Urinary CXCL9 and CXCL10 Levels and Acute Renal Graft Rejection

BACKGROUND

Monitoring of chemokines, CXCL9 and CXCL10, in serum may present a non-invasive detection method for rejection.

OBJECTIVE

To investigate the relationship between urinary levels of CXCL9 and CXCL10 and graft function following renal transplantation.

METHODS

75 living-related donor renal transplant recipients were studied. Urinary levels of chemokines were collected pre-operatively, on post-operative 1^st day, 7^th day, 1^st month, 3^rd month, and at the time of rejection. Chemokines levels were assayed using and enzyme-linked immunosorbent assay.

RESULTS

Clinical variables were monitored. 10 (15%) patients had biopsy-proven rejection during the follow-up period. The urinary CXCL9 level in those with rejection was significantly higher than that in those with non-rejection group at the 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.002). The urinary CXCL10 level was also significantly higher in those with rejection compared with non-rejection group at 1^st day (p<0.001), 7^th day (p<0.001), and at the time of rejection (p=0.001). Serum creatinine level was strongly correlated with the urinary CXCL9 and CXCL10 levels at the time of rejection (r=0.615, p=0.002; and r=0.519, p=0.022, respectively). Among those with T cell-mediated rejections the mean urinary CXCL10 level increased to as high as 258.12 ng/mL.

CONCLUSION

Urinary CXCL9 and CXCL10 levels might have a predictive value for T cell-mediated rejection in early post-transplantation period. Measurement of urinary CXCL9 and CXCL10 levels could provide an additional tool for the diagnosis of rejection.

Predictive Value of Interleukin 2 and Interleukin 8 on Early Rejection in Living Related Kidney Transplant Recipients

INTRODUCTION

Early diagnosis of rejection in kidney transplant (KTx) recipients is of paramount importance for long-term graft survival. Cytokines play an important role in rejection via activating T cells. Neutrophil accumulation in the graft indicates cell-mediated rejection. Cellular infiltration is mediated through chemoattractant factors. The aim of this study was to investigate the relationship between graft function and serum levels of interleukin 2 (IL-2) and interleukin 8 (IL-8) in KTx.

METHOD

Sixty-five patients undergoing KTx were enrolled in the study. Serum samples of IL-2 and IL-8 were collected the day before the operation, on postoperative days 1 and 7 day, and during the first and third month after the onset of rejection. The enzyme-linked immunosorbent assay method was used to determine the IL-2 and IL-8 values.

RESULTS

A total of 9 (13.8%) patients had rejection documented on biopsy samples. Fifty-six patients had stable graft function (SGF). IL-2 and IL-8 values before KTx of both the rejected and SGF patients were not statistically different. Univariate analysis revealed that IL-2 and IL-8 were correlated with rejection (P = .046, P = .015). IL-8 levels were higher in the rejection group compared to the SGF group on the seventh day and first month postoperatively (P = .023, P = .038). The rejection group maintained higher levels of IL-8 for 11 days (range: 7-30) compared to the SGF group (P = .002) and the IL-8 levels correlated with serum creatinine levels (r = 0.621, P = .001). IL-2 levels were higher in the rejection group on days 1 and 7 compared to the SGF group (P = .042, P = .031). IL-2 and IL-8 levels were correlated with low eGFR in the third month in the rejection group (r = 0.421, P = .037; r = 0.518, P = .008).

CONCLUSION

Determining the cytokine levels in the early post-KTx period may be helpful in tailoring immunosuppressive regimens in patients with a risk of rejection.

Deceased Donor Kidney Transplantation in a Human Immunodeficiency Virus-Infected Recipient: A Case Report

Human immunodeficiency virus (HIV) infection has traditionally been considered an absolute contraindication for transplantation because immunosuppression will accelerate the disease progression and increase mortality. New antiretroviral agents have given rise to new perspectives and transplantation practices. Now renal transplantation is the gold standard treatment for end-stage renal disease in HIV-infected patients, but increased rejection and toxicity rates and compliance with treatment are important issues. Therefore, patient selection and follow-up should be done carefully in this patient group. Here we present a 51-year-old, male, HIV-infected patient who was diagnosed with HIV at his routine serologic investigation at 2015. Highly active antiretroviral therapy was initiated. One haplotype-matched kidney transplantation from a deceased donor was performed on October 19, 2016. Induction therapy was not administered, and the immunosuppressive regimen included tacrolimus, mycophenolate mofetil, and prednisolone. After 26 months, serum creatinine was 1.1 mg/dL and proteinuria 0.1 g/day. There was no development of donor-specific antibodies. The patient's current HIV viral load remains undetectable (and had been the entire time post-transplantation) while his CD4⁺ T-cell count currently is 543/mm³.

