Displaying publications 21 - 40 of 59 in total

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  1. Hussein N, Rajasuriar R, Khan AM, Lim YA, Gan GG
    Mol Cancer Res, 2024 Jan 02;22(1):7-20.
    PMID: 37906201 DOI: 10.1158/1541-7786.MCR-23-0080
    Humans are in a complex symbiotic relationship with a wide range of microbial organisms, including bacteria, viruses, and fungi. The evolution and composition of the human microbiome can be an indicator of how it may affect human health and susceptibility to diseases. Microbiome alteration, termed as dysbiosis, has been linked to the pathogenesis and progression of hematological cancers. A variety of mechanisms, including epithelial barrier disruption, local chronic inflammation response trigger, antigen dis-sequestration, and molecular mimicry, have been proposed to be associated with gut microbiota. Dysbiosis may be induced or worsened by cancer therapies (such as chemotherapy and/or hematopoietic stem cell transplantation) or infection. The use of antibiotics during treatment may also promote dysbiosis, with possible long-term consequences. The aim of this review is to provide a succinct summary of the current knowledge describing the role of the microbiome in hematological cancers, as well as its influence on their therapies. Modulation of the gut microbiome, involving modifying the composition of the beneficial microorganisms in the management and treatment of hematological cancers is also discussed. Additionally discussed are the latest developments in modeling approaches and tools used for computational analyses, interpretation and better understanding of the gut microbiome data.
  2. Kalidasan V, Suresh D, Zulkifle N, Hwei YS, Kok Hoong L, Rajasuriar R, et al.
    Bioinform Biol Insights, 2024;18:11779322241234772.
    PMID: 38425413 DOI: 10.1177/11779322241234772
    D-amino acid oxidase (DAO) is a flavoenzyme that metabolizes D-amino acids by oxidative deamination, producing hydrogen peroxide (H2O2) as a by-product. The generation of intracellular H2O2 may alter the redox-homeostasis mechanism of cells and increase the oxidative stress levels in tissues, associated with the pathogenesis of age-related diseases and organ decline. This study investigates the effect of DAO knockdown using clustered regularly interspaced short palindromic repeats (CRISPR) through an in silico approach on its protein-protein interactions (PPIs) and their potential roles in the process of aging. The target sequence and guide RNA of DAO were designed using the CCTop database, PPI analysis using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, Reactome biological pathway, protein docking using GalaxyTongDock database, and structure analysis. The translated target sequence of DAO lies between amino acids 43 to 50. The 10 proteins that were predicted to interact with DAO are involved in peroxisome pathways such as acyl-coenzyme A oxidase 1 (ACOX1), alanine-glyoxylate and serine-pyruvate aminotransferase (AGXT), catalase (CAT), carnitine O-acetyltransferase (CRAT), glyceronephosphate O-acyltransferase (GNPAT), hydroxyacid oxidase 1 (HAO1), hydroxyacid oxidase 2 (HAO2), trans-L-3-hydroxyproline dehydratase (L3HYPDH), polyamine oxidase (PAOX), and pipecolic acid and sarcosine oxidase (PIPOX). In summary, DAO mutation would most likely reduce activity with its interacting proteins that generate H2O2. However, DAO mutation may result in peroxisomal disorders, and thus, alternative techniques should be considered for an in vivo approach.
  3. Ho WY, Neelamegam M, Earnshaw VA, Chong V, Lee HG, Rajasuriar R
    AIDS Behav, 2024 May;28(5):1601-1611.
    PMID: 38261221 DOI: 10.1007/s10461-024-04272-8
    Globally and in Malaysia, there are increasing rates of HIV infection among older adults but a corresponding decline in other younger age groups. We aimed to investigate the HIV-related knowledge, perceived risks, attitudes, and risk behaviours among multi-ethnic urban-dwelling older adults in Malaysia. A cross-sectional, questionnaire-based study was conducted among 320 adults aged 50 years and above residing in urban Klang Valley, Malaysia. Participants were recruited via convenience sampling in the community and in the outpatient clinics and pharmacy of University Malaya Medical Centre, Malaysia, from April 2021 to January 2022. The median (IQR) age of participants was 58 (55-64) and 42.5% were males. The median (IQR) knowledge score was 10 (8-12) out of 14. Significant knowledge gaps were noted and ethnic Chinese, higher education levels and better HIV-related attitudes were associated with better scores. The median (IQR) attitude score was 49 (41-55) out of 65. Ethnic Chinese and Indian, knowing people living with HIV (PLHIV), and better HIV-related knowledge were associated with better attitude scores. Many (43.8%) older adults were sexually active however rates of consistent condom use was low (19%) and the majority (89.9%) of participants had low self-perceived risk of HIV. These findings highlight underlying drivers for HIV transmission and delayed treatment among older adults in Malaysia and indicate a need for targeted HIV prevention programs for this population.
  4. Chua LL, Rajasuriar R, Lim YAL, Woo YL, Loke P, Ariffin H
    BMC Cancer, 2020 Feb 24;20(1):151.
    PMID: 32093640 DOI: 10.1186/s12885-020-6654-5
    BACKGROUND: Alteration in gut microbiota has been recently linked with childhood leukemia and the use of chemotherapy. Whether the perturbed microbiota community is restored after disease remission and cessation of cancer treatment has not been evaluated. This study examines the chronological changes of gut microbiota in children with acute lymphoblastic leukemia (ALL) prior to the start-, during-, and following cessation of chemotherapy.

