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Cureus Oct 2023Acute pancreatitis is an acute inflammatory process of the pancreas with high prevalence and varying degrees of severity that can be potentially life-threatening. Much... (Review)
Review
Acute pancreatitis is an acute inflammatory process of the pancreas with high prevalence and varying degrees of severity that can be potentially life-threatening. Much is still unknown about which mechanisms determine the course and severity of acute pancreatitis. The primary objective of this review is to identify the potential association between circulating lymphocytes and the severity of acute pancreatitis. A systematic search was performed in Medline, Web of Science, Cochrane Central Register of Controlled Trials and ClinicalTrails.gov. The authors independently did the selection process as well as data extraction that was recorded into a flow diagram following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). Our initial search identified 27,783 studies which were narrowed down to 13 by applying strict inclusion and exclusion algorithms. The consistent findings across the studies indicated that peripheral blood lymphocytes are related to acute pancreatitis severity.
PubMed: 38022062
DOI: 10.7759/cureus.47532 -
The Cochrane Database of Systematic... Apr 2020Guidelines and clinical practice for the prevention of complications associated with central venous catheters (CVC) around the world vary greatly. Most institutions... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Guidelines and clinical practice for the prevention of complications associated with central venous catheters (CVC) around the world vary greatly. Most institutions recommend the use of heparin to prevent occlusion; there is debate, however, regarding the need for heparin and evidence to suggest normal saline (0.9% sodium chloride) may be as effective. The use of heparin is not without risk, may be unnecessary and is also associated with increased cost. This is an update of the review published in 2015.
OBJECTIVES
To assess the clinical effects (benefits and harms) of intermittent flushing of normal saline versus heparin to prevent occlusion in long-term central venous catheters in infants and children.
SEARCH METHODS
The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases; World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 9 April 2019. We also undertook reference checking, citation searching and contact with study authors to identify additional studies.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) that compared the efficacy of intermittent flushing with normal saline versus heparin to prevent occlusion of long-term CVCs in infants and children aged up to 18 years of age. We excluded temporary CVCs and peripherally inserted central catheters (PICC).
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trial inclusion criteria, trial quality and extracted data. We assessed study quality with the Cochrane 'Risk of bias' tool. For dichotomous outcomes, we calculated the rate ratio (RR) and corresponding 95% confidence interval (CI). We pooled data using a random-effects model; and we used GRADE to assess the overall certainty of the evidence supporting the outcomes assessed in this review.
MAIN RESULTS
We identified one new study for this update, bringing the total number of included studies to four (255 participants). The four trials directly compared the use of normal saline and heparin; the studies all used different protocols for the intervention and control arms, however, and all used different concentrations of heparin. Different frequencies of flushes were also reported between studies. In addition, not all studies reported on all outcomes. The certainty of the evidence ranged from moderate to very low because there was no blinding; heterogeneity and inconsistency between studies was high; and the CIs were wide. CVC occlusion was assessed in all four trials. We were able to pool the results of two trials for the outcomes of CVC occlusion and CVC-associated blood stream infection. The estimated RR for CVC occlusion per 1000 catheter days between the normal saline and heparin groups was 0.75 (95% CI 0.10 to 5.51; 2 studies, 229 participants; very low certainty evidence). The estimated RR for CVC-associated blood stream infection was 1.48 (95% CI 0.24 to 9.37; 2 studies, 231 participants; low-certainty evidence). The duration of catheter placement was reported to be similar for the two study arms in one study (203 participants; moderate-certainty evidence), and not reported in the remaining studies.
AUTHORS' CONCLUSIONS
The review found that there was not enough evidence to determine the effects of intermittent flushing with normal saline versus heparin to prevent occlusion in long-term central venous catheters in infants and children. It remains unclear whether heparin is necessary to prevent occlusion, CVC-associated blood stream infection or effects duration of catheter placement. Lack of agreement between institutions around the world regarding the appropriate care and maintenance of these devices remains.
