Reena Rajasuriar
University of Malaya
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Featured researches published by Reena Rajasuriar.
The Journal of Infectious Diseases | 2010
Reena Rajasuriar; David R. Booth; Ajantha Solomon; Kyra Chua; Tim Spelman; Maelenn Gouillou; Timothy E. Schlub; Miles P. Davenport; Suzanne M. Crowe; Julian Elliott; Jennifer Hoy; Christopher K. Fairley; Graeme J. Stewart; Paul U. Cameron; Sharon R. Lewin
BACKGROUND Multiple host factors may influence CD4(+) T cell reconstitution in human immunodeficiency virus (HIV)-infected patients after suppressive antiretroviral therapy (ART). We hypothesized that residual immune activation and polymorphisms in the interleukin 7 (IL-7) receptor α (IL-7Rα) gene were important for immune recovery. METHODS We examined HIV-infected patients receiving suppressive ART (n = 96) for their IL-7Rα haplotypes and measured levels of lipopolysaccharide (LPS), soluble CD14, and IL-7 in plasma samples collected before and after ART initiation. Levels of soluble IL-7Rα were measured in HIV-infected patients with IL-7Rα haplotype 2 (n = 11) and those without IL-7Rα haplotype 2 (n = 22). Multivariate analysis was used to identify variables associated with faster recovery to CD4(+) T cell counts of >500 and >200 cells/μL. RESULTS Both LPS and soluble CD14 levels were significantly decreased with ART (P < .001, respectively) but remained elevated compared with uninfected controls. In a multivariate analysis, faster recovery to a CD4(+) T cell count of >500 cells/μL was significantly associated with higher baseline CD4(+) T cell count, younger age, lower pre-ART LPS level, higher pre-ART soluble CD14 level, lower pre-ART IL-7 level, and IL-7Rα haplotype 2 (hazard ratio, 1.50; 95% confidence interval, 1.03-2.19; P = .034). HIV-infected patients with haplotype 2 had significantly lower soluble IL-7Rα levels compared with those of patients without haplotype 2 (P < .001). CONCLUSION Both the extent of immune depletion prior to ART and IL-7Rα haplotype 2 are important determinants of time to CD4(+) T cell recovery to counts of >500 cells/μL.
Journal of Immunology | 2012
Gregor F Lichtfuss; Wan-Jung Cheng; Yagmur Farsakoglu; Geza Paukovics; Reena Rajasuriar; Pusparaj Velayudham; Marit Kramski; Anna C. Hearps; Paul U. Cameron; Sharon R. Lewin; Suzanne M. Crowe; Anthony Jaworowski
FcRγ is an ITAM-containing adaptor required for CD16 signaling and function in NK cells. We have previously shown that NK cells from HIV patients receiving combination antiretroviral therapy (cART) have decreased FcRγ expression, but the factors causing this are unknown. We conducted a cross-sectional study of cART-naive viremic patients (ART−), virologically suppressed patients receiving cART (ART+), and HIV-uninfected controls. CD8+ T cells were activated, as assessed by CD38+HLA-DR+ expression, in ART− patients (p < 0.0001), which was significantly reduced in ART+ patients (p = 0.0005). In contrast, CD38+HLA-DR+ NK cells were elevated in ART− patients (p = 0.0001) but did not decrease in ART+ patients (p = 0.88). NK cells from both ART− and ART+ patients showed high levels of spontaneous degranulation in ex vivo whole blood assays as well as decreased CD16 expression (p = 0.0001 and p = 0.0025, respectively), FcRγ mRNA (p < 0.0001 for both groups), FcRγ protein expression (p = 0.0016 and p < 0.0001, respectively), and CD16-dependent Syk phosphorylation (p = 0.0001 and p = 0.003, respectively). HIV-infected subjects showed alterations in NK activation, degranulation, CD16 expression and signaling, and elevated plasma markers of inflammation and macrophage activation, that is, neopterin and sCD14, which remained elevated in ART+ patients. Alterations in NK cell measures did not correlate with viral load or CD4 counts. These data show that in HIV patients who achieve viral suppression following cART, NK cell activation persists. This suggests that NK cells respond to factors different from those driving T cell activation, but which are associated with inflammation in HIV patients.
