T-cell activation follows Th1 rather than Th2 pattern in haemodialysis patients

Comparison of Humoral Response between Third and Fourth Doses of COVID-19 Vaccine in Hemodialysis Patients

Dialysis patients are more likely to die or become hospitalized from coronavirus disease 2019 (COVID-19). Currently, only a few studies have evaluated the efficacy of a fourth booster vaccination in hemodialysis (HD) patients and there is not enough evidence to recommend for or against a fourth booster vaccination. This study compared the humoral response and disease severity of patients on HD who received either three or four doses of COVID-19 vaccine. A total of 88 patients were enrolled. Humoral response to vaccination was measured by quantifying immunoglobulin G levels against the receptor binding domain of SARS-CoV-2 (anti-RBD IgG) at five different times and plaque reduction neutralization tests (PRNT) at two different times after vaccination over a period of 18 months. Antibody levels were measured at approximately two-month intervals after the first and second dose, then four months after the third dose, and then one to six months after the fourth dose of vaccine. PRNT was performed two months after the second and four months after the third dose of vaccine. We classified patients into four groups according to the number of vaccine doses and presence of COVID-19 infection. Severe infection was defined as hospital admission for greater than or equal to two weeks or death. There was no difference in antibody levels between naïve and infