Dimitrios Pilalas
Aristotle University of Thessaloniki
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Publication
Featured researches published by Dimitrios Pilalas.
Journal of Antimicrobial Chemotherapy | 2011
Lemonia Skoura; Simeon Metallidis; Andrew J. Buckton; Jean L Mbisa; Dimitrios Pilalas; Evagelia Papadimitriou; Androniki Papoutsi; Anna-Bettina Haidich; Theofilos Chrysanthidis; Olga Tsachouridou; Zoe A. Antoniadou; Panagiotis Kollaras; Pavlos Nikolaidis; Nikolaos Malisiovas
OBJECTIVES To determine the contribution of transmission clusters to transmitted drug resistance (TDR) in newly diagnosed antiretroviral-naive HIV-1-infected patients in Northern Greece during 2000-07. METHODS The prevalence of TDR was estimated in 369 individuals who were diagnosed with HIV-1 infection in the period 2000-07 at the National AIDS Reference Laboratory of Northern Greece. Phylogenetic analysis was performed using a maximum likelihood method on partial pol sequences. TDR was defined in accordance with the surveillance drug resistance mutation list (2009 update). RESULTS The overall prevalence of TDR in our population was 12.5% [46/369, 95% confidence interval (CI) 9.1%-15.8%], comprising 7.6% (28/369) resistant to nucleoside reverse transcriptase inhibitors, 5.4% (20/369) resistant to non-nucleoside reverse transcriptase inhibitors and 3.3% (12/369) resistant to protease inhibitors. Dual class resistance was identified in 3.8% (14/369). Infection with subtype A was the sole predictor associated with TDR in multivariate analysis (odds ratio 2.15, 95% CI 1.10-4.19, P = 0.025). Phylogenetic analyses revealed three statistically robust transmission clusters involving drug-resistant strains, including one cluster of 12 patients, 10 of whom were infected with a strain carrying both T215 revertants and Y181C mutations. CONCLUSIONS Our findings underline the substantial impact of transmission networks on TDR in our population.
Journal of Clinical Epidemiology | 2013
Anna-Bettina Haidich; Dimitrios Pilalas; Despina G. Contopoulos-Ioannidis; John P. A. Ioannidis
OBJECTIVE To assess the extent to which meta-analysis publications of drugs and biologics focus on specific named agents or even only a single agent, and identify characteristics associated with such focus. STUDY DESIGN AND SETTING We evaluated 499 articles with meta-analyses published in 2010 and estimated how many did not cover all the available comparisons of tested interventions for a given condition (not all-inclusive); focused on specific named agent(s), or focused strictly on comparisons of only one specific active agent vs. placebo/no treatment or different doses/schedules. RESULTS Of 499 eligible articles, 403 (80.8%) were not all-inclusive, 214 (42.9%) covered only specific named agent(s), and 74 (14.8%) examined only comparisons with one active agent vs. placebo/no treatment or different doses/schedules. Only 39 articles (7.8%) covered all possible indications for the examined agent(s). After adjusting for type of treatment/field, focus on specific named agent(s) was associated with publication in journal venues (odds ratio [OR]: 1.95; 95% confidence interval [CI]: 1.17-3.26) vs. Cochrane, industry sponsoring (OR: 3.94; 95% CI: 1.66-10.66), and individual patient data analyses (OR: 6.59; 95% CI: 2.24-19.39). Individual patient data analyses primarily (29/34) focused on specific named agent(s). CONCLUSION The scope of meta-analysis publications frequently is narrow and shaped to serve particular agents.
Journal of the International AIDS Society | 2012
Simeon Metallidis; Dimitrios Pilalas; Lemonia Skoura; Anna-Bettina Haidich; Olga Tsachouridou; Maria Papaioannou; Theofilos Chrysanthidis; Isidora Bakaimi; Zoe A. Antoniadou; Apostolia Margariti; Nicolaos Malisiovas; Pavlos Nikolaidis
The aim of our study was to assess the extent of late presentation for HIV care in Northern Greece during the period 2000 to 2010 and to explore correlations aiming to provide guidance for future interventions.
