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Fulltext A Review of L-Asparaginase Hypersensitivity in Paediatric Acute Lymphoblastic Leukaemia Patients with Regard to the Measurement of Anti-Asparaginase Antibodies and Their Genetic Predisposition

Tan YQ, Loh CK, Makpol S

Malays J Med Sci, 2023 Oct;30(5):40-51.
PMID: 37928798 DOI: 10.21315/mjms2023.30.5.4

L-asparaginase is effective as part of the first line childhood acute lymphoblastic leukaemia (ALL) treatment regimen but suffers the risk of antibody production causing immune-mediated sequelae. This article aimed to describe the clinical implication of L-asparaginase hypersensitivity and review the types of antibodies and genetic polymorphisms contributing to it. Clinical or subclinical L-asparaginase hypersensitivity may lead to suboptimum therapeutic effect and jeopardise the clinical outcome in ALL children. Anti-asparaginase antibodies immunoglobulin (Ig)G, IgM and IgE were identified in the L-asparaginase hypersensitivities. Enzyme-linked immunosorbent assay (ELISA) is commonly used to quantify the IgG and IgM levels. The role of IgE in mediating L-asparaginase hypersensitivity is contradictory. Moreover, the presence of antibodies may not necessarily correlate inversely with the L-asparaginase efficacies in some studies. Patients with specific genetic variants have been shown to be more susceptible to clinical hypersensitivity of L-asparaginase. With the advance of technology, gene polymorphisms have been identified among Caucasians using whole-genome or exon sequencing, but the evidence is scanty among Asians. There is lack of pre-clinical study models that could help in understanding the pathophysiological pathway co-relating the gene expression and anti-asparaginase antibody formation. In conclusion, future research studies are required to fill the current gap in understanding the immune mediated reactions towards L-asparaginase upon its administration and its potential impact to the disease outcome.
Altered gut microbiome and metabolome in patients with multiple system atrophy

Tan AH, Chong CW, Song SL, Teh CSJ, Yap IKS, Loke MF, et al.

Mov Disord, 2018 01;33(1):174-176.
PMID: 29083071 DOI: 10.1002/mds.27203
Gut Microbial Ecosystem in Parkinson Disease: New Clinicobiological Insights from Multi-Omics

Tan AH, Chong CW, Lim SY, Yap IKS, Teh CSJ, Loke MF, et al.

Ann Neurol, 2021 03;89(3):546-559.
PMID: 33274480 DOI: 10.1002/ana.25982

OBJECTIVE: Gut microbiome alterations in Parkinson disease (PD) have been reported repeatedly, but their functional relevance remains unclear. Fecal metabolomics, which provide a functional readout of microbial activity, have scarcely been investigated. We investigated fecal microbiome and metabolome alterations in PD, and their clinical relevance.
METHODS: Two hundred subjects (104 patients, 96 controls) underwent extensive clinical phenotyping. Stool samples were analyzed using 16S rRNA gene sequencing. Fecal metabolomics were performed using two platforms, nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry.
RESULTS: Fecal microbiome and metabolome composition in PD was significantly different from controls, with the largest effect size seen in NMR-based metabolome. Microbiome and NMR-based metabolome compositional differences remained significant after comprehensive confounder analyses. Differentially abundant fecal metabolite features and predicted functional changes in PD versus controls included bioactive molecules with putative neuroprotective effects (eg, short chain fatty acids [SCFAs], ubiquinones, and salicylate) and other compounds increasingly implicated in neurodegeneration (eg, ceramides, sphingosine, and trimethylamine N-oxide). In the PD group, cognitive impairment, low body mass index (BMI), frailty, constipation, and low physical activity were associated with fecal metabolome compositional differences. Notably, low SCFAs in PD were significantly associated with poorer cognition and low BMI. Lower butyrate levels correlated with worse postural instability-gait disorder scores.
INTERPRETATION: Gut microbial function is altered in PD, characterized by differentially abundant metabolic features that provide important biological insights into gut-brain pathophysiology. Their clinical relevance further supports a role for microbial metabolites as potential targets for the development of new biomarkers and therapies in PD. ANN NEUROL 2021;89:546-559.
Fulltext Psychological Health of Surgeons in a Time of COVID-19: A Global Survey

Tan YQ, Wang Z, Yap QV, Chan YH, Ho RC, Hamid ARAH, et al.

Ann Surg, 2023 Jan 01;277(1):50-56.
PMID: 33491983 DOI: 10.1097/SLA.0000000000004775

OBJECTIVE: To assess the degree of psychological impact among surgical providers during the COVID-19 pandemic.
SUMMARY OF BACKGROUND DATA: The COVID-19 pandemic has extensively impacted global healthcare systems. We hypothesized that the degree of psychological impact would be higher for surgical providers deployed for COVID-19 work, certain surgical specialties, and for those who knew of someone diagnosed with, or who died, of COVID-19.
METHODS: We conducted a global web-based survey to investigate the psychological impact of COVID-19. The primary outcomes were the depression anxiety stress scale-21 and Impact of Event Scale-Revised scores.
RESULTS: A total of 4283 participants from 101 countries responded. 32.8%, 30.8%, 25.9%, and 24.0% screened positive for depression, anxiety, stress, and PTSD respectively. Respondents who knew someone who died of COVID-19 were more likely to screen positive for depression, anxiety, stress, and PTSD (OR 1.3, 1.6, 1.4, 1.7 respectively, all P < 0.05). Respondents who knew of someone diagnosed with COVID-19 were more likely to screen positive for depression, stress, and PTSD (OR 1.2, 1.2, and 1.3 respectively, all P < 0.05). Surgical specialties that operated in the head and neck region had higher psychological distress among its surgeons. Deployment for COVID- 19-related work was not associated with increased psychological distress.
CONCLUSIONS: The COVID-19 pandemic may have a mental health legacy outlasting its course. The long-term impact of this ongoing traumatic event underscores the importance of longitudinal mental health care for healthcare personnel, with particular attention to those who know of someone diagnosed with, or who died of COVID-19.
Fulltext Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

Klionsky DJ, Abdel-Aziz AK, Abdelfatah S, Abdellatif M, Abdoli A, Abel S, et al.

Autophagy, 2021 Jan;17(1):1-382.
PMID: 33634751 DOI: 10.1080/15548627.2020.1797280

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.