Topics: Adolescent; Catheter Obstruction; Catheter-Related Infections; Central Venous Catheters; Child; Child, Preschool; Fibrinolytic Agents; Heparin; Humans; Infant; Randomized Controlled Trials as Topic; Sodium Chloride
PubMed: 32352563
DOI: 10.1002/14651858.CD010996.pub3 -
BMC Psychiatry Nov 2023Mitochondrial dysfunction leading to disturbances in energy metabolism has emerged as one of the risk factors in the pathogenesis of depression. Numerous studies have... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Mitochondrial dysfunction leading to disturbances in energy metabolism has emerged as one of the risk factors in the pathogenesis of depression. Numerous studies have identified alterations in the content of mitochondrial DNA (mtDNA) in peripheral blood and cerebrospinal fluid of individuals with depression. Researchers have sought to establish a clear association between mtDNA and depression. Consequently, we conducted a comprehensive meta-analysis to assess the existing evidence regarding the impact of mtDNA on depression.
METHODS
This study conducted a thorough search of the following databases up to March 13, 2023: PubMed, Embase, the Cochrane Library, the Web of Science, Wanfang Database, SINOMED, the China Science and Technology Journal Database, and China National Knowledge Infrastructure. The meta-analysis was carried out using RevMan (version 5.4) and Stata (version 16.0) software. In addition, publication bias was assessed with funnel plots, Begg's test and Egger's test.
RESULTS
Our analysis included data from 10 articles, including 12 studies for further examination. A total of 1400 participants were included in this study, comprising 709 (including 300 males and 409 females) patients with depression and 691 (including 303 males and 388 females) healthy controls. The average age of depressed patients was (42.98 ± 2.55) years, and the average age of healthy people was (41.71 ± 2.6) years. The scales used to assess outcomes are Hamilton-rating scale for Depression(4 articles), Montgomery-Asberg Depression Rating Scale(3 articles), and Mini-Internatioal Neuropsychiatric Interview (1 articles). The meta-analysis revealed significantly higher levels of mtDNA in circulating blood samples and skin fibroblasts of individuals with depression in comparison to healthy controls [standardized mean difference(SMD) = 0.42, 95% confidence intervals(CI): 0.16, 0.67].
CONCLUSIONS
Our study concludes that there is a significant (p < 0.05) increase in mtDNA levels in serum, plasma, and cerebrospinal fluid in individuals with depression. These findings suggest that mtDNA could serve as a potential biomarker for diagnosing depression.
REGISTRATION NUMBER
PROSPERO CRD42023414285.
Topics: Male; Female; Humans; Adult; Middle Aged; Depression; DNA, Mitochondrial; Risk Factors; Health Status; Mitochondria
PubMed: 37993802
DOI: 10.1186/s12888-023-05358-8 -
Cancer Jul 2022Depressive symptoms in patients with cancer are associated with poor quality of life and decreased survival. Although inflammation is reliably associated with depression... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Depressive symptoms in patients with cancer are associated with poor quality of life and decreased survival. Although inflammation is reliably associated with depression in otherwise healthy individuals, the association in patients with cancer remains unclear. Given the high prevalence of cancer-related inflammation, the authors aimed to establish the relationship between inflammation and depression in cancer patients based on extant literature.
METHODS
A systematic review and meta-analysis was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and registered under Prospero ID CRD42021226743. Three databases were searched including PubMed, the Cochrane Library, and PsycINFO using the following criteria for inclusion: 1) measurement of a peripheral inflammatory marker, 2) use of a validated tool/scale to measure depression, and 3) a cancer diagnosis. Risk of publication bias was assessed by Funnel plot and Egger test.
RESULTS
Seventy-three studies were included in the systematic review and 54 studies (n = 5017) were included in meta-analyses. Associations with depressive symptoms were significant for peripheral blood interleukin (IL)-6 (standardized mean difference [SMD] = 0.59; 95% confidence interval [CI], 0.35-0.82), I = 57.9%; tumor necrosis factor (TNF) (SMD = 0.73; 95% CI, 0.35-1.11), I = 74.1%; and C-reactive protein (CRP) (SMD = 0.57; 95% CI, 0.27-0.87), I = 0%. IL-5, IL-13, albumin, and neutrophil-to-lymphocyte ratio were associated with depressive symptoms but based on fewer studies. Most cancer settings were represented; the number of studies per inflammatory marker varied from 1 to 52.
CONCLUSIONS
Although peripheral inflammatory markers were unevenly studied, the most studied markers (IL-6, TNF, and CRP) were associated with depressive symptoms in cancer patients and may be useful for management of depressive symptoms in the cancer setting.
LAY SUMMARY
Peripheral blood inflammatory markers (IL-6, TNF, and CRP) were associated with depressive symptoms in various cancer settings. Although further studies are warranted, these findings may help identify and manage depressive symptoms in patients with cancer.
