Marian Klinger

Polyomavirus BK replication in de novo kidney transplant patients receiving tacrolimus or cyclosporine: a prospective, randomized, multicenter study.

Polyomavirus BK (BKV)‐associated nephropathy causes premature kidney transplant (KT) failure. BKV viruria and viremia are biomarkers of disease progression, but associated risk factors are controversial. A total of 682 KT patients receiving basiliximab, mycophenolic acid (MPA), corticosteroids were randomized 1:1 to cyclosporine (CsA) or tacrolimus (Tac). Risk factors were analyzed in 629 (92.2%) patients having at least 2 BKV measurements until month 12 posttransplant. Univariate analysis associated CsA‐MPA with lower rates of viremia than Tac‐MPA at month 6 (10.6% vs. 16.3%, p = 0.048) and 12 (4.8% vs. 12.1%, p = 0.004) and lower plasma BKV loads at month 12 (3.9 vs. 5.1 log10 copies/mL; p = 0.028). In multivariate models, CsA‐MPA remained associated with less viremia than Tac‐MPA at month 6 (OR 0.60; 95% CI 0.36–0.99) and month 12 (OR 0.33; 95% CI 0.16–0.68). Viremia at month 6 was also independently associated with higher steroid exposure until month 3 (OR 1.19 per 1 g), and with male gender (OR 2.49) and recipient age (OR 1.14 per 10 years) at month 12. The data suggest a dynamic risk factor evolution of BKV viremia consisting of higher corticosteroids until month 3, Tac‐MPA compared to CsA‐MPA at month 6 and Tac‐MPA, older age, male gender at month 12 posttransplant.

Two corticosteroid-free regimens-tacrolimus monotherapy after basiliximab administration and tacrolimus/mycophenolate mofetil-in comparison with a standard triple regimen in renal transplantation : results of the Atlas study.

Background. The side effects associated with corticosteroids have led to efforts to minimize their use in renal transplant patients. In this study we compared two corticosteroid-free tacrolimus-based regimens with a standard triple therapy. Methods. This was a 6-month, phase III, open-label, parallel-group, multicenter study. The total analysis set comprised 451 patients, randomized (1:1:1) to receive tacrolimus (Tac) monotherapy following basiliximab (Bas) administration (n=153), Tac/mycophenolate mofetil (MMF) (n=151), or, Tac/MMF/corticosteroids triple therapy as a control (n=147). Results. The study was completed by 91.2% (triple therapy), 94.7% (Tac/MMF), and 82.4% (Bas/Tac) of patients. Patient baseline characteristics were similar in all groups. The incidences of biopsy-proven acute rejection were 8.2% (triple therapy), 30.5% (Tac/MMF), and 26.1% (Bas/Tac), p<0.001 (multiple test for comparison with triple therapy); Bas/Tac vs. Tac/MMF, p=ns. The incidences of corticosteroid-resistant acute rejection were 2.0%, 4.0%, and 5.2%, p=ns. Graft survival (95.9%, 96.7%, and 94.7%, p=ns) and patient survival (100%, 99.3%, and 99.3%, p=ns) were similar in all groups. Median serum creatinine at month 6 was 123.0 &mgr;mol/L (triple therapy), 134.7 &mgr;mol/L (Tac/MMF) and 135.8 &mgr;mol/L (Bas/Tac). The overall safety profiles were similar; differences (p<0.05) were reported for anaemia (24.5% vs. 12.6% vs. 14.5%), diarrhoea (12.9% vs. 17.9% vs. 5.9%), and leukopenia (7.5% vs. 18.5% vs. 5.9%) for the triple therapy, Tac/MMF, and Bas/Tac group, respectively. The incidences of new-onset diabetes mellitus were 4.6%, 7.1%, and 1.4%, respectively. Conclusion. Corticosteroid-free immunosuppression was feasible with the Bas/Tac and the Tac/MMF regimens. Both corticosteroid-free regimens were equally effective in preventing acute rejection, with the Bas/Tac therapy offering some safety benefits.