    METHODOLOGY: We conducted a longitudinal observational study in gut microbiota profile in a group of paediatric patients diagnosed with ALL using 16 s ribosomal RNA sequencing and compared these patients' microbiota pattern with age and ethnicity-matched healthy children. Temporal changes of gut microbiota in these patients with ALL were also examined at different time-points in relation to chemotherapy.

    RESULTS: Prior to commencement of chemotherapy, gut microbiota in children with ALL had larger inter-individual variability compared to healthy controls and was enriched with bacteria belonging to Bacteroidetes phylum and Bacteroides genus. The relative abundance of Bacteroides decreased upon commencement of chemotherapy. Restitution of gut microbiota composition to resemble that of healthy controls occurred after cessation of chemotherapy. However, the microbiota composition (beta diversity) remained distinctive and a few bacteria were different in abundance among the patients with ALL compared to controls despite completion of chemotherapy and presumed restoration of normal health.

    CONCLUSION: Our findings in this pilot study is the first to suggest that gut microbiota profile in children with ALL remains marginally different from healthy controls even after cessation of chemotherapy. These persistent microbiota changes may have a role in the long-term wellbeing in childhood cancer survivors but the impact of these changes in subsequent health perturbations in these survivors remain unexplored.

  5. Rajasuriar R, Kong YY, Nadarajah R, Abdullah NK, Spelman T, Yuhana MY, et al.
    J Transl Med, 2015;13:30.
    PMID: 25622527 DOI: 10.1186/s12967-015-0391-6
    HIV-infected individuals have an increased risk of cardiovascular disease (CVD). T-allele carriers of the CD14 C-260T single-nucleotide polymorphism (SNP) have reported increased expression of the LPS-binding receptor, CD14 and inflammation in the general population. Our aim was to explore the relationship of this SNP with monocyte/macrophage activation and inflammation and its association with sub-clinical atherosclerosis in HIV-infected individuals.
  6. Petoumenos K, Choi JY, Hoy J, Kiertiburanakul S, Ng OT, Boyd M, et al.
    Antivir Ther, 2017;22(8):659-668.
    PMID: 28291735 DOI: 10.3851/IMP3155
    BACKGROUND: In the era of effective antiretroviral treatment (ART) CD4:CD8 ratio is proposed as a potential marker for HIV-positive (HIV+) patients at increased risk for non-AIDS comorbidities. The current study aims to compare CD4:CD8 ratio between Asian and Caucasian HIV+ patients.

    METHODS: HIV+ patients from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD) meeting specific criteria were included. In these analyses Asian and Caucasian status were defined by cohort. Factors associated with a low CD4:CD8 ratio (cutoff <0.2) prior to ART commencement, and with achieving a normal CD4:CD8 ratio (>1) at 12 and 24 months post ART commencement were assessed using logistic regression.

