Consensus on definition and severity grading of lymphatic complications after kidney transplantation.

BACKGROUND: The incidence of lymphatic complications after kidney transplantation varies considerably in the literature. This is partly because a universally accepted definition has not been established. This study aimed to propose an acceptable definition and severity grading system for lymphatic complications based on their management strategy. METHODS: Relevant literature published in MEDLINE and Web of Science was searched systematically. A consensus for definition and a severity grading was then sought between 20 high-volume transplant centres. RESULTS: Lymphorrhoea/lymphocele was defined in 32 of 87 included studies. Sixty-three articles explained how lymphatic complications were managed, but none graded their severity. The proposed definition of lymphorrhoea was leakage of more than 50 ml fluid (not urine, blood or pus) per day from the drain, or the drain site after removal of the drain, for more than 1 week after kidney transplantation. The proposed definition of lymphocele was a fluid collection of any size near to the transplanted kidney, after urinoma, haematoma and abscess have been excluded. Grade A lymphatic complications have a minor and/or non-invasive impact on the clinical management of the patient; grade B complications require non-surgical intervention; and grade C complications require invasive surgical intervention. CONCLUSION: A clear definition and severity grading for lymphatic complications after kidney transplantation was agreed. The proposed definitions should allow better comparisons between studies.

ANTECEDENTES: La incidencia de complicaciones linfáticas tras el trasplante renal (post-kidney-transplantation lymphatic, PKTL) varía considerablemente en la literatura. Esto se debe en parte a que no se ha establecido una definición universalmente aceptada. Este estudio tuvo como objetivo proponer una definición aceptable para las complicaciones PKTL y un sistema de clasificación de la gravedad basado en la estrategia de tratamiento. MÉTODOS: Se realizó una búsqueda sistemática de la literatura relevante en MEDLINE y Web of Science. Se logró un consenso para la definición y la clasificación de gravedad de las PKTL entre veinte centros de trasplante de alto volumen. RESULTADOS: En 32 de los 87 estudios incluidos se definía la linforrea/linfocele. Sesenta y tres artículos describían como se trataban las PKTL, pero ninguno calificó la gravedad de las mismas. La definición propuesta para la linforrea fue la de un débito diario superior a 50 ml de líquido (no orina, sangre o pus) a través del drenaje o del orificio cutáneo tras su retirada, más allá del 7º día postoperatorio del trasplante renal. La definición propuesta para linfocele fue la de una colección de líquido de tamaño variable adyacente al riñón trasplantado, tras haber descartado un urinoma, hematoma o absceso. Las PKTL de grado A fueron aquellas con escaso impacto o que no requirieron tratamiento invasivo; las PKTL de grado B fueron aquellas que precisaron intervención no quirúrgica y las PKTL de grado C aquellas en que fue necesaria la reintervención quirúrgica. CONCLUSIÓN: Se propone una definición clara y una clasificación de gravedad basada en la estrategia de tratamiento de las PKTLs. La definición propuesta y el sistema de calificación en 3 grados son razonables, sencillos y fáciles de comprender, y servirán para estandarizar los resultados de las PKTL y facilitar las comparaciones entre los diferentes estudios.

Increased natural killer cell subsets with inhibitory cytokines and inhibitory surface receptors in patients with recurrent miscarriage and decreased or normal subsets in kidney transplant recipients late post-transplant.

