Intrarenal Cytokine and Chemokine Gene Expression and Kidney Graft Outcome

Chronic Active T-Cell Mediated Kidney Rejection as a Clinically Significant Type of Allograft Loss?

The purpose of this article is to assess the present knowledge about chronic active (CA) T-cell mediated rejection (TCMR) of a kidney. In the research authors review current Banff diagnostic criteria used in kidney rejection, focus on their possible future evolution, and investigate the role of currently available molecular methods that could be implemented into the diagnostic scheme. Research also points out previously and currently available treatment methods applied to CA TCMR and takes into account possible side effects consequent upon the therapy. Moreover, attention is being paid to the CA TCMR coincidence with other kidney rejection types such as antibody-mediated rejection (ABMR) and its influence on the treatment approach. Authors also mark the possibility of non-HLA antibodies coexistence in patients with CA TCMR and describe its possible resonance on kidney allograft function. Nonetheless, it seems that current knowledge about CA TCMR is not sufficient and requires further investigation.

Chemokine Profiles Are Affected in Serum of Patients with Acute Rejection of Kidney Allograft

Kidney allograft transplantation improved the prognosis and quality of life of patients with end-stage renal diseases but the occurrence of acute rejection represents a limitation of the final outcome. Noninvasive biomarkers are needed as well as further advancements in the understanding of immune mechanisms of reaction to the allograft. Our study of 138 patients focused on one-year monitoring of serum concentrations of 12 chemokines regulating the recruitment of different immune cells into transplanted allograft and on in vitro regulation of the same chemokines release by interactions of renal proximal epithelial cells with monocyte/macrophage cell line stimulated with TNF alpha. In a group of 44 patients with acute rejection, higher serum pretransplant levels of CXCL1, CXCL5, CXCL6, CCL2, CCL21, and particularly CXCL10 and CX3CL1(both p < 0.001) were found suggesting their higher proinflammatory status as compared to subjects with the uncomplicated outcome. In samples collected at the day of biopsy positive for acute rejection, chemokines CXCL9 and CXCL11 attracting preferentially Th1 lymphocytes were found to be upregulated. In our in vitro model with TNF alpha induction, renal proximal epithelial cells seemed to be a more potent source of chemokines attracting neutrophils as compared to monocyte/macrophage cell line but the coculture of these cells potentiated release of neutrophilic chemokines CXCL5 and CXCL6. Similar augmentation of chemokine production was found also in the case of CCL2. On the other hand, adding of monocytes/macrophages to a culture of renal epithelial cells suppressed the release of CXCL10 and CXCL11 attracting T lymphocytes. We assume from our data that in kidney allograft transplantation, chemokines attracting neutrophils, T lymphocytes, and monocytes are induced simultaneously and measurement some of them in combination might be used as biomarkers of acute rejection. Mutual cell-cell interactions of immune cells with renal parenchyma seem to be important for fine regulation of chemokine release.

Molecular Assessment of Kidney Allografts: Are We Closer to a Daily Routine?

Kidney allograft pathology assessment has been traditionally based on clinical and histological criteria. Despite improvements in Banff histological classification, the diagnostics in particular cases is problematic reflecting a complex pathogenesis of graft injuries. With the advent of molecular techniques, polymerase-chain reaction, oligo- and microarray technologies allowed to study molecular phenotypes of graft injuries, especially acute and chronic rejections. Moreover, development of the molecular microscope diagnostic system (MMDx) to assess kidney graft biopsies, represents the first clinical application of a microarray-based method in transplantation. Whether MMDx may replace conventional pathology is the subject of ongoing research, however this platform is particularly useful in complex histological findings and may help clinicians to guide the therapy.

Clinical importance of chemokines and inflammatory cytokines for patient care following percutaneous nephrolithotripsy

Chemokines are a class of proteins with low molecular weight that serve important roles in the progression of inflammation. Percutaneous nephrolithotripsy is a surgical technique in which lasers or ultrasound are utilized to break down and/or remove kidney stones. In order to ensure a full recovery following surgery, effective patient care and nursing are required. In the present study, a total of 348 patients with kidney stones were recruited and the clinical importance of chemokines and inflammatory cytokines for the nursing of patients during perioperative period was investigated. Plasma levels of inflammatory cytokines, as well as chemokines in the C, CC and CXC families, were analyzed in patients following percutaneous nephrolithotripsy. Correlations between chemokines and inflammatory cytokines and the urinary concentration of calcium oxalate were also investigated. The results indicated that plasma levels of C and CC chemokines were downregulated in patients following percutaneous nephrolithotripsy, whereas the plasma concentrations of CXC chemokines were upregulated. Plasma concentration levels of inflammatory cytokines interleukin (IL)-8, IL-1, IL-17 and tumor necrosis factor (TNF)-α were significantly downregulated in patients following percutaneous nephrolithotripsy; however, no significant differences were observed in plasma levels of IL-6 and IL-10 pre- and post-surgery. Regression analysis revealed that plasma concentration levels of chemokine C motif ligand, which is a C chemokine, chemokine ligand 2, which is a CC chemokine, and TNF-α were positively correlated with the urinary concentration of calcium oxalate during the perioperative period. The results of the present study indicate that plasma levels of chemokines and inflammatory cytokines are clinically important for nursing of patients who experienced percutaneous nephrolithotripsy.

Gene expression profile in delay graft function: inflammatory markers are associated with recipient and donor risk factors

Background. Delayed graft function (DGF) remains an important problem after kidney transplantation and reduced long-term graft survival of the transplanted organ. The aim of the present study was to determine if the development of DGF was associated with a specific pattern of inflammatory gene expression in expanded criteria of deceased donor kidney transplantation. Also, we explored the presence of correlations between DGF risk factors and the profile that was found. Methods. Seven days after kidney transplant, a cDNA microarray was performed on biopsies of graft from patients with and without DGF. Data was confirmed by real-time PCR. Correlations were performed between inflammatory gene expression and clinical risk factors. Results. From a total of 84 genes analyzed, 58 genes were upregulated while only 1 gene was downregulated in patients with DGF compared with no DGF (P = 0.01). The most relevant genes fold changes observed was IFNA1, IL-10, IL-1F7, IL-1R1, HMOX-1, and TGF-β. The results were confirmed for IFNA1, IL-1R1, HMOX-1 and TGF-β. A correlation was observed between TGF-β, donor age, and preablation creatinine, but not body mass index (BMI). Also, TGF-β showed an association with recipient age, while IFNA1 correlated with recipient BMI. Furthermore, TGF-β, IFNA1 and HMOX-1 correlated with several posttransplant kidney function markers, such as diuresis, ultrasound Doppler, and glycemia. Conclusions. Overall, the present study shows that DGF is associated with inflammatory markers, which are correlated with donor and recipient DGF risk factors.

Significance of urinary proteome pattern in renal allograft recipients

Urinary proteomics is developing as a platform of urinary biomarkers of immense potential in recent years. The definition of urinary proteome in the context of renal allograft and characterization of different proteome patterns in various graft dysfunctions have led to the development of a distinct science of this noninvasive tool. Substantial numbers of studies have shown that different renal allograft disease states, both acute and chronic, could portray unique urinary proteome pattern enabling early diagnosis of graft dysfunction and proper manipulation of immunosuppressive strategy that could impact graft prognosis. The methodology of the urinary proteome is nonetheless not more complex than that of other sophisticated assays of conventional urinary protein analysis. Moreover, the need for a centralized database is also felt by the researchers as more and more studies have been presenting their results from different corners and as systems of organizing these newly emerging data being developed at international and national levels. In this context concept of urinary proteomics in renal allograft recipients would be of significant importance in clinical transplantation.

CD14+CD16+ and CD14+CD163+ monocyte subpopulations in kidney allograft transplantation

Background

Monocytes represent a heterogeneous population of cells subdivided according to the expression level of membrane antigens. A pro-inflammatory (intermediate/nonclassical) subpopulation of monocytes is defined by expression of CD16. CD163 seems to be characteristically preferentially expressed by immunosuppressive monocytes. The aim of our study was to evaluate the distribution of monocyte subpopulations in 71 patients with kidney allograft transplantation.

Results

The phenotype was evaluated by flow cytometry in defined time points. The proportions of peripheral CD14+CD16+ monocytes were downregulated immediately after the kidney transplantation and basiliximab treatment partially attenuated this trend. The transient downregulation of the CD14+CD16+ subpopulation was adjusted to basal values in two months. The proportions of CD14+CD163+ monocytes were transiently upregulated early after the kidney transplantation and remained higher during the first month in most patients. In ATG treated patients, the expansion of CD14+CD163+ monocytes was delayed but their upregulation lasted longer. In vitro data showed the direct effect of ATG and methylprednisolone on expression of CD16 and CD163 molecules while basiliximab did not affect the phenotype of cultured monocytes.

Conclusions

We assume from our data that kidney allograft transplantation is associated with modulation of monocyte subpopulations (CD14+CD16+ and CD14+CD163+) partially affected by an immunosuppressive regime used.