    RESULTS: There were 591 patients from AHOD and 2,620 patients from TAHOD who met the inclusion criteria. TAHOD patients had a significantly (P<0.001) lower odds of having a baseline (prior to ART initiation) CD4:CD8 ratio greater than 0.2. After 12 months of ART, AHOD patients were more than twice as likely to achieve a normal CD4:CD8 ratio compared to TAHOD patients (15% versus 6%). However, after adjustment for confounding factors there was no significant difference between cohorts in the odds of achieving a CD4:CD8 ratio >1 (P=0.475).

    CONCLUSIONS: We found a significantly lower CD4:CD8 ratio prior to commencing ART in TAHOD compared to AHOD even after adjusting for confounders. However, after adjustment, there was no significant difference between the cohorts in odds of achieving normal ratio. Baseline CD4+ and CD8+ counts seem to be the main driver for this difference between these two populations.

  7. Leng CY, Low HC, Chua LL, Chong ML, Sulaiman H, Azwa I, et al.
    HIV Med, 2017 05;18(5):321-331.
    PMID: 27649852 DOI: 10.1111/hiv.12432
    OBJECTIVES: Human papillomavirus (HPV)-associated cancers disproportionately affect those infected with HIV despite effective combination antiretroviral therapy (cART). The primary aim of this study was to quantify HPV16 and HPV52 E6-specific interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) T-cell responses, a correlate of protective immunity, in the first year following cART initiation and subsequently in those patients with suboptimal (sIR) and optimal (oIR) immune reconstitution.

    METHODS: Ninety-four HIV-infected patients were recruited to the study; a longitudinal cohort of patients recruited just prior to commencing cART and followed up for 48 weeks (n = 27), and a cross-sectional cohort (n = 67) consisting of patients with sIR (CD4 T-cell count < 350 cells/μL) and oIR (CD4 T-cell count > 500 cells/μL) after a minimum of 2 years on cART. Controls (n = 29) consisted of HIV-negative individuals. IFN-γ ELISPOT responses against HPV16 and HPV52 E6 were correlated to clinical characteristics, anal and oral HPV carriage, T-cell maturational subsets, markers of activation, senescence and T-regulatory cells.

    RESULTS: HPV16 and HPV52 E6-specific T-cell responses were detected in only one of 27 patients (3.7%) during the initial phase of immune recovery. After at least 2 years of cART, those who achieved oIR had significantly higher E6-specific responses (9 of 34; 26.5%) compared with those with sIR (2 of 32; 6.3%) (P = 0.029). Apart from higher CD4 T-cell counts and lower CD4 T-cell activation, no other immunological correlates were associated with the detection of HPV16 and HPV52 E6-specific responses.

    CONCLUSIONS: HPV16 and HPV52 E6-specific IFN-γ T-cell responses, a correlate of protective immunity, were detected more frequently among HIV-infected patients who achieved optimal immune recovery on cART (26.5%) compared with those with suboptimal recovery (6.3%).

