Konstantinos Tsiakos

Dr. Konstantinos Tsiakos

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 September 2021 in Nature Medicine
Verified
Journal Article
Open access
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EKEvdoxia Kyriazopoulou
Evdoxia Kyriazopoulou
GPGaryfallia Poulakou
Garyfallia Poulakou
HMHaralampos Milionis
Haralampos Milionis
SMSimeon Metallidis
Simeon Metallidis
GAGeorgios Adamis
Georgios Adamis
EGEvangelos J Giamarellos-Bourboulis
Evangelos J Giamarellos-Bourboulis
Early increase of soluble urokinase plasminogen activator receptor (suPAR) serum levels is indicative of increased risk of progression of coronavirus disease 2019 (COVID-19) to respiratory failure. The SAVE-MORE double-blind, randomized controlled trial evaluated the efficacy and safety of anakinra, an IL-1α/β inhibitor, in 594 patients with COVID-19 at risk of progressing to respiratory failure as identified by plasma suPAR ≥6 ng ml−1, 85.9% (n = 510) of whom were receiving dexamethasone. At day 28, the adjusted proportional odds of having a worse clinical status (assessed by the 11-point World Health Organization Clinical Progression Scale (WHO-CPS)) with anakinra, as compared to placebo, was 0.36 (95% confidence interval 0.26–0.50). The median WHO-CPS decrease on day 28 from baseline in the placebo and anakinra groups was 3 and 4 points, respectively (odds ratio (OR) = 0.40, P < 0.0001); the respective median decrease of Sequential Organ Failure Assessment (SOFA) score on day 7 from baseline was 0 and 1 points (OR = 0.63, P = 0.004). Twenty-eight-day mortality decreased (hazard ratio = 0.45, P = 0.045), and hospital stay was shorter.

1 February 2022 in Infection and Drug Resistance
Verified
Journal Article
Open access
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MKMarios Karvouniaris
Marios Karvouniaris
Alexandros G. BrotisAlexandros G. Brotis
Alexandros G. Brotis
KTKonstantinos Tsiakos
Konstantinos Tsiakos
EPEleni Palli
Eleni Palli
Despoina KoulentiDespoina Koulenti
Despoina Koulenti
Ventriculitis or post-neurosurgical meningitis or healthcare-associated ventriculitis and meningitis (VM) is a severe infection that complicates central nervous system operations or is related to the use of neurosurgical devices or drainage catheters. It can further deteriorate patients who have already presented significant neurologic injury and is associated with high morbidity, mortality, and poor functional outcome. VM can be difficult to distinguish from aseptic meningitis, inflammation that follows hemorrhagic strokes and neurosurgical operations. The associated microorganisms can be either skin flora or nosocomial pathogens, most commonly, Gram-negative bacteria. Classical microbiology can fail to isolate the culprit pathogen. Novel cerebrospinal fluid (CSF) biomarkers and molecular microbiology can fill the diagnostic gap and expedite pathogen identification and treatment. The pathogens may demonstrate significant resistant patterns and their antibiotic treatment can be difficult, as many important drug classes, including the beta-lactams and the glycopeptides, hardly penetrate to the CSF, and do not achieve therapeutic levels at the site of the infection. Treatment modifications, such as higher daily dose and prolonged or continuous administration, might increase antibiotic levels in the site of infection and facilitate pathogens clearance. However, in the case of therapeutic failure or infection due to difficult-to-treat bacteria, the direct antibiotic instillation into the CSF, in addition to the intravenous antibiotic delivery, may help in the resolution of infection. However, intraventricular antibiotic therapy may result in aseptic meningitis and seizures, concerning the administration of aminoglycosides, polymyxins, and vancomycin. Meanwhile, bacteria form biofilms on the catheter or the device that should routinely be removed. Novel neurosurgical treatment modalities comprise endoscopic evacuation of debris and irrigation of the ventricles. VM prevention includes perioperative antibiotics, antimicrobial impregnated catheters, and the implementation of standardized protocols, regarding catheter insertion and manipulation.

8 October 2021 in Nature Medicine
Verified
Journal Article
Open access
PDF file
EKEvdoxia Kyriazopoulou
Evdoxia Kyriazopoulou
GPGaryfallia Poulakou
Garyfallia Poulakou
HMHaralampos Milionis
Haralampos Milionis
SMSimeon Metallidis
Simeon Metallidis
GAGeorgios Adamis
Georgios Adamis
EGEvangelos J Giamarellos-Bourboulis
Evangelos J Giamarellos-Bourboulis

