Oral microbiota as a potential therapeutic target in progression and malignant
transformation of proliferative verrucous leukoplakia | Lucie Nechutná
The role of oral microbiota in PVL
Authors: Lucie Nechutná (1,2)
Supervisor: Jaroslav Hrabák (1)
(1) Department of Microbiology, Faculty of Medicine in Pilsen, Charles University and University
Hospital, Pilsen
(2) Department of Stomatology, Faculty of Medicine in Pilsen, Charles University and University
Hospital, Pilsen
State-of-the-Art: Proliferative verrucous leukoplakia (PVL) is a rare oral potentially malignant
disorder characterised by a high recurrence rate and up to 40% risk of malignant transformation
to oral squamous cell carcinoma. Increasing evidence suggests that dysbiosis of the oral micro
biota contributes to PVL pathogenesis and disease progression. In our department, a pilot study
analysing 12 periodontal pathogens demonstrated significantly higher bacterial prevalence in
PVL lesions compared with other oral mucosal conditions. A recent study published in 2025 fur
ther indicates that interactions between oral microbiota and oncogenic viruses, particularly hu
man papillomavirus (HPV), may influence inflammation, immune response and carcinogenesis.
Objective: To characterise the oral microbiota in 35 patients with proliferative verrucous leuko
plakia and compare bacterial composition according to radiographic findings, clinical progres
sion and viral positivity (HPV, EBV, CMV) to identify microbial patterns associated with disease
development.
Material and Methods: After establishing inclusion criteria samples were collected from 35 pa
tients diagnosed with PVL using sterile paper points inserted into periodontal pockets. DNA was
isolated and subjected to Illumina metagenomic sequencing targeting the V3–V4 region of the
16S rRNA gene. Sequencing libraries were prepared using barcoded primers and pooled prior to
analysis. In parallel PCR screening for oncogenic viruses, including human papillomavirus (HPV),
Epstein–Barr virus (EBV) and cytomegalovirus (CMV) is currently ongoing. Virus-positive sam
ples will subsequently undergo sequencing for viral typing and to assess potential associations
with alterations in bacterial community composition.
Results & Discussion: In our pilot study 12 aggressive periodontal pathogens were monitored
in 38 PVL cases, 38 patients with oral lichen planus presenting as desquamative gingivitis and
38 with chronic periodontitis. Pathogens were relatively quantified using qPCR with TaqMan
probes. PVL samples showed a threefold higher bacterial abundance compared with control
groups (p = 0.0009). Subsequent metagenomic sequencing confirmed these findings and re
vealed dysbiosis of the oral microbiota associated with progression of PVL lesions. These results
support a significant role of microbial imbalance in PVL pathogenesis and highlight the impor
tance of analysing the full spectrum of oral bacteria and potential viral cofactors.
Conclusion: The findings highlight microbial dysbiosis as a potential cofactor in PVL pathogene
sis. Targeting microbial communities and their products may represent a promising therapeutic
approach, as current treatment options remain largely ineffective.
Funding: This work was supported by the project Nr. LX22NPO5103 „National Institute of virolo
gy and bacteriology“ supported by the National Recovery Plan (EXCELES Programme)
Submucosal fibrosis in oral lichen planus | Nikoleta Molnárová
A common complication of oral lichen planus
Authors: Nikoleta Molnárová (1), Jan Liška (1), Veronika Lišková (1)
Supervisor: Jan Liška (1)
(1) Department of Stomatology, Faculty of Medicine in Pilsen, Charles University and University
Hospital, Pilsen
State-of-the-Art: Oral lichen planus (OLP) is the most frequent chronic non-infectious inflam
matory disease of the oral mucosa with a prevalence of 0.5-2.5%. The issue of submucosal fi
brosis (SMF) in OLP is rarely discussed in the literature. According to the only available study,
the incidence of SMF in OLP is 30.1%. No relationship was found between SMF and erosive OLP
lesions, extraoral manifestations of lichen, smoking, age, VAS pain assessment, or duration of
disease. The development of SMF can lead to restricted mouth opening (RMO) with an interincis
al distance (IID) of less than 35 mm, which impairs many functions of the mouth.