Fabry Disease Prevalence in Renal Replacement Therapy in Turkey

BACKGROUND

Fabry disease (FD) is an X-linked lysosomal storage disorder resulting from lack of alpha-galactosidase A (AGALA) activity in lysosomes.

OBJECTIVE

In this multicenter study, we aimed to evaluate the prevalence of FD in renal transplant (Tx) recipients in Turkey. We also screened dialysis patients as a control group.

METHODS

All Tx and dialysis patients were screened regardless of the presence of a primary disease. We measured the AGALA activity in all male patients as initial analysis. Mutation analysis was performed in male patients with decreased AGALA activity and in female patients as the initial diagnostic assay.

RESULTS

We screened 5,657 patients. A total of 17 mutations were identified. No significant difference was observed between the groups regarding the prevalence of patients with mutation. We found FD even in patients with presumed primary kidney diseases. Seventy-one relatives were analyzed and mutation was detected in 43 of them. We detected a patient with a new, unknown mutation (p.Cys223) in the GLA gene.

CONCLUSIONS

There are important implications of the screening. First, detection of the undiagnosed patients leads to starting appropriate therapies for these patients. Second, the transmission of the disease to future generations may be prevented by prenatal screening after appropriate genetic counseling. In conclusion, we suggest screening of kidney Tx candidates for FD, regardless of etiologies of chronic kidney disease.

Influence of uridine diphosphate-glucuronosyltransferases (1A9) polymorphisms on mycophenolic acid pharmacokinetics in patients with renal transplant

Background: There are differences in pharmacokinetic of mycophenolic acid among individuals. The UGT1A9 enzyme is of special interest since it is the main enzyme involved in the glucuronidation of MPA. Single nucleotide polymorphisms in the UGT1A9 gene may be responsible for individual differences in the pharmacokinetics of MPA. The aim of this study was to explain MPA pharmacokinetics in UGT1A9 1399 C > T polymorphisms in Turkish renal transplant patients.

Patients and methods: One hundred and twenty-five living-donor transplant recipients and 100 healthy control subjects underwent UGT1A9 1399 C > T genotyping using polymerase chain reaction–restriction fragment length polymorphism. Concentrations of MPA were determined with Cloned Enzyme Donor Immunoassay (CEDIA). Besides that, all the patients were monitored for acute rejection and graft function during the study period.

Results: The UGT1A9 1399 C > T CC, CT, and TT genotype frequencies among patients were, respectively, 68.0%, 23.2%, and 8.8%. The CC, CT, and TT genotype frequencies among controls were, respectively, 63.0%, 23.0%, and 14.0%. There was no significant difference between patients and controls (p = .480, p = .999, p = .286, respectively). At first month, respectively, through blood concentrations of MPA were significantly higher in UGT1A9 1399 C > T TT carriers than in CT and CC carriers (p = .046). The doses for these patients were lower at first month (p = .021). Acute rejection episodes were not associated with the CC vs CT or TT genotypes (p = .064).

Conclusions: Our results demonstrated a correlation between the UGT1A9 1399 C > T polymorphism and MPA pharmacokinetics among renal transplant patients. Determination of UGT1A9 polymorphism may help to achieve target of MPA blood concentrations.

Acute renal infarction in Turkey: a review of 121 cases

PURPOSE

Renal infarction is a clinical condition which is caused by renal artery occlusion and leads to permanent renal parenchymal damage. In the literature, there are generally case reports on this subject, and few studies that include a large group of patients. Therefore, we aimed to present the data of a large group of patients who were diagnosed with acute renal infarction in our country in this retrospective study.

METHODS

The data of patients who were diagnosed with acute renal infarction according to clinical and radiological findings in Turkey in the last 3 years were examined. For this purpose, we contacted with more than 40 centers in 7 regions and obtained support from clinically responsible persons. Demographic data of patients, laboratory data at the time of diagnosis, tests performed for etiologic evaluation, given medications, and patients' clinical status during follow-up were obtained from databases and statistical analysis was performed.