The Journal of Infectious Diseases | 2011
Sonia Fernandez; Sara Tanaskovic; Karla J. Helbig; Reena Rajasuriar; Marit Kramski; John M. Murray; Michael R. Beard; Damian F. J. Purcell; Sharon R. Lewin; Patricia Price; Martyn A. French
Most patients with human immunodeficiency virus (HIV) who remain CD4(+) T-cell deficient on antiretroviral therapy (ART) exhibit marked immune activation. As CD4(+) T-cell activation may be mediated by microbial translocation or interferon-alpha (IFN-α), we examined these factors in HIV patients with good or poor CD4(+) T-cell recovery on long-term ART. Messenger RNA levels for 3 interferon-stimulated genes were increased in CD4(+) T cells of patients with poor CD4(+) T-cell recovery, whereas levels in patients with good recovery did not differ from those in healthy controls. Poor CD4(+) T-cell recovery was also associated with CD4(+) T-cell expression of markers of activation, senescence, and apoptosis, and with increased serum levels of the lipopolysaccharide receptor and soluble CD14, but these were not significantly correlated with expression of the interferon-stimulated genes. Therefore, CD4(+) T-cell recovery may be adversely affected by the effects of IFN-α, which may be amenable to therapeutic intervention.
AIDS | 2013
Reena Rajasuriar; Gabriela Khoury; Adeeba Kamarulzaman; Martyn A. French; Paul U. Cameron; Sharon R. Lewin
The availability of combination antiretroviral therapy (cART) has led to substantial reduction in morbidity and mortality in HIV-infected patients; however, life expectancy remains reduced especially in HIV-infected patients who initiate cART with CD4 T-cell counts less than 200 cells/μl [1]. Increased immune activation in patients on long-term suppressive cART [2–4] has been associated with increased mortality [5,6] and both AIDS and non-AIDS-defining illnesses [7–10], suggesting that chronic immune activation may have a potential role in driving increased morbidity and mortality.
Current Hiv\/aids Reports | 2014
Anna C. Hearps; Genevieve E. Martin; Reena Rajasuriar; Suzanne M. Crowe
Increased life expectancy due to improved efficacy of cART has uncovered an increased risk of age-related morbidities in HIV+ individuals and catalyzed significant research into mechanisms driving these diseases. HIV infection increases the risk of non-communicable diseases common in the aged, including cardiovascular disease, neurocognitive decline, non-AIDS malignancies, osteoporosis, and frailty. These observations suggest that HIV accelerates immunological ageing, and there are many immunological similarities with the aged, including shortened telomeres, accumulation of senescent T cells and altered monocyte phenotype/function. However, the most critical similarity between HIV+ individuals and the elderly, which most likely underpins the heightened risk of non-communicable diseases, is chronic inflammation and associated immune activation. Here, we review the similarities between HIV+ individuals and the aged regarding the pathogenesis of inflammatory diseases, the current evidence for mechanisms driving these processes and discuss current and potential therapeutic strategies for addressing inflammatory co-morbidity in HIV+ infection.
Biomarkers in Medicine | 2011
Gregor F Lichtfuss; Jennifer Hoy; Reena Rajasuriar; Marit Kramski; Suzanne M. Crowe; Sharon R. Lewin
Combination antiretroviral therapy (cART) has significantly reduced morbidity and mortality of HIV-infected patients, yet their life expectancy remains reduced compared with the general population. Most HIV-infected patients receiving cART have some persistent immune dysfunction characterized by chronic immune activation and premature aging of the immune system. Here we review biomarkers of T-cell activation (CD69, -25 and -38, HLA-DR, and soluble CD26 and -30); generalized immune activation (C-reactive protein, IL-6 and D-dimer); microbial translocation (lipopolysaccharide, 16S rDNA, lipopolysaccharide-binding protein and soluble CD14); and immune dysfunction of specific cellular subsets (T cells, natural killer cells and monocytes) in HIV-infected patients on cART and their relationship to adverse clinical outcomes including impaired CD4 T-cell recovery, as well as non-AIDS clinical events, such as cardiovascular disease.
Nucleic Acids Research | 2012
David J. Hooker; Masqura Mobarok; Jenny L. Anderson; Reena Rajasuriar; Lachlan Robert Gray; Anne Ellett; Sharon R. Lewin; Paul R. Gorry; Catherine L. Cherry
Several critical events of apoptosis occur in the cell nucleus, including inter-nucleosomal DNA fragmentation (apoptotic DNA) and eventual chromatin condensation. The generation of apoptotic DNA has become a biochemical hallmark of apoptosis because it is a late ‘point of no return’ step in both the extrinsic (cell-death receptor) and intrinsic (mitochondrial) apoptotic pathways. Despite investigators observing apoptotic DNA and understanding its decisive role as a marker of apoptosis for over 20 years, measuring it has proved elusive. We have integrated ligation-mediated PCR and qPCR to design a new way of measuring apoptosis, termed ApoqPCR, which generates an absolute value for the amount (picogram) of apoptotic DNA per cell population. ApoqPCR’s advances over current methods include a 1000-fold linear dynamic range yet sensitivity to distinguish subtle low-level changes, measurement with a 3- to 4-log improvement in sample economy, and capacity for archival or longitudinal studies combined with high-throughput capability. We demonstrate ApoqPCR’s utility in both in vitro and in vivo contexts. Considering the fundamental role apoptosis has in vertebrate and invertebrate health, growth and disease, the reliable measurement of apoptotic nucleic acid by ApoqPCR will be of value in cell biology studies in basic and applied science.
