Platelet Aggregation in the Diagnosis of Acute Graft Rejection

NCT07275541 | Recruiting

• 2 other identifiers: TNO_AGREUK/3248/2024
• Study Type: observational
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

The study titled "Platelet Aggregation in the Diagnosis of Acute Graft Rejection" is a pilot observational study evaluating whether alterations in platelet function can serve as non-invasive markers of acute rejection in kidney transplant recipients. Platelet aggregation is assessed using optical aggregometry, flow-cytometric P-selectin (CD62-P) expression, and soluble P-selectin levels before kidney transplantation and at the time of protocol biopsies performed at 3 and 12 months after kidney transplantation. Patients with suspected graft dysfunction undergoing indication biopsy are also included. Platelet activation markers are correlated with histopathological findings, donor-specific antibodies, metabolic parameters, and clinical outcomes. The goal is to determine whether platelet activation profiles can identify acute cellular or antibody-mediated rejection and contribute to the development of a non-invasive diagnostic tool.

Conditions

Platelet Aggregation; Kidney Transplant Rejection

Keywords

kidney transplantation; platelet aggregation; acute rejection; non-invasive marker

Outcome Measures

Primary Outcomes (3)

• To compare changes in platelet aggregation in patients before and after kidney transplantation

  Platelet aggregation measured by optical aggregometry before kidney transplantation will be compared with platelet aggregation measured at 3 and 12 months after transplantation to assess changes in platelet function over time.

  Pre-transplant baseline; 3 months post-transplant; 12 months post-transplant

• To evaluate the changes in platelet aggregation in the diagnosis of humoral/cellular graft rejection (at the time of biopsy due to graft dysfunction)

  Platelet aggregation will be assessed at the time of an indication biopsy performed for graft dysfunction and compared between patients with biopsy-proven humoral or cellular rejection and those without rejection. The aim is to determine whether altered platelet aggregation is associated with acute graft rejection identified on histopathology.

  At the time of indication biopsy (any time after transplantation)

• To investigate the use of P-selectin as a potential marker of platelet activation in the diagnosis of acute graft rejection as part of a non-invasive investigation

  Flow-cytometric P-selectin (CD62-P) expression on platelets and soluble P-selectin levels in plasma will be measured before and after kidney transplantation and at the time of protocol or indication biopsy. These values will be compared between patients with and without biopsy-proven rejection to assess whether P-selectin can serve as a reliable marker of platelet activation associated with acute graft injury and support the development of a non-invasive diagnostic approach.

  Pre-transplant baseline; at 3- and 12-month protocol biopsies; and at the time of any indication biopsy after kidney transplantation

Study Arms (2)

kidney transplant recipients - Protocol Biopsy Cohort

Adult kidney transplant recipients undergoing routine protocol biopsies at 3 and 12 months post-transplant, regardless of clinical graft function. Platelet aggregation, flow-cytometric P-selectin expression, soluble P-selectin levels, and biochemical and immunological parameters are collected at each time point. Findings from platelet function testing are subsequently correlated with the histopathological results of the protocol biopsy, including the presence or absence of subclinical rejection.

kidney transplant recipients - Indication Biopsy Cohort

Kidney transplant recipients presenting with clinical signs of graft dysfunction-such as rising serum creatinine, increasing proteinuria, or abnormal ultrasound findings or with newly positive donor-specific antibodies (DSA) detected by Luminex testing, prompting the need for an indication biopsy due to suspected acute rejection. At the time of biopsy, platelet aggregation testing, P-selectin markers, comprehensive biochemical parameters, and DSA levels are collected. This cohort represents patients with clinically or immunologically apparent graft injury, allowing comparison with protocol-biopsied patients, including those with subclinical or biopsy-confirmed rejection.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with chronic kidney disease who underwent kidney transplantation

You may qualify if:

• adult patients (≥18 years)
• primary kidney transplantation
• living / deceased donor kidney transplantation
• ability and consent to participate

You may not qualify if:

• non-adult patients
• secondary / tertiary kidney transplantation
• antiplatelet therapy
• patients unable to provide informed consent

Sponsors & Collaborators

• University Hospital, Martin: lead

Study Sites (1)

Transplant-Nephrology Department, University Hospital Martin

Martin, 03601, Slovakia

RECRUITING

Study Officials

• Matej Vnucak, ass prof, MD, PhD.

  University Hospital Martin and Jessenius Faculty of Medicine, Comenius University

  STUDY CHAIR

Central Study Contacts

Timea Blichova, MD

CONTACT

+421434203184; tc@unm.sk

Patricia Kleinova, MD

CONTACT

+421434203184; tc@unm.sk

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: ass. prof., Deputy Head of Transplant-Nephrology Department

Study Record Dates

• First Submitted: November 27, 2025
• First Posted: December 10, 2025
• Study Start: November 26, 2024
• Primary Completion (Estimated): November 26, 2026
• Study Completion (Estimated): November 26, 2027
• Last Updated: December 10, 2025

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will not share

Locations

SL (1)