  8. Chan YT, Cheong HC, Tang TF, Rajasuriar R, Cheng KK, Looi CY, et al.
    Biomedicines, 2022 Nov 04;10(11).
    PMID: 36359329 DOI: 10.3390/biomedicines10112809
    The progressive decline of CD8+ cytotoxic T cells in human immunodeficiency virus (HIV)-infected patients due to infection-triggered cell exhaustion and cell death is significantly correlated with disease severity and progression into the life-threatening acquired immunodeficiency syndrome (AIDS) stage. T cell exhaustion is a condition of cell dysfunction despite antigen engagement, characterized by augmented surface expression of immune checkpoint molecules such as programmed cell death protein 1 (PD-1), which suppress T cell receptor (TCR) signaling and negatively impact the proliferative and effector activities of T cells. T cell function is tightly modulated by cellular glucose metabolism, which produces adequate energy to support a robust reaction when battling pathogen infection. The transition of the T cells from an active to an exhausted state following pathogen persistence involves a drastic change in metabolic activity. This review highlights the interplay between immune checkpoint molecules and glucose metabolism that contributes to T cell exhaustion in the context of chronic HIV infection, which could deliver an insight into the rational design of a novel therapeutic strategy.
  9. Khoo SP, Muhammad Ridzuan Tan NA, Rajasuriar R, Nasir NH, Gravitt P, Ng CW, et al.
    PLoS One, 2022;17(12):e0278477.
    PMID: 36538522 DOI: 10.1371/journal.pone.0278477
    To increase the coverage of HPV vaccination, Malaysia implemented a national school-based vaccination program for all 13-year-old girls in 2010. Two years later, a clinic-based catch-up program was started for 16 to 21-year-old girls. We assessed the prevalence of a range of HPV genotypes, among a sample of urban women within the age groups of 18-24 and 35-45 years in 2019-2020, a decade into the national vaccination program. The HPV prevalence was then compared to that reported in an unvaccinated population in 2013-2015. We sampled a total of 1134 participants, comprising of 277 women aged 18-24 years and 857 women aged 35-45 years, from several urban clinics in the state of Selangor. Participants provided a self-acquired vaginal sample for HPV genotyping. Comprehensive sociodemographic and vaccination history were collected. The HPV vaccination coverage among women in the younger age group increased from 9.3% in 2013-2015 to 75.5% in 2019-2020. The prevalence of vaccine-targeted HPV16/18 decreased 91% (CI: 14.5%-99.0%) among the younger women, from 4.0% in 2013-2015 to 0.4% in 2019-2020. There was also an 87% (CI: 27.5%-97.5%) reduction in HPV6/11/16/18. There was no difference in the prevalence of non-vaccine targeted HPV genotypes among younger women. The HPV prevalence among older women, for both vaccine targeted and non-vaccine targeted genotypes in 2019-2020, did not differ from 2013-2015. The observed decline in prevalence of vaccine-targeted HPV genotype among younger women a decade after the national HPV vaccination program is an early indication of its effectiveness in reducing the burden of cervical cancer.
  10. Barber TJ, Crabtree B, Cortes CP, Guaraldi G, Hoy JF, Rajasuriar R, et al.
    AIDS Care, 2023 Aug;35(8):1149-1153.
    PMID: 36994591 DOI: 10.1080/09540121.2023.2190956
    ABSTRACTGlobally the community of people with HIV is ageing, and some of these have increasingly complex care needs, with a known excess of non-HIV related comorbidities and related issues including consequent polypharmacy. At the 2022 International AIDS Conference in Montréal, Canada, the "Silver Zone" was created in the Global Village as a safe space for older people with HIV. As part of the Silver Zone activities, a session discussing global models of care for in this group was held. HIV treatment providers and advocates from diverse resource settings and with a diversity of expertise were invited to share their experience, reflections, and ideas, and this consensus statement was formed based on these discussions. Different approaches to care emerged, based on local needs and resources, and it became clear that issues of complexity and frailty need not be age limited. Despite clear regional differences, some common themes became apparent, and a consensus was established on basic principles that may be considered in diverse settings. These are discussed here, with agreement on necessary proximal steps to develop bespoke person-centred care models.
  11. Yap SH, Lee CS, Zulkifli ND, Suresh D, Hamase K, Das KT, et al.
    Amino Acids, 2024 Feb 03;56(1):6.
    PMID: 38310167 DOI: 10.1007/s00726-023-03360-8
    Studies in vivo have demonstrated that the accumulation of D-amino acids (D-AAs) is associated with age-related diseases and increased immune activation. However, the underlying mechanism(s) of these observations are not well defined. The metabolism of D-AAs by D-amino oxidase (DAO) produces hydrogen peroxide (H2O2), a reactive oxygen species involved in several physiological processes including immune response, cell differentiation, and proliferation. Excessive levels of H2O2 contribute to oxidative stress and eventual cell death, a characteristic of age-related pathology. Here, we explored the molecular mechanisms of D-serine (D-Ser) and D-alanine (D-Ala) in human liver cancer cells, HepG2, with a focus on the production of H2O2 the downstream secretion of pro-inflammatory cytokine and chemokine, and subsequent cell death. In HepG2 cells, we demonstrated that D-Ser decreased H2O2 production and induced concentration-dependent depolarization of mitochondrial membrane potential (MMP). This was associated with the upregulation of activated NF-кB, pro-inflammatory cytokine, TNF-α, and chemokine, IL-8 secretion, and subsequent apoptosis. Conversely, D-Ala-treated cells induced H2O2 production, and were also accompanied by the upregulation of activated NF-кB, TNF-α, and IL-8, but did not cause significant apoptosis. The present study confirms the role of both D-Ser and D-Ala in inducing inflammatory responses, but each via unique activation pathways. This response was associated with apoptotic cell death only with D-Ser. Further research is required to gain a better understanding of the mechanisms underlying D-AA-induced inflammation and its downstream consequences, especially in the context of aging given the wide detection of these entities in systemic circulation.
  12. Meng Li C, Jie Ying F, Raj D, Pui Li W, Kukreja A, Omar SF, et al.
    J Int AIDS Soc, 2020 Nov;23(11):e25638.
    PMID: 33206473 DOI: 10.1002/jia2.25638
    INTRODUCTION: The rapidly growing epidemic of non-communicable diseases (NCDs) including mental health among aging people living with HIV (PLWH) has put a significant strain on the provision of health services in many HIV clinics globally. We constructed care cascades for specific NCDs and mental health among PLWH attending our centre to identify potential areas for programmatic improvement.

