NephritisVARIOUSNCT07469059
Characterization of Renal Microvascular Alterations in Patients With Active Urinary Sediment and/or Proteinuria Using Ultrasound Localization Microscopy
An observational study of Nephritis, run by University of Erlangen-Nürnberg Medical School at 1 site in Germany.
Trial summary
The goal of this study is the non-invasive visualization and quantification of renal microvascular dynamics in adult kidneys with proteinuria and/or active sediment. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Nephritis
- How many people
- 30 participants
- Where
- 1 siteGermany
- Study dates
- 18 Sep 2025to Sep 2028
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: One study population. Anticipated approx. n=30 adultswith above mentioned inclusion criteria with active sediment and/or proteinuria and indication for kidney biopsy
Who may be able to join
- Age ≥ 18 years
- Evidence of active urinary sediment and/or proteinuria >1 g/g creatinine
- Indication for kidney biopsy as part of study-independent diagnostics
- Written informed consent
Who cannot join
- Known allergic disposition to SonoVue®
- Contraindication to the use of SonoVue®
- Pregnancy
- Breastfeeding mothers
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Germany1 site, 1 recruiting
- Recruiting
University Hospital Erlangen
Erlangen, Bavaria, 91054
About this study
The goal of this study is the non-invasive visualization and quantification of renal microvascular dynamics in adult kidneys with proteinuria and/or active sediment.
Read the detailed description
In this study, the microvascular architecture of the kidney in adults with active urinary sediment or proteinuria is to be examined non-invasively using Ultrasound Localization Microscopy (ULM).
Kidney diseases can broadly be classified according to the affected nephron compartment into glomerular, tubular, and tubulointerstitial diseases. Glomerular diseases include, among others, the nephrotic and nephritic syndromes, which differ in their clinical and laboratory characteristics: while the nephrotic syndrome is typically characterized by marked proteinuria (>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia, the nephritic syndrome is dominated by hematuria with acanthocytes, mild to moderate proteinuria, arterial hypertension, and impaired renal function. Tubular and tubulointerstitial diseases, on the other hand, often manifest as acute kidney injury (e.g., in ischemic or toxic injury), polyuria, salt wasting, or metabolic acidosis, often accompanied by nonspecific symptoms such as fatigue or dehydration.
In addition to these classical nephron compartments, renal vascular structures may also be primarily or secondarily affected, as in vasculitis, thrombotic microangiopathies, or hypertensive nephropathy. Although these vascular structures are not directly part of the nephron, they are functionally closely linked to it and have a significant impact on renal function.
To assess kidney status, pathophysiology, and the site of injury non-invasively, urinary sediment is analyzed. Urinary sediment represents a central diagnostic tool that provides information on the localization of kidney damage, thereby functioning as a type of "liquid biopsy."
If there is clinical suspicion of acute or rapidly progressive renal failure, nephrotic syndrome, significant non-nephrotic proteinuria, glomerular hematuria, or if a systemic disease with possible renal involvement is present, a kidney biopsy is usually indicated for further diagnostic clarification. Obtaining tissue samples for histological examination is an invasive procedure associated with inpatient hospitalization, considerable burden for patients, and potential complications. Currently, alternative imaging methods cannot replace kidney biopsy. Furthermore, CT, PET, or MR imaging is associated with radiation exposure or considerable additional effort (e.g., sedation).
Ultrasound Localization Microscopy (ULM) enables visualization of vascular architecture using contrast-enhanced ultrasound. Recently, glomeruli-the smallest functional units of the kidney-were visualized and even counted in both rats and humans. Thus, ULM enables an assessment of renal function potentially comparable to kidney biopsy, in which glomeruli are also counted and examined. Beyond the kidney, the microvascular architecture of the human brain has also been depicted at previously unknown resolution using ULM. ULM therefore offers both qualitative and quantitative visualization of vascular architecture and perfusion dynamics. In the latest studies, 3D ULM imaging has been achieved, allowing volumetric visualization of vascular architecture and thereby overcoming the limitations of 2D imaging. This three-dimensional depiction of vascular structures may potentially provide more realistic insights into disease-related changes that would otherwise not be possible.
In the following, the term 'ULM' is used inclusively for both 2D and 3D ULM. In this study, renal function and perfusion in patients with active urinary sediment and indication for kidney biopsy will be evaluated, compared, and correlated with results from histology (biopsy), laboratory tests, and ultrasound diagnostics. If possible, a follow up assessment via ULM/CEUS after treatment (for example pharmacological therapy) will be scheduled.
With ULM the investigators aim to visualize the microvascular architecture and glomeruli, and to investigate whether differences detectable by ULM can be identified for the various causes of active sediment. In addition, the investigators seek to establish alterations in perfusion dynamics as potential imaging markers of kidney function.