Objective: The aim of this study is to draw attention to the etiological and clinical context of
OLP, which is neglected in the literature. Submucosal fibrosis in OLP has an impact on patients‘
quality of life, the possibility of dental treatment, and the examination of oral mucosa.
Material and Methods: The presence of SMF and actual interdental distance were evaluated
in 400 confirmed cases of OLP. All patients were monitored at the Department of Oral Medicine
of the Dental Clinic of the University Hospital in Pilsen. Correlation of SMF cofactors was per
formed. The one-year development of the SMF phenomenon was studied in 330 cases of OLP.
Results & Discussion: Significant associations between SMF and specific aspects of OLP, such
as erosive form and desquamative gingivitis, have been confirmed. Ventrally located SMF bun
dles have a greater effect on RMO. Critical RMO below 35 mm was present in almost 7% of SMF
positive cases. Even one year of SMF presence leads to a significant reduction in mouth opening
with p-value=0.0005.
Conclusion: This is the first study to demonstrate significant associations with erosive lichen,
desquamative gingivitis, extraoral lichen, and higher symptomatology of SMF positive cases of
OLP. This comprehensive approach may improve the outcomes of OLP monitoring
Exploring the combined prognostic Value of Age and mir-1972 expression
in hepatocellular carcinoma | Venkata Ramana Mallela
Age and miR-1972 Expression in Hepatocellular Carcinoma
Authors: Venkata Ramana Mallela (1), Andriy Trailin (1), Václav Liška (2,3), Kari Hemminki (1,4), and
Filip Ambrozkiewicz (1)
Supervisor: Filip Ambrozkiewicz (1)
(1) Laboratory of Translational Cancer Genomics, Biomedical Center, Faculty of Medicine in Pils
en, Charles University, Pilsen, Czech Republic
(2) Laboratory of Cancer Treatment and Tissue Regeneration, Biomedical Center, Faculty of Med
icine in Pilsen, Charles University, Pilsen, Czech Republic
(3) Department of Surgery, Faculty of Medicine in Pilsen, Charles University and University Hos
pital, Pilsen
(4) Department of Cancer Epidemiology, German Cancer Research Center, Heidelberg, Germany
State-of-the-Art: Hepatocellular carcinoma (HCC) is an aggressive malignancy with poor prog
nosis due to high recurrence rates and limited reliable prognostic biomarkers. MicroRNAs (miR
NAs) regulate gene expression and play key roles in cancer progression. miR-1972 has been im
plicated in cancer biology, and our previous work identified its prognostic relevance in non-viral
HCC.
Objective: This study aimed to investigate the impact of patient age and miR-1972 expression
on survival outcomes in non-viral HCC.
Material and Methods: Tumour samples from 45 patients with non-viral HCC who underwent
surgical resection were analysed using a miRNA expression microarray. Associations between
age and miR-1972 expression were evaluated. Cox proportional hazards regression and Kaplan
Meier analyses were performed to assess the effects of age and miR-1972 expression on dis
ease-free survival (DFS) and time to recurrence (TTR).
Results & Discussion: Older age showed a trend towards longer DFS and was significantly asso
ciated with longer TTR (HR = 0.39, 95% CI: 0.39–0.96, p = 0.04). Multivariable analysis confirmed
that older age independently predicted longer DFS (HR = 0.42, 95% CI: 0.20–0.88, p = 0.02) and
TTR (HR = 0.30, 95% CI: 0.12–0.77, p = 0.01). High miR-1972 expression was also associated with
improved DFS (HR = 0.30, 95% CI: 0.13–0.69, p = 0.005) and TTR (HR = 0.27, 95% CI: 0.10–0.77, p =
0.01). The combination of older age and high miR-1972 expression was strongly associated with
improved DFS (HR = 0.13, 95% CI: 0.04–0.43, p < 0.001) and TTR (HR = 0.08, 95% CI: 0.02–0.31,
p < 0.001), which was further confirmed by Kaplan–Meier analysis (p = 0.006 and p = 0.001,
respectively).
