Georgios Michalopoulos

Dr. Georgios Michalopoulos

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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20 March 2020 in Microorganisms
Verified
Journal Article
Open access
PDF file
Nikolas DovrolisNikolas Dovrolis
Nikolas Dovrolis
GMGeorgios Michalopoulos
Georgios Michalopoulos
George TheodoropoulosGeorge Theodoropoulos
George Theodoropoulos
KAKonstantinos Arvanitidis
Konstantinos Arvanitidis
GKGeorge Kolios
George Kolios
Maria GazouliMaria Gazouli
Maria Gazouli
Even though anti-TNF therapy significantly improves the rates of remission in inflammatory bowel disease (IBD) patients, there is a noticeable subgroup of patients who do not respond to treatment. Dysbiosis emerges as a key factor in IBD pathogenesis. The aim of the present study is to profile changes in the gut microbiome and transcriptome before and after administration of the anti-TNF agent Infliximab (IFX) and investigate their potential to predict patient response to IFX at baseline. Mucosal biopsy samples from 20 IBD patients and nine healthy controls (HC) were examined for differences in microbiota composition (16S rRNA gene sequencing) and mucosal gene expression (RT-qPCR) at baseline and upon completion of IFX treatment, accordingly, via an in silico pipeline. Significant differences in microbiota composition were found between the IBD and HC groups. Several bacterial genera, which were found only in IBD patients and not HC, had their populations dramatically reduced after anti-TNF treatment regardless of response. Alpha and beta diversity metrics showed significant differences between our study groups. Correlation analysis revealed six microbial genera associated with differential expression of inflammation-associated genes in IFX treatment responders at baseline. This study shows that IFX treatment has a notable impact on both the gut microbial composition and the inflamed tissue transcriptome in IBD patients. Importantly, our results identify enterotypes that correlate with transcriptome changes and help differentiate IFX responders versus non-responders at baseline, suggesting that, in combination, these signatures can be an effective tool to predict anti-TNF response.

20 December 2024 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
BFBernadett Farkas
Bernadett Farkas
TBTalat Bessissow
Talat Bessissow
JLJimmy K. Limdi
Jimmy K. Limdi
KSKarishma Sethi-Arora
Karishma Sethi-Arora
AKAnna Kagramanova
Anna Kagramanova
TMTamás Molnár
Tamás Molnár
Background/Objectives: Data on the real-world effectiveness and safety of selective JAK inhibitors (JAKis) in ulcerative colitis (UC) and Crohn’s disease (CD) are limited. Methods: We conducted a multicentre, retrospective study to assess clinical, biochemical, and endoscopic outcomes of selective JAKis in bio-experienced UC and CD. Results: A total of 246 patients (mean age: 40.5 ± 14.5 years; 131 UC and 115 CD) were included with a median follow-up of 7.5 months. Among the CD patients receiving upadacitinib (n = 115), 76.2% achieved clinical remission (CR) at week 12. Furthermore, 59.5% of the upadacitinib-treated UC patients (n = 100) experienced CR at week 8. Corticosteroid-free CR (CSFCR) was achieved by 76.9% of the CD patients and 80.6% of the UC patients at week 24, while 50.0% and 36.1% experienced endoscopic remission. At week 52, 66.7% of the CD and 86.2% of the UC patients achieved CSFCR, whereas 54.5% and 52.9% had endoscopic remission. In UC, the effectiveness of upadacitinib was not compromised by prior tofacitinib failure, while the upadacitinib-treated CD patients with stricturing and penetrating disease were less likely to achieve CR by the end of the induction phase (p = 0.04). C-reactive protein (p[CD] < 0.0001; p[UC] < 0.0001) and faecal calprotectin (p[CD] < 0.0001; p[UC] = 0.02) decreased significantly in both patient groups as early as week 2. Among the filgotinib-treated UC patients (n = 31), 28.6% were in CR at week 12. At week 24 and 52, 59.1% and 60% achieved CSFCR, while 0.0% and 20.0% had endoscopic remission. Both C-reactive protein (p = 0.04) and faecal calprotectin (p = 0.04) decreased significantly by week 12. Hyperlipidaemia (9.7–9.8%) was the most common adverse event. Conclusions: Selective JAKis are rapidly effective and safe for treating refractory, moderate-to-severe CD and UC.

