyopathy, which is now becoming the most common form of cardiac amyloidosis. This review focuses on the oral drugs that have been recently introduced for the treatment of ATTR cardiac amyloidosis, for their ease of use in the clinic. They include both old repurposed drugs or fit-for-purpose designed compounds which bind and stabilize the TTR tetramer, thus reducing the formation of new amyloid fibrils, such as tafamidis, diflunisal, and acoramidis, as well as fibril disruptors which have the potential to promote the clearance of amyloid deposits, such as doxycycline. The development of novel therapies is based on the advances in the understanding of the molecular events underlying amyloid cardiomyopathy.
Topics: Humans; Amyloid Neuropathies, Familial; Prealbumin; Diflunisal; Cardiomyopathies; Amyloid
PubMed: 36555787
DOI: 10.3390/ijms232416145 -
European Journal of Heart Failure Jun 2023Epidemiology of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) remains poorly defined. A better characterization of pathways leading to ATTRwt-CA diagnosis is...
AIM
Epidemiology of wild-type transthyretin cardiac amyloidosis (ATTRwt-CA) remains poorly defined. A better characterization of pathways leading to ATTRwt-CA diagnosis is of key importance, and potentially informative of disease course and prognosis. The aim of this study was to describe the characteristics of contemporary pathways leading to ATTRwt-CA diagnosis, and their potential association with survival.
METHODS AND RESULTS
This was a retrospective study of patients diagnosed with ATTRwt-CA at 17 Italian referral centres for CA. Patients were categorized into different 'pathways' according to the medical reason that triggered the diagnosis of ATTRwt-CA (hypertrophic cardiomyopathy [HCM] pathway, heart failure [HF] pathway, incidental imaging or incidental clinical pathway). Prognosis was investigated with all-cause mortality as endpoint. Overall, 1281 ATTRwt-CA patients were included in the study. The diagnostic pathway leading to ATTRwt-CA diagnosis was HCM in 7% of patients, HF in 51%, incidental imaging in 23%, incidental clinical in 19%. Patients in the HF pathway, as compared to the others, were older and had a greater prevalence of New York Heart Association (NYHA) class III-IV and chronic kidney disease. Survival was significantly worse in the HF versus other pathways, but similar among the three others. In multivariate model, older age at diagnosis, NYHA class III-IV and some comorbidities but not the HF pathway were independently associated with worse survival.
CONCLUSIONS
Half of contemporary ATTRwt-CA diagnoses occur in a HF setting. These patients had worse clinical profile and outcome than those diagnosed either due to suspected HCM or incidentally, although prognosis remained primarily related to age, NYHA functional class and comorbidities rather than the diagnostic pathway itself.
Topics: Humans; Prealbumin; Amyloid Neuropathies, Familial; Retrospective Studies; Heart Failure; Cardiomyopathies
PubMed: 36907828
DOI: 10.1002/ejhf.2823 -
American Journal of Transplantation :... Jun 2022Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing...
Hereditary transthyretin-mediated (hATTR) amyloidosis, or ATTRv amyloidosis, is a progressive disease, for which liver transplantation (LT) has been a long-standing treatment. However, disease progression continues post-LT. This Phase 3b, open-label trial evaluated efficacy and safety of patisiran in patients with ATTRv amyloidosis with polyneuropathy progression post-LT. Primary endpoint was median transthyretin (TTR) reduction from baseline. Twenty-three patients received patisiran for 12 months alongside immunosuppression regimens. Patisiran elicited a rapid, sustained TTR reduction (median reduction [Months 6 and 12 average], 91.0%; 95% CI: 86.1%-92.3%); improved neuropathy, quality of life, and autonomic symptoms from baseline to Month 12 (mean change [SEM], Neuropathy Impairment Score, -3.7 [2.7]; Norfolk Quality of Life-Diabetic Neuropathy questionnaire, -6.5 [4.9]; least-squares mean [SEM], Composite Autonomic Symptom Score-31, -5.0 [2.6]); and stabilized disability (Rasch-built Overall Disability Scale) and nutritional status (modified body mass index). Adverse events were mild or moderate; five patients experienced ≥1 serious adverse event. Most patients had normal liver function tests. One patient experienced transplant rejection consistent with inadequate immunosuppression, remained on patisiran, and completed the study. In conclusion, patisiran reduced serum TTR, was well tolerated, and improved or stabilized key disease impairment measures in patients with ATTRv amyloidosis with polyneuropathy progression post-LT (www.clinicaltrials.gov NCT03862807).