In the future, this could enable non-invasive differentiation of the underlying disease and assessment of renal function, potentially reducing the need for invasive, high-risk procedures and allowing faster diagnosis in patients with an indication for kidney biopsy due to active sediment or proteinuria.
- Conditions
- Nephritis
- Keywords
- kidney, ultrasound localization microscopy (ULM)
- Medical subject headings
- Nephritis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Study group | Patients with active sediment and/or proteinuria (>1g/g Krea) and indication for renal biopsy |
What is being measured
The primary outcome is the main question the study is designed to answer.
CEUS Time intensity curves
All CEUS outcomes will be generated in order to achieve time intensity curves in contrast enhanced ultrasound analysis
Measured: baseline and up to 10 weeks after baseline
CEUS Measurement1
PE (Peak-Enhancement) is an established measurement in CEUS analysis. It describes the highest signal intensity after administration of contrast agents and is measured in arbitrary units.
All CEUS measurements are established measurements in Time intensity analysis (TIC) of contrast enhanced ultrasound data.
Measured: baseline and up to 10 weeks after baseline
CEUS Measurement2
Description: WiAUC (Wash-in Area Under the Curve (AUC(TI: TTP)))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement 3
RT (Rise Time = arterial inflow until maximum signal intensity), measured in seconds, higer RT means faster arterial inflow
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement5
mTT (mean Transit Time local) (mTT-TI))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement6
TTP (Time to Peak)
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement7
WiR (Wash-in-Rate )
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement8
WiPI (Wash-in Perfusion Index (WiAUC/RT))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement9
WoAUC (Wash-out AUC (AUC(TTP:TO)))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement10
WiWoAUC (Wash-in- und Wash-out-AUC (WiAUC+WoAUC))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement11
FT (Fall Time - (TO-TTP))
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement12
WOR (Wash-out-Rate) QOF (Quality Of Fit between the echo-power signal and f(t)
Measured: Baseline and up to 10 weeks after baseline
CEUS Measurement13
QOF (Quality Of Fit between the echo-power signal and f(t)
Measured: Baseline and up to 10 weeks after baseline
Visualization and quantification of kidney perfusion with CEUS
CEUS imaging for kidney perfusion in kidney disease
Measured: Baseline and up to 10 weeks after baseline
Visualization and quantification of kidney mikrovaskularisation with ULM
ULM imaging for kidney perfusion and microvaskularisation in kidney disease
Measured: Baseline and up to 10 weeks after baseline
Visualization and quantification of glomeruli in the kidney with ULM
ULM imaging for glomeruli in the kidney
Measured: Baseline and up to 10 weeks after baseline
Secondary outcomes (10)
ULM and Ultrasound
Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with sonographic parameters (including resistance index a.o.)
Measured: Baseline and up to 10 weeks after baseline
ULM and CEUS
Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with parameters of contrast-enhanced ultrasound (CEUS)
Measured: Baseline and up to 10 weeks after baseline
ULM and biopsy
Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (including the number of segmented glomeruli) with histological parameters.
Measured: Baseline and up to 10 weeks after baseline
2D and 3D ULM
Comparison of visualized and quantified microvascular dynamics (including glomeruli) using 2D and 3D ULM
Measured: Baseline and up to 10 weeks after baseline
ULM and diagnosis
Comparison of the vascular architecture visualized by ULM (including the number of segmented glomeruli) with the underlying diagnosis in patients with active sediment and/or proteinuria >1 g/g creatinine and indication for kidney biopsy.
Measured: Baseline and up to 10 weeks after baseline
Comparison before and after treatment
Comparison of microvascular dynamics via ULM/CEUS in the kidney before and after treatment (e.g., pharmacological therapy)
Measured: Baseline and up to 10 weeks after baseline
Correlation between ULM and laboratory parameters
Correlation of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) with laboratory parameters (including kidney function parameters, inflammatory markers, immunological parameters.
Measured: Baseline and up to 10 weeks after baseline
ULM on different diagnoses
Comparison of the vascular architecture visualized by ULM and parameters of quantified microvascular perfusion dynamics of the kidney (e.g., number of segmented glomeruli) between different diagnoses.
Measured: Baseline and up to 10 weeks after baseline
Assessment of renal function GFR
GFR (ml/min/1,73 m2)
Measured: Baseline and up to 10 weeks after baseline
Assessment of renal function urea
urea (mg/dl)
Measured: Baseline and up to 10 weeks after baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Mar 2026
- Study start18 Sep 2025
- Primary completionSep 2027 (estimated)
- Study completionSep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for NephritisStudies of the same condition, open and under way.
