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Cellular and molecular immune profiles in renal transplant recipients after conversion from tacrolimus to sirolimus.

Gallon L, Traitanon O, Sustento-Reodica N, Leventhal J, Ansari MJ, Gehrau RC, Ariyamuthu V, De Serres SA, Alvarado A, Chhabra D, Mathew JM, Najafian N, Mas V - Kidney Int. (2014)

Bottom Line: While tacrolimus-maintained patients showed a decrease in indirect alloreactivity over time post transplant, sirolimus conversion increased indirect alloreactive T-cell frequencies compared with tacrolimus-maintained patients.No histological differences were found in graft biopsies, but molecular profiles showed activation of the antigen presentation, IL-12 signaling, oxidative stress, macrophage-derived production pathways, and increased inflammatory and immune response in sirolimus-converted patients.Despite the molecular profile being favorable to calcineurin inhibitor-based regimen, there was no impact in renal function over 30 months of follow-up.

View Article: PubMed Central - PubMed

Affiliation: 1] Comprehensive Transplant Center, Northwestern University, Chicago, Illinois, USA [2] Department of Medicine-Nephrology, Northwestern University, Chicago, Illinois, USA.

ABSTRACT
Tacrolimus and sirolimus are commonly used maintenance immunosuppressants in kidney transplantation. As their effects on immune cells and allograft molecular profiles have not been elucidated, we characterized the effects of tacrolimus to sirolimus conversion on the frequency and function of T cells, and on graft molecular profiles. Samples from renal transplant patients in a randomized trial of 18 patients with late sirolimus conversion and 12 on tacrolimus maintenance were utilized. Peripheral blood was collected at 0, 6, 12, and 24 months post randomization, with T-cell subpopulations analyzed by flow cytometry and T-cell alloreactivity tested by IFN-γ ELISPOT. Graft biopsy samples obtained 24 months post randomization were used for gene expression analysis. Sirolimus conversion led to an increase in CD4(+)25(+++)Foxp3(+) regulatory T cells. While tacrolimus-maintained patients showed a decrease in indirect alloreactivity over time post transplant, sirolimus conversion increased indirect alloreactive T-cell frequencies compared with tacrolimus-maintained patients. No histological differences were found in graft biopsies, but molecular profiles showed activation of the antigen presentation, IL-12 signaling, oxidative stress, macrophage-derived production pathways, and increased inflammatory and immune response in sirolimus-converted patients. Thus, chronic immune alterations are induced after sirolimus conversion. Despite the molecular profile being favorable to calcineurin inhibitor-based regimen, there was no impact in renal function over 30 months of follow-up.

No MeSH data available.


Direct and indirect donor T cell alloreactivity measured by IFN-γ ELISPOT at baseline, 6 months and 12 months post-randomization comparing between TAC maintained and SRL converted group. (A) IFN-γ production by PBMC incubated with PHA shows that cell viability was excellent in both groups. (B) IFN-γ production by PBMC incubated with irradiated donor cells showed no difference in direct T cell alloreactivity at 6- and 12-months. (p=0.082 for interaction group*time). (C and D) Indirect T cell alloreactivity, as measured by incubating PBMC either with a donors’ cell membrane preparation or donors’ HLA mismatched synthetic peptides, increased significantly over time in SRL group (p=0.009 and p=0.001 for interaction group*time, respectively). Results are expressed as mean ± SE for log-transformed ELISPOT counts. Analysis was performed using generalized estimating equations.
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Figure 4: Direct and indirect donor T cell alloreactivity measured by IFN-γ ELISPOT at baseline, 6 months and 12 months post-randomization comparing between TAC maintained and SRL converted group. (A) IFN-γ production by PBMC incubated with PHA shows that cell viability was excellent in both groups. (B) IFN-γ production by PBMC incubated with irradiated donor cells showed no difference in direct T cell alloreactivity at 6- and 12-months. (p=0.082 for interaction group*time). (C and D) Indirect T cell alloreactivity, as measured by incubating PBMC either with a donors’ cell membrane preparation or donors’ HLA mismatched synthetic peptides, increased significantly over time in SRL group (p=0.009 and p=0.001 for interaction group*time, respectively). Results are expressed as mean ± SE for log-transformed ELISPOT counts. Analysis was performed using generalized estimating equations.

Mentions: We used PBMC samples from the same patient cohort to measure both direct (stimulation by irradiated donor cells) and indirect (stimulation with synthetic peptides derived from mismatched donor class I and class II MHC molecules 13 or donor cell membrane sonicates) donor alloreactivity by IFN-γ ELISPOT assay as previously described.13–15 We found that subjects converted to SRL demonstrated significantly increased frequencies of indirectly-primed donor alloreactive T cells, while direct alloreactivity was similar between the two groups at 12-months post-randomization (Figure 4). While IFN-γ production by PBMC incubated with PHA (control ELISPOT, Figure 4A) or irradiated donor cells (direct ELISPOT, Figure 4B) showed no difference in alloreactivity when compared between groups at 6- or 12-months, TAC-maintained patients showed a decrease in indirect alloreactivity over time post-transplant (Figure 4C, 4D). In contrast, SRL conversion increased the frequencies of indirect alloreactive T cells, measured by PBMC incubation with either donor’s cell membrane preparation or donor-specific HLA mismatched synthetic peptides and the difference between groups was found to be significant over time (p=0.009 and p=0.001, respectively) (Figure 4C, 4D).