Topics: Biomarkers; C-Reactive Protein; Depression; Humans; Inflammation; Interleukin-6; Neoplasms; Quality of Life; Tumor Necrosis Factor-alpha
PubMed: 35417925
DOI: 10.1002/cncr.34193 -
The Cochrane Database of Systematic... Mar 2023Traumatic hyphema is the entry of blood into the anterior chamber, the space between the cornea and iris, following significant injury to the eye. Hyphema may be... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Traumatic hyphema is the entry of blood into the anterior chamber, the space between the cornea and iris, following significant injury to the eye. Hyphema may be associated with significant complications that uncommonly cause permanent vision loss. Complications include elevated intraocular pressure, corneal blood staining, anterior and posterior synechiae, and optic nerve atrophy. People with sickle cell trait or disease may be particularly susceptible to increases in intraocular pressure and optic atrophy. Rebleeding is associated with an increase in the rate and severity of complications.
OBJECTIVES
To assess the effectiveness of various medical interventions in the management of traumatic hyphema.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 3); MEDLINE Ovid; Embase.com; PubMed (1948 to March 2022); the ISRCTN registry; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). The last date of the search was 22 March 2022.
SELECTION CRITERIA
Two review authors independently assessed the titles and abstracts of all reports identified by the electronic and manual searches. We included randomized and quasi-randomized trials that compared various medical (non-surgical) interventions versus other medical interventions or control groups for the treatment of traumatic hyphema following closed-globe trauma. We applied no restrictions on age, gender, severity of the closed-globe trauma, or level of visual acuity at time of enrollment.
DATA COLLECTION AND ANALYSIS
We used standard methodological procedures expected by Cochrane and assessed the certainty of evidence using GRADE.
MAIN RESULTS
We included 23 randomized and seven quasi-randomized studies with a total of 2969 participants. Interventions included antifibrinolytic agents (systemic and topical aminocaproic acid, tranexamic acid, and aminomethylbenzoic acid), corticosteroids (systemic and topical), cycloplegics, miotics, aspirin, conjugated estrogens, traditional Chinese medicine, monocular versus bilateral patching, elevation of the head, and bed rest. We found no evidence of an effect on visual acuity for any intervention, whether measured within two weeks (short term) or for longer periods. In a meta-analysis of two trials, we found no evidence of an effect of aminocaproic acid on long-term visual acuity (RR 1.03, 95% confidence interval (CI) 0.82 to 1.29) or final visual acuity measured up to three years after the hyphema (RR 1.05, 95% CI 0.93 to 1.18). Oral tranexamic acid appeared to provide little to no benefit on visual acuity in four trials (RR 1.12, 95% CI 1.00 to 1.25). The remaining trials evaluated the effects of various interventions on short-term visual acuity; none of these interventions was measured in more than one trial. No intervention showed a statistically significant effect (RRs ranged from 0.75 to 1.10). Similarly, visual acuity measured for longer periods in four trials evaluating different interventions was also not statistically significant (RRs ranged from 0.82 to 1.02). The evidence supporting these findings was of low or very low certainty. Systemic aminocaproic acid reduced the rate of recurrent hemorrhage (RR 0.28, 95% CI 0.13 to 0.60), as assessed in six trials with 330 participants. A sensitivity analysis omitting two studies not using an intention-to-treat analysis reduced the strength of the evidence (RR 0.43, 95% CI 0.17 to 1.08). We obtained similar results for topical aminocaproic acid (RR 0.48, 95% CI 0.20 to 1.10) in two trials with 131 participants. We assessed the certainty of the evidence as low. Systemic tranexamic acid had a significant effect in reducing the rate of secondary hemorrhage (RR 0.33, 95% CI 0.21 to 0.53) in seven trials with 754 participants, as did aminomethylbenzoic acid (RR 0.10, 95% CI 0.02 to 0.41), as reported in one study. Evidence to support an associated reduction in risk of complications from secondary hemorrhage (i.e. corneal blood staining, peripheral anterior synechiae, elevated intraocular pressure, and development of optic atrophy) by antifibrinolytics was limited by the small number of these events. Use of aminocaproic acid was associated with increased nausea, vomiting, and other adverse events compared with placebo. We found no evidence of an effect on the number of adverse events with the use of systemic versus topical aminocaproic acid or with standard versus lower drug dose. The number of days for the primary hyphema to resolve appeared to be longer with the use of systemic aminocaproic acid compared with no use, but this outcome was not altered by any other intervention. The available evidence on usage of systemic or topical corticosteroids, cycloplegics, or aspirin in traumatic hyphema was limited due to the small numbers of participants and events in the trials. We found no evidence of an effect between a single versus binocular patch on the risk of secondary hemorrhage or time to rebleed. We also found no evidence of an effect on the risk of secondary hemorrhage between ambulation and complete bed rest.