    METHODS: This was a follow-up study of participants recruited in the Malaysian HIV & Aging study (MHIVA) from 2014 to 2016 at the University Malaya Medical Centre (n = 336). PLWH on suppressive antiretroviral therapy (ART) for a minimum of 12 months were invited to participate. At study entry, all participants underwent screening for diabetes (DM), hypertension (HTN) and dyslipidaemia; and completed assessments using the depression, anxiety and stress scale (DASS-21). Screening results were recorded in medical charts and clinical management provided as per standard of care. A subsequent review of medical records was performed at 24 months following study completion among participants who remained on active follow-up. Treatment pathways for NCD treatment and psychiatric referrals were assessed based on local practice guidelines to construct the care cascade.

    RESULTS: A total of 329 participants (median age = 43 years, 83% male, 100% on ART) completed follow-up at 24 months. The prevalence of diabetes was 13%, dyslipidaemia 88% and hypertension 44%, whereas 23% presented with severe/extremely severe symptoms of depression, anxiety and/or stress. More than 50% of participants with dyslipidaemia and hypertension were not diagnosed until study screening, whereas over 80% with prevalent psychiatric symptoms were not previously recognized clinically. Suboptimal control of fasting lipids, sugar and blood pressure were found in the majority of participants despite optimal HIV treatment outcomes maintained over this same period. Only 32% of participants with severe/extremely severe mental health symptoms received psychiatric referrals and 83% of these attended their psychiatry clinic appointments.

    CONCLUSIONS: Systematic screening must be introduced to identify NCDs and mental health issues among PLWH followed by proper linkage and referrals for management of screen-positive cases. Assessment of factors associated with attrition at each step of the care cascade is critically needed to improve health outcomes in our aging patients.

  13. Neelamegam M, Nawi N, Bashah NSA, Hwei YS, Zulhaimi NS, Kamarulzaman A, et al.
    PMID: 38983023 DOI: 10.3389/fopht.2023.1251126
    OBJECTIVE: Antiretroviral therapy has decreased the prevalence of retinal opportunistic infections in people living with HIV (PLWH). However, abnormalities in visual function are evident and may be associated with an early onset of aging in PLWH. In this study, we examined the Retinal Nerve Fibre Layer (RNFL) thickness and visual function in PLWH and HIV non-infected controls in Malaysia.

    DESIGN: Cross-sectional study.

