Driving forces in amyloidosis: How does a light chain make a heavy heart?
Ontology highlight
ABSTRACT:
SUBMITTER: Otzen DE
PROVIDER: S-EPMC8191319 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Light chain (AL) amyloidosis is caused by a usually small plasma-cell clone that is able to produce the amyloidogenic light chains. They are able to misfold and aggregate, deposit in tissues in the form of amyloid fibrils and lead to irreversible organ dysfunction and eventually death if treatment is late or ineffective. Cardiac damage is the most important prognostic determinant. The risk of dialysis is predicted by the severity of renal involvement, defined by the baseline proteinuria and glomerular filtration rate, and by the response to therapy. The specific treatment is chemotherapy targeting the underlying plasma-cell clone. It needs to be risk-adapted, according to the severity of cardiac and/or multi-organ involvement. Autologous stem cell transplant (preceded by induction and/or followed by consolidation with bortezomib-based regimens) can be considered for low-risk patients (~20%). Bortezomib combined with alkylators is used in the majority of intermediate-risk patients, and with possible dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents were investigated in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. In addition, the use of novel approaches based on antibodies targeting the amyloid deposits or small molecules interfering with the amyloidogenic process gave promising results in preliminary studies. Some of them are under evaluation in controlled trials. These molecules will probably add powerful complements to standard chemotherapy. The understanding of the specific molecular mechanisms of cardiac damage and the characteristics of the amyloidogenic clone are unveiling novel potential treatment approaches, moving towards a cure for this dreadful disease.
| S-EPMC5841939 | biostudies-literature
Project description: Not available
| S-EPMC8288708 | biostudies-literature
Project description:Light chain (AL) amyloidosis is the most common form of amyloidosis involving the kidney. It is characterized by albuminuria, progressing to overt nephrotic syndrome and eventually end-stage renal failure if diagnosed late or ineffectively treated, and in most cases by concomitant heart involvement. Cardiac amyloidosis is the main determinant of survival, whereas the risk of dialysis is predicted by baseline proteinuria and glomerular filtration rate, and by response to therapy. The backbone of treatment is chemotherapy targeting the underlying plasma cell clone, that needs to be risk-adapted due to the frailty of patients with AL amyloidosis who have cardiac and/or multiorgan involvement. Low-risk patients (?20%) can be considered for autologous stem cell transplantation that can be preceded by induction and/or followed by consolidation with bortezomib-based regimens. Bortezomib combined with alkylators, such as melphalan, preferred in patients harboring t(11;14), or cyclophosphamide, is used in most intermediate-risk patients, and with cautious dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents, such as pomalidomide, ixazomib, and daratumumab, prove effective in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. Novel approaches based on small molecules interfering with the amyloidogenic process and on antibodies targeting the amyloid deposits gave promising results in preliminary uncontrolled studies, are being tested in controlled trials, and will likely prove powerful complements to chemotherapy. Finally, improvements in the understanding of the molecular mechanisms of organ damage are unveiling novel potential treatment targets, moving toward a cure for this dreadful disease.
| S-EPMC5976806 | biostudies-literature
Project description: Not available
| S-EPMC7364018 | biostudies-literature
Project description: Not available
| S-EPMC8083944 | biostudies-literature
Project description:Information detailing the experience of patients with light chain (AL) amyloidosis is lacking. The primary aim of this study was to gather data on the patient experience to understand the challenges in diagnosis and to gain insight into barriers to accessing appropriate care.Patients with amyloidosis, family members, and caregivers were invited to participate in an online 16-question survey (available from January 29 to February 5, 2015). Participants with AL amyloidosis were sent an eight-question follow-up survey.The initial survey was completed by 533 participants (follow-up survey completed by 201 participants). AL amyloidosis was the most common diagnosis. For 37.1% of respondents, the diagnosis of amyloidosis was not established until ? 1 year after the onset of initial symptoms. Diagnosis was received after visits to 1, 2, 3, 4, or ? 5 physicians by 7.6%, 23.5%, 20.3%, 16.8%, and 31.8% of respondents, respectively. Correct diagnosis was most often made by hematologists/oncologists (34.1%). Treatments included chemotherapy (63.1%) and stem cell transplantation (38.9%) and were difficult to tolerate for 54.1% of respondents. A significant number of respondents felt uninformed about clinical trials. Nevertheless, approximately half (46.1%) believed that enrolling in a trial would enhance their care.Establishing a diagnosis of amyloidosis is difficult. Current treatments are difficult to tolerate and do not substantially improve quality of life for most patients. There is an urgent need for well-tolerated therapies with clear treatment benefit. Patient awareness of clinical trials can be improved, especially given that respondents indicated high willingness to participate.