Allergologia Et Immunopathologia | 2013
T. Alexandropoulos; Anna-Bettina Haidich; Dimitrios Pilalas; Theodore Dardavessis; M. Daniilidis; Malamatenia Arvanitidou
BACKGROUND Allergic rhinitis affects a significant proportion of the European population. Few surveys have investigated this disorder in Greek adults. Our objective was to describe the characteristics of patients with allergic rhinitis in an adult outpatient clinic in Thessaloniki, Greece. METHODS We studied the medical records of adult patients referred to a Clinical Immunology outpatient clinic from 2001 to 2007. The diagnostic procedure was not changed during the whole study period, including the same questionnaire used at the time of diagnosis, skin prick tests, and serum specific IgE. RESULTS A total of 1851 patient files with diagnosed allergies were analysed and allergic rhinitis was confirmed in 711 subjects (38.4%). According to ARIA classification, persistent allergic rhinitis was more prevalent than intermittent (54.9% vs. 45.1%), while 60.8% of subjects suffered from moderate/severe disease. In multivariable analysis, factors associated with allergic rhinitis were age (for every 10 years increase, OR: 0.84, 95% CI: 0.77-0.91; p<0.001); working in school environment (teachers or students) (OR: 1.46, 95% CI: 1.05-2.02; p=0.023); parental history of respiratory allergy (OR: 2.41, 95% CI: 1.69-3.43; p<0.001); smoking (OR: 0.71, 95% CI: 0.55-0.91; p=0.007); presence of allergic conjunctivitis (OR: 6.16, 95% CI: 4.71-8.06; p<0.001); and asthma (OR: 2.17, 95% CI: 1.57-3.01; p<0.001). Analysis after multiple imputation corroborated the complete case analysis results. CONCLUSIONS Allergic rhinitis was documented in 38.4% of studied patients and was frequently characterised by significant morbidity. Factors associated with allergic rhinitis provide insight into the epidemiology of this disorder in our region. Further studies on the general population would contribute to evaluating allergic rhinitis more comprehensively.
Journal of Medical Virology | 2016
Apostolia Margariti; Dimitrios Chatzidimitriou; Simeon Metallidis; Dimitrios Pilalas; A. Kourelis; Evangelia Papadimitriou; Anna-Bettina Haidich; Nicolaos Malisiovas; Lemonia Skoura
Viral load testing is a valuable tool in HIV clinical care and research. Discrepancies among diverse viral load assays, especially with regard to non‐B HIV‐1 subtypes have been reported. Our study aimed to explore the impact of HIV subtype (B versus non‐B) on the agreement between CAP/CTM, v2.0 and m2000 RealTime in treated HIV patients, focusing on low viral loads (<200 copies/ml). Our findings indicate that there is a significant difference in the performance of the compared assays in the low‐viremic range and non–B subtypes, suggesting that a single assay should be used for follow‐up. J. Med. Virol. 88:724–727, 2016.
International Journal of Infectious Diseases | 2015
Dimitrios Pilalas; Lemonia Skoura; Simeon Metallidis; A. Kourelis; Olga Tsachouridou; Nicolaos Malisiovas; Anna Papa
OBJECTIVES This study sought to assess the West Nile Virus (WNV) seroprevalence and behavioral risk factors for WNV infection in HIV-1 infected individuals in Northern Greece in 2011. METHODS We prospectively enrolled 91 HIV-1 consecutive patients followed up in the HIV clinic of the AHEPA University Hospital in the period from November to December 2011. Serum samples were tested for the presence of WNV IgG antibodies. All subjects were administered a standardized questionnaire to evaluate for risk factors for WNV infection. RESULTS WNV IgG antibodies were detected in three subjects (3.3%, 95% CI 0.7-9.3%), two of whom were of African origin. The prevalence of WNV antibodies in HIV patients of Greek origin was 1.2% (95% CI: 0.03% - 6.3%). In the sample surveyed, 53.6% (95% CI: 42.4% to 64.5%) were aware of WNV prevention measures; 2.2% reported no implementation of prevention measures, whereas 46.1% implemented at least three measures. Approximately one half of the patients reported outdoor activities for more than two hours from dusk to dawn. None of the IgG-positive patients reported any symptoms compatible with WNV disease during the season at risk. CONCLUSIONS Among native Greek HIV patients, the WNV seroprevalence is 1.2%. A considerable proportion of patients was aware of WNV prevention measures and implemented some of these. HIV patients and other categories of immunocompromised patients are at increased risk of neuroinvasive disease, and widespread implementation of prevention measures should be strongly encouraged in this patient population.