9 March 2021 in Digestive Diseases and Sciences
Verified
Journal Article
Closed access
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GBGiorgos Bamias
Giorgos Bamias
GKGeorgios Kokkotis
Georgios Kokkotis
MGMichalis Gizis
Michalis Gizis
CKChristina Kapizioni
Christina Kapizioni
KKKonstantinos Karmiris
Konstantinos Karmiris
GMGerassimos J Mantzaris
Gerassimos J Mantzaris

1 January 2018 in Annals of Gastroenterology
Verified
Journal Article
Open access
GMGeorgios Michalopoulos
Georgios Michalopoulos
SVSpyridon Vrakas
Spyridon Vrakas
KMKonstantinos Makris
Konstantinos Makris
CTCharalampos Tzathas
Charalampos Tzathas
The interaction between sleep and the immune system has been increasingly studied over the last decades. The aim of this study was to investigate the association between sleep quality and mucosal healing in patients with inflammatory bowel disease (IBD) currently in clinical remission. Ninety patients with IBD in clinical remission were studied: 54 (60%) with Crohn's disease and 36 (40%) with ulcerative colitis. All completed the Pittsburgh Sleep Quality Index, and mucosal healing was estimated with ileocolonoscopy. A subgroup analysis was also performed in order to investigate these associations in Crohn's disease and ulcerative colitis separately. Of the 90 patients, 45.56% had poor sleep quality. Patients without mucosal healing expressed higher absolute values of the Pittsburgh Sleep Quality Index (P0.05). In patients with IBD in clinical remission, absence of mucosal healing seems to be associated with poor sleep quality, especially in patients with Crohn's disease.

11 December 2021 in Current Research in Pharmacology and Drug Discovery
Verified
Journal Article
Open access
GMGeorgios Michalopoulos
Georgios Michalopoulos
KKKonstantinos Karmiris
Konstantinos Karmiris
Patients with ulcerative proctitis represent a sub-group of ulcerative colitis patients with specific characteristics. Disease-related symptoms, endoscopic findings and patient's personality perspectives create a difficult-to-assess condition in certain cases. To summarize available evidence on the management of refractory ulcerative proctitis and provide insights in treatment options. /Conclusion: Topical therapy plays a central role due to the location of the disease. However, well-established treatment options may become exhausted in a considerable proportion of ulcerative proctitis patients, indicating the need to advance to more potent therapies in order to induce and maintain clinical response and remission in these refractory cases. Systemic corticosteroids, thiopurines, calcineurin inhibitors, biologic agents and small molecules have all been tested with variable success rates. Investigational interventions as well as surgical procedures are kept as the ultimate resort in multi-treatment resistant cases. Identifying early prognostic factors that herald a disabling disease progression will help in optimizing treatment and avoiding surgery.

27 January 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
EOEleni Orfanoudaki
Eleni Orfanoudaki
EZEIRINI ZACHAROPOULOU
EIRINI ZACHAROPOULOU
VKVassiliki Kitsou
Vassiliki Kitsou
KKKonstantinos Karmiris
Konstantinos Karmiris
ATAngeliki Theodoropoulou
Angeliki Theodoropoulou
OIon behalf of the Hellenic Group for the Study of IBD
on behalf of the Hellenic Group for the Study of IBD
Since inflammatory bowel disease (IBD) patients were excluded from vaccine authorization studies, limited knowledge exists regarding perceptions and unfavorable effects of COVID-19 vaccination in this group. We aimed to investigate the real-world use and adverse events (AEs) of COVID-19 vaccines in Greek IBD patients. Fully vaccinated IBD patients followed in Greek centers were invited to participate. All patients filled out an anonymous online survey concerning the vaccination program, which included information regarding demographics, clinical characteristics, treatment, vaccination perceptions and potential AEs. Overall, 1007 IBD patients were included. Vaccine hesitancy was reported by 49%. Total AEs to vaccination were reported by 81% after dose 1 (D1) and 76% after dose 2 (D2), including isolated injection site reactions (36% and 24% respectively). Systemic AEs were more common after D2 (51%, D2 vs. 44%, D1, p < 0.0001). Very few patients reported new onset abdominal symptoms (abdominal pain 4% (D1), 6% (D2) and diarrhea 5% (D1), 7% (D2)). There were no serious AEs leading to emergency room visit or hospitalization. In multivariate analysis, AEs occurrence was positively associated with young age and female gender (p < 0.0005 for both doses), whereas inactive disease was negatively associated with AE in D1 (p = 0.044). SARS-CoV-2 vaccination in Greek IBD patients demonstrated a favorable and reassuring safety profile.