Conclusion: Patient age and miR-1972 expression are favourable prognostic indicators in
non-viral HCC. Their combined assessment may improve patient stratification and survival pre
diction, highlighting potential differences in prognostic biology between viral and non-viral HCC.
Funding: This research has received funding from the National Institute for Cancer Research—
NICR (Programme EXCELES, ID Project No. LX22NPO5102) and the Cooperation project “Surgical
disciplines” (COOPERATION-207043, Charles University).
Evaluation of proenkephalin and uromodulin in relation to renal function in patients
with hematological malignancies | Pavel Prokop
Renal Markers in Hematologic Malignancies
Authors: Pavel Prokop (1), Hana Vimmerová (1), Lenka Fait Dvořáková (1), Somu Yadav (1), Daniel
Lysák (2), Daniel Rajdl (1)
Supervisor: Daniel Rajdl (1)
(1) Department of Clinical Biochemistry and Haematology, Faculty of Medicine in Pilsen, Charles
University and University Hospital, Pilsen
(2) Department of Haematology and Oncology, Faculty of Medicine in Pilsen, Charles University
and University Hospital, Pilsen
State-of-the-Art: Renal dysfunction is a frequent and clinically relevant complication in pa
tients with hematological malignancies. Routine assessment is commonly based on serum
creatinine, cystatin C, and estimated glomerular filtration rate (eGFR), but these markers may
have limitations in this specific clinical setting. Proenkephalin A 119–159 (penKid) and uromod
ulin have emerged as promising biomarkers reflecting different aspects of kidney function and
injury. Their role in patients with hematological malignancies, however, remains insufficiently
characterized.
Objective: The aim of the study is to assess the relationship of proenkephalin A 119–159 (pen
Kid) and uromodulin to parameters of renal function in hospitalized hemato-oncological pa
tients and to evaluate their potential as complementary biomarkers in comparison with routine
ly used laboratory markers.
Material and Methods: The ongoing analysis includes hospitalized hemato-oncological pa
tients with available residual plasma samples and a urea/creatinine ratio > 70. Renal function is
assessed using estimated glomerular filtration rate (eGFR) calculated according to the CKD-EPI
2021 creatinine equation, the CKD-EPI cystatin C equation, and the combined creatinine–cys
tatin C equation. penKid concentrations are measured by immunofluorescence assay on the
AFIAS-4 analyzer, while uromodulin is measured by chemiluminescent immunoassay on the
Kleeya analyzer. The evaluation includes descriptive statistics, comparison of individual eGFR
estimates, correlation analysis, and assessment of biomarker changes over time.
Results & Discussion: The analysis of the cohort is currently ongoing. Preliminary observations
suggest differences among individual approaches to renal function estimation and at the same
time indicate a possible contribution of the studied biomarkers as complementary indicators
to routine laboratory parameters. Further analysis is focused on evaluating the relationship of
penKid and uromodulin to eGFR and other laboratory markers, including the assessment of
their temporal dynamics in repeated sampling.