Topics: Amyloid Neuropathies, Familial; Humans; Liver Transplantation; Polyneuropathies; Prealbumin; Quality of Life; RNA, Small Interfering
PubMed: 35213769
DOI: 10.1111/ajt.17009 -
Frontiers in Cellular and Infection... 2024The primary aim of this study is to investigate the correlation between serum levels of fibrinogen-to-prealbumin ratio (FPR) and C-reactive protein-to-prealbumin ratio...
BACKGROUND
The primary aim of this study is to investigate the correlation between serum levels of fibrinogen-to-prealbumin ratio (FPR) and C-reactive protein-to-prealbumin ratio (CPR) and prognostic outcomes among patients with severe fever with thrombocytopenia syndrome (SFTS). SFTS, characterized by elevated mortality rates, represents a substantial public health challenge as an emerging infectious disease.
METHODS
The study included 159 patients with SFTS. Clinical and laboratory data were compared between the survival and death groups. Univariate and multivariate logistic regression analysis were utilized to identify independent risk factors for mortality. The predictive efficacy of FPR and CPR was evaluated using receiver operating characteristic (ROC) curve. Survival analysis was conducted using the Kaplan-Meier curve and the log-rank test was employed for comparison.
RESULTS
The death group exhibited significantly elevated levels of FPR and CPR compared to the survival group ( < 0.05). Multivariate logistic regression analysis confirmed that both FPR and CPR independently correlated with a poorer prognosis among patients with SFTS. The ROC curve analysis indicated that FPR and CPR had superior predictive capabilities compared to C-reactive protein and fibrinogen. Kaplan-Meier survival analysis demonstrated that patients with SFTS who have FPR > 0.045 (log-rank test; χ2 = 17.370, < 0.001) or CPR > 0.05 (log-rank test; χ2 = 19.442, < 0.001) experienced significantly lower survival rates within a 30-day follow-up period.
CONCLUSION
Elevated levels of FPR and CPR serve as distinct risk factors for mortality among patients with SFTS, indicating their potential to predict an unfavorable prognosis in these patients.
Topics: Humans; C-Reactive Protein; Male; Female; Fibrinogen; Prognosis; Middle Aged; Aged; Severe Fever with Thrombocytopenia Syndrome; ROC Curve; Prealbumin; Biomarkers; Risk Factors; Adult; Phlebovirus; Kaplan-Meier Estimate; Retrospective Studies
PubMed: 38915920
DOI: 10.3389/fcimb.2024.1397789 -
International Journal of Molecular... Dec 2019Preeclampsia (PE) is a multisystem heterogeneous complication of pregnancy remaining a leading cause of maternal and perinatal morbidity and mortality over the world. PE... (Review)
Review
Preeclampsia (PE) is a multisystem heterogeneous complication of pregnancy remaining a leading cause of maternal and perinatal morbidity and mortality over the world. PE has a large spectrum of clinical features and symptoms, which make diagnosis challenging. Despite a long period of studying, PE etiology is still unclear and there are no reliable rapid tests for early diagnosis of this disease. During the last decade, it was shown that proteins misfolding and aggregation are associated with PE. Several proteins, including amyloid beta peptide, transthyretin, alpha-1 antitrypsin, albumin, IgG k-free light chains, and ceruloplasmin are dysregulated in PE, resulting in toxic deposition of amyloid-like aggregates in the placenta and body fluids. It is also possible that aggregated proteins induce defective trophoblast invasion, placental ischemia, ER stress, and promote PE manifestation. The fact that protein aggregation is an emerging biomarker of PE provides an opportunity to develop new diagnostic approaches based on amyloids special features, such as Congo red (CR) staining and thioflavin T (ThT) enhanced fluorescence.