    METHODS: Two hundred and two (202) PLWH without retinal opportunistic infection and 182 age-matched, HIV seronegative individuals were enrolled. PLWH were recruited from the Infectious Disease clinic at the University Malaya Medical Centre. Controls were recruited among the hospital staff and community volunteers. RNFL thickness was measured with spectral domain optical coherence tomography (SDOCT). Visual functions include visual acuity using LogMAR chart and contrast sensitivity using Pelli- Robson Chart.

    RESULTS: All PLWH (mean age 46.1 years ± 9.9 years) in the study were on ART and 61.2% had a CD4+ T-cell count more than 500 cell/μl. The mean visual acuity was similar between the two groups (LogMAR 0.05 vs. 0.07, p = 0.115). Contrast sensitivity was lower in PLWH compared to HIV seronegative individuals (1.90 vs 1.93, p = 0.032). RNFL thickness was significantly thinner in the temporal quadrant for PLWH compared to controls (68.89 μm vs 74.08 μm, p = 0.001).

    CONCLUSION: Changes in RNFL thickness and contrast sensitivity were seen in PLWH despite their relatively young age and well controlled HIV disease. The changes reflect structural and functional deficits, and could have long-term implications on their health trajectory.

  14. Mukherjee T, Sakthivel R, Fong HY, McStea M, Chong ML, Omar SF, et al.
    AIDS Behav, 2018 Oct;22(10):3226-3233.
    PMID: 29508103 DOI: 10.1007/s10461-018-2073-x
    This study determines the optimal cut-off scores for the Montreal Cognitive Assessment (MoCA) to detect HIV-associated neurocognitive disorders (HAND) in a multi-ethnic Malaysian HIV-positive cohort by developing demographically corrected normative standards among 283 HIV-negative community-based controls with overlapping demographic characteristics. The norms (corrected for age, sex, education, ethnicity) were applied to 342 HIV-positive virally suppressed individuals on cART. Impairment rates were classified using the Global Deficit Score (GDS ≥ .5) method. The MoCA was also scored according to the recommended cut-off of ≤ 26, and functional decline was applied to both impairment definitions to classify HAND per the Frascati criteria. The ≤ 26 cut-off considerably overestimated cognitive impairment in both samples (59.4% HIV-negative; 69.3% HIV-positive). In contrast, corrected scores yielded impairment rates consistent with what has been reported internationally in virally suppressed cohorts (23.4% with 83.3% mild impairment, 16.7% moderate impairment). A supplemental file allowing the computation of corrected MoCA scores and impairment status is included.
  15. Azanan MS, Chandrasekaran S, Rosli ES, Chua LL, Oh L, Chin TF, et al.
    J Pediatr Hematol Oncol, 2020 08;42(6):e394-e400.
    PMID: 32118813 DOI: 10.1097/MPH.0000000000001766
    BACKGROUND: Microvascular endothelial dysfunction is central to the pathogenesis of cardiovascular disease (CVD). The eye offers direct access for endothelial health assessment via the retinal microvasculature. The aim of the study was to investigate whether image-based retinal vessel analysis is a feasible method of assessing endothelial health in survivors of childhood acute lymphoblastic leukemia (cALL).

    MATERIALS AND METHODS: Cardiovascular risk factors (CRFs) were estimated using the 30-year Framingham Risk Score in 73 childhood leukemia survivors (median age: 25; median years from diagnosis: 19) and 78 healthy controls (median age: 23). Radial arterial stiffness was measured using pulse wave analyzer, while endothelial activation markers were measured by soluble intercellular adhesion molecule 1 (sICAM-1) and soluble vascular cell adhesion molecule 1 (sVCAM-1). Retinal fundus images were analyzed for central retinal artery/vein equivalents (CRAE/CRVE) and arteriolar-venular ratio (AVR).

    RESULTS: cALL survivors had higher CRF (P<0.0001), arterial stiffness (P=0.001), and sVCAM-1 (P=0.007) compared with controls. Survivors also had significantly higher CRVE (P=0.021) while AVR was significantly lower (P=0.026) in survivors compared with controls, compatible with endothelial dysfunction. In cALL survivors with intermediate risk for CVD, CRAE, and AVR are significantly lower, while sVCAM-1 and sICAM-1 are significantly higher when compared with survivors with low CVD risk after adjusting with covariates (age, sex, and smoking status).