- More trials run by University of Erlangen-Nürnberg Medical SchoolThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Erlangen-Nürnberg Medical School
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ferdinand Knieling, University of Erlangen-Nürnberg Medical School
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07469059
- Sponsor's protocol ID
- ULM_VARIOUS
- Acronym
- VARIOUS
- Status last verified
- Mar 2026
- First submitted
- 16 Sep 2025
- Last updated
- 13 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Characterization of Renal Microvascular Alterations in Patients With Active Urinary Sediment and/or Proteinuria Using Ultrasound Localization Microscopy
- ClinicalTrials.gov ID
- NCT07469059
- Acronym / sponsor ID
- VARIOUS / ULM_VARIOUS
- Conditions
- Nephritis
- Keywords
- kidney, ultrasound localization microscopy (ULM)
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- University of Erlangen-Nürnberg Medical SchoolUniversity, hospital or other
- Study start
- 18 Sep 2025 (actual)
- Primary completion
- Sep 2027 (estimated)
- Study completion
- Sep 2028 (estimated)
- First posted
- 13 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is the non-invasive visualization and quantification of renal microvascular dynamics in adult kidneys with proteinuria and/or active sediment.
Detailed description
In this study, the microvascular architecture of the kidney in adults with active urinary sediment or proteinuria is to be examined non-invasively using Ultrasound Localization Microscopy (ULM).
Kidney diseases can broadly be classified according to the affected nephron compartment into glomerular, tubular, and tubulointerstitial diseases. Glomerular diseases include, among others, the nephrotic and nephritic syndromes, which differ in their clinical and laboratory characteristics: while the nephrotic syndrome is typically characterized by marked proteinuria (>3.5 g/day), hypoalbuminemia, edema, and hyperlipidemia, the nephritic syndrome is dominated by hematuria with acanthocytes, mild to moderate proteinuria, arterial hypertension, and impaired renal function. Tubular and tubulointerstitial diseases, on the other hand, often manifest as acute kidney injury (e.g., in ischemic or toxic injury), polyuria, salt wasting, or metabolic acidosis, often accompanied by nonspecific symptoms such as fatigue or dehydration.
In addition to these classical nephron compartments, renal vascular structures may also be primarily or secondarily affected, as in vasculitis, thrombotic microangiopathies, or hypertensive nephropathy. Although these vascular structures are not directly part of the nephron, they are functionally closely linked to it and have a significant impact on renal function.
To assess kidney status, pathophysiology, and the site of injury non-invasively, urinary sediment is analyzed. Urinary sediment represents a central diagnostic tool that provides information on the localization of kidney damage, thereby functioning as a type of "liquid biopsy."
If there is clinical suspicion of acute or rapidly progressive renal failure, nephrotic syndrome, significant non-nephrotic proteinuria, glomerular hematuria, or if a systemic disease with possible renal involvement is present, a kidney biopsy is usually indicated for further diagnostic clarification. Obtaining tissue samples for histological examination is an invasive procedure associated with inpatient hospitalization, considerable burden for patients, and potential complications. Currently, alternative imaging methods cannot replace kidney biopsy. Furthermore, CT, PET, or MR imaging is associated with radiation exposure or considerable additional effort (e.g., sedation).
Ultrasound Localization Microscopy (ULM) enables visualization of vascular architecture using contrast-enhanced ultrasound. Recently, glomeruli-the smallest functional units of the kidney-were visualized and even counted in both rats and humans. Thus, ULM enables an assessment of renal function potentially comparable to kidney biopsy, in which glomeruli are also counted and examined. Beyond the kidney, the microvascular architecture of the human brain has also been depicted at previously unknown resolution using ULM. ULM therefore offers both qualitative and quantitative visualization of vascular architecture and perfusion dynamics. In the latest studies, 3D ULM imaging has been achieved, allowing volumetric visualization of vascular architecture and thereby overcoming the limitations of 2D imaging. This three-dimensional depiction of vascular structures may potentially provide more realistic insights into disease-related changes that would otherwise not be possible.
In the following, the term 'ULM' is used inclusively for both 2D and 3D ULM. In this study, renal function and perfusion in patients with active urinary sediment and indication for kidney biopsy will be evaluated, compared, and correlated with results from histology (biopsy), laboratory tests, and ultrasound diagnostics. If possible, a follow up assessment via ULM/CEUS after treatment (for example pharmacological therapy) will be scheduled.
With ULM the investigators aim to visualize the microvascular architecture and glomeruli, and to investigate whether differences detectable by ULM can be identified for the various causes of active sediment. In addition, the investigators seek to establish alterations in perfusion dynamics as potential imaging markers of kidney function.