AUTHORS' CONCLUSIONS
We found no evidence of an effect on visual acuity of any of the interventions evaluated in this review. Although the evidence was limited, people with traumatic hyphema who receive aminocaproic acid or tranexamic acid are less likely to experience secondary hemorrhage. However, hyphema took longer to clear in people treated with systemic aminocaproic acid. There is no good evidence to support the use of antifibrinolytic agents in the management of traumatic hyphema, other than possibly to reduce the rate of secondary hemorrhage. The potentially long-term deleterious effects of secondary hemorrhage are unknown. Similarly, there is no evidence to support the use of corticosteroids, cycloplegics, or non-drug interventions (such as patching, bed rest, or head elevation) in the management of traumatic hyphema. As these multiple interventions are rarely used in isolation, further research to assess the additive effect of these interventions might be of value.
Topics: Humans; Adrenal Cortex Hormones; Aminocaproic Acid; Antifibrinolytic Agents; Aspirin; Glaucoma; Hyphema; Mydriatics; Tranexamic Acid
PubMed: 36912744
DOI: 10.1002/14651858.CD005431.pub5 -
Annals of Palliative Medicine Nov 2021Vascular punctures are widely used in clinical applications; however, clinical trials have identified complications and poor prognosis for patients undergoing common... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Vascular punctures are widely used in clinical applications; however, clinical trials have identified complications and poor prognosis for patients undergoing common peripheral vein puncture as compared to ultrasound-guided peripheral venipuncture and catheterization. Ultrasound-guided peripheral venipuncture and catheterization is accurate, simple, has fewer associated complications, and will gradually take the place of common peripheral vein puncture.
METHODS
To study the safety of ultrasound-guided peripheral venous catheterization, a meta-analysis was conducted of relevant articles dating from establishment date of the database (such as PubMed, MEDLINE and EMBASE) to March 2021, with the search keywords being peripheral venipuncture, ultrasound guidance, vascular injury rate, and hematoma formation rate. A total of 8 trials were used to determine accuracy indicators, which included puncture failure rate, arterial injury rate, hematoma formation rate, pneumothorax incidence rate, and hemothorax incidence rate.
RESULTS
There were statistically significant differences between the two methods for peripheral venipuncture and catheterization in terms of puncture failure rate [odds ratio (OR) =0.08; 95% CI: 0.04-0.16; P<0.00001], incidence of vascular injury (OR =0.15; 95% CI: 0.07-0.32; P<0.00001), probability of hematoma formation during the puncture process (OR =0.24; 95% CI: 0.08-0.69; P=0.008), and probability of pneumothorax during puncture (OR =0.10; 95% CI: 0.02-0.55; P=0.008).
DISCUSSION
Eight articles were included for meta-analysis. Ultrasound-guided peripheral venipuncture and catheterization is a commonly used puncture method for patients needing rapid fluid infusion with pressure or a pressure pump, repeated transfusion of blood product, or multiple daily venous blood drawing test. The results were very clear, and the puncture failure rate and other complications of ultrasound-guided peripheral venipuncture catheterization were low.
Topics: Catheterization, Central Venous; Clinical Trials as Topic; Humans; Incidence; Phlebotomy; Ultrasonography; Ultrasonography, Interventional
PubMed: 34872297
DOI: 10.21037/apm-21-3163 -
Molecular Psychiatry Apr 2023Neuroinflammatory processes have been hypothesized to play a role in the pathogenesis of psychiatric and neurological diseases. Studies on this topic often rely on... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Neuroinflammatory processes have been hypothesized to play a role in the pathogenesis of psychiatric and neurological diseases. Studies on this topic often rely on analysis of inflammatory biomarkers in peripheral blood. Unfortunately, the extent to which these peripheral markers reflect inflammatory processes in the central nervous system (CNS) is unclear.
