An In-vitro Standardization of B Cell Elispot Assays

This study has been terminated.
(Technical difficulties perfecting laboratory test used on blood samples.)
Sponsor:
Information provided by (Responsible Party):
Anat Tambur, Northwestern University
ClinicalTrials.gov Identifier:
NCT01334281
First received: April 13, 2009
Last updated: April 19, 2013
Last verified: April 2013
  Purpose

This study is being done because the study doctor is trying to develop a new test which will help transplant doctors monitor patients with high panel reactive antibodies (PRA). The test would be used to monitor patients' PRA when doctors are trying to lower it through a process known as desensitization. Desensitization lowers high PRA levels and allows patients to receive transplants. This is a single center study to evaluate and optimize the use of a new laboratory test to detect and measure the immune system's functioning.


Condition Intervention Phase
Transplant Sensitization
Panel Reactive Antibody
Sensitization to HLA Antigens
Procedure: Blood Draw
Phase 1

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective
Official Title: A Phase 1, Investigatory Initiated, In-vitro Standardization of B Cell Elispot Assays

Resource links provided by NLM:


Further study details as provided by Northwestern University:

Primary Outcome Measures:
  • To optimize an in-vitro assay to enumerate HLA-specific memory B cells in order to monitor efficacy of desensitization protocols. [ Time Frame: Enrollment (baseline), midpoint of desensitization (only if receiving high dose IVIg); prior to transplant; 3, 6, 12 and 24 months post-transplant. ] [ Designated as safety issue: No ]
    B cells will be tested for their ability to produce IgG and tetanus antibodies (as controls) and HLA specific antibodies corresponding to those detected by the flow PRA assay. In subjects not undergoing desensitization, 3 tubes (30 ml) of blood will be drawn twice (total of 60 ml blood taken) 8-12 weeks apart. In subjects undergoing desensitization 3 tubes (30 ml) of blood will be taken at 7 points; enrollment, anticipated midpoint of desensitization, prior to transplant, 3, 6, 12 and 24 Months post-transplant (total of 210 ml blood taken).


Secondary Outcome Measures:
  • Evaluate the relationships between antibody strength, measured by flow cytometry, number of memory B cells in circulation of highly sensitized patients awaiting organ transplant or undergoing desensitization procedures to facilitate organ transplant. [ Time Frame: Enrollment (baseline), midpoint of desensitization (only if receiving high dose IVIg); prior to transplant; 3, 6, 12 and 24 months post-transplant. ] [ Designated as safety issue: No ]
    B cells will be tested unstimulalated or stimulated with a cocktail of CpG, anti-CD40-L, IL-10 and IL-4.


Biospecimen Retention:   Samples Without DNA

Subjects will serve as a source of B-lineage cells, which will be tested for their ability to produce IgG, tetanus antibodies, (as controls) and HLA specific antibodies that coorespond to those detected by the flow PRA assay. They will be retained until they are used up.


Enrollment: 19
Study Start Date: February 2008
Study Completion Date: October 2012
Primary Completion Date: April 2011 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
Blood: Undergoing Desensitization
Transplant subjects give blood at specified time points. Sensitization to HLA antigens is a barrier to transplant. Several U.S. institutions have protocols for desensitization where patients are treated with IV immunoglobulins (IVIg) and plasmapheresis (PP) to reduce circulating HLA-directed antibody levels. Labs provide doctors information on circulating donor-specific antibody (DSA) levels. These results are the main indicator whether to proceed with transplant. However, no information is given on the fate of the B cells that produce the DSA.
Procedure: Blood Draw
Three tubes of blood will be drawn (three 10ml-green top), 7 times (total of 210 ml for study) at the indicated time points: 1) enrollment, 2) anticipated midpoint of desensitization, 3) prior to transplant, 4) three months post-transplant, 5) six months post-transplant, 6) 12 months post-transplant, and 7) 24 months post-transplant.
Blood: NOT Undergoing Desensitization
Transplant subjects give blood at specified time points. Sensitization to HLA antigens is a barrier to transplant. Several U.S. institutions have protocols for desensitization where patients are treated with IV immunoglobulins (IVIg) and plasmapheresis (PP) to reduce circulating HLA-directed antibody levels. Labs provide doctors information on circulating donor-specific antibody (DSA) levels. These results are the main indicator whether to proceed with transplant. However, no information is given on the fate of the B cells that produce the DSA.
Procedure: Blood Draw
Three tubes of blood will be drawn (three 10ml-green top) twice (60 ml total for study), 8-12 weeks apart. Can be drawn during clinic visit or separate standard of care dialysis visit.

Detailed Description:

Sensitization to HLA antigens is the main barrier to solid organ transplantation. Currently, HLA sensitization is monitored by testing patients' serum against a panel of HLA antigens (whether those will be presented on cell surface or on solid phase matrixes) and calculating the % of positive responses. Such result give indication of the relative breadth of sensitization but not on it "depth" - the relative strength of specific antibodies, nor does it provide any information regarding the memory B cells / plasma cells that can manufacture a specific HLA directed antibody.

This is a single center study to evaluate and optimize the use of in-vitro assay to enumerate B cells producing human leukocyte antigens (HLA)-specific antibodies. The proposed assay is based on principles used for enumeration of specific cytokine producing memory T cells - an ELISPOT assay. The investigators are currently using the T cell ELISPOT assay in our laboratory.

The investigators believe that the proposed assay will provide biologically relevant immune measures that are crucial for the long term outcome of transplantation in highly sensitized patients.

Highly sensitized patients encompass a high risk patient group among transplant recipients. The proposed assay is designed to predict the fate of DSA producing (or capable of producing) memory and plasma cells. Thus, it should allow prediction and early detection of activation of the humoral arm of the immune system, specifically against the donor. This, in turn, may prompt early intervention and preservation of the allograft. Three tubes of blood will be drawn twice, 8-12 weeks apart, during clinic or standard of care dialysis visits following optimization. Subjects undergoing desensitization will have three tubes of blood drawn seven times over the course of two years for the analysis.

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Any kidney, pancreas or heart transplant waitlisted subjects > or = to 18 years of age, and of either gender. Subjects must be capable of understanding the study, informed consent form, HIPPA process, and be willing to give informed consent.

Criteria

Inclusion Criteria:

  • Subjects should be listed for solid organ transplant at NU/NMH
  • Subjects should be > or = to 18 years of age, either gender
  • Subjects should have history of prior sensitization of HLA antigens
  • Subjects should have documented antibody specificity previously tested at the transplant immunology lab at NU
  • Subjects should be capable of understanding the study, consents, HIPAA process and be able to give informed consent.

Exclusion Criteria:

  • Subjects younger than 18 years of age
  • Subjects with no sensitization history
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01334281

Locations
United States, Illinois
Northwestern Memorial Hospital
Chicago, Illinois, United States, 60611
Sponsors and Collaborators
Northwestern University
Investigators
Principal Investigator: Anat Tambur, DMD, PhD Northwestern University
  More Information

No publications provided

Responsible Party: Anat Tambur, Director, Transplant Immunology Laboratory, Comprehensive Transplant Center; Research Professor, Feinberg School of Medicine, Northwestern University
ClinicalTrials.gov Identifier: NCT01334281     History of Changes
Other Study ID Numbers: STU00027653 1682-05, 0037-370-285V-AT
Study First Received: April 13, 2009
Last Updated: April 19, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Northwestern University:
Panel Reactive Antibody (PRA)
Sensitization
Organ Transplant

ClinicalTrials.gov processed this record on April 17, 2014