RESULTS

One-hundred and twenty-one patients were included in the study. The mean age was 53 ± 1.4 (19-91) years. Seventy-one (58.7%) patients were male, 18 (14.9%) had diabetes, 53 (43.8%) had hypertension, 36 (30%) had atrial fibrillation (AF), and 6 had a history of lupus + antiphospholipid syndrome (APS). Forty-five patients had right renal infarction, 50 patients had left renal infarction, and 26 (21.5%) patients had bilateral renal infarction. The examinations for the ethiologies revealed that, 36 patients had thromboemboli due to atrial fibrillation, 10 patients had genetic anomalies leading to thrombosis, 9 patients had trauma, 6 patients had lupus + APS, 2 patients had hematologic diseases, and 1 patient had a substance abuse problem. Fifty-seven (57%) patients had unknown. The mean follow-up period was 14 ± 2 months. The mean creatinine and glomerular filtration rate (GFR) values at 3 months were found to be 1.65 ± 0.16 mg/dl and 62 ± 3 ml/min, respectively. The final mean creatinine and GFR values were found to be 1.69 ± 0.16 mg/dl and 62 ± 3 ml/min, respectively.

CONCLUSIONS

Our study is the second largest series published on renal infarction in the literature. More detailed studies are needed to determine the etiological causes of acute renal infarction occurring in patients.

Extreme hypercalcemia in a kidney transplant recipient

Post-transplant hypercalcemia is a major problem in renal transplant recipients, which may negatively affect both graft and patient survival. In this paper, we present a 66-year-old male kidney transplant recipient, who was admitted to our clinic with symptoms of fever, nausea, vomiting and lethargy. Laboratory data showed good renal function; however, a serum calcium level of 22.1 mg/dL. The patient was treated by isotonic saline together with furosemide and methylprednisolone. Because of treatment resistance, subcutaneous calcitonin and ibandronate were added to the treatment protocol as well. Since all these medications were not effective, hemodialysis with low-calcium (1.25 mmol/L) dialysate was applied for three consecutive days, which resulted in normalization of serum calcium. Several investigations were carried out for diagnosing the underlying etiology. Positron-emission tomography (PET)/CT revealed a strong diffuse uptake of FDG in the bones and spleen. A bone marrow biopsy showed diffuse interstitial infiltration of CD20 + neoplastic B cells and, thus, post transplant lymphoproliferative disease (PTLD) was diagnosed. Tacrolimus was switched to everolimus, mycophenolate mofetil was stopped, while treatment with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) was initiated. Despite all therapeutic interventions, the patient died of septic shock in the intensive care unit on the 10th day of emergency service admission. Importance of hemodialysis as an emergent treatment modality in extreme hypercalcemia, and unfavorable course of PTLD were underlined.

Serum and Urinary Levels of Tumor Necrosis Factor-Alpha in Renal Transplant Patients

OBJECTIVES

Allograft rejection is an important cause of early and long-term graft loss in kidney transplant recipients. Tumor necrosis factor-alpha promotes T-cell activation, the key reaction leading to allograft rejection. Here, we investigated whether serum and urinary tumor necrosis factor-alpha levels can predict allograft rejection.

MATERIALS AND METHODS

This study included 65 living related-donor renal transplant recipients with mean follow-up of 26 ± 9 months. Serum and urinary tumor necrosis factor-alpha levels were measured at pretransplant and at posttransplant time points (days 1 and 7 and months 3 and 6); serum creatinine levels were also monitored during posttransplant follow-up. Standard enzyme-linked immunoabsorbent assay was used to detect tumor necrosis factor-alpha levels. Clinical variables were monitored.

RESULTS

Nine of 65 patients (13.8%) had biopsy-proven rejection during follow-up. Preoperative serum and urinary tumor necrosis factor-alpha levels were not significantly different when we compared patients with and without rejection. Serum tumor necrosis factor-alpha levels (in pg/mL) were significantly higher in the allograft rejection versus nonrejection group at day 7 (11.5 ± 4.7 vs 15.4 ± 5.8; P = .029) and month 1 (11.1 ± 4.8 vs 17.8 ± 10.9; P =.003). Urinary tumor necrosis factor-alpha levels (in pg/mL) were also elevated in the allograft rejection versus the nonrejection group at days 1 (10.2 ± 2.5 vs 14.1 ± 6.8; P = .002) and 7 (9.8 ± 2.2 vs 14.5 ± 2.7; P < .001) and at months 1 (8.0 ± 1.7 vs 11.8 ± 2.4; P < .001), 3 (7.7 ± 1.6 vs 9.6 ± 1.7; P = .002), and 6 (7.4 ± 1.6 vs 8.9 ± 0.9; P = .005).