Evidence of enhanced systemic inflammation in stable kidney transplant recipients with low Framingham risk scores

BACKGROUND

While the Framingham risk score (FRS) predicts cardiovascular risk in the general population, it underestimates cardiovascular events in renal transplant recipients (RTR). Inflammation is common in RTR, and it is also a hallmark of vascular injury contributing to cardiovascular events.

OBJECTIVE

To explore the relationship between inflammatory chemokines (CCL family) and FRS in a stable RTR.

METHODS

The modified FRS (2009) was used to calculate the 10-yr probability of CVE in 150 RTR. A cross-sectional study measured plasma levels of 14 CCLs by Luminex technique in 53% (79/150) of the cohort and 28 controls.

RESULTS

43.3% of RTR was classified as low, 16% moderate, and 40.7% high FRS. FRS correlated with eGFR and all CCLs with R of <0.2(p = n.s). Compared with controls, CCL 1,4,8,15, and 27 were equally increased in both the high and low FRS groups (p < 0.04 and 0.03, respectively). The percentage of patients with low FRS and CCL 8,15, and 27 values above the 95% cutoff control levels was 46.1%, 76.9%, and 53.8%, respectively.

CONCLUSIONS

Over one half of stable RTR, including those with low FRS, have increased inflammatory chemokine levels. Inflammation is not accounted for in the FRS, and this may explain the poor performance of FRS in transplant patients.

Molecular markers of rejection and tolerance: lessons from clinical research

In terms of finding specific molecular markers associated with graft outcome, attempts have been made to study whole genome transcripts using microarray assays or to study the effect of number of genes of interest using quantitative real-time polymerase chain reaction. Using these techniques, molecular phenotypes of rejection have been characterized, and the variability of the clinical outcome besides similar morphology explained in part. Recently, several specific transcripts including naïve B cell regulation have been identified in the peripheral blood of operationally tolerant kidney transplant recipients. The decrease in immature B cell-related transcripts in the peripheral blood in patients with immunosuppression was shown to be associated with acute rejection. Similarly, tolerance-associated antigen 1 transcripts were identified in biopsies and regulatory T cell transcripts in urine and biopsies in patients without rejection. Better understanding of molecular processes associated with allograft rejection or alloantigen hyporesponsiveness/tolerance may help to improve our knowledge about graft pathology and identify novel markers suitable for future monitoring and guided therapy and finally improve the outcome of kidney transplantation.

Immunomodulating options for liver transplant patients

Much has changed since the early years of liver transplantation. Improvements in post-transplant survival are largely due to more selective and less toxic immunosuppression regimens and advances in operative and perioperative care. This has allowed liver transplantation to become an extremely successful treatment option for patients with endstage liver disease. Beginning with cyclosporine, a cyclic endecapeptide of fungal origin and the first of the calcineurin inhibitors to find widespread use, immunosuppressive regimens have evolved to include additional calcineurin inhibitors, steroids, mTOR inhibitors, antimetabolites and antibodies, mostly targeting T-cell activation. This review will present currently available immunosuppressive agents used in the perioperative period of liver transplantation, as well as maintenance treatments, tailoring therapeutic strategies for specific populations, and advances in immune monitoring and tolerance.

Early expression of tumor necrosis factor α and nuclear factor kappa B after Descemet stripping endothelial keratoplasty in rabbits

PURPOSE

To investigate immune rejection after Descemet stripping endothelial keratoplasty (DSEK) compared with that after penetrating keratoplasty (PKP) in New Zealand rabbit eyes and to identify the relationship between tumor necrosis factor alpha (TNF-α) and nuclear factor kappa B (NFκB) and evaluate their involvement in graft rejection.

METHODS

Sixty-nine New Zealand rabbits were divided into 3 groups: group A comprised the control group, which did not undergo either of the procedures; group B underwent DSEK; and group C underwent PKP. Twenty-three Chinese rabbits (46 eyes) were used as donors. The corneal transparency, graft placement, and anterior chamber were observed for 28 days. Blood serum, aqueous humor, and corneal samples were obtained on days 7, 14, 21, and 28 after the procedures. TNF-α levels were measured weekly by double-antibody enzyme-linked immunosorbent assay. NFκB in the cornea was checked by immunofluorescence.

RESULTS

There were no graft rejections in group B. Group C showed a 50% rejection frequency with an increase in both the TNF-α concentrations and NFκB expression observed at 7 days and peak levels observed at 28 days after PKP. TNF-α concentrations did not differ significantly (P > 0.05) between groups B and A. NFκB expression was slightly increased at 7 days and returned to normal levels by day 14 after DSEK.