| S-EPMC4635176 | biostudies-literature
Project description:Segmental duplication and deletion were implicated for a region containing the human immunoglobulin heavy chain variable (IGHV) gene segments, 1.9III/hv3005 (possible allelic variants of IGHV3-30) and hv3019b9 (a possible allelic variant of IGHV3-33). However, very little is known about the ranges of the duplication and the polymorphic region. This is mainly because of the difficulty associated with distinguishing between allelic and paralogous sequences in the IGHV region containing extensive repetitive sequences. Inability to separate the two parental haploid genomes in the subjects is another serious barrier. To address these issues, unique DNA sequence tags evenly distributed within and flanking the duplicated region implicated by the previous studies were selected. The selected tags in single sperm from six unrelated healthy donors were amplified by multiplex PCR followed by microarray detection. In this way, individual haplotypes of different parental origins in the sperm donors could be analyzed separately and precisely. The identified polymorphic region was further analyzed at the nucleotide sequence level using sequences from the three human genomic sequence assemblies in the database.A large polymorphic region was identified using the selected sequence tags. Four of the 12 haplotypes were shown to contain consecutively undetectable tags spanning in a variable range. Detailed analysis of sequences from the genomic sequence assemblies revealed two large duplicate sequence blocks of 24,696 bp and 24,387 bp, respectively, and an incomplete copy of 961 bp in this region. It contains up to 13 IGHV gene segments depending on haplotypes. A polymorphic region was found to be located within the duplicated blocks. The variants of this polymorphism unusually diverged at the nucleotide sequence level and in IGHV gene segment number, composition and organization, indicating a limited selection pressure in general. However, the divergence level within the gene segments is significantly different from that in the intergenic regions indicating that these regions may have been subject to different selection pressures and that the IGHV gene segments in this region are functionally important.Non-reciprocal genetic rearrangements associated with large duplicate sequence blocks could substantially contribute to the IGHV region diversity. Since the resulting polymorphisms may affect the number, composition and organization of the gene segments in this region, it may have significant impact on the function of the IGHV gene segment repertoire, antibody diversity, and therefore, the immune system. Because one of the gene segments, 3-30 (1.9III), is associated with autoimmune diseases, it could be of diagnostic significance to learn about the variants in the haplotypes by using the multiplex haplotype analysis system used in the present study with DNA sequence tags specific for the variants of all gene segments in this region.
| S-EPMC3042411 | biostudies-literature
Project description:Paired antibody heavy-light chain sequencing
| PRJEB25901 | ENA
Project description:Amyloid formation and deposition of immunoglobulin light-chain proteins in systemic amyloidosis (AL) cause major organ failures. While the ? light-chain is dominant (?/?=1:2) in healthy individuals, ? is highly overrepresented (?/?=3:1) in AL patients. The structural basis of the amyloid formation and the sequence preference are unknown. We examined the correlation between sequence and structural stability of dimeric variable domains of immunoglobulin light chains using molecular dynamics simulations of 24 representative dimer interfaces, followed by energy evaluation of conformational ensembles for 20 AL patients' light chain sequences. We identified a stable interface with displaced N-terminal residues, provides the structural basis for AL protein fibrils formation. Proline isomerization may cause the N-terminus to adopt amyloid-prone conformations. We found that ? light-chains prefer misfolded dimer conformation, while ? chain structures are stabilized by a natively folded dimer. Our study may facilitate structure-based small molecule and antibody design to inhibit AL. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang.
| S-EPMC5927852 | biostudies-literature
Project description:BACKGROUND:Light chain (AL) amyloidosis is a rare, complex disease associated with significant morbidity and mortality. Delays in diagnosis are common and may have detrimental consequences on patients' prognosis. Too little is known regarding the patient journey to diagnosis. OBJECTIVE:The objective of this study was to describe the patient-reported journey to a correct diagnosis for AL amyloidosis. METHODS:Using a mixed-methods approach, data were collected from clinician (n = 4) and patient (n = 10) interviews and a survey of community-based patients with AL amyloidosis (n = 341). Data were used to document the patient experience between the onset of symptoms and the receipt of a diagnosis. RESULTS:Delays in diagnosis were common. Qualitative and quantitative data indicated that initial symptoms were varied and similar to other more prevalent diseases. Two themes regarding the journey to diagnosis emerged: (1) barriers to an early diagnosis; and (2) the emotional toll of the journey. Time to diagnosis was heavily influenced by how patients interpreted their initial symptoms, whether they sought early medical help, and challenges associated with making differential diagnoses. Survey results indicate that patients with primary cardiac involvement were more likely to receive a delayed diagnosis than those with primary kidney involvement. Patients described mixed emotions associated with the eventual diagnosis of AL amyloidosis. CONCLUSIONS:These data support a need for better early identification and support for patients seeking a diagnosis. Increasing clinician awareness may reduce the time to diagnosis. Additional research is needed to identify optimal diagnostic testing to reduce delays in treatment initiation and subsequent severe impacts on health.
| S-EPMC5845075 | biostudies-literature