Cellular and molecular immune profiles in renal transplant recipients after conversion from tacrolimus to sirolimus.

Gallon L, Traitanon O, Sustento-Reodica N, Leventhal J, Ansari MJ, Gehrau RC, Ariyamuthu V, De Serres SA, Alvarado A, Chhabra D, Mathew JM, Najafian N, Mas V - Kidney Int. (2014)

Direct and indirect donor T cell alloreactivity measured by IFN-γ ELISPOT at baseline, 6 months and 12 months post-randomization comparing between TAC maintained and SRL converted group. (A) IFN-γ production by PBMC incubated with PHA shows that cell viability was excellent in both groups. (B) IFN-γ production by PBMC incubated with irradiated donor cells showed no difference in direct T cell alloreactivity at 6- and 12-months. (p=0.082 for interaction group*time). (C and D) Indirect T cell alloreactivity, as measured by incubating PBMC either with a donors’ cell membrane preparation or donors’ HLA mismatched synthetic peptides, increased significantly over time in SRL group (p=0.009 and p=0.001 for interaction group*time, respectively). Results are expressed as mean ± SE for log-transformed ELISPOT counts. Analysis was performed using generalized estimating equations.
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Related In: Results  -  Collection

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Figure 4: Direct and indirect donor T cell alloreactivity measured by IFN-γ ELISPOT at baseline, 6 months and 12 months post-randomization comparing between TAC maintained and SRL converted group. (A) IFN-γ production by PBMC incubated with PHA shows that cell viability was excellent in both groups. (B) IFN-γ production by PBMC incubated with irradiated donor cells showed no difference in direct T cell alloreactivity at 6- and 12-months. (p=0.082 for interaction group*time). (C and D) Indirect T cell alloreactivity, as measured by incubating PBMC either with a donors’ cell membrane preparation or donors’ HLA mismatched synthetic peptides, increased significantly over time in SRL group (p=0.009 and p=0.001 for interaction group*time, respectively). Results are expressed as mean ± SE for log-transformed ELISPOT counts. Analysis was performed using generalized estimating equations.
Mentions: We used PBMC samples from the same patient cohort to measure both direct (stimulation by irradiated donor cells) and indirect (stimulation with synthetic peptides derived from mismatched donor class I and class II MHC molecules 13 or donor cell membrane sonicates) donor alloreactivity by IFN-γ ELISPOT assay as previously described.13–15 We found that subjects converted to SRL demonstrated significantly increased frequencies of indirectly-primed donor alloreactive T cells, while direct alloreactivity was similar between the two groups at 12-months post-randomization (Figure 4). While IFN-γ production by PBMC incubated with PHA (control ELISPOT, Figure 4A) or irradiated donor cells (direct ELISPOT, Figure 4B) showed no difference in alloreactivity when compared between groups at 6- or 12-months, TAC-maintained patients showed a decrease in indirect alloreactivity over time post-transplant (Figure 4C, 4D). In contrast, SRL conversion increased the frequencies of indirect alloreactive T cells, measured by PBMC incubation with either donor’s cell membrane preparation or donor-specific HLA mismatched synthetic peptides and the difference between groups was found to be significant over time (p=0.009 and p=0.001, respectively) (Figure 4C, 4D).

Bottom Line: While tacrolimus-maintained patients showed a decrease in indirect alloreactivity over time post transplant, sirolimus conversion increased indirect alloreactive T-cell frequencies compared with tacrolimus-maintained patients.No histological differences were found in graft biopsies, but molecular profiles showed activation of the antigen presentation, IL-12 signaling, oxidative stress, macrophage-derived production pathways, and increased inflammatory and immune response in sirolimus-converted patients.Despite the molecular profile being favorable to calcineurin inhibitor-based regimen, there was no impact in renal function over 30 months of follow-up.

View Article: PubMed Central - PubMed

Affiliation: 1] Comprehensive Transplant Center, Northwestern University, Chicago, Illinois, USA [2] Department of Medicine-Nephrology, Northwestern University, Chicago, Illinois, USA.

ABSTRACT
Tacrolimus and sirolimus are commonly used maintenance immunosuppressants in kidney transplantation. As their effects on immune cells and allograft molecular profiles have not been elucidated, we characterized the effects of tacrolimus to sirolimus conversion on the frequency and function of T cells, and on graft molecular profiles. Samples from renal transplant patients in a randomized trial of 18 patients with late sirolimus conversion and 12 on tacrolimus maintenance were utilized. Peripheral blood was collected at 0, 6, 12, and 24 months post randomization, with T-cell subpopulations analyzed by flow cytometry and T-cell alloreactivity tested by IFN-γ ELISPOT. Graft biopsy samples obtained 24 months post randomization were used for gene expression analysis. Sirolimus conversion led to an increase in CD4(+)25(+++)Foxp3(+) regulatory T cells. While tacrolimus-maintained patients showed a decrease in indirect alloreactivity over time post transplant, sirolimus conversion increased indirect alloreactive T-cell frequencies compared with tacrolimus-maintained patients. No histological differences were found in graft biopsies, but molecular profiles showed activation of the antigen presentation, IL-12 signaling, oxidative stress, macrophage-derived production pathways, and increased inflammatory and immune response in sirolimus-converted patients. Thus, chronic immune alterations are induced after sirolimus conversion. Despite the molecular profile being favorable to calcineurin inhibitor-based regimen, there was no impact in renal function over 30 months of follow-up.

No MeSH data available.