The role of phase I, phase II, and DNA-repair gene polymorphisms in the damage induced by formaldehyde in pathologists

The Impact of Genetic Polymorphisms on Genotoxicity (DNA Damage) Induced by Cigarette Smoke in Humans: A Systematic Review

The present systematic review aims to put together human population studies that include some relationship between genetic polymorphisms and genotoxicity as well as to evaluate the quality of the published studies induced by cigarette smoke exposure in vivo. The present systematic review was built according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Different genotoxicity assays were used by different authors, although the major goal was the genotoxicity assessment by means of micronucleus, comet, sister chromatid exchange, and chromosomal aberration assays. Also, different genetic polymorphisms were analyzed by different authors, being closely related to xenobiotics metabolizing and DNA repair genes. Our aim, therefore, was to collect these data so that a quality assessment could be properly carried out. Out of the 18 included studies, 15 reported genotoxicity due to cigarette smoking, and all of these reported some association between a genetic polymorphism and the aforementioned genotoxicity. Also, 14 studies were classified as either strong or moderate, which suggests the aforementioned findings can be trusted in regard to the studies' quality. Taken as a whole, the results suggest that genes associated with detoxification genes and DNA repair genes play a substantial role in the determination of an individual's susceptibility to genomic damage due to cigarette smoking.

The mutagenic properties of formaldehyde and acetaldehyde: Reflections on half a century of progress

Formaldehyde and acetaldehyde are reactive, small compounds that humans are exposed to routinely, variously from endogenous and exogenous sources. Both small aldehydes are classified as human carcinogens. Investigation of the DNA damaging properties of these two compounds began some 50 years ago. In this review, we summarize progress in this field since its inception over half a century ago, distilling insights gained by the collective efforts of many research groups while highlighting areas for future directions. Over the decades, general consensus about aspects of the mutagenicity of formaldehyde and acetaldehyde has been reached. But other characteristics of formaldehyde and acetaldehyde remain incompletely understood and require additional investigation. These include crucial details about the mutational signature(s) induced and possible mechanistic role(s) during carcinogenesis.

The impact of genetic polymorphism for detecting genotoxicity in workers occupationally exposed to formaldehyde: A systematic review

Formaldehyde is a chemical compound capable of preserving cells and tissue morphology, being extensively used worldwide in industrial and medical processes. However, due to the many biological effects that take place after an individual is chronically exposed to formaldehyde, this compound poses a greater cancer risk for workers under its occupational exposure, even at lower concentrations. Thus, the present systematic review aimed to understand whether there may be a positive relation between polymorphism (in terms of individual susceptibility) and genotoxicity in individuals occupationally exposed to formaldehyde. For this purpose, a total of eight selected studies were carefully analyzed by two reviewers, who attributed scores to each study according to the used analysis parameters. First, all studies investigated either pathologists under formaldehyde exposure or anatomical laboratory pathology workers. In addition, the majority of studies were categorized as moderate or strong in the quality assessment. The results revealed a positive association between some polymorphism and genotoxicity in individuals exposed to formaldehyde, since more than half of the studies observed positive relations between genotoxicity and polymorphisms in xenobiotics metabolizing genes. We understand such parameters influence individuals' susceptibility to genomic damage induced by formaldehyde in peripheral blood. In conclusion, individuals with certain genotypes may show higher or lower DNA damage and/or lower or higher DNA repair potential.

Regular Sport Activity Is Able to Reduce the Level of Genomic Damage

Regular physical activity is considered one of the most valid tools capable of reducing the risk of onset of many diseases in humans. However, it is known that intense physical activity can induce high levels of genomic damage, while moderate exercise can elicit a favorable adaptive response by the organism. We evaluated, by the buccal micronuclei assay, the frequencies of micronuclei, nuclear buds and binucleated cells in a sample of amateur athletes practicing different disciplines, comparing the obtained data with those of subjects who practiced sports just occasionally and subjects that did not practice sport at all. The aim was to evaluate whether physical activity affects background levels of genomic damage and whether the different sports disciplines, as well as some gene polymorphisms, differentially affect these levels. A total of 206 subjects, 125 athletes and 81 controls, were recruited. Athletes showed significantly lower values of micronuclei, nuclear buds and binucleated cells with respect to controls. Sprinters and Martial Artists displayed significantly higher frequencies of micronuclei than other categories of athletes. Finally, neither sex nor gene polymorphisms seemed to influence the levels of genomic damage, confirming that the observed genomic damage is probably due to the nature of the sport activity.

Pre-existing non-human leukocyte antigen antibodies are associated with allograft rejection after thoracic transplantation

BACKGROUND

There is growing evidence on the important role of non-human leukocyte antigen (HLA) antibodies in lung and heart transplant rejection. Since data on the prevalence and clinical significance of non-HLA antibodies in the Asian population are scarce, we analyzed non-HLA antibodies in heart and lung transplant patients.