Topics: Amyloid; Benzothiazoles; Biomarkers; Female; Humans; Placenta; Pre-Eclampsia; Prealbumin; Pregnancy; Protein Aggregation, Pathological; Protein Folding
PubMed: 31817906
DOI: 10.3390/ijms20246183 -
Nutrients Mar 2022Vitamin A is vital to maternal-fetal health and pregnancy outcomes. However, little is known about pregnancy associated changes in maternal vitamin A homeostasis and...
Vitamin A is vital to maternal-fetal health and pregnancy outcomes. However, little is known about pregnancy associated changes in maternal vitamin A homeostasis and concentrations of circulating retinol metabolites. The goal of this study was to characterize retinoid concentrations in healthy women ( = 23) during two stages of pregnancy (25-28 weeks gestation and 28-32 weeks gestation) as compared to ≥3 months postpartum. It was hypothesized that plasma retinol, retinol binding protein 4 (RBP4), transthyretin and albumin concentrations would decline during pregnancy and return to baseline by 3 months postpartum. At 25-28 weeks gestation, plasma retinol (-27%), 4-oxo-13--retinoic acid (-34%), and albumin (-22%) concentrations were significantly lower, and -retinoic acid (+48%) concentrations were significantly higher compared to ≥3 months postpartum in healthy women. In addition, at 28-32 weeks gestation, plasma retinol (-41%), retinol binding protein 4 (RBP4; -17%), transthyretin (TTR; -21%), albumin (-26%), 13--retinoic acid (-23%) and 4-oxo-13--retinoic acid (-48%) concentrations were significantly lower, whereas plasma -retinoic acid concentrations (+30%) were significantly higher than ≥3 months postpartum. Collectively, the data demonstrates that in healthy pregnancies, retinol plasma concentrations are lower, but -retinoic acid concentrations are higher than postpartum.
Topics: Female; Humans; Prealbumin; Pregnancy; Pregnant Women; Retinoids; Retinol-Binding Proteins, Plasma; Tretinoin; Vitamin A
PubMed: 35405978
DOI: 10.3390/nu14071365 -
Annals of Clinical and Translational... Aug 2022Hereditary transthyretin-mediated amyloidosis is a treatable condition caused by amyloidogenic variants in the transthyretin-gene resulting in severe peripheral...
OBJECTIVE
Hereditary transthyretin-mediated amyloidosis is a treatable condition caused by amyloidogenic variants in the transthyretin-gene resulting in severe peripheral neuropathy or cardiomyopathy. Only about a third of over 130 known variants are clearly pathogenic, most are classified as variants of uncertain significance. A clear delineation of these into pathogenic or non-pathogenic is highly desirable but hampered by low frequency and penetrance. We thus sought to characterize their amylogenic potential by an unbiased in vitro approach.
METHODS
Thioflavin T and turbidity assays were used to compare the potential of mammalian cell expressed wt-transthyretin and 12 variant proteins (either variants of uncertain significance, benign, pathogenic) to aggregate and produce amyloid fibrils in vitro. As proof of principle, the assays were applied to transthyretin-Ala65Val, a variant that was newly detected in a family with peripheral neuropathy and amyloid deposits in biopsies. In silico analysis was performed to compare the position of the benign and pathogenic variants.
RESULTS
Transthyretin-Ala65Val showed a significantly higher amyloidogenic potential than wt-transthyretin, in both turbidity- and Thioflavin T-assays, comparable to known pathogenic variants. The other eight tested variants did not show an increased amyloidogenic potential. In silico structural analysis further confirmed differences between pathogenic and benign variants in position and interactions.
INTERPRETATION
We propose a biochemical approach to assess amyloidogenic potential of transthyretin variants. As exemplified by transthyretin-Ala65Val, data of three assays together with histopathology clearly demonstrates its amyloidogenicity.