    CONCLUSIONS: cALL survivors have an increased risk of CVD compared with age-matched peers. The survivors demonstrated microvasculopathy, as measured by retinal vascular analysis, in addition to physical and biochemical evidence of endothelial dysfunction. These changes predate other measures of CVD. Retinal vessel analysis may be utilized as a robust screening tool for identifying survivors at increased risk for developing CVD.

  16. Azanan MS, Abdullah NK, Chua LL, Lum SH, Ghafar SS, Kamarulzaman A, et al.
    Eur J Immunol, 2016 Apr 30.
    PMID: 27129782 DOI: 10.1002/eji.201646356
    Many treatment complications which occur late in childhood cancer survivors resemble age-related co-morbidities observed in the elderly. An immune phenotype characterized by increased immune activation, systemic inflammation and accumulation of late-differentiated memory CD57(+) CD28(-) T cells has been associated with co-morbidities in the elderly. Here we explored if this phenotype was present in young adult leukemia survivors following an average of 19 years from chemotherapy and/or radiotherapy completion, and compared this with that in age-matched controls. We found that markers of systemic inflammation - IL-6 and human C-reactive protein (hCRP) and immune activation - CD38 and HLA-DR on T cells, sCD163 from monocytes and macrophages - were increased in survivors compared to controls. T-cell responses specific to cytomegalovirus (CMV) were also increased in survivors compared to controls while CMV IgG levels in survivors were comparable to levels measured in the elderly (>50years) and correlated with IL-6, hCRP, sCD163 and CD57(+) CD28(-) memory T cells. Immune activation and inflammation markers correlated poorly with prior chemotherapy and radiotherapy exposure. These data suggest that CMV infection/reactivation is strongly correlated with the immunological phenotype seen in young childhood leukemia survivors and these changes may be associated with the early onset of age-related co-morbidities in this group. This article is protected by copyright. All rights reserved.
  17. Chua LL, Rajasuriar R, Azanan MS, Abdullah NK, Tang MS, Lee SC, et al.
    Microbiome, 2017 03 20;5(1):35.
    PMID: 28320465 DOI: 10.1186/s40168-017-0250-1
    BACKGROUND: Adult survivors of childhood cancers such as acute lymphoblastic leukemia (ALL) have health problems that persist or develop years after cessation of therapy. These late effects include chronic inflammation-related comorbidities such as obesity and type 2 diabetes, but the underlying cause is poorly understood.

    RESULTS: We compared the anal microbiota composition of adult survivors of childhood ALL (N = 73) with healthy control subjects (N = 61). We identified an altered community with reduced microbial diversity in cancer survivors, who also exhibit signs of immune dysregulation including increased T cell activation and chronic inflammation. The bacterial community among cancer survivors was enriched for Actinobacteria (e.g. genus Corynebacterium) and depleted of Faecalibacterium, correlating with plasma concentrations of IL-6 and CRP and HLA-DR+CD4+ and HLA-DR+CD8+ T cells, which are established markers of inflammation and immune activation.

    CONCLUSIONS: We demonstrated a relationship between microbial dysbiosis and immune dysregulation in adult ALL survivors. These observations suggest that interventions that could restore microbial diversity may ameliorate chronic inflammation and, consequently, development of late effects of childhood cancer survivors.

