-
Journal of Alzheimer's Disease Reports 2023The relationship between alpha 2-macroglobulin (A2M) gene and Alzheimer's disease (AD) has been widely studied across populations; however, the results are inconsistent.
BACKGROUND
The relationship between alpha 2-macroglobulin (A2M) gene and Alzheimer's disease (AD) has been widely studied across populations; however, the results are inconsistent.
OBJECTIVE
This study aimed to evaluate the association of A2M gene with AD by the application of meta-analysis.
METHODS
Relevant studies were identified by comprehensive searches. The quality of each study was assessed using the Newcastle-Ottawa Scale. Allele and genotype frequencies were extracted from each of the included studies. Odds ratio (OR) with corresponding 95% confidence intervals (CI) was calculated using a random-effects or fixed-effects model. The Cochran Q statistic and I metric was used to evaluate heterogeneity, and Egger's test and Funnel plot were used to assess publication bias.
RESULTS
A total of 62 studies were identified and included in the current meta-analysis. The G allele of rs226380 reduced AD risk (OR: 0.64, 95% CI: 0.47-0.87, pFDR = 0.012), but carrier with the TT genotype was more likely to develop AD in Asian populations (OR: 1.56, 95% CI: 1.12-2.19, pFDR = 0.0135). The V allele of the A2M-I/V (rs669) increased susceptibility to AD in female population (OR, 95% CI: 2.15, 1.38-3.35, pFDR = 0.0024); however, the II genotype could be a protective factor in these populations (OR, 95% CI: 0.43, 0.26-0.73, pFDR = 0.003). Sensitivity analyses confirmed the reliability of the original results.
CONCLUSIONS
Existing evidence indicate that A2M single nucleotide polymorphisms (SNPs) may be associated with AD risk in sub-populations. Future studies with larger sample sizes will be necessary to confirm the results.
PubMed: 38143774
DOI: 10.3233/ADR-230131 -
Sao Paulo Medical Journal = Revista... 2022Chronically elevated alpha-2-macroglobulin (A2MG) in the blood has been correlated with diabetes and the HbA1c profile; however, no systematic review has been conducted... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Chronically elevated alpha-2-macroglobulin (A2MG) in the blood has been correlated with diabetes and the HbA1c profile; however, no systematic review has been conducted to evaluate the association of A2MG salivary levels and glycemia or HbA1c levels in diabetes mellitus type 2 (DM2) patients.
OBJECTIVE
To evaluate whether A2MG salivary levels are related to the glycemia or HbA1c levels in DM2 patients.
DESIGN AND SETTING
Systematic review developed at Universidade Federal de Uberlândia (UFU), Brazil.
METHODS
Eight databases were used as research sources. The eligibility criteria included studies that reported data regarding mean salivary A2MG and the correlation between glycemia and/or HbA1c levels of DM2 subjects (uncontrolled and well-controlled) and non-diabetic subjects. The risk of bias of the studies selected was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools for use in JBI systematic reviews. Pooled correlation coefficients were estimated using the Hunter-Schmidt method. Study estimates were weighted according to their sample size, and heterogeneity was calculated using the chi-square statistic.
RESULTS
Four studies on DM2 patients were included in this systematic review after careful analysis of 1482 studies. Three studies compared A2MG with HbA1c and glycemia. Overall, the correlation between A2MG and HbA1c was strong (r = 0.838). In contrast, the correlation between A2MG and glycemia was low (r = 0.354).
CONCLUSION
The strong association between HbA1C and salivary A2MG suggests that this salivary protein has the potential to be a surrogate for HbA1C, if corroboratory further evidence is obtained through large-scale studies.
Topics: Humans; Blood Glucose; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Pregnancy-Associated alpha 2-Macroglobulins
PubMed: 36102452
DOI: 10.1590/1516-3180.2021.0816.R2.19052022 -
International Journal of Molecular... Sep 2022Biological material is one of the most important aspects that allow for the correct diagnosis of the disease, and tears are an interesting subject of research because of... (Review)
Review
Biological material is one of the most important aspects that allow for the correct diagnosis of the disease, and tears are an interesting subject of research because of the simplicity of collection, as the well as the relation to the components similar to other body fluids. In this review, biomarkers for Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS) in tears are investigated and analyzed. Records were obtained from the PubMed and Google Scholar databases in a timeline of 2015-2022. The keywords were: tear film/tear biochemistry/tear biomarkers + diseases (AD, PD, or MS). The recent original studies were analyzed, discussed, and biomarkers present in tears that can be used for the diagnosis and management of AD, PD, and MS diseases were shown. α-synTotal and α-synOligo, lactoferrin, norepinephrine, adrenaline, epinephrine, dopamine, α-2-macroglobulin, proteins involved in immune response, lipid metabolism and oxidative stress, apolipoprotein superfamily, and others were shown to be biomarkers in PD. For AD as potential biomarkers, there are: lipocalin-1, lysozyme-C, and lacritin, amyloid proteins, t-Tau, p-Tau; for MS there are: oligoclonal bands, lipids containing choline, free carnitine, acylcarnitines, and some amino acids. Information systematized in this review provides interesting data and new insight to help improve clinical outcomes for patients with neurodegenerative disorders.
Topics: Alzheimer Disease; Biomarkers; Humans; Lacrimal Apparatus Diseases; Multiple Sclerosis; Parkinson Disease; Tears
PubMed: 36077520
DOI: 10.3390/ijms231710123 -
Therapeutic Apheresis and Dialysis :... Aug 2022Medium cut-off (MCO) dialyzers were designed to provide better clearance of uremic toxins. We conducted a meta-analysis comparing MCO with high-flux (HF) dialyzers for... (Meta-Analysis)
Meta-Analysis
Medium cut-off (MCO) dialyzers were designed to provide better clearance of uremic toxins. We conducted a meta-analysis comparing MCO with high-flux (HF) dialyzers for the effect on uremic toxins in maintenance hemodialysis (HD) patients. Five databases were systematically searched for relevant studies and nine studies were identified finally. Reduction ratio (RR) of urea, urea, creatinine, β2-macroglobulin (β2-MG), kappa free light chain (κFLC), and lambda FLC (λFLC) levels were not significantly different between MCO and HF dialyzers. But RR of β2-MG, κFLC, and λFLC were greater for MCO than HF dialyzers. MCO dialyzers could better reduce tumor necrosis factor-α (TNF-α) levels. Subgroup analysis stratified by study design indicated that in randomized controlled trial (RCT) studies, albumin levels was lower in MCO than HF dialyzers group, but the two dialyzers treatments were equivalent in non-RCT subgroup. Compared with HF dialyzers, MCO dialyzers provided higher middle-molecules uremic toxins clearance and obviously reduced TNF-α levels.
Topics: Creatinine; Hemodiafiltration; Humans; Immunoglobulin Light Chains; Membranes, Artificial; Renal Dialysis; Tumor Necrosis Factor-alpha; Urea
PubMed: 34773675
DOI: 10.1111/1744-9987.13755