Patients with recurrent miscarriage (RM) show up-regulated cytotoxic natural killer (NK) cells that are suspected to play a causal role in abortion. In the present study, we investigated counter-regulating inhibitory mechanisms and compared the results in RM patients with those of healthy controls (HC), patients with end-stage renal disease (ESRD) and kidney transplant recipients late post-transplant (TX). NK, NK T and T cell subsets were analysed in the peripheral blood of 31 RM, 14 female ESRD and nine female TX patients as well as 21 female HC using eight-colour fluorescence flow cytometry. Compared with HC, RM patients showed significantly higher absolute numbers of CD56+ NK cells co-expressing the phenotype interferon (IFN)-γR+ , IL-4+ , transforming growth factor (TGF)-ß+ , IL-4+ human leucocyte antigen D-related (HLA-DR)+ , TGF-ß+ HLA-DR+ , IL-4+ TGF-ß+ , IL-4+ TGF-ß- , IFN-γ+ and/or IL-10- IFN-γ+ (all P ≤ 0·01), more IL-17+ CD56bright (P = 0·028) NK cells and more CD56dim CD16+ NK cells co-expressing IFN-γR, IFN-γ, IL-4 and/or TGF-ß (all P ≤ 0·01). When the same cell subsets were analysed in ESRD or TX patients, cytokine-producing NK cell subsets were not significantly different from those of HC. RM patients showed significantly higher absolute numbers of CD158a+ , CD158b+ , CD158a- CD158e+ (all P < 0·05), NKG2D+ NKG2A+ , NKG2D + NKG2A- , NKG2D+ and/or NKG2A+ (all P ≤ 0·01) CD56+ NK cells and higher CD158a+ , CD158b+ (all P < 0·05), NKG2D+ and/or NKG2A+ (all P < 0·01) CD56dim+ CD16+ NK cells than HC. In contrast, ESRD patients had normal and TX recipients had lower CD158a+ and NKG2D+ NKG2A- CD56+ NK cells and lower CD158a+ CD56dim+ CD16+ NK cells (all P < 0·05) than HC. RM patients have abnormally high circulating NK cells expressing inhibitory cytokines and inhibitory surface receptors which might contribute to the pathogenesis of RM.

Association of peripheral NK cell counts with Helios+ IFN-γ- Tregs in patients with good long-term renal allograft function.

Little is known about a possible interaction of natural killer (NK) cells with regulatory T cells (Treg ) in long-term stable kidney transplant recipients. Absolute counts of lymphocyte and Treg subsets were studied in whole blood samples of 136 long-term stable renal transplant recipients and 52 healthy controls using eight-colour fluorescence flow cytometry. Patients were 1946 ± 2201 days (153-10 268 days) post-transplant and showed a serum creatinine of 1·7 ± 0·7 mg/dl. Renal transplant recipients investigated > 1·5 years post-transplant showed higher total NK cell counts than recipients studied < 1·5 years after transplantation (P = 0·006). High NK cells were associated with high glomerular filtration rate (P = 0·002) and low serum creatinine (P = 0·005). Interestingly, high NK cells were associated with high CD4+ CD25+ CD127- forkhead box protein 3 (FoxP3+ ) Treg that co-express the phenotype Helios+ interferon (IFN)-γ- and appear to have stable FoxP3 expression and originate from the thymus. Furthermore, high total NK cells were associated with Treg that co-express the phenotypes interleukin (IL)-10- transforming growth factor (TGF)-ß+ (P = 0·013), CD183+ CD62L- (P = 0·003), CD183+ CD62+ (P = 0·001), CD183- CD62L+ (P = 0·002), CD252- CD152+ (P < 0·001), CD28+ human leucocyte antigen D-related (HLA-DR- ) (P = 0·002), CD28+ HLA-DR+ (P < 0·001), CD95+ CD178- (P < 0·001) and CD279- CD152+ (P < 0·001), suggesting that these activated Treg home in peripheral tissues and suppress effector cells via TGF-ß and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). The higher numbers of NK and Treg cell counts in patients with long-term good allograft function and the statistical association of these two lymphocyte subsets with each other suggest a direct or indirect (via DC) interaction of these cell subpopulations that contributes to good long-term allograft acceptance. Moreover, we speculate that regulatory NK cells are formed late post-transplant that are able to inhibit graft-reactive effector cells.

Tissue Expression of Aquaporin 2 Is Correlated to Urine Output and Allograft Function in Sensitized Kidney Transplant Patients.

BACKGROUND: Salt and water disturbances often occur during acute kidney allograft dysfunction that contribute to graft failure, but this condition has been poorly investigated in the alloreactivity setting. We evaluated the tissue expression of aquaporins (AQP1 and AQP2) and the epithelial sodium channel (ENAC) in kidney biopsy specimens from sensitized kidney transplant recipients. METHODS: Eighty-six biopsy specimens from 33 sensitized patients were divided into 3 groups according to clinical context: time-zero (n = 9), protocol (n = 9), and indication (n = 68). The indication biopsy specimens were further divided into 3 subgroups according to the presence of acute tubular necrosis or rejection. Normal kidney tissue samples (n = 6) served as the control specimens. Immmunohistochemical expression of AQP1, AQP2, and ENAC was determined by using image analyzing software. RESULTS: Significantly lower AQP1 expression was observed in the time-zero and indication biopsy specimens with rejection compared with control specimens (P = .03 and P = .04, respectively). AQP2 expression was significantly lower in patients with an indication biopsy specimen compared with control and protocol biopsy specimens (P = .05 and P = .005). For ENAC, a lower expression was noted in the indication biopsy specimens compared with the control specimens (P = .04). Both AQP1 and AQP2 tissue expressions were significantly correlated to urine output (r = 0.45 and r = 0.32; P = .001 and P = .02), and AQP2 was correlated with the glomerular filtration rate estimated by using the Modification of Diet in Renal Disease Study equation at biopsy (r = 0.23; P = .05). CONCLUSIONS: These findings partially confirm previous experimental data showing downregulation of AQP1 expression after ischemia/reperfusion injury and during rejection. AQP2 downregulation seems to be rejection-independent, occurring during deteriorating or poor kidney graft function.

