Brief Summary

Hantaviruses are globally distributed viruses that cause haemorrhagic fever with renal syndrome (HFRS) in Europe, a disease characterised by acute kidney failure and, in some cases, significant bleeding complications. The mechanisms underlying clotting abnormalities in HFRS remain poorly understood. This study aims to investigate the pathological mechanisms of clotting dysfunction in hospitalised HFRS patients, assess the impact of different hantavirus types on disease severity, and evaluate the accuracy of a severity scoring system developed in China for predicting mortality in European patients. Hospitalised patients with laboratory-confirmed HFRS will be prospectively recruited from University Medical Centre Ljubljana, Slovenia. Blood samples will be analysed for routine laboratory markers, thromboelastography (TEG) will assess real-time clotting function, and transcriptomic analysis will identify hantavirus strains and gene expression patterns linked to disease severity. Patients will be stratified into haemorrhagic and non-haemorrhagic groups, with statistical analyses comparing clinical and laboratory parameters to identify predictors of bleeding risk. Findings from this study may contribute to improved risk stratification and potential therapeutic targets for HFRS.

Trial Health

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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at P25-P50 for all trials

Timeline

16mo left

Started May 2026

Status

not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

1.3 years study duration

Study Progress1%

May 2026Aug 2027

First Submitted

Initial submission to the registry

February 13, 2025

Completed

2 months until next milestone

First Posted

Study publicly available on registry

April 25, 2025

Completed

1 year until next milestone

Study Start

First participant enrolled

May 1, 2026

Completed

1.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 31, 2027

Expected

1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

August 31, 2027

Last Updated

November 19, 2025

Status Verified

November 1, 2025

Enrollment Period

1.2 years

First QC Date

February 13, 2025

Last Update Submit

November 18, 2025

Conditions

Haemorrhagic Fever With Renal Syndrome

Outcome Measures

Primary Outcomes (7)

Change in Reaction Time (R) on thromboelastography from admission to follow-up (3-7 days), assessing clot initiation and its association with haemostatic dysfunction in HFRS.
Reaction time (R): The amount of time between the start of the test and the beginning of coagulation. Measured in minutes (min). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in K-Time (K) on thromboelastography from admission to follow-up (3-7 days), evaluating clot kinetics and fibrin polymerisation in relation to haemostatic abnormalities in HFRS.
K-time (K): The speed of formation of the clot from Reaction Time (R) to a specific clot strength. Measured in minutes (min). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in Alpha Angle (α-Angle) on thromboelastography from admission to follow-up (3-7 days), reflecting fibrin build-up and clot formation rate in patients with HFRS.
Alpha Angle (α-Angle): The speed of clot strengthening. Measured in degrees (°). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in Maximum Amplitude (MA) on thromboelastography from admission to follow-up (3-7 days), assessing overall clot strength and platelet contribution to clot stability in HFRS.
Maximum Amplitude (MA): The ultimate strength of the clot. Measured in millimetres (mm). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in Lysis 30 (LY30) on thromboelastography from admission to follow-up (3-7 days), measuring fibrinolysis and clot breakdown in relation to bleeding risk in HFRS.
Lysis 30 (LY30): Percent lysis 30 minutes after Maximum Amplitude (MA) is finalised. The LY30 measurement is based on the reduction of the tracing area that occurs between the time that MA is measured until 30 minutes after the MA is finalised. Measured as a percentage (%). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in Percentage Inhibition (% Inhibition) on thromboelastography from admission to follow-up (3-7 days), evaluating the effect of antithrombotic pathways on clot formation in HFRS.
Percentage Inhibition (% Inhibition): Indicates the reduction in platelet contribution to overall clot strength. Measured as a percentage (%). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later
Change in Percentage Aggregation (% Aggregation) on thromboelastography from admission to follow-up (3-7 days), assessing platelet function and its role in haemostatic dysfunction in HFRS.
Percentage Aggregation (% Aggregation): Indicates the percent of platelets not inhibited, determined by comparing the uninhibited platelet contribution to the baseline platelet contribution. Measured as a percentage (%). Measured according to standardised assay on the TEG 6s haemostasis analyser.
Baseline and 3-7 days later

Secondary Outcomes (21)

Change in platelet count over the course of illness, assessing thrombocytopenia and its role in haemostatic dysfunction in HFRS.
Baseline (day 1) and daily thereafter through hospitalisation, up to 21 days
Change in prothrombin time (PT) over the course of illness, evaluating coagulation factor activity and clotting dysfunction in HFRS.
Baseline (day 1) and daily thereafter through hospitalisation, up to 21 days
Change in activated partial thromboplastin time (APTT) over the course of illness, assessing abnormalities in the intrinsic clotting pathway in HFRS.
Baseline (day 1) and daily thereafter through hospitalisation, up to 21 days
Change in fibrinogen levels over the course of illness, investigating fibrinogen consumption and clot formation abnormalities in HFRS.
Baseline (day 1) and daily thereafter through hospitalisation, up to 21 days
Change in D-dimer levels over the course of illness, evaluating fibrinolysis and its association with haemorrhagic complications in HFRS
Baseline (day 1) and daily thereafter through hospitalisation, up to 21 days
+16 more secondary outcomes

Study Arms (2)

Non-haemorrhagic cases

This cohort will include laboratory confirmed cases of haemorrhagic fever with renal syndrome without any evidence of haemorrhagic manifestations.

Procedure: Blood draw for thromboelastography - admissionProcedure: Blood draw for thromboelastography - follow-upProcedure: Blood draw for transcriptomic analysisOther: Data collection - clinical/demographic/epidemiological dataOther: Data collection - routine laboratory parametersOther: Severity score calculation

Haemorrhagic cases

This cohort will include laboratory confirmed cases of haemorrhagic fever with renal syndrome with evidence of haemorrhagic manifestations.

Interventions

Blood draw for thromboelastography - admissionPROCEDURE

Two blood samples will be collected at admission for thromboelastography using the TEG 6s platform (Haemonetics®). One sample will be collected in a citrated blood tube for global haemostasis assessment, and one sample will be collected in a heparinised tube for platelet function analysis.