Conclusion: Proenkephalin and uromodulin may represent promising complementary bio
markers of renal function in patients with hematological malignancies. This study may help clar
ify their relationship to standard renal markers and their potential clinical relevance
Effect of Virtual reality exercise on range of motion and pain perception in patients with limited shoulder mobility | Andrea Kunschová
VR Exercise and Shoulder Pain
Authors: Andrea Kunschová (1), Pavla Marešová (2)
Supervisor: Petr Zeman (1)
(1) Department of Orthopaedics and Locomotive Apparatus Traumatology, Faculty of Medicine
in Pilsen, Charles University and University Hospital, Pilsen
(2) Department of Rehabilitation and Physical Medicine, Faculty of Medicine in Pilsen, Charles
University and University Hospital, Pilsen
State-of-the-Art: Pain and limited range of motion will commonly restrict progress in the re
habilitation of shoulder disorders. Patients will often limit movement due to pain perception or
fear of pain, which may reduce therapeutic effectiveness. Virtual reality (VR) will be used as a
supportive rehabilitation tool providing interactive environments that promote active partici
pation in exercise. Previous studies suggest that VR may decrease perceived pain through dis
traction while increasing patient engagement. However, objective evidence on the relationship
between VR-assisted exercise, range of motion, and pain perception in individuals with shoulder
mobility limitations will remain limited. This study will examine this interaction to help optimize
rehabilitation strategies and improve functional outcomes.
Objective: To evaluate whether short-term VR-based exercise influences active range of motion
and subjective pain perception in patients with limited shoulder mobility during rehabilitation.
Material and Methods: Patients with painful shoulder mobility limitations will be evaluated in
a single session. Active shoulder range of motion (ROM) will first be measured using a standard
goniometer. Participants will then engage in 10–15 minutes of active exercise in a virtual reality
(VR) environment targeting upper limb movements. During VR exercise, movement range will be
recorded via the VR tracking system. Subjective pain intensity will be assessed using the Visual
Analogue Scale (VAS) before, during, and immediately after the session. Collected data will be
analyzed to determine whether VR-assisted exercise will enhance movement range and modu
late perceived pain during rehabilitation.
Results & Discussion: Preliminary observations suggest that patients often achieve greater
active range of motion during VR-based exercise compared with baseline goniometric meas
urement. Many participants report lower perceived pain during the initial phase of VR activity,
which may be explained by distraction from pain due to immersive visual and motor engage
ment. Toward the end of the exercise session, some patients report increased fatigue and a mild
increase in pain intensity. Despite this, the achieved range of motion frequently remains higher
than during baseline assessment. These findings indicate that VR-assisted exercise may tempo
rarily reduce pain perception and facilitate larger movement amplitudes during rehabilitation
tasks.
Conclusion: Virtual reality exercise may enable patients with painful shoulder mobility limita
tion to perform movements with greater range while temporarily reducing perceived pain. VR
could represent a useful supportive tool in rehabilitation programs focused on improving active
mobility
Clinical Trial: Effect of Respiratory Infections on Serum 25(OH)D Levels During Vitamin D₃ supplementation | Hedvika Mikolášová
Clinical trial: Vigantol
Authors: Hedvika Mikolášová (1,3), Michal Jirásko (1,3), Radek Kučera (1,3), Monika Bludovská (4),
Pavel Sedláček (4), Daniela Fránová (2)
Supervisor: Radek Kučera (1,3)
(1) Department of Pharmacology and Toxicology, Faculty of Medicine in Pilsen, Charles Univer
sity (2) Department of Infectious Diseases and Travel Medicine, Faculty of Medicine in Pilsen,
Charles University and University Hospital, Pilsen (3) Central Laboratory for Immunoanalysis,
Faculty of Medicine in Pilsen, Charles University and University Hospital, Pilsen (4) Department
of Public Health and Preventive Medicine, Faculty of Medicine in Pilsen, Charles University
State-of-the-Art: Vitamin D is primarily obtained through sunlight, which enables its synthesis
in the skin. At latitudes above approximately 33°, cutaneous vitamin D production is limited
to the period from May to September, resulting in seasonal declines in vitamin D levels and a
high prevalence of deficiency during winter. Respiratory infections, which are more common in
winter, may further contribute to reductions in vitamin D levels. Some studies have reported de
creases in serum vitamin D concentrations following respiratory infections, even in individuals
receiving vitamin D₃ supplementation. This clinical trial evaluates short-term changes in serum
25(OH)D levels following respiratory infection.