Journal of Clinical Microbiology | 2011
Marit Kramski; A Gaeguta; Gregor F Lichtfuss; Reena Rajasuriar; Suzanne M. Crowe; Martin French; Sharon R. Lewin; Damian F. J. Purcell
ABSTRACT We developed a real-time PCR to quantify 16S rRNA gene levels in plasma from HIV-infected patients as a marker of microbial translocation. The assay uses shrimp nuclease (SNuc) to eliminate DNA contamination, giving high sensitivity and low variability. The 16S rRNA gene levels measured in plasma from HIV patients correlated significantly with lipopolysaccharide levels.
Human & Experimental Toxicology | 2007
Reena Rajasuriar; Rahmat Awang; Sirajuddin Hashim; H. R. B. H. Rahmat
We retrospectively reviewed poisoning admissions to all government health facilities from 1999 to 2001, in an effort to expand our current knowledge on poisoning in Malaysia to a level that better reflects a nationwide burden. There were 21 714 admissions reported with 779 deaths. The case-fatality rate was 35.88/1000 admissions. The majority of admissions (89.7%) and deaths (98.9%) occurred in adults. Some 55.1% of all admissions were female, mostly involving pharmaceutical agents. Male poisoning admissions were more often due to chemical substances. The prevalence of poisoning and death was highest among Indians compared to all other races in Malaysia. Overall, the majority of poisoning admissions were due to pharmaceutical agents, with agents classified as non-opioid analgesics, antipyretics and anti-rheumatics the most common. Pesticides accounted for the largest number of fatalities. It was also the commonest substance reported in cases of intentional self-harm. Most cases of poisoning admissions occurred due to accidental exposure (47%), followed by cases of intentional self-harm (20.7%). Overall, this study has managed to contribute substantial additional information regarding the epidemiology of poisoning in Malaysia, highlighting important issues, such as the rampant poisonings involving pesticides and analgesics, as well as the high prevalence of poisoning among Indians in Malaysia. Human & Experimental Toxicology (2007) 26, 73- 81
PLOS ONE | 2011
Reena Rajasuriar; Maelenn Gouillou; Tim Spelman; Timothy D. Read; Jennifer Hoy; Matthew Law; Paul U. Cameron; Kathy Petoumenos; Sharon R. Lewin
Background A small but significant number of patients do not achieve CD4 T-cell counts >500cells/µl despite years of suppressive cART. These patients remain at risk of AIDS and non-AIDS defining illnesses. The aim of this study was to identify clinical factors associated with CD4 T-cell recovery following long-term cART. Methods Patients with the following inclusion criteria were selected from the Australian HIV Observational Database (AHOD): cART as their first regimen initiated at CD4 T-cell count <500cells/µl, HIV RNA<500copies/ml after 6 months of cART and sustained for at least 12 months. The Cox proportional hazards model was used to identify determinants associated with time to achieve CD4 T-cell counts >500cells/µl and >200cells/µl. Results 501 patients were eligible for inclusion from AHOD (n = 2853). The median (IQR) age and baseline CD4 T-cell counts were 39 (32–47) years and 236 (130–350) cells/µl, respectively. A major strength of this study is the long follow-up duration, median (IQR) = 6.5(3–10) years. Most patients (80%) achieved CD4 T-cell counts >500cells/µl, but in 8%, this took >5 years. Among the patients who failed to reach a CD4 T-cell count >500cells/µl, 16% received cART for >10 years. In a multivariate analysis, faster time to achieve a CD4 T-cell count >500cells/µl was associated with higher baseline CD4 T-cell counts (p<0.001), younger age (p = 0.019) and treatment initiation with a protease inhibitor (PI)-based regimen (vs. non-nucleoside reverse transcriptase inhibitor, NNRTI; p = 0.043). Factors associated with achieving CD4 T-cell counts >200cells/µl included higher baseline CD4 T-cell count (p<0.001), not having a prior AIDS-defining illness (p = 0.018) and higher baseline HIV RNA (p<0.001). Conclusion The time taken to achieve a CD4 T-cell count >500cells/µl despite long-term cART is prolonged in a subset of patients in AHOD. Starting cART early with a PI-based regimen (vs. NNRTI-based regimen) is associated with more rapid recovery of a CD4 T-cell count >500cells/µl.