METHODS
We performed a systematic review and found 29 studies examining the association between inflammatory marker levels in blood and cerebrospinal (CSF) samples. We performed a random effects meta-analysis of 21 studies (pooled n = 1679 paired samples) that reported the correlation of inflammatory markers in paired blood-CSF samples.
RESULTS
A qualitative review revealed moderate to high quality of included studies with the majority of studies reporting no significant correlation of inflammatory markers between paired blood-CSF. Meta-analyses revealed a significant low pooled correlation between peripheral and CSF biomarkers (r = 0.21). Meta-analyses of individual cytokines revealed a significant pooled correlation for IL-6 (r = 0.26) and TNFα (r = 0.3) after excluding outlier studies, but not for other cytokines. Sensitivity analyses showed that correlations were highest among participants with a median age above 50 (r = 0.46) and among autoimmune disorder patients (r = 0.35).
CONCLUSION
This systematic review and meta-analysis revealed poor correlation between peripheral and central inflammatory markers in paired blood-CSF samples, with increased correlations in certain study populations. Based on the current findings, peripheral inflammatory markers are a poor reflection of the neuroinflammatory profile.
Topics: Humans; Cytokines; Central Nervous System; Biomarkers
PubMed: 37055513
DOI: 10.1038/s41380-023-01976-6 -
International Journal of Molecular... Jan 2023Chemokines are known to be immunoregulatory proteins involved not only in lymphocyte chemotaxis to the site of inflammation, but also in neuromodulation, neurogenesis,... (Review)
Review
Chemokines are known to be immunoregulatory proteins involved not only in lymphocyte chemotaxis to the site of inflammation, but also in neuromodulation, neurogenesis, and neurotransmission. Multiple lines of evidence suggest a peripheral proinflammatory state and neuroinflammation in at least a third of patients with schizophrenia. Therefore, chemokines can be active players in these processes. In this systematic review, we analyzed the available data on chemokine dysregulation in schizophrenia and the association of chemokines with neuroinflammation. It has been shown that there is a genetic association of chemokine and chemokine receptor gene polymorphisms in schizophrenia. Besides, the most reliable data confirmed by the results of meta-analyses showed an increase in CXCL8/IL-8, CCL2/MCP-1, CCL4/MIP-1β, CCL11/eotaxin-1 in the blood of patients with schizophrenia. An increase in CXCL8 has been found in cerebrospinal fluid, but other chemokines have been less well studied. Increased/decreased expression of genes of chemokine and their receptors have been found in different areas of the brain and peripheral immune cells. The peripheral proinflammatory state may influence the expression of chemokines since their expression is regulated by pro- and anti-inflammatory cytokines. Mouse models have shown an association of schizophrenia with dysregulation of the CX3CL1-CX3CR1 and CXCL12-CXCR4 axes. Altogether, dysregulation in chemokine expression may contribute to neuroinflammation in schizophrenia. In conclusion, this evidence indicates the involvement of chemokines in the neurobiological processes associated with schizophrenia.
Topics: Animals; Mice; Schizophrenia; Neuroinflammatory Diseases; Chemokines; Cytokines; Chemokine CCL2; Chemokine CCL4; Chemotaxis, Leukocyte; Chemokine CCL5
PubMed: 36768537
DOI: 10.3390/ijms24032215 -
JAMA Network Open Dec 2022Peripheral neuropathies are common conditions and can result in numbness, paresthesia, motor deficits, and pain. There is increasing evidence for the use of biomarkers... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Peripheral neuropathies are common conditions and can result in numbness, paresthesia, motor deficits, and pain. There is increasing evidence for the use of biomarkers as clinical indicators of the presence, severity, and prognosis of nerve lesions; however, biomarker identification has largely been focused on disorders of the central nervous system, and less is known about their role in the peripheral nervous system.
OBJECTIVE
To assess blood-based biomarker concentrations associated with nerve involvement in patients with peripheral neuropathy compared with control participants.
DATA SOURCES
Ovid, MEDLINE, Embase, and CINAHL were searched from inception to September 23, 2021.
STUDY SELECTION
Observational studies reporting on blood biomarkers in patients diagnosed with peripheral neuropathy were included. This review was preregistered on PROSPERO and followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data were abstracted by 1 investigator and independently reviewed by a second.
DATA EXTRACTION AND SYNTHESIS
Data were meta-analyzed when at least 2 studies reported the same biomarker with comparable methodology. Fixed-effects models were used when only 2 studies were included; random-effects models were used when more than 2 studies were included.