Topics: Amyloid; Amyloid Neuropathies, Familial; Humans; Prealbumin
PubMed: 35903975
DOI: 10.1002/acn3.51626 -
Orphanet Journal of Rare Diseases Oct 2023Hereditary transthyretin (ATTRv) amyloidosis is a rare and autosomal dominant disorder associated with mutations in the transthyretin gene. Patients present with diverse... (Review)
Review
Hereditary transthyretin (ATTRv) amyloidosis is a rare and autosomal dominant disorder associated with mutations in the transthyretin gene. Patients present with diverse symptoms related to sensory, motor, and autonomic neuropathy, as well as gastrointestinal, ocular, cardiac, renal and orthopedic symptoms, resulting from the deposition of transthyretin amyloid fibrils in multiple organs. The progressive nature of ATTRv amyloidosis necessitates pre- and post-onset monitoring of the disease. This review article is primarily based on a collation of discussions from a medical advisory board meeting in August 2021. In this article, we summarize the best practices in amyloidosis centers in three major endemic countries for ATTRv amyloidosis (Japan, Brazil, and Portugal), where most patients carry the Val30Met mutation in the transthyretin gene and the patients' genetic background was proven to be the same. The discussions highlighted the similarities and differences in the management of asymptomatic gene mutation carriers among the three countries in terms of the use of noninvasive tests and tissue biopsies and timing of starting the investigations. In addition, this article discusses a set of practical tests and examinations for monitoring disease progression applicable to neurologists working in diverse medical settings and generalizable in non-endemic countries and areas. This set of assessments consists of periodic (every 6 to 12 months) evaluations of patients' nutritional status and autonomic, renal, cardiac, ophthalmologic, and neurological functions. Physical examinations and patient-reported outcome assessments should be also scheduled every 6 to 12 months. Programs for monitoring gene mutation carriers and robust referral networks can aid in appropriate patient management in pre- to post-onset stages. For pre- and post-symptom onset testing for ATTRv amyloidosis, various noninvasive techniques are available; however, their applicability differs depending on the medical setting in each country and region, and the optimal option should be selected in view of the clinical settings, medical environment, and available healthcare resources in each region.
Topics: Humans; Prealbumin; Japan; Brazil; Portugal; Amyloid Neuropathies, Familial
PubMed: 37828588
DOI: 10.1186/s13023-023-02910-3 -
World Journal of Surgical Oncology Jan 2020Provide an updated and comprehensive evaluation of the prognostic value of the albumin-fibrinogen ratio (AFR) and the fibrinogen-prealbumin ratio (FPR) for patients with... (Review)
Review
OBJECTIVE
Provide an updated and comprehensive evaluation of the prognostic value of the albumin-fibrinogen ratio (AFR) and the fibrinogen-prealbumin ratio (FPR) for patients with cancer.
MATERIALS AND METHODS
Four databases (PubMed, Web of Science, Cochrane Library, and WanFang) were searched. The primary endpoints were overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS). Pooled data were synthesized using StataMP 14 and expressed as hazard ratios (HRs) and 95% confidence intervals (CIs).
RESULTS
This update examined 19 studies (7282 cases) that assessed the correlation of AFR with cancer prognosis. Pooled univariate and multivariate analyses indicated significant correlations of low AFR with poor OS (HR 2.18, 95%CI 1.87-2.55 and HR 1.75, 95%CI 1.54-2.00, respectively), poor DFS (HR 1.89, 95%CI 1.54-2.32 and HR 1.51, 95%CI 1.29-1.76, respectively), and poor PFS (HR 1.68, 95%CI 1.42-1.99 and HR 1.48, 95%CI 1.16-1.88, respectively). Pooled univariate and multivariate analyses of 6 studies (2232 cases) indicated high FPR significantly correlated with poor OS (HR 2.37, 95%CI 2.03-2.77 and HR 1.97, 95%CI 1.41-2.77, respectively). One study reported that high FPR correlated with poor DFS (univariate analysis: HR 2.20, 95%CI 1.35-3.57; multivariate analysis: HR 1.77, 95%CI 1.04-2.99) and one study reported a correlation of high FPR with poor PFS in univariate analysis alone (HR 1.79, 95%CI 1.11-2.88).
CONCLUSION
A low AFR and a high FPR correlated with increased risk of cancer mortality and recurrence. AFR and FPR may be promising prognostic markers for cancers.
Topics: Albumins; Biomarkers, Tumor; Fibrinogen; Humans; Neoplasms; Prealbumin; Prognosis
PubMed: 31931816
DOI: 10.1186/s12957-020-1786-2