Pre-transplant soluble CD30 in combination with total DSA but not pre-transplant C1q-DSA predicts antibody-mediated graft loss in presensitized high-risk kidney transplant recipients.

Presensitized kidney transplant recipients are at high-risk for early antibody-mediated rejection. We studied the impact of pre- and post-transplant donor-specific human leukocyte antigen (HLA) antibodies (DSA) and T-cell-activation on the occurrence of antibody-mediated rejection episodes (AMR) and graft loss (AMR-GL) in a unique cohort of 80 desensitized high-risk kidney transplant recipients. Patients with pre-transplant DSA demonstrated more AMR episodes than patients without DSA, but did not show a significantly increased rate of AMR-GL. The rates of AMR and AMR-GL were not significantly increased in patients with complement split product (C1q)-binding pre-transplant DSA. Pre-transplant C1q-DSA became undetectable post-transplant in 11 of 13 (85%) patients; 2 (18%) of these 11 patients showed AMR but no AMR-GL. In contrast, the post-transplant presence of C1q-DSA was associated with significantly higher rates of AMR (86 vs 33 vs 0%; P < 0.001) and AMR-GL (86 vs 0 vs 0%; log-rank P < 0.001) compared with post-transplant DSA without C1q-binding or the absence of DSA. Patients with both pre-transplant DSA and evidence of pre-transplant T-cell-activation as indicated by soluble CD30-positivity showed a significantly increased risk for AMR-GL [HR = 11.1, 95% confidence interval (CI) = 1.68-73.4; log-rank P = 0.013]. In these high-risk patients, AMR-GL was associated with total DSA in combination with T-cell-activation pre-transplant, and de novo or persistent C1q-binding DSA post-transplant.

A Single-center Experience on the Value of Pancreas Graft Biopsies and HLA Antibody Monitoring After Simultaneous Pancreas-Kidney Transplantation.

BACKGROUND: In simultaneous pancreas-kidney transplantation (SPKT), monitoring of the pancreas allograft is more complex than the kidney allograft due to difficulties in obtaining pancreas histology and weak clinical evidence supporting the role of donor-specific antibodies (DSA). METHODS: We performed a single-center retrospective analysis of all 17 SPKT recipients who underwent a total of 22 pancreas allograft indication biopsies from October 2009 to September 2012. Fifteen patients had at least 2 DSA measurements: pretransplantation and at the time of biopsy. RESULTS: All 7 patients (100%) with post-transplantation DSA-positivity (de novo: n = 6; persistent: n = 1) at biopsy had at least 1 rejection episode either of the pancreas (n = 4) or the kidney (n = 3), with 3 antibody-mediated rejections (AMR). In contrast, only 4 of 8 patients (50%) without post-transplantation DSA had evidence of rejection, with 1 AMR. Findings during pancreas allograft biopsy procedures led to a change of immunosuppressive therapy in 11 of 15 (73%) patients. Patient survival, graft survival, and function were not adversely affected by the presence of post-transplantation DSA. One major and 2 minor procedure-related complications occurred during the pancreas biopsies. CONCLUSIONS: In this small retrospective analysis, pancreas allograft histology provided the most therapeutically relevant information, rather than the kidney histology or DSA monitoring.

Contrast-enhanced ultrasonography in the early period after kidney transplantation predicts long-term allograft function.