In the future, this could enable non-invasive differentiation of the underlying disease and assessment of renal function, potentially reducing the need for invasive, high-risk procedures and allowing faster diagnosis in patients with an indication for kidney biopsy due to active sediment or proteinuria.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Study group | – | –Patients with active sediment and/or proteinuria (>1g/g Krea) and indication for renal biopsy |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- One study population. Anticipated approx. n=30 adultswith above mentioned inclusion criteria with active sediment and/or proteinuria and indication for kidney biopsy
Key inclusion criteria (4 listed)
- Age ≥ 18 years
- Evidence of active urinary sediment and/or proteinuria >1 g/g creatinine
- Indication for kidney biopsy as part of study-independent diagnostics
- Written informed consent
Key exclusion criteria (4 listed)
- Known allergic disposition to SonoVue®
- Contraindication to the use of SonoVue®
- Pregnancy
- Breastfeeding mothers
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
CEUS Time intensity curves
Time frame: baseline and up to 10 weeks after baseline
All CEUS outcomes will be generated in order to achieve time intensity curves in contrast enhanced ultrasound analysis
CEUS Measurement1
Time frame: baseline and up to 10 weeks after baseline
PE (Peak-Enhancement) is an established measurement in CEUS analysis. It describes the highest signal intensity after administration of contrast agents and is measured in arbitrary units. All CEUS measurements are established measurements in Time intensity analysis (TIC) of contrast enhanced ultrasound data.
CEUS Measurement2
Time frame: Baseline and up to 10 weeks after baseline
Description: WiAUC (Wash-in Area Under the Curve (AUC(TI: TTP)))
CEUS Measurement 3
Time frame: Baseline and up to 10 weeks after baseline
RT (Rise Time = arterial inflow until maximum signal intensity), measured in seconds, higer RT means faster arterial inflow
CEUS Measurement5
Time frame: Baseline and up to 10 weeks after baseline
mTT (mean Transit Time local) (mTT-TI))
CEUS Measurement6
Time frame: Baseline and up to 10 weeks after baseline
TTP (Time to Peak)
CEUS Measurement7
Time frame: Baseline and up to 10 weeks after baseline
WiR (Wash-in-Rate )
CEUS Measurement8
Time frame: Baseline and up to 10 weeks after baseline
WiPI (Wash-in Perfusion Index (WiAUC/RT))
CEUS Measurement9
Time frame: Baseline and up to 10 weeks after baseline
WoAUC (Wash-out AUC (AUC(TTP:TO)))
CEUS Measurement10
Time frame: Baseline and up to 10 weeks after baseline
WiWoAUC (Wash-in- und Wash-out-AUC (WiAUC+WoAUC))
CEUS Measurement11
Time frame: Baseline and up to 10 weeks after baseline
FT (Fall Time - (TO-TTP))
CEUS Measurement12
Time frame: Baseline and up to 10 weeks after baseline
WOR (Wash-out-Rate) QOF (Quality Of Fit between the echo-power signal and f(t)
CEUS Measurement13
Time frame: Baseline and up to 10 weeks after baseline
QOF (Quality Of Fit between the echo-power signal and f(t)
Visualization and quantification of kidney perfusion with CEUS
Time frame: Baseline and up to 10 weeks after baseline
CEUS imaging for kidney perfusion in kidney disease
Visualization and quantification of kidney mikrovaskularisation with ULM
Time frame: Baseline and up to 10 weeks after baseline
ULM imaging for kidney perfusion and microvaskularisation in kidney disease
Visualization and quantification of glomeruli in the kidney with ULM
Time frame: Baseline and up to 10 weeks after baseline
ULM imaging for glomeruli in the kidney
10 secondary outcomes
ULM and Ultrasound
Time frame: Baseline and up to 10 weeks after baseline
ULM and CEUS
Time frame: Baseline and up to 10 weeks after baseline
ULM and biopsy
Time frame: Baseline and up to 10 weeks after baseline
2D and 3D ULM
Time frame: Baseline and up to 10 weeks after baseline
ULM and diagnosis
Time frame: Baseline and up to 10 weeks after baseline
Comparison before and after treatment
Time frame: Baseline and up to 10 weeks after baseline
Correlation between ULM and laboratory parameters
Time frame: Baseline and up to 10 weeks after baseline
ULM on different diagnoses
Time frame: Baseline and up to 10 weeks after baseline
Assessment of renal function GFR
Time frame: Baseline and up to 10 weeks after baseline
Assessment of renal function urea
Time frame: Baseline and up to 10 weeks after baseline
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Nephritis, run by University of Erlangen-Nürnberg Medical School at 1 site in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ferdinand Knieling, MD, PhD, MHBA (091318533118, ferdinand.knieling@uk-erlangen.de), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
CEUS Time intensity curves (time frame: baseline and up to 10 weeks after baseline). The study lists 16 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Mar 2026.