The effects of FK778 in combination with tacrolimus and steroids: A phase II Multicenter study in renal transplant patients

Background. In animal and in vitro models, FK778 inhibits acute rejection, modifies vasculopathy, and shows anti-viral activity. We report first efficacy and safety data of FK778 in human kidney transplant recipients at two concentration-controlled ranges. Methods. In a double-blind manner, 149 patients were randomized to a 12-week treatment with FK778 in combination with tacrolimus (Tac) and corticosteroids (S). Of the high-level group (H), 49 patients received 2×600 mg/day FK778 and continued on 150 mg/day, 54 patients of the low-level group (L) got 1×600 mg/day followed by 75 mg/day, and 46 patients received placebo (P). Subsequent FK778 doses were adjusted to trough levels of 100–200 &mgr;g/mL (H) and 10–100 &mgr;g/mL (L). The primary endpoint was the incidence of biopsy proven acute rejection (AR). Results. In 93% of the patients in group L, targeted plasma trough levels were reached by Day 3; in half of the patients in group H, the targeted levels were reached by Day 9. Graft survival at week 16 was 89.7%, 88.8%, and 91.3%, and the incidences of AR were 26.5%, 25.9%, and 39.1% for groups H, L, and P. For the subgroup of patients in which target levels were reached by week 2, incidences were 7.7%, 27.1%, and 39.1%, respectively. Anemia, the most frequently reported adverse event especially in group H, was reversible. Mean total cholesterol and LDL-cholesterol levels were reduced during FK778 treatment compared with group P. Conclusion. FK778 is pharmacologically active, well-tolerated, and safe. To fully benefit from this promising new drug, FK778 dosing will be optimized in subsequent studies.

Cytokine gene expression in kidney allograft biopsies after donor brain death and ischemia-reperfusion injury using in situ reverse-transcription polymerase chain reaction analysis.

Background. This study focuses on the cytokine genes expression after brain-death, ischemia-reperfusion injury, and during allograft rejection. Methods. A total of 49 needle core biopsies from kidney transplant recipients, performed before and during transplantation procedures were studied. The first biopsy was taken during procurement of the organ, the second after cold ischemia, and the third after approximately 30 min of reperfusion. We also assessed 34 allograft biopsies obtained during acute rejection. Tubular and glomerular expression of interferon (IFN)-&ggr;, transforming growth factor (TGF)-&bgr;1, platelet-desired growth factor-B (PDGF-B), interleukin (IL)-2, IL-6, IL-10 mRNA was analyzed with reverse-transcription polymerase chain reaction (RT-PCR) in situ technique, which allows to detect a few copies of the target gene without destruction of the tissue architecture. Results. Compared with normal kidney tissue from living donor, high gene expression of IFN-&ggr;, TGF-&bgr;1, PDGF-B, IL-2, IL-6, and IL-10 was detected in all procurement specimens. After reperfusion gene expressions of IL-2, IL-6, and IL-10 were significantly upregulated in renal tubules compared to biopsies taken after cold ischemia. The gene expression of IFN-&ggr;, TGF-&bgr;1, and PDGF-B remained stable after organ procurement, during cold ischemia, and after reperfusion. Gene expression of IFN-&ggr;, IL-2, IL-6, IL-10, and PDGF-B in procurement biopsies, as well as in those taken after cold ischemia and reperfusion, were significantly higher than during the period of acute rejection. Conclusion. The data presented herein strongly point out the importance of the immunological and morphological injury that occurs before and during transplantation. The increase of inflammatory response after brain death is important for further stimulation of the immune response and long-term kidney survival.

IL-18 is involved in vascular injury in end-stage renal disease patients.