METHODS

We used the Luminex method to measure non-HLA antibodies in patients who underwent heart transplantation (N = 28) or lung transplantation (N = 36) between 2016 and 2019. We evaluated the association between pre-existing non-HLA antibodies and acute rejection-free days in these recipients.

RESULTS

Of 64 patients, 27 (42.2%) patients underwent rejection, with 26 (40.6%) acute cellular rejection and one (1.6%) acute antibody-mediated rejection. Among 33 identified different non-HLA antibodies, only the anti-glutathione S-transferase theta-1 (GSTT1) antibody positive rate was significantly higher in patients with acute rejection compared to those without rejection (14.8% vs. 0%, p = 0.016). The angiotensin II type I receptor positive rate was not significantly different between the two groups (40% vs. 18.5%, p = 0.129). In the multivariate Cox regression analysis, anti-GSTT1 antibody-positive patients had a higher risk of acute allograft rejection (hazard ratio, 4.19; 95% confidence interval [CI], 1.41-12.49; p = 0.010). The Kaplan-Meier curve showed that anti-GSTT1 antibody-positive patients had fewer acute rejection-free days (χ² = 7.892; p = 0.005). Additionally, patients who underwent platelet transfusion (odds ratio, 1.49; 95% CI, 1.16-1.91; p = 0.002) before transplantation were more likely to be positive for anti-GSTT1 antibody.

CONCLUSION

Patients with antibodies against GSTT1 before heart or lung transplantation have an increased risk of acute rejection.

The formation of SCEs as an effect of occupational exposure to formaldehyde

Formaldehyde (FA) is a ubiquitous toxic chemical employed worldwide due to its disinfectant and preservative properties. Despite being classified as a human carcinogen, FA is still employed as formalin in pathology wards as standard fixative. We evaluated its relationship with the formation of sister-chromatid exchanges (SCEs) in cultured peripheral blood lymphocytes on 57 pathologists and 48 controls and the risk/protective role played by several genetic polymorphisms. All subjects were assessed for SCEs and genotyped for the most common cancer-associated gene polymorphisms: CYP1A1 exon 7 (A > G), CYP1A1*2A (T > C), CYP2C19*2 (G > A), GSTT1 (presence/absence), GSTM1 (presence/absence), GSTP1 (A > G), XRCC1 (G399A), XRCC1 (C194T), XRCC1 (A280G), XPC exon 15 (A939C), XPC exon 9 (C499T), TNFα − 308 G > A), IL10 − 1082 (G > A), and IL6 − 174 (G > C). Air-FA concentration was assessed through passive personal samplers. Pathologists, exposed to 55.2 μg/m³ of air-FA, showed a significantly higher SCEs frequency than controls, exposed, respectively, to 18.4 μg/m³. Air-FA was directly correlated with SCEs frequency and inversely with the replication index (RI). Regression models showed FA exposure as a significant predictor in developing SCEs, while did not highlight any role of the selected polymorphisms. Our study confirms the role of low air-FA levels as genotoxicity inductor, highlighting the importance to define exposure limits that could be safer for exposed workers.

Formaldehyde in Hospitals Induces Oxidative Stress: The Role of GSTT1 and GSTM1 Polymorphisms

Despite the toxicity and health risk characteristics of formaldehyde (FA), it is currently used as a cytological fixative and the definition of safe exposure levels is still a matter of debate. Our aim was to investigate the alterations in both oxidative and inflammatory status in a hospital working population. The 68 workers recruited wore a personal air-FA passive sampler, provided a urine sample to measure 15-F_2t-Isoprostane (15-F_2t-IsoP) and malondialdehyde (MDA) and a blood specimen to measure tumour necrosis factor α (TNFα). Subjects were also genotyped for GSTT1 (Presence/Absence), GSTM1 (Presence/Absence), CYP1A1 exon 7 (A > G), and IL6 (−174, G > C). Workers were ex post split into formalin-employers (57.3 μg/m³) and non-employers (13.5 μg/m³). In the formalin-employers group we assessed significantly higher levels of 15-F_2t-IsoP, MDA and TNFα (<0.001) in comparison to the non-employers group. The air-FA levels turned out to be positively correlated with 15-F_2t-IsoP (p = 0.027) and MDA (p < 0.001). In the formalin-employers group the MDA level was significantly higher in GSTT1 Null (p = 0.038), GSTM1 Null (p = 0.031), and CYP1A1 exon 7 mutation carrier (p = 0.008) workers, compared to the wild type subjects. This study confirms the role of FA in biomolecular profiles alterations, highlighting how low occupational exposure can also result in measurable biological outcomes.