MAIN OUTCOMES AND MEASURES
The outcome of interest was concentration of biomarkers.
RESULTS
This review included 36 studies reporting on 4414 participants, including 2113 control participants and 2301 patients with peripheral neuropathy with 13 distinct peripheral neuropathy diagnoses. Diabetic neuropathy was the most common neuropathy diagnosis (13 studies), followed by Charcot-Marie-Tooth disease (6 studies) and Guillain-Barre syndrome (6 studies). Overall, 16 different blood-based biomarkers associated with nerve involvement were evaluated. The most used were neurofilament light chain, S100B, brain-derived neurotrophic factor, and neuron-specific enolase. Patients with peripheral neuropathy demonstrated significantly higher levels of neurofilament light chain compared with controls (standardized mean difference [SMD], 0.93 [95% CI, 0.82 to 1.05]; P < .001). There were no significant differences in levels of S100B (SMD, 1.10 [95% CI, -3.08 to 5.28]; P = .38), brain-derived neurotrophic factor (SMD, -0.52 [95% CI, -2.23 to 1.19]; P = .40), or neuron-specific enolase (SMD, -0.00 [95% CI, -1.99 to 1.98]; P = .10) in patients with peripheral neuropathy compared with control participants.
CONCLUSIONS AND RELEVANCE
The findings of this systematic review and meta-analysis support the use of neurofilament light chain as a blood-based measure associated with the presence of neuronal injury in patients with peripheral neuropathy.
Topics: Humans; Adult; Brain-Derived Neurotrophic Factor; Biomarkers; Diabetic Neuropathies; Prognosis; Pain
PubMed: 36574244
DOI: 10.1001/jamanetworkopen.2022.48593 -
Reviews on Environmental Health Mar 2023Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens.... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Inappropriate processing and disposal of electronic waste (e-waste) expose workers and surrounding populations to hazardous chemicals, including clastogens and aneugens. Recently, considerable literature has grown around e-waste recycling, associated chemical exposures and intermediate health outcomes, including DNA damage. Micronuclei (MN) frequency has been widely used as a biomarker to investigate DNA damage in human populations exposed to genotoxic agents. We conducted a systematic review of published studies to assess DNA damage in e-waste-exposed populations and performed a meta-analysis to evaluate the association between e-waste exposure and DNA damage.
METHODS
This systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement checklist. Articles published in English from January 2000 through December 2020 investigating the associations between e-waste exposure and DNA damage were retrieved from the following three major databases: MEDLINE, ProQuest, and Scopus. Studies that reported the use of MN assay as a biomarker of DNA damage were included for meta-analysis. Studies that also reported other DNA damage biomarkers such as chromosomal aberrations, comet assay biomarkers, 8-hydroxy-2'-deoxyguanosine (8-OHdG), telomere length, apoptosis rate were reported using narrative synthesis.
RESULTS
A total of 20 publications were included in this review, of which seven studies were within the occupational setting, and the remaining 13 studies were ecological studies. The review found six biomarkers of DNA damage (micronuclei, comets assay parameters (tail length, % tail DNA, tail moment, and olive tail moment), 8-OHdG, telomere length, apoptosis rate and chromosomal aberrations) which were assessed using seven different biological matrices (buccal cells, blood, umbilical cord blood, placenta, urine and semen). Most studies showed elevated levels of DNA damage biomarkers among e-waste exposed populations than in control populations. The most commonly used biomarkers were micronuclei frequency (n=9) in peripheral blood lymphocytes or buccal cells and 8-OHdG (n=7) in urine. The results of the meta-analysis showed that electronic waste recycling has contributed to an increased risk of DNA damage measured using MN frequency with a pooled estimate of the standardized mean difference (SMD) of 2.30 (95% CI: 1.36, 3.24, p<0.001) based on 865 participants.
CONCLUSIONS
Taken together, evidence from this systematic review with meta-analysis suggest that occupational and non-occupational exposure to e-waste processing is associated with increased risk of DNA damage measured through MN assay and other types of DNA damage biomarkers. However, more studies from other developing countries in Africa, Latin America, and South Asia are needed to confirm and increase these results' generalizability.
Topics: Humans; Electronic Waste; Mouth Mucosa; DNA Damage; Chromosome Aberrations; Biomarkers
PubMed: 34727591
DOI: 10.1515/reveh-2021-0074