17 March 2022 in Antibiotics
Verified
Journal Article
Open access
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MKMarios Karvouniaris
Marios Karvouniaris
GPGaryphallia Poulakou
Garyphallia Poulakou
KTKonstantinos Tsiakos
Konstantinos Tsiakos
MCMaria Chatzimichail
Maria Chatzimichail
PPPanagiotis Papamichalis
Panagiotis Papamichalis
AKApostolos Komnos
Apostolos Komnos
Intensive care unit patients may present infections by difficult-to-treat-resistant Gram-negative microorganisms. Colistin resurfaced as a last resort antibiotic for the treatment of multi-drug-resistant Gram-negative bacteria. However, colistin might not improve survival, particularly after the emergence of colistin-resistant isolates. We aimed to (1) examine the first Gram-negative-associated-bloodstream infection (GN-BSI) effect on 28-day mortality and (2) distinguish mortality risk factors. From 1 January 2018 to 31 December 2019, we retrospectively studied all adult patients admitted for more than 48 h in the critical care department of a regional Greek hospital, with prevalent difficult-to-treat Gram-negative pathogens. We examined the patient records for the first GN-BSI. The local laboratory used broth microdilution to evaluate bacterial susceptibility to colistin. Seventy-eight patients fulfilled the entry criteria: adult and first GN-BSI. They developed GN-BSI on day 10 (6–18), while the overall mortality was 26.9%. Thirty-two and 46 individuals comprised the respective colistin-resistant and colistin-sensitive groups. The admission Acute Physiology Assessment and Chronic Health Evaluation II score was associated with acquiring colistin-resistant GN-BSI in the multivariable logistic regression analysis (οdds ratio (CI), 1.11 (1.03–1.21)). Regarding mortality, the index day sequential organ failure assessment score was solely associated with the outcome (hazard-ratio (CI), 1.23 (1.03–1.48), Cox proportional hazard analysis). GN-BSI was often caused by colistin-resistant bacteria. Concerning our data, sepsis severity was the independent predictor of mortality regardless of the colistin-resistance phenotype or empirical colistin treatment.

1 June 2022 in Journal of Immunotherapy
Verified
Journal Article
Closed access
KTKonstantinos Tsiakos
Konstantinos Tsiakos
KKKonstantinos G. Kyriakoulis
Konstantinos G. Kyriakoulis
AKAnastasios Kollias
Anastasios Kollias
IKIoannis G. Kyriakoulis
Ioannis G. Kyriakoulis
GPGaryphallia Poulakou
Garyphallia Poulakou
KSKonstantinos Syrigos
Konstantinos Syrigos
The safety and efficacy of influenza vaccination is not well-studied in cancer patients receiving immune checkpoint inhibitors (ICIs). A systematic review and meta-analysis was performed aiming to summarize available data regarding influenza vaccination in ICI-treated cancer patients. Peer-reviewed studies or nonpeer-reviewed conference abstracts including ICI-treated cancer patients who received at least 1 dose of influenza vaccine were deemed eligible. A systematic search in PubMed/EMBASE was performed until October 26, 2021. Endpoints of interest included mortality as the primary outcome and secondary safety outcomes such as the incidence of immune-related adverse events (irAEs). Twenty-five studies were included in the systematic review, among which 9 were included in the meta-analysis. Meta-analysis of 3 studies (n=589, weighted age 64 y, men 61%, influenza vaccinated 32%) showed pooled odds ratio for death in influenza vaccinated versus nonvaccinated patients at 1.25 [(95% confidence intervals (CI): 0.81–1.92), P=non significant (NS)]. Meta-analysis of 6 studies studies (n=1285, weighted age 60 y, men 59%, influenza vaccinated 48%) showed pooled odds ratio for any irAEs in influenza vaccinated versus nonvaccinated patients at 0.82 [95% CI: 0.63–1.08, P=NS]. Similar results were observed in sensitivity analyses for serious irAEs, as well as when only peer-reviewed studies were included. Influenza vaccination appears to be a safe and reasonable intervention for cancer patients receiving ICIs. Most data are derived from retrospective observational studies. Randomized studies are needed to provide high-quality evidence.

10 September 2024 in Critical Care Explorations
Verified
Journal Article
Open access
EKEleni Karakike
Eleni Karakike
Symeon MetallidisSymeon Metallidis
Symeon Metallidis
GPGaryphallia Poulakou
Garyphallia Poulakou
MKMaria Kosmidou
Maria Kosmidou
Nikolaos GatselisNikolaos Gatselis
Nikolaos Gatselis
EGEvangelos J Giamarellos-Bourboulis
Evangelos J Giamarellos-Bourboulis
OBJECTIVES: It is suggested that sepsis may be classified into four clinical phenotypes, using an algorithm employing 29 admission parameters. We applied a simplified phenotyping algorithm among patients with bacterial sepsis and severe COVID-19 and assessed characteristics and outcomes of the derived phenotypes. DESIGN: Retrospective analysis of data from prospective clinical studies. SETTING: Greek ICUs and Internal Medicine departments. PATIENTS AND INTERVENTIONS: We analyzed 1498 patients, 620 with bacterial sepsis and 878 with severe COVID-19. We implemented a six-parameter algorithm (creatinine, lactate, aspartate transaminase, bilirubin, C-reactive protein, and international normalized ratio) to classify patients with bacterial sepsis intro previously defined phenotypes. Patients with severe COVID-19, included in two open-label immunotherapy trials were subsequently classified. Heterogeneity of treatment effect of anakinra was assessed. The primary outcome was 28-day mortality. MEASUREMENTS AND MAIN RESULTS: The algorithm validated the presence of the four phenotypes across the cohort of bacterial sepsis and the individual studies included in this cohort. Phenotype α represented younger patients with low risk of death, β was associated with high comorbidity burden, and δ with the highest mortality. Phenotype assignment was independently associated with outcome, even after adjustment for Charlson Comorbidity Index. Phenotype distribution and outcomes in severe COVID-19 followed a similar pattern. CONCLUSIONS: A simplified algorithm successfully identified previously derived phenotypes of bacterial sepsis, which were predictive of outcome. This classification may apply to patients with severe COVID-19 with prognostic implications.