INTRODUCTION: Real-time contrast-enhanced sonography (CES) can assess microvascular tissue perfusion using gas-filled microbubbles. The purpose of the study was to evaluate the feasibility of early CES in predicting long-term kidney allograft function in comparison to color Doppler ultrasonography (CDUS). METHODS: We prospectively studied 68 consecutive kidney transplant recipients using CES and conventional CDUS investigation 1 week after transplantation. Transplant tissue perfusion imaging was performed by low-power imaging during intravenous administration of the sonocontrast SonoVue. Renal tissue perfusion was assessed quantitatively using flash replenishment kinetics of microbubbles to estimate renal blood flow (RBF). The obtained sonography values were correlated with clinical data 1 week up to 1 year after transplantation. RESULTS: In contrast with conventional CDUS resistive indices, RBF estimated by CES 1 week posttransplantation significantly correlated with kidney function after 1 year (r = 0.67; P < .001). Determination of RBF by CES revealed a significant correlation with donor age but not recipient age, whereas conventional CDUS resistive index was significantly correlated to recipient age (r = 0.54; P < .001) but not donor age. Furthermore RBF was associated with vascular fibrosis and intimal thickening of the engraftment biopsies. CONCLUSION: This is the first prospective study demonstrating the prognostic value of CES early after kidney transplantation. In contrast with CDUS, CES reveals information about kidney allograft perfusion independent of recipient vascular compliance.

[Modern immunosuppression after solid organ transplantation]. / Moderne Immunsuppression nach Organtransplantation.

The one common factor in solid organ transplantation is the need for lifelong maintenance immunosuppression. Drug regimens after organ transplantation typically comprise a combination of different immunosuppressive drugs. In most cases a triple drug regimen with different mechanisms of action is used. The aim is to improve both patient and graft survival while minimizing potential side effects of immunosuppressive medication. The basis of most immunosuppressive regimens is calcineurin inhibitors in combination with mycophenolic acid. There are various stages of immunosuppression after solid organ transplantation involving induction therapy, initial and long-term maintenance therapy. In each phase an individual combination of immunosuppressants is set up depending on the risk profile of the individual patient to prevent transplant rejection and organ loss. Based on these considerations, concepts of calcineurin inhibitor or steroid reduction have been established in transplant medicine in recent years. The key role in terms of development of new immunosuppressive strategies is taken by kidney transplantation, the most common solid organ transplantation performed.

Influence of test technique on sensitization status of patients on the kidney transplant waiting list.

The exquisitely sensitive single antigen bead (SAB) technique was shown to detect human leukocyte antigen (HLA) antibodies in sera of healthy male blood donors. Such false reactions can have an impact on critical decisions, especially with respect to the determination of unacceptable HLA-antigen mismatches in patients awaiting a kidney transplant. We tested pretransplant sera of 534 patients on the kidney waiting list using complement-dependent cytotoxicity (CDC), enzyme-linked immunosorbent assay (ELISA) and SAB in parallel. Evidence of HLA antibodies was obtained in 5% of patients using CDC, 14% using ELISA, and 81% using SAB. Among patients without history of an immunizing event, 77% showed evidence of HLA antibodies in SAB. In contrast 98% of these patients were negative in ELISA and CDC. In patients without an immunizing event, SAB-detected antibodies reacted not always weakly but with mean fluorescence intensity (MFI) values as high as 14 440. High-MFI-value antibodies were found in some of these patients with HLA specificities that are rather common in general population, consideration of which would lead to unjustified exclusion of potential kidney donors. False SAB reactions can be unveiled by testing with additional antibody assays. Denial of donor kidneys to recipients based on HLA-antibody specificities detected exclusively in the SAB assay is not advisable.

Superiority of AbCross enzyme-linked immunosorbent assay cross-match over the B-cell complement-dependent lymphocytotoxicity cross-match.

BACKGROUND: The AbCross enzyme-linked immunosorbent assay (ELISA) cross-match is a recently introduced solid phase cross-match technique with several technical advantages over the currently available Antibody Monitoring System ELISA cross-match. METHODS: In the present study, we investigated the potential superiority of AbCross over the traditional complement-dependent lymphocytotoxicity (CDC) B-cell cross-match (BXM). Pretransplant sera of 271 kidney transplant recipients who were transplanted at our center between 1998 and 2010 were tested in ELISA screening for the presence of human leukocyte antigen (HLA) antibodies and in AbCross and CDC for antibody reactivity against solubilized donor HLA class I and II antigens and donor B cells, respectively. RESULTS: Patients positive for HLA class I or II antibodies on ELISA screening had a significantly poorer graft outcome 2 years after transplantation than recipients who were negative for HLA antibodies (21% vs 6% graft loss; P = .002). Corresponding with this finding, 37 recipients positive for HLA antibodies in AbCross against donor HLA class I or II antigens had a 2-year post-transplant graft loss rate of 19%, which is significantly higher than the 8% rate in 186 recipients who were negative for both antibody classes in AbCross (P = .043). The 2-year graft loss rate in 34 AbCross positive but BXM negative patients was 21%, compared with 7% in 172 AbCross and BXM negative patients (P = .012) and 9% in 11 AbCross negative but BXM positive patients (P = .39). CONCLUSIONS: Our data indicate that the AbCross ELISA cross-match is superior to the CDC BXM, most likely because it detects antibodies against donor HLA antigens at a higher sensitivity.