  18. Kared H, Martelli S, Tan SW, Simoni Y, Chong ML, Yap SH, et al.
    Front Immunol, 2018;9:686.
    PMID: 29731749 DOI: 10.3389/fimmu.2018.00686
    Repetitive stimulation by persistent pathogens such as human cytomegalovirus (HCMV) or human immunodeficiency virus (HIV) induces the differentiation of natural killer (NK) cells. This maturation pathway is characterized by the acquisition of phenotypic markers, CD2, CD57, and NKG2C, and effector functions-a process regulated by Tim-3 and orchestrated by a complex network of transcriptional factors, involving T-bet, Eomes, Zeb2, promyelocytic leukemia zinc finger protein, and Foxo3. Here, we show that persistent immune activation during chronic viral co-infections (HCMV, hepatitis C virus, and HIV) interferes with the functional phenotype of NK cells by modulating the Tim-3 pathway; a decrease in Tim-3 expression combined with the acquisition of inhibitory receptors skewed NK cells toward an exhausted and cytotoxic phenotype in an inflammatory environment during chronic HIV infection. A better understanding of the mechanisms underlying NK cell differentiation could aid the identification of new immunological targets for checkpoint blockade therapies in a manner that is relevant to chronic infection and cancer.
  19. Lim LM, McStea M, Chung WW, Nor Azmi N, Abdul Aziz SA, Alwi S, et al.
    PLoS One, 2017;12(3):e0173466.
    PMID: 28273128 DOI: 10.1371/journal.pone.0173466
    BACKGROUND: Polypharmacy has been associated with increased morbidity and mortality in the older population.

    OBJECTIVES: The aim of this study was to determine the prevalence, risk factors and health outcomes associated with polypharmacy in a cohort of urban community-dwelling older adults receiving chronic medications in Malaysia.

    METHODS: This was a baseline study in the Malaysian Elders Longitudinal Research cohort. The inclusion criteria were individuals aged ≥55years and taking at least one medication chronically (≥3 months). Participants were interviewed using a structured questionnaire during home visits where medications taken were reviewed. Health outcomes assessed were frequency of falls, functional disability, potential inappropriate medication use (PIMs), potential drug-drug interactions (PDDIs), healthcare utilisation and quality of life (QoL). Risk factors and health outcomes associated with polypharmacy (≥5 medications including dietary supplements) were determined using multivariate regression models.

    RESULTS: A total of 1256 participants were included with a median (interquartile range) age of 69(63-74) years. The prevalence of polypharmacy was 45.9% while supplement users made up 56.9% of the cohort. The risk factors associated with increasing medication use were increasing age, Indian ethnicity, male, having a higher number of comorbidities specifically those diagnosed with cardiovascular, endocrine and gastrointestinal disorders, as well as supplement use. Health outcomes significantly associated with polypharmacy were PIMS, PDDIs and increased healthcare utilisation.

    CONCLUSION: A significant proportion of older adults on chronic medications were exposed to polypharmacy and use of dietary supplements contributed significantly to this. Medication reviews are warranted to reduce significant polypharmacy related issues in the older population.

  20. Lee SC, Chua LL, Yap SH, Khang TF, Leng CY, Raja Azwa RI, et al.
    Sci Rep, 2018 09 24;8(1):14277.
    PMID: 30250162 DOI: 10.1038/s41598-018-32585-x
    We explored the gut microbiota profile among HIV-infected individuals with diverse immune recovery profiles following long-term suppressive ART and investigated the relationship between the altered bacteria with markers of immune dysfunction. The microbiota profile of rectal swabs from 26 HIV-infected individuals and 20 HIV-uninfected controls were examined. Patients were classified as suboptimal responders, sIR (n = 10, CD4 T-cell <350 cells/ul) and optimal responders, oIR (n = 16, CD4 T-cell >500 cells/ul) after a minimum of 2 years on suppressive ART. Canonical correlation analysis(CCA) and multiple regression modelling were used to explore the association between fecal bacterial taxa abundance and immunological profiles in optimal and suboptimal responders. We found Fusobacterium was significantly enriched among the HIV-infected and the sIR group. CCA results showed that Fusobacterium abundance was negatively correlated with CD4 T-cell counts, but positively correlated with CD4 T-cell activation and CD4 Tregs. Multiple linear regression analysis adjusted for age, baseline CD4 T-cell count, antibiotic exposure and MSM status indicated that higher Fusobacterium relative abundance was independently associated with poorer CD4 T-cell recovery following ART. Enrichment of Fusobacterium was associated with reduced immune recovery and persistent immune dysfunction following ART. Modulating the abundance of this bacterial taxa in the gut may be a viable intervention to improve immune reconstitution in our setting.
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