PLOS ONE | 2018
Dimitrios Pilalas; Lemonia Skoura; Apostolia Margariti; Fani Chatzopoulou; Dimitrios Chatzidimitriou; Olga Tsachouridou; Pantelis Zebekakis; Simeon Metallidis; Maria Papaioannou
Objectives Despite successful virological suppression, HIV transcription frequently persists intracellularly. In this study, we hypothesize that HIV persistent transcription(HIVpt) may affect to a different extent patients on stable efavirenz(EFV) versus atazanavir(ATV)-based regimens. The role of the expression of drug efflux transporters in HIVpt was also investigated. Methods We prospectively enrolled 51 virologically suppressed patients on first-line treatment for one year with EFV or ATV combined with emtricitabine and tenofovir and followed them up for one year. Simultaneous ultrasensitive subpopulation staining/hybridization in situ(SUSHI) was performed to identify HIVpt in CD4+ T-cells and in the CD4+CD45RO+ T-cell subpopulation. The differential mRNA expression of P-glycoprotein(P-gp/ABCB1) and multidrug resistance-associated protein-1(MRP1/ABCC1) was also evaluated. Univariate logistic regression models were used to evaluate predictors of HIVpt. Results In the CD4+ T-cell population, HIVpt affected 13/30 of patients on EFV versus 10/21 on ATV. In the CD4+CD45RO+ T-cell population, HIVpt was present in 14/30 of patients on EFV versus 15/21 on ATV. A trend for association was observed between the risk of HIVpt and ATV treatment in the CD4+CD45RO+ T-cell population (OR 2.86, 95% CI 0.87–9.37, p = 0.083). HIVpt status was not associated with loss of virological suppression or CD4 evolution. We found no evidence of differential expression of the drug efflux transporters P-gp and MRP1. Conclusions Further study is required to evaluate whether the HIVpt profile in specific cell populations may differ across different antiretroviral regimens and to elucidate the potential clinical impact.
new microbes and new infections | 2017
Dimitrios Pilalas; Lemonia Skoura; Apostolia Margariti; Dimitrios Chatzidimitriou; Alexandros Sarantopoulos; Olga Tsachouridou; Anna Papa; Simeon Metallidis
The emergence of West Nile virus lineage 2 in central Macedonia, Greece, in 2010 resulted in large outbreaks for 5 consecutive years. We report a case of viral meningitis in an individual infected with human immunodeficiency virus type 1, which preceded the recognition of the outbreak and was confirmed retrospectively as West Nile virus neuroinvasive disease.
World journal of virology | 2016
Olga Tsachouridou; Lemonia Skoura; Pantelis Zebekakis; Apostolia Margariti; Dimitrios Bougiouklis; Dimitrios Pilalas; Antonios Galanos; Michael Daniilidis; Symeon Metallidis
AIM To evaluate alterations of memory B cell subpopulations during a 48-wk period in human immunodeficiency virus type 1 (HIV-1) patients. METHODS Forty-one antiretroviral naïve and 41 treated HIV-1 patients matched for age and duration of HIV infection were recruited. All clinical, epidemiological and laboratory data were recorded or measured. The different B cell subsets were characterized according to their surface markers: Total B cells (CD19+), memory B cells (CD19+CD27+, BMCs), resting BMCs (CD19+CD27+CD21high, RM), exhausted BMCs (CD19+CD21lowCD27-, EM), IgM memory B (CD19+CD27+IgMhigh), isotype-switched BMCs (CD19+CD27+IgM-, ITS) and activated BMCs (CD19+CD21low+CD27+, AM) at baseline on week 4 and week 48. RESULTS Mean counts of BMCs were higher in treated patients. There was a marginal upward trend of IgM memory B cell proportions which differed significantly in the treated group (overall trend, P = 0.004). ITS BMC increased over time significantly in all patients. Naive patients had of lower levels of EM B cells compared to treated, with a downward trend, irrespectively of highly active antiretroviral therapy (HAART) intake. Severe impairment of EM B cells was recorded to both treated (P = 0.024) and naive (P = 0.023) and patients. Higher proportions of RM cells were noted in HAART group, which differed significantly on week 4th (P = 0.017) and 48th (P = 0.03). Higher levels of AM were preserved in HAART naive group during the whole study period (week 4: P = 0.018 and 48: P = 0.035). HIV-RNA viremia strongly correlated with AM B cells (r = 0.54, P = 0.01) and moderately with RM cells (r = -0.45, P = 0.026) at baseline. CONCLUSION HIV disrupts memory B cell subpopulations leading to impaired immunologic memory over time. BMC, RM, EM and ITS BMC were higher in patients under HAART. Activated BMCs (AM) were higher in patients without HAART. Viremia correlated with AM and RM. Significant depletion was recorded in EM B cells irrespectively of HAART intake. Perturbations in BMC-populations are not fully restored by antiretrovirals.
European Archives of Oto-rhino-laryngology | 2012
Olga Tsachouridou; Artemis Christoforidou; Symeon Metallidis; Maria Papaioannou; Panagiotis Kollaras; Alexandros Kolokotronis; Theofilos Chrysanthidis; Dimitrios Pilalas; Konstantinos Markou