CONCLUSIONS

Our preliminary findings suggest that tumor necrosis factor-alpha has a role in diagnosing renal transplant rejection. Serum and urinary tumor necrosis factor-alpha levels may be a possible predictor for allograft rejection.

A Novel Biomarker for Post-Transplant Recurrent IgA Nephropathy

BACKGROUND

The serum levels of galactose-deficient immunoglobulin (Ig)A1 (Gd-IgA1) represent the most promising candidate biomarker for IgA nephropathy (IgAN). The aim of this study was to evaluate the serum levels of Gd-IgA1 as a novel noninvasive biomarker for post-transplant IgAN recurrence.

METHODS

Serum Gd-IgA1 levels of 18 patients with recurrent IgAN were compared with control renal transplant recipients (n = 23) with non-recurrent IgAN and control non-transplant IgAN patients (n = 44) and healthy relatives (n = 11). Serum Gd-IgA1 levels of patients were measured with the use of KM55 enzyme-linked immunosorbent assay (ELISA). The effects of serum Gd-IgA1 concentrations on IgAN recurrence, post-transplant events, and graft survival were evaluated.

RESULTS

All recurrent IgAN patients presented with renal dysfunction (mean serum creatinine, 1.62 ± 0.39 mg/dL) and detectable proteinuria at the time of diagnosis. Serum Gd-IgA1 levels of recurrent IgAN patients (8735 ± 10854 ng/mL [log10: 3.71 ± 0.45]) were significantly higher than those of non-recurrent IgAN patients (4790 ± 6089 ng/μL [log10: 3.31 ± 0.64]) (P = .027). Serum Gd-IgA1 levels of non-transplant IgAN patients were significantly higher (8791 ± 8700 ng/μL [log10: 3.79 ± 0.36]) than those of non-recurrent IgAN patients (4790 ± 6089 ng/μL [log10: 3.31 ± 0.64]) and healthy relatives (2615 ± 1611 ng/μL [log10: 3.34 ± 0.27]) (P < .001 and P = .021, respectively). Receiver-operating characteristic curve analysis revealed that the area under the curve for recurrence of IgAN was 0.69 (0.53-0.85) for serum Gd-IgA1 (P = .038). Biopsy-confirmed allograft rejection rates were similar in the recurrent IgAN group [3 (17%)] compared with the non-recurrent IgAN [6 (26%)] group (P = .47). Graft failure rate was not also significantly different in the recurrent IgAN group [4 (22.2%)] compared with the non-recurrent IgAN group [2 (8.7%)] (P = .224).

CONCLUSIONS

This novel lectin-independent Gd-IgA1 ELISA that can detect serum Gd-IgA1 in patients with recurrent IgAN can be used as a biomarker for diagnosis and activity assessment of post-transplant recurrent IgAN.

Association Between HLA Antibodies and Different Sensitization Events in Renal Transplant Candidates

BACKGROUND

Human leukocyte antigen (HLA) allo-immunization is caused by various events such as blood transfusions, pregnancies, or organ transplantations, which can lead to sensitization. In this retrospective study, we evaluated different sensitization models and their effects on panel-reactive antibody (PRA) profiles of renal transplantation candidates.

METHODS

Anti-HLA class I/II antibody screening tests were performed in 906 renal transplantation candidates with the use of a microbead-based assay (Luminex).

RESULTS

Two hundred ninety-seven (32.8%) of the patients were determined as positive in terms of PRA, and 609 (67.2%) were negative. Sensitized and non-sensitized patients were compared separately in terms of each sensitization type. The anti-HLA class I, II, and I+II positivity rates in patients sensitized only by blood transfusion were 13.1%, 6.3%, and 14.1%, the rates with pregnancy sensitization were 35.5%, 29%, and 45.2%, and rates with previous transplantation sensitization were 15.6%, 34.4%, and 38.9%, respectively. Prevalence of PRA positivity was significantly higher in patients with previous pregnancy than with transplantation and transfusion (odds ratio, 1.003; 95% confidence interval, 0.441-2.281; P = .031). The risk of developing HLA class I antibodies was higher in pregnancies (P < .001), and the risk of developing anti-HLA class II antibodies was higher in patients who had undergone a previous transplantation (P < .001). The rate of developing HLA-B antibodies in patients sensitized by pregnancy were significantly higher compared with sensitization after transfusion (P = .015), as was the rate of developing HLA-DQ antibodies in patients sensitized by previous transplantation compared with sensitization through pregnancy (P = .042).

