Anti-BK Virus Immune Response and Kidney Transplantation

Study Overview
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Brief Summary
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BK virus infections are very frequent during months following a kidney transplantation: a viral reactivation is observed for almost 50% of patients during first year. This reactivation leads to a viremia for 10 to 15% of patient during this same period. The most frequent complication is interstitial nephritis for 2 to 8% of patients (27 patients representing 2.7% during 6 years in Nantes). An intensive et persisting viral replication, assessed by detection of high blood viral load, could evolved to a viral nephropathy which lead to a very pejorative functional issue for the graft. Biological follow-up of these infections lay on the measures of viral load. Their positivity must alert the physician and lead him to modulate immunosuppressive treatment. Actually, there is no real consensus about the modalities of pharmacological immunosuppression decrease (decrease dose or change of molecule). Specific lymphocytic anti-BKv evaluated on several cohorts of patients permit to prove: weakness of immune cellular response for patient with high viremia increase of this response when viral load decrease These studies laid on detection of INFg synthesis by Elispot after stimulation with viral antigens and in vitro cellular expansion. New prospective and longitudinal data comparing the immune cellular response (systematic and early) after graft between patients controlling or not BKv infection are necessary to improve the comprehension of illness natural history. The investigators propose to enlarge the investigation of anti-BKv immune cellular response to other functions than IFNg synthesis in the aim of detecting the eventual role of polyfunctional lymphocytes for infection control. Furthermore, the investigators propose to identify better diagnostic and prognostic makers.

Official Title
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Role of Specific Immune Cellular Response in the Control of BK Virus Infection: Prospective Study, Monocentric and Longitudinal During the First Nine Months After a Kidney Transplantation

Conditions
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Kidney Transplantation

Intervention / Treatment
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* Other: biological parameters


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Kidney-transplanted patient, since less than 30 days Older than 18 years old Treatment with tacrolimus and mycophénolate mofetil Exclusion Criteria: No informed consent Pregnant women Patient under legal guardianship Treated by ciclosporin or mTOR-inhibitor

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| kidney-transplanted patients<br> | Other: biological parameters<br>* blood sample at M1, M2, M3; M4; M5, M6, M7, M8 and M9 after kidney transplantation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of the level of response between patient with a non-controlled infection and patients for who the blood viral load is under 103 copBKv/ml. | Analyse the role of T-lymphocytes response in the control of BKv infection | at 1month, 2months, 3months, 4, 5, 6, 7, 8 and 9 months after kidney transplantation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analyse of the other causes that could influence the occurence of a viremia higher than 103 copBKv/ml | Other causes for abnormal viremia | at 1month, 2months, 3months, 4, 5, 6, 7, 8 and 9 months after kidney transplantation | 
| Measurement of histological consequences of a BKv non-controlled infection during the first year post-graft | Determine the frequence of occurence of nephropathy due to BKv for the population with a non-controlled infection | at 12 months after kidney transplantation | 
| Measurement of increase of immune response due to modifications of immunosuppressive treatment for patient with a non-controlled infection | Comparision between the level of immune response and the time when the first viremia is higher than 103 copBKv/ml and 1, 3 et 6 months after modification of immunosuppressive treatment. | at 1, 3 et 6 months after modification of immunosuppressive treatment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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patient with a kidney transplantation since less than 30 days