IVIM-DWI of transplanted kidneys: reduced diffusion and perfusion dependent on cold ischemia time.

PURPOSE: To evaluate the effect of cold ischemia time (CIT) of renal allografts on diffusion and perfusion using intravoxel incoherent motion (IVIM) derived parameters. MATERIAL AND METHODS: A total of 37 patients with renal allografts (CIT: 27 <15 h, 10 ≥15 h) and 30 individuals with healthy kidneys were examined at 1.5 T using a single-shot echo-planar diffusion-weighted pulse sequence with nine b-values ranging from 0 to 800 s/mm(2). ADC, perfusion fraction f, and the diffusion coefficient D were calculated using the IVIM model. Parameters of allografts stratified by CIT were compared with healthy kidney groups using the Mann-Whitney U test for unpaired data. We computed the Spearman correlation coefficient for correlation with creatinine values. RESULTS: ADC, D, and f of transplanted kidneys were significantly lower than in the healthy controls. The long-CIT group showed significantly lower diffusion parameters compared with the short-CIT group [mean±SD]: ADC: 1.63±0.14 µm(2)/ms, f: 11.90±5.22%, D: 1.55±0.25 µm(2)/ms versus ADC: 1.79±0.13 µm(2)/ms, f: 16.12±3.43%, D: 1.73±0.14 µm(2)/ms, P(ADC), (f), (D)<0.05. CONCLUSION: Our results suggest that diffusion parameters, especially the ADC, depend on the CIT of the kidney allograft. Potentially, this stands for functional changes in renal allografts. Diffusion-weighted imaging could be used for follow-up examinations. Thus, diffusion parameters may help guide therapy in patients with delayed graft function.

Recent developments in desensitization of crossmatch-positive kidney transplant recipients.

Currently, there are two major options for the successful and timely transplantation of sensitized kidney transplant recipients: (1) avoidance of the sensitization barrier using special allocation programs, or (2) desensitization. In the case of broadly sensitized kidney patients, a combination of both options might be necessary. This review focuses on new advances in desensitization of crossmatch-positive kidney transplant recipients which include immunoadsorption and the administration of new substances such as the complement C5 inhibitor eculizumab. Finally, integrated algorithms that combine different measures are acknowledged.

Kidney transplantation for high-risk sensitized patients - the "Heidelberg algorithm".

Presensitized patients on kidney transplant waiting lists have a lower chance of receiving a crossmatch-negative kidney and, if transplanted, are at increased risk of immunologic graft loss. We developed an algorithm for pretransplant risk estimation and peritransplant treatment which contains 7 independent steps: 1) pretransplant identification of high-risk patients; 2) good HLA match; 3) inclusion in the Acceptable Mismatch Program of Eurotransplant if applicable; 4 and 5) pre- and posttransplantation desensitization; 6) monitoring of donor-specific antibodies after transplantation; and 7) protocol biopsies. Between April 1, 2006, and March 31, 2009, 34 patients were transplanted according to this algorithm. Graft and patient survival rates did not differ from those in nonsensitized recipients. Antibody-mediated rejection episodes were <10% and infectious complications infrequent.

Immunosuppression after kidney transplantation.

Today kidney transplantation features excellent short-term outcomes with decreasing acute rejection episodes. In contrast, improvement of long-term allograft survival is much less impressive over the last decades. Thus, the goal of current immunosuppressive therapies is keeping the balance between the reduction of acute rejection episodes and organ specific and systemic side effects. With the development of a broad armamentarium of new immunosuppressive agents with different mechanisms of action, the minimization or avoidance of corticosteroids and calcineurin inhibitors became feasible.

Current approaches to the management of highly sensitized kidney transplant patients.