CONCLUSIONS

In patients who are waiting for kidney transplantation, sensitization by pregnancy and transplantation have a significant impact on development of HLA class I and class II antibodies.

Evaluation of TH17 and TH1 Immune Response Profile in Patients After Renal Transplant

BACKGROUND

Renal transplantation (RT) is the best treatment option for patients with end-stage renal disease (ESRD) because it improves both quality of life and survival. However, allograft rejection remains the most important barrier to successful transplantation. Underlying immunologic mechanisms should be understood to develop appropriate treatment strategies.

METHODS

In this prospective study, we followed renal transplant recipients for 6 months. The study population comprised 50 recipients of renal transplants, and these were divided into 2 groups: 44 patients with stable graft function (SGF) and 6 patients with rejection (RX). Peripheral blood samples were drawn from patients on the pre-RT day, at post-RT day 7, month 1, and month 6, and on the day of rejection for analysis of the percentages of cytokines interleukin (IL) 17 and interferon (IFN) γ with the use of flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

The percentages of intracellular IFN-γ were not significant in the group with RX compared with SGF. Levels of intracellular IL-17 obtained at the 6th month after RT were significantly higher in the RX group than in the SGF group. Plasma levels of pre-RT IL-17 were also higher in the RX group; therefore, it may be a predictive biomarker of acute rejection of renal transplants.

CONCLUSIONS

The present study provides information about pre-RT and post-RT cytokine profiles of Turkish patients with ESRD. We consider cytokine analysis to be a valuable biomarker panel in the prevention of rejection and in assisting with new treatment strategies for patients undergoing renal transplant.

Influence of Proton Pump Inhibitors on Mycophenolic Acid Pharmacokinetics in Patients With Renal Transplantation and the Relationship With Cytochrome 2C19 Gene Polymorphism

BACKGROUND

Most patients have serious digestive complications after renal transplantation. Therefore, it is important to protect gastrointestinal function to improve the survival rate of transplant patients. Proton pump inhibitors (PPIs) such as lansoprazole and rabeprazole are widely administered to renal transplant patients with mycophenolic acid (MPA) in the perioperative period. PPIs are metabolized by cytochrome (CYP) 2C19 enzymes. Mycophenolate sodium (MYF) and mycophenolate mofetil (MMF) have been used in immunosuppression. Clinically relevant drug-drug interactions have been described between immunosuppressive drugs. In the present study, we investigated the drug interaction between MPA and lansoparazole or rabeprazole and the impact of CYP2C19 polymorphisms on these drug interactions after renal transplantation.

MATERIALS AND METHODS

A total of 125 renal transplant patients taking MPA derivatives between 2012 and 2016 were included in this study. The 125 patients were divided into 6 groups: MMF/tacrolimus/steroid together with lansoprazole or rabeprazole; MYF/tacrolimus/steroid together with lansoprazole or rabeprazole and without PPI. The single nucleotide polymorphisms of CYP2C19 were determined by the polymerase chain reaction-restriction fragment length polymorphism. Plasma concentrations of MPA were measured by cloned enzyme donor immunoassay. Clinical parameters such as incidence of delayed graft function and acute rejection, the rate of change of serum creatinine, toxicity, and gastrointestinal adverse effects were analyzed retrospectively.

RESULTS

The mean concentrations of MPA in the MYF group were higher than those in the MMF group. The mean dose-adjusted blood concentration of MPA coadministered with lansoprazole was lower than that of MPA with rabeprazole or without PPI in MMF and MYF groups (P < .05). In patients with the CYP2C19*2/*2 genotype, the mean concentrations of MMF with lansoprazole were significantly lower than those with rabeprazole with MMF or without PPI (P < .05). Gastrointestinal side effects were significantly higher in MMF with lansoprazole group than in MYF with lansoprazole group (P < .05). However, no differences were found according to genotype distribution in all groups (P > .05).

CONCLUSION

Polymorphisms in CYP2C19 are related to the metabolic oxidation of drugs to varying degrees. Both genetic and clinical factors in pharmacokinetics may help to make further progress toward individualized therapy to yield maximum efficacy with minimal side effects.