Alexandros Ioannou

Dr. Alexandros Ioannou

orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

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

Representative Publications

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1 April 2020 in Digestive and Liver Disease
Verified
Journal Article
Closed access
DMDaniele Mandolesi
Daniele Mandolesi
PSPatrizia Schiavon
Patrizia Schiavon
AIAlexandros Ioannou
Alexandros Ioannou
MMMichela Mancini
Michela Mancini
MCMaria Chiara Cimatti
Maria Chiara Cimatti
FTFrancesco Torresan
Francesco Torresan

Verified
Journal Article
Open access
PDF file
KKKanellos Koustenis
Kanellos Koustenis
Nikolas DovrolisNikolas Dovrolis
Nikolas Dovrolis
NVNikos Viazis
Nikos Viazis
AIAlexandros Ioannou
Alexandros Ioannou
GBGiorgos Bamias
Giorgos Bamias
Maria GazouliMaria Gazouli
Maria Gazouli
Introduction: Optimizing treatment with biological agents is an ideal goal for patients with ulcerative colitis (UC). Recent data suggest that mucosal inflammation patterns and serum cytokine profiles differ between patients who respond and those who do not. Ustekinumab, a monoclonal antibody targeting the p40 subunit of interleukin (IL)-12 and IL-23, has shown promise, but predicting treatment response remains a challenge. We aimed to identify prognostic markers of response to ustekinumab in patients with active UC, utilizing information from their mucosal transcriptome. Methods: We performed a prospective observational study of 36 UC patients initiating treatment with ustekinumab. Colonic mucosal biopsies were obtained before treatment initiation for a gene expression analysis using a microarray panel of 84 inflammatory genes. A differential gene expression analysis (DGEA), correlation analysis, and network centrality analysis on co-expression networks were performed to identify potential biomarkers. Additionally, machine learning (ML) models were employed to predict treatment response based on gene expression data. Results: Seven genes, including BCL6, CXCL5, and FASLG, were significantly upregulated, while IL23A and IL23R were downregulated in non-responders compared to responders. The co-expression analysis revealed distinct patterns between responders and non-responders, with key genes like BCL6 and CRP highlighted in responders and CCL11 and CCL22 in non-responders. The ML algorithms demonstrated a high predictive power, emphasizing the significance of the IL23R, IL23A, and BCL6 genes. Conclusions: Our study identifies potential biomarkers associated with ustekinumab response in UC patients, shedding light on its underlying mechanisms and variability in treatment outcomes. Integrating transcriptomic approaches, including gene expression analyses and ML, offers valuable insights for personalized treatment strategies and highlights avenues for further research to enhance therapeutic outcomes for patients with UC.

21 September 2021 in Journal of Gastrointestinal and Liver Diseases
Verified
Journal Article
Open access
PDF file
DKDimitrios Kypraios
Dimitrios Kypraios
EMEleni Manthopoulou
Eleni Manthopoulou
DDDimitrios Dimitroulopoulos
Dimitrios Dimitroulopoulos
APAris Plastiras
Aris Plastiras
AIAlexandros Ioannou
Alexandros Ioannou
KTKlisthenis Tsamakidis
Klisthenis Tsamakidis
Various endoscopic techniques have been described for the treatment of post-operative colonic strictures. Our aim is to report a solely EUS-guided recanalization procedure for a complete rectal stricture, without the use of fluoroscopy or stenting. A 66-year-old male was submitted to low anterior resection and protective ileostomy for rectal adenocarcinoma, complicated with complete anastomotic stricture 6 months later. The patient was treated with a modified EUS-guided rendezvous technique. A colonoscope was advanced through the ileostomy to the sigmoid colon, which was subsequently filled with water. A linear echoendoscope was advanced transanally to the distal part of the rectal anastomosis. The proximal colon was punctured with a 19G needle and a guidewire was advanced through the needle. The rectocolonic fistula tract was first dilated by graduated dilation catheters. Subsequently, progressive pneumatic dilatation was performed. There were no post-procedural complications. At 6-month follow-up the anastomosis was patent, with no significant stricture recurrence. In conclusion, a rendezvous technique for EUS-guided recanalization of complete rectal anastomotic strictures is feasible and safe in a non-radiology assisted setting. In selected cases of distal stenoses balloon dilation could effectively serve as the sole treatment, without the adjunct of stent placement.

1 March 2019 in Journal of Gastrointestinal and Liver Diseases
Verified
Journal Article
Open access
AIAlexandros Ioannou
Alexandros Ioannou
DMDaniele Mandolesi
Daniele Mandolesi
FBFranco Bazzoli
Franco Bazzoli
FTFrancesco Torresan
Francesco Torresan

1 December 2021 in Forum of Clinical Oncology
Verified
Journal Article
Open access
PDF file
AIAlexandros Ioannou
Alexandros Ioannou
PGPapaxoinis Georgios
Papaxoinis Georgios
DDDimitroulopoulos Dimitrios
Dimitroulopoulos Dimitrios
TDTryfonopoulos Dimitrios
Tryfonopoulos Dimitrios
GPGouveris Panagiotis
Gouveris Panagiotis
Cancer immunotherapy is an emerging beneficial treatment for cancer that acts by activating the immune system to produce antitumour effects. In particular, immune checkpoint therapy has recently provided novel strategies for cancer treatments. Nevertheless, these new therapeutic approaches have introduced immune-related adverse events to clinical practice. In the elderly, checkpoint inhibitors might have limited efficacy because of immunosenescence. Limited literature data demonstrate a higher incidence of irAEs and an earlier discontinuation of immunotherapy in these patients. We report the case of an 89-year-old male patient with metastatic urothelial carcinoma, who presented with Grade 4 immune-related hepatitis after receiving pembrolizumab treatment.

26 July 2024 in United European Gastroenterology Journal
Verified
Journal Article
Open access
AIAlexandros Ioannou
Alexandros Ioannou
KDKonstantina Dimopoulou
Konstantina Dimopoulou
EREvripidis Rizos
Evripidis Rizos
EMEleni Manthopoulou
Eleni Manthopoulou
OSOrestis Sidiropoulos
Orestis Sidiropoulos
Ioannis PapanikolaouIoannis Papanikolaou
Ioannis Papanikolaou
Resident Survey of Gastroenterology Training in Greece.