Objective: The aim of this clinical trial was to assess whether declines in serum 25(OH)D levels
were greater in participants who experienced respiratory infection during vitamin D₃ supple
mentation than in those who remained healthy.
Material and Methods: A total of 130 volunteers were enrolled in the study, including 35 older
adults aged 65–85 years and 95 young adults aged 20–27 years. All participants received vitamin
D₃ supplementation (Vigantol®, cholecalciferol oral drops) at a dose of 1000 IU daily for 60 days
during October and November 2025. Blood samples were collected and serum 25(OH)D levels
were measured before the start and after the end of the supplementation period. Participants
were instructed to report any respiratory infection during the supplementation period and to
attend an additional study visit for blood sampling 7–10 days after symptom onset.
Results & Discussion: During the supplementation period, respiratory infection was reported
in 14 participants, including 5 individuals aged 65–85 years, and additional blood samples were
collected in these cases. At 7–10 days after symptom onset, serum 25(OH)D levels increased in 6
infected participants, while a mild decrease was observed in the remaining 8.
After the supplementation period, 25(OH)D levels decreased in most participants, with a mean
decline of 15.9 nmol/L. The extent of decline was comparable between participants who ex
perienced respiratory infection and those who remained healthy during the supplementation
period.
Conclusion: Respiratory infections did not appear to significantly affect serum 25(OH)D levels
during vitamin D₃ supplementation, although the small number of infected participants limits
interpretation. A daily dose of 1000 IU was insufficient in winter. Further study phases evaluating
higher doses ongoing.
Funding: This work was supported by the Cooperatio Program, research area Pharmaceutical
Science
Bisphenol A and its Analogues: implications for gut microbiome health | Andrea Fričová
Bisphenols and the Gut Microbiome
Authors: Andrea Fričová (1), Monika Bludovská (1,2), Anna Zavaďáková (1), Dana Müllerová (1)
Supervisor: Dana Müllerová (1)
(1) Department of Public Health and Preventive Medicine, Faculty of Medicine in Pilsen, Charles
University, Czech Republic
(2) Department of Pharmacology and Toxicology, Faculty of Medicine in Pilsen, Charles Univer
sity, Czech Republic
State-of-the-Art: Recent research has identified bisphenol A (BPA) and its structural analogues
as widespread endocrine disruptors with emerging impacts on the gut microbiome. Experimen
tal studies consistently demonstrate that exposure to BPA, BPS, and BPF alters microbial com
position, reduces diversity, and promotes pro-inflammatory profiles linked to metabolic and
immune dysregulation. However, most evidence is derived from animal and in vitro models,
while human data remain limited. In addition, newer bisphenol analogues and mixture effects
are still insufficiently characterized, highlighting a need for integrative microbiome-focused tox
icological research.
Objective: To synthesize current evidence on the effects of bisphenol A and its analogues on the
gut microbiome, identify key mechanisms of microbiome-mediated toxicity, and highlight major
research gaps relevant to human health and risk assessment.
Material and Methods: This narrative review is based on a structured literature search con
ducted in PubMed covering the period from January 2010 to December 2025. Search terms in
cluded combinations of “bisphenol,” “BPA,” “BPS,” “BPF,” “gut microbiome,” “intestinal barrier,”
and “dysbiosis.” Experimental (in vivo and in vitro), epidemiological, and mechanistic studies
were included. Non-English publications, studies without microbiome-related outcomes, and
inaccessible full texts were excluded.
Results & Discussion: Evidence across animal, in vitro, and limited human studies indicates
that bisphenol exposure consistently disrupts gut microbial composition and function. BPA and
its analogues (notably BPS and BPF) reduce microbial diversity, deplete beneficial taxa such
as Bifidobacterium and Akkermansia, and promote pro-inflammatory microbial profiles. These
changes are associated with impaired intestinal barrier integrity, altered short-chain fatty acid
production, and downstream metabolic and immune disturbances. Importantly, several BPA
substitutes demonstrate microbiome-disrupting effects comparable to or exceeding BPA, rais
ing concerns about regrettable substitution. However, the predominance of experimental mod
els highlights the lack of long-term, low-dose human data.