CONCLUSION

Rabbits with DSEK had a lower rejection rate than rabbits with PKP. NFκB and TNF-α may contribute to the early rejection of corneal allografts.

Impact of patterns of proteinuria on renal allograft function and survival: a prospective cohort study

BACKGROUND

Proteinuria is an important complication in renal transplant recipients. The aim of this prospective study was to evaluate the long-term impact of transplant proteinuria patterns on allograft function and survival.

METHODS

We analyzed urinary protein of a cohort of 83 renal transplants with proteinuria ≥0.5 g/d by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radial immunogel diffusion assay. After initial stratification and analysis, the cohort was followed up for 16 yr. The graft outcome and survival were analyzed using Cox regression model to determine their association with different patterns of initial transplant proteinuria.

RESULTS

Group with predominantly glomerular (middle- and high-molecular-weight with or without low-molecular-weight) proteinuria (61%) had higher serum creatinine (p < 0.001) than the group with predominantly tubular (low-molecular-weight) proteinuria (39%). The incidences of chronic graft dysfunction and graft loss had increased in the glomerular proteinuria group (p < 0.001, hazard ratio 3.6, 95% confidence interval 1.7-7.5 and p < 0.001, hazard ratio 4.9, 95% confidence interval 1.9-12.1, respectively). Patient death did not differ (p = 0.434, hazard ratio 1.5, 95% confidence interval 0.5-4.5).

CONCLUSION

  Proteinuria in renal transplants can be differentiated into glomerular and tubular types based on molecular weight. Glomerular proteinuria is associated with significant increase in graft dysfunction and graft loss.

Intragraft expression of the IL-10 gene is up-regulated in renal protocol biopsies with early interstitial fibrosis, tubular atrophy, and subclinical rejection

Grafts with subclinical rejection associated with interstitial fibrosis and tubular atrophy (SCR+IF/TA) show poorer survival than grafts with subclinical rejection without IF/TA (SCR). Aiming to detect differences among SCR+IF/TA and SCR, we immunophenotyped the inflammatory infiltrate (CD45, CD3, CD20, CD68) and used a low-density array to determine levels of T(H)1 (interleukin IL-2, IL-3, gamma-interferon, tumor necrosis factor-alpha, lymphotoxin-alpha, lymphotoxin-beta, granulocyte-macrophage colony-stimulating factor) and T(H)2 (IL-4, IL-5, IL-6, IL-10, and IL-13) transcripts as well as of IL-2R (as marker for T-cell activation) in 31 protocol biopsies of renal allografts. Here we show that grafts with early IF/TA and SCR can be distinguished from grafts with SCR on the basis of the activation of IL-10 gene expression and of an increased infiltration by B-lymphocytes in a cellular context in which the degree of T-cell activation is similar in both groups of biopsies, as demonstrated by equivalent levels of IL-2R mRNA. These results suggest that the up-regulation of the IL-10 gene expression, as well as an increased proportion of B-lymphocytes in the inflammatory infiltrates, might be useful as markers of early chronic lesions in grafts with SCR.

Molecular phenotypes of acute rejection predict kidney graft prognosis

Earlier detection of antibody-mediated rejection of kidney allografts may improve graft outcomes. Profiling of gene expression holds promise for the diagnosis and prognosis of antibody-mediated rejection. Here, we identified 730 patients who received kidney transplants during 2002-2005, including 21 patients (2.9%) who experienced early acute antibody-mediated rejection. We also identified a matched group of 43 patients with early acute T cell-mediated rejection to serve as controls. Compared with patients with T cell-mediated rejection, those with antibody-mediated rejection had significantly higher intrarenal mRNA expression of the cytoprotective heme oxygenase-1 but had lower expression of the regulatory T cell marker forkhead box P3 (FoxP3), the B cell marker CD20, and the chemokine regulated upon activation, normal T cell expressed and secreted (RANTES). T cell infiltration was similar in both groups of patients. Compared with grafts that had a favorable course, those that failed as a result of antibody-mediated rejection had expression profiles suggesting a lack of regulation (less FoxP3, TGF-beta1, RANTES, and CD20). Grafts that failed as a result of T cell-mediated rejection only revealed lower expression of CD20 mRNA. In summary, these data suggest that severe antibody-mediated rejection and T cell-mediated rejection result in graft loss by distinct mechanisms. Molecular phenotypes of early acute rejection might help to identify grafts with poor prognosis, allowing earlier application of additional therapies.