Kidney Transplant Rejection
Conditions
Keywords
CXCL10, CXCR3+T cells, ccfDNA, dd-cfDNA, ABMR, TCMR
Brief summary
Kidney transplant rejection remains a significant challenge to long-term graft survival. While histological biopsy continues to be the gold standard for diagnosing rejection, noninvasive biomarkers such as donor-derived cell-free DNA (dd-cfDNA) have gained traction for their ability to detect allograft injury. However, dd-cfDNA may lack sensitivity in certain clinical scenarios particularly in cases of localized immune activation leading to false negatives despite biopsy-confirmed rejection.
Detailed description
One promising biomarker is CXCL10 (C-X-C motif chemokine ligand 10), a chemokine induced by interferon-γ that plays a central role in recruiting CXCR3+ T cells during immune responses. A 2021 study by Arnau et al. found that urinary CXCL10 levels were significantly associated with Banff scores of acute graft injury and donor-specific antibodies, and could discriminate both T-cell-mediated and antibody-mediated rejection in kidney transplant recipients, identifying CXCL10 as a promising candidate non-invasive biomarker for monitoring allograft rejection.
Interventions
OTHERRetrospective Cohort Enrollment
Subjects for this cohort will be selected from existing research database and criteria include: hx of kidney transplantation, clinically indicated biopsy, positive histology, \<1% circulating donor-derived cell-free DNA (dd-cfDNA) result at the time of biopsy, and Availability of frozen urine samples.
OTHERProspective Cohort Enrollment
Subjects for this cohort will be selected based on ability to provide urine sample, recent kidney transplant recipient and underwent a clinically indicated biopsy
Sponsors
Virginia Commonwealth University
Thermo Fisher Scientific, Inc
Study design
Observational model
OTHER
Time perspective
OTHER
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Prospective Inclusion Criteria: * Age ≥18 years * Undergoing a clinically indicated biopsy * Able to provide informed consent * Willing to provide a urine sample and allow access to relevant clinical Retrospective Inclusion Criteria: * Age ≥18 years * Biopsy-confirmed rejection (positive histology) * Donor-derived cell-free DNA\<1% result at time of biopsy * Availability of stored urine sample collected at time of biopsy
Exclusion criteria
(applies to both arms): * Individuals under 18 years of age * Individuals unable to provide informed consent (for prospective enrollment) * Pregnant women * Prisoners * Adults unable to consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Assess urinary CXCL10 compared to dd-cfDNA for diagnosing acute rejection in kidney transplant recipients | From date of inclusion until loss of follow-up, graft loss or death assessed up to 5 years. | Assess whether urinary CXCL10 concentration (pg/mL) demonstrates improved sensitivity compared to donor-derived cell-free DNA (dd-cfDNA) for diagnosing acute rejection in kidney transplant recipients, specifically among discordant cases with biopsy-confirmed rejection and dd-cfDNA levels below 1%. Urine sample collected prospectively, during clinically indicated biopsy visit. Urine sample collected retrospectively, during clinically indicated retrospective biopsy visit. |
| Assess the stability of urinary CXCL10 under different transport conditions | From date of inclusion until loss of follow-up, graft loss or death assessed up to 5 years. | Assess the stability of urinary CXCL10 (percent recovery) under different transport conditions-refrigerated, and ambient (room temperature)-to determine whether ambient shipping is a viable alternative to cold-chain transport for clinical testing. Urine sample collected prospectively, during clinically indicated biopsy visit. Urine sample collected retrospectively, during clinically indicated retrospective biopsy visit. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Compare urinary CXCL10 concentrations to assess potential degradation or variability. | From date of inclusion until loss of follow-up, graft loss or death assessed up to 5 years. | Compare urinary CXCL10 concentrations across the two transport conditions to assess potential degradation or variability. * Mean absolute difference (pg/mL) * Coefficient of variation (CV) * Bland-Altman plots to assess agreement Urine sample collected prospectively, during clinically indicated biopsy visit. Urine sample collected retrospectively, during clinically indicated retrospective biopsy visit. |
| Determine whether ambient shipping (urine sample) affects the clinical reliability of CXCL10 measurements | From date of inclusion until loss of follow-up, graft loss or death assessed up to 5 years. | Determine whether ambient shipping (urine sample) affects the clinical reliability of CXCL10 measurements * CXCL10 results dichotomized using predefined clinical thresholds * Percent agreement and Cohen's kappa statistic calculated between transport conditions Urine sample collected prospectively, during clinically indicated biopsy visit. Urine sample collected retrospectively, during clinically indicated retrospective biopsy visit. |
| Assess the feasibility of implementing ambient (urine sample) shipping as a cost-effective alternative | From date of inclusion until loss of follow-up, graft loss or death assessed up to 5 years. | Assess the feasibility of implementing ambient (urine sample) shipping as a cost-effective alternative to current cold-chain methods. * Proportion of samples meeting laboratory acceptance criteria * Shipping duration summarized in hours from collection to laboratory receipt Urine sample collected prospectively, during clinically indicated biopsy visit. Urine sample collected retrospectively, during clinically indicated retrospective biopsy visit. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORGaurav Gupta, MD
Virginia Commonwealth University
Outcome results
None listed