BACKGROUND The role of interleukin (IL)-6 and IL-18 in induction of the inflammatory reaction underlying arteriosclerosis, and protective effect of an anti-inflammatory cytokine IL-10 in this process, have been confirmed by experimental and clinical observations. A systemic inflammatory reaction marker, C-reactive protein (CRP), is known to be associated with the induction of IL-6 and IL-18 release. The chronic inflammatory state associated with renal insufficiency contributes to acceleration of arteriosclerosis, reflected by decreased elasticity which can be measured with aortal pulse wave velocity (PWV). It is well known that chronic kidney disease (CKD) is associated with the chronic inflammatory process, as evidenced by increase in CRP and IL-6 level. It also results in a drop of fetuin-A concentration which is the calcification inhibitor negatively regulated by inflammation. Part of the derangements associated with the progressive renal failure is also the rise of activated monocyte pool, which among others produces IL-18. The aim of the present study was to evaluate, through measurements of CRP, fetuin-A and aortal pulse wave velocity (aoPWV), whether IL-6 and IL-18 affect the arterial wall of CKD patients as a part of general inflammatory process or locally, through their effect on the arterial lesion development. Materials and methods. The study was performed in a group of 102 patients with stage V CKD (73 treated with haemodialysis and 29 treated with continuous ambulatory peritoneal dialysis) (CKD5 group) and in 30 healthy controls. We measured serum high-sensitivity C-reactive protein (hs-CRP), fetuin-A, IL-6, IL-18, IL-10 (ELISA) and others (haemoglobin level, white blood cell count, serum calcium, phosphate, calcium-phosphate product, albumin, fibrinogen, cholesterol, high-density lipoprotein (HDL), triglycerides and parathormone). ECG-gated carotid and femoral artery waveforms were recorded and analysed. RESULTS Serum levels of hs-CRP, IL-6, IL-10 and IL-18 were higher and fetuin-A levels were lower in the CKD5 group than in controls [6.4 (0.6-22.3) mg/dl versus 2.5 (0.5-5.2) mg/dl; 8.29 pg/ml (0.96-74.48)] versus 2.78 (7.91-0.77) pg/ml; 6.5 (3.7-29.7) pg/ml versus 4.1 (3.8-7.2) pg/ml; 254.4 (468.8-47.5) pg/ml versus 89.3 (91.3-27.5) pg/ml]. The aoPWV was higher in the CKD5 group patients than in the control group (9.4 +/- 1.75 m/s versus 7.76 +/- 1.67 m/s; P < 0.05, respectively). Serum fetuin-A level was negatively associated with hs-CRP and IL-6 but not with IL-18 or IL-10. The aoPWV positively correlated with hs-CRP (r = 0.246; P < 0.05), IL-6 and IL-18 (r = 0.220; P < 0.05) and negatively correlated with fetuin-A (r = -0.204; P < 0.05). No relationship between IL-10 and aoPWV was found. In a multiple regression analysis model respecting inflammatory markers the influence of hs-CRP, IL-18 and fetuin-A on aoPWV remained significant. CONCLUSIONS The novel observations in the present study are the data indicating that the distinctive contribution of IL-18, but not IL-6, to the arteriosclerosis occurrence in CKD patients, is independent from CRP, fetuin A or other factors involved in the general inflammatory process.