With the introduction of sensitive antibody detection techniques, effective antibody elimination devices, therapeutic agents, such as bortezomib and eculizumab, and new concepts, such as Heidelberg algorithm, kidney paired exchange, and acceptable mismatch programs, several effective options are now available for the management of highly sensitized kidney transplant patients. However, as the number of human leukocyte antigen-mismatched transplantations is increasing with each year and as long as the elimination or long-term control of donor-specific antibody-producing clones remains an unresolved issue, sensitization will continue to represent a major problem in kidney transplantation.

Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers after renal transplantation.

Renin-angiotensin system blockade retards the progression of diabetic and non-diabetic chronic kidney disease of the native kidneys. Though most patients suffer from a significant renal insufficiency (chronic kidney disease stage III) and a concomitant heart disease after renal transplantation, there is up to now no evidence supporting the use of inhibitors of the renin-angiotensin system in these patients. We wish to summarize the available evidence on the use of inhibitors of the renin-angiotensin system after renal transplantation. We specifically discuss potential beneficial as well as adverse effects of a renin-angiotensin system blockade. In addition, we review their influence on morphologic and biochemical markers as well as on renal function, graft and patient survival after renal transplantation.

Simultaneous pancreas-kidney transplantation in type 1 diabetes.

The outcome of simultaneous pancreas-kidney (SPK) transplantation in type 1 diabetes has dramatically improved in recent years because of optimized surgical techniques and new immunosuppressive drug regimens. Normoglycemia is followed by stabilization or even regression of diabetic lesions, i.e., of heart and kidneys. However, these effects are only visible after more than five yr of normoglycemia (achieved by a functioning allograft). This is also a likely explanation for the conflicting results of studies that investigated patient or kidney graft survival in SPK transplantation compared to kidney transplantation alone. Most studies had too short follow-up periods, i.e., less than five yr, to compare effectively different transplant strategies in patients with type 1 diabetes and therefore failed to discover a survival benefit in favor of simultaneously transplanted patients. Recent data now indicate that, with a longer follow-up, there is an increasing survival benefit for simultaneously transplanted patients compared to patients who received a single kidney transplant. This is paralleled by the comparison of simultaneously transplanted patients to patients who received a single kidney transplant from a living donor. A survival benefit for the combined procedure was here visible after 10 yr of follow-up. We give a short overview on SPK transplantation, with a focus on the effects of this procedure on diabetic complications as well as patient and kidney graft survival.

Coulomb drag in the exciton regime in electron-hole bilayers.

Electron-hole bilayers are expected to make a transition from a pair of weakly coupled two-dimensional systems to a strongly coupled exciton system as the barrier between the layers is reduced. Coulomb drag measurements on devices with a 30 nm barrier are consistent with two weakly coupled 2D Fermi systems where the drag decreases with temperature. For a 20 nm barrier, however, we observe an increase in the drag resistance as the temperature is reduced when a current is driven in the electron layer and voltage measured in the hole layer. These results indicate the onset of strong coupling possibly due to exciton formation or phenomena related to exciton condensation.

Effects of mycophenolic acid on human fibroblast proliferation, migration and adhesion in vitro and in vivo.

Mycophenolic acid (MPA) is a potent inhibitor of the inosine monophosphate dehydrogenase and used as an immunosuppressive drug in transplantation. MPA inhibits proliferation of T- and B-lymphocytes by guanosine depletion. Since fibroblasts rely on the de novo synthesis of guanosine nucleotides, it is assumed that MPA interacts with fibroblasts causing an increased frequency of wound healing problems. We show a downregulation of the cytoskeletal proteins vinculin, actin and tubulin in fibroblasts exposed to pharmacological doses of MPA using microarray technology, real-time polymerase chain reaction (PCR) and Western blot. This reduction in RNA and protein content is accompanied by a substantial rearrangement of the cytoskeleton in MPA-treated fibroblasts as documented by immunofluorescence. The dysfunctional fibroblast growth was validated by scratch test documenting impaired migrational capacity. In contrast, cell adhesion was increased in MPA-treated fibroblasts. The results of the cultured human fibroblasts were applied to skin biopsies of renal transplant recipients. Skin biopsies of patients treated with MPA expressed less vinculin, actin and tubulin as compared to control biopsies that could explain potential wound healing problems posttransplantation. The perspective of MPA-induced cytoskeletal dysfunction may go beyond wound healing disturbances and may have beneficial effects on (renal) allografts with respect to scarring.