Conclusion: Growing evidence identifies bisphenols and their analogues as microbiome-dis
rupting chemicals, underscoring the need to integrate microbiome endpoints into risk assess
ment and expand human-centered research.
Expression of plasminogen activator inhibitor-1 (PAI-1) in patients recovered from
coViD-19 disease | Simona Bílková
PAI expression and COVID-19 disease
Authors: Simona Bílková (1,2), Jan Filipovský (1,2), Jana Hirmerová (1,2), Petr Pazdiora (3), Jindra
Windrichová (4), Tereza Nezbedová (1), Petra Karnosová(1), Otto Mayer (1,2)
Supervisor: Otto Mayer (1,2)
(1) Department of Internal Medicine II, Faculty of Medicine in Pilsen, Charles University and Uni
versity Hospital, Pilsen (2) Biomedical Center, Faculty of Medicine in Pilsen, Charles University
and University Hospital, Pilsen (3) Department of Epidemiology, Faculty of Medicine in Pilsen,
Charles University and University Hospital, Pilsen (4) Department of Immunodiagnostics, Facul
ty of Medicine in Pilsen, Charles University and University Hospital, Pilsen
State-of-the-Art: In patients infected with the SARS-CoV-2 coronavirus causing COVID-19,
overexpression of plasminogen activator inhibitor-1 (PAI-1) was observed, and this increased
expression was also found to be closely correlated with the severity of the viral disease.PAI
1 is produced by endothelial cells, and its elevated levels in post-COVID patients represent a
manifestation of endothelial damage induced by SARS-CoV-2 infection. PAI-1 plays a key role in
fibrinolysis. During the COVID-19 pandemic, it was globally observed that this disease causes a
specific type of coagulopathy (COVID-19-associated coagulopathy, CAC), in which mechanisms
of the innate immune response damage endothelial cells primarily in the microcirculation, lead
ing to thrombus formation (so-called immunothrombosis).
Objective: The aim of our study was to determine how long elevated PAI-1 concentrations per
sist in patients who have fully recovered from COVID-19. We were also interested in whether
persistent elevated PAI-1 levels after COVID-19 correlate with the clinical course of the disease.
Material and Methods: A total of 1,261 individuals were analyzed in the study, including 377
patients who had recovered from COVID-19 and 884 healthy COVID-negative controls. We com
pared 377 patients who were 30 to 210 days after PCR-confirmed COVID-19 with a total of 884
control individuals who had not had COVID-19.We included only patients with mild to moderate
COVID-19 in our study. Patients who required mechanical ventilation or other intensive care
were excluded, as were patients with secondary complications (e.g., pulmonary embolism).
Results & Discussion: Our study showed that elevated PAI-1 levels persisted for several months
(up to 1 year) after COVID-19, and it likely revealed for the first time that increased PAI-1 levels
also persist in completely asymptomatic patients (fully recovered individuals).The strongest pre
dictor of elevated PAI-1 in these patients was the β mutation of SARS-CoV-2, which was associat
ed with approximately an 11-fold higher risk of PAI-1 ≥32 ng/mL.A surprising finding of our study
was that we did not observe any decrease in PAI-1 among patients recovered from COVID-19;
on the contrary, PAI-1 levels tended to increase. Regarding CAC we did not find an association
between PAI-1 and D-dimer or other basic coagulation factors. We did´nt observe a relationship
between PAI-1 and ferritin.
Conclusion: The key finding of our analysis was that elevated PAI-1 levels can be present in
patients even several months after full recovery from COVID-19, at a time when the observed
individuals were almost completely asymptomatic,