Does the KIR2DS5 Gene Protect from Some Human Diseases

Background KIR2DS5 gene encodes an activating natural killer cell receptor whose ligand is not known. It was recently reported to affect the outcome of hematopoietic stem cell transplantation. Methodology/Principal Findings In our studies on KIR2DS5 gene associations with human diseases, we compared the frequencies of this gene in patients and relevant controls. Typing for KIR2DS5 gene was performed by either individual or multiplex polymerase chain reactions which, when compared in the same samples, gave concordant results. We noted an apparently protective effect of KIR2DS5 gene presence in several clinical conditions, but not in others. Namely, this effect was observed in ankylosing spondylitis (p = 0.003, odds ratio [OR] = 0.47, confidence interval [CI] = 0.28–0.79), endometriosis (p = 0.03, OR = 0.25, CI = 0.07–0.82) and acute rejection of kidney graft (p = 0.0056, OR = 0.44, CI = 0.24–0.80), but not in non-small-cell lung carcinoma, rheumatoid arthritis, spontaneous abortion, or leukemia (all p>0.05). In addition, the simultaneous presence of KIR2DS5 gene and HLA-C C1 allotype exhibited an even stronger protective effect on ankylosing spondylitis (p = 0.0003, OR = 0.35, CI = 0.19–0.65), whereas a lack of KIR2DS5 and the presence of the HLA-C C2 allotype was associated with ankylosing spondylitis (p = 0.0017, OR = 1.92, CI = 1.28–2.89), whereas a lack of KIR2DS5 and presence of C1 allotype was associated with rheumatoid arthritis (p = 0.005, OR = 1.47, CI = 1.13–1.92). The presence of both KIR2DS5 and C1 seemed to protect from acute kidney graft rejection (p = 0.017, OR = 0.47, CI = 0.25–0.89), whereas lack of KIR2DS5 and presence of C2 seemed to favor rejection (p = 0.0015, OR = 2.13, CI = 1.34–3.37). Conclusions/Significance Our results suggest that KIR2DS5 may protect from endometriosis, ankylosing spondylitis, and acute rejection of kidney graft.

The influence of non‐HLA antibodies directed against angiotensin II type 1 receptor (AT1R) on early renal transplant outcomes

Non‐HLA antibodies (Abs) targeting vascular receptors are thought to have an impact on renal transplant injury. Anti‐angiotensin II type 1‐receptor‐activating antibodies (anti‐AT1R) have been mentioned to stimulate a severe vascular rejection, but the pretransplant screening has not been introduced yet. The aim of our study was to assess the incidence and importance of anti‐AT1R antibodies and their influence on renal transplant in the 1st year of observation. We prospectively evaluated the presence of anti‐AT1R antibodies in 117 consecutive renal transplant recipients in pre‐ and post‐transplant screening. Anti‐AT1R antibodies were observed in 27/117 (23%) of the analyzed recipients already before transplantation. The function of renal transplant was considerably worse in anti‐AT1R(+) group. The patients with anti‐AT1R Abs >9 U/ml lost their graft more often. Biopsy‐proven AR was described in 4/27 (15%) pts in the anti‐AT1R(+) group and 13/90 (14.4%) in the anti‐AT1R(−) group, but more severe cases of Banff IIB or antibody‐mediated rejection (AMR) were more often observed in anti‐AT1R (+) 4/27 (15%) vs. 1/90 (1.1%) in anti‐AT1R(+) (P = 0.009). Patients with anti‐AT1R Abs level >9 U/ml run a higher risk of graft failure independently of classical immunological risk factors. The recipients with anti‐AT1R Abs developed more severe acute rejections described as IIB or AMR in Banff classification. More recipients among the anti‐AT1R‐positive ones lost the graft. Our study suggests monitoring of anti‐AT1R Abs before renal transplantation for assessment of immunologic risk profiles and the identification of patients highly susceptible to immunologic events, graft failure, and graft loss.

The Complement Cascade and Renal Disease

Serum complement cascade, a part of innate immunity required for host protection against invading pathogens, is also a mediator of various forms of disease and injury. It is activated by classical, lectin, and alternative pathways that lead to activation of C3 component by C3 convertases, release of C3b opsonin, C5 conversion and eventually membrane attack complex formation. The tightly regulated activation process yields also C3a and C5a anaphylatoxins, which target a broad spectrum of immune and non-immune cells. The review discusses the involvement of the complement cascade in kidney disease pathogenesis and injury. The role of the complement pathways in autoantibody-mediated forms of glomerulonephritis (lupus nephritis, anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic autoantibody-induced or membranoproliferative glomerulonephritis, membranous nephropathy), C3 glomerulopathy, atypical forms of hemolytic uremic syndrome, ischemic-reperfusion injury of transplanted kidney, and antibody-mediated renal allograft rejection are discussed. The disturbances in complement activation and regulation with underlying genetics are presented and related to observed pathology. Also promising strategies targeting the complement system in complement-related disorders are mentioned.

The influence of calcineurin inhibitors on mycophenolic acid pharmacokinetics

Despite the fact that concentrations of mycophenolic acid (MPA) are not routinely measured, accumulating data suggest the usefulness of this monitoring to optimize therapy. The aim of this study was to assess the influence of CsA and tacrolimus on MPA pharmacokinetics. Concentrations of MPA were measured using HPLC. An assay was performed before dose (the C(0)), as well as at 40 minutes and 1, 2, 4, 6, 8, 10, 12 hours after administration of mycophenolate mofetil (MMF). MPA profiles were assessed in 51 patients receiving tacrolimus at a dose of 1.0 g/d and prednisone as well as in 97 patients receiving CsA (2.0 g/d) and prednisone. Significant correlations of MPA levels with serum albumin and GFR were observed in both groups. Women presented with higher levels of MPA than men. C(0) MPA level among the tacrolimus group were significantly higher than those in CsA group: 3.18 +/- 2.21 microg/mL versus 1.68 +/- 1.03 microg/mL (P </=.001). The level of MPA AUC((0-12)) in the tacrolimus group was nonsignificantly higher than that in the CsA group. There was no second peak of MPA level in a group of patients receiving CsA. We developed a limited sampling strategy to estimate MPA AUC((0-12)) in both tacrolimus and CsA groups. We observed a correlation between C(0) MPA and C(0) CsA (r =.35; P </=.001) as well as, between tacrolimus dose and MPA C(40) and MPA C(max) (r =.24; P </=.05; r =.27; P </= 0.05, respectively). No relationship between MPA pharmacokinetics and tacrolimus blood concentrations was noticed. Tacrolimus and CsA both affect the pharmacokinetics of MPA; high MPA concentrations in patients treated with tacrolimus justify MMF dose reduction in this group. Alterations of CsA concentrations must be used to guide MMF dose adjustments.

Tacrolimus-based, steroid-free regimens in renal transplantation: 3-year follow-up of the ATLAS trial.

Background Long-term use of corticosteroids is associated with considerable morbidity, including cardiovascular and metabolic adverse effects. Methods This study evaluated the long-term efficacy and safety of two steroid-free regimens compared with a triple immunosuppressive therapy in renal transplant recipients. This was a 3-year follow-up to a 6-month, open-label, randomized, multicenter study. Results Data from 3 years were available for 421 (93.3%) of 451 patients in the original intent-to-treat population (143 tacrolimus/basiliximab [Tac/Bas], 139 tacrolimus/mycophenolate mofetil [Tac/MMF], and 139 tacrolimus/MMF/steroids [triple therapy]). In the time interval from 6 months to 3 years after transplantation, the incidence of biopsy-proven acute rejection was low and similar (Tac/Bas, 2.1%; Tac/MMF, 2.2%; triple therapy, 2.2%); Most rejection episodes occurred during the first 6 months of the study. Graft survival was high (Kaplan-Meier estimates: 92.7%, 92.5%, and 92.5%), as was patient survival (93.1%, 96.4%, and 97.0%). There were 10 graft losses (n=2, 4, and 4) and 12 patient deaths (n=5, 2, and 5). Renal function was well preserved throughout the study and similar between groups. There was a trend toward improved cardiovascular risk factors in the Tac/Bas group, including reduced total and low-density lipoprotein cholesterol and lower new-onset insulin use. There were no between-group differences in the incidence or type of adverse events. Conclusion Higher rates of acute rejection early in treatment were seen with the steroid-free regimens, but this did not translate into poorer long-term outcomes, such as graft and patient survival and renal function. A trend for a more favorable cardiovascular risk profile was observed for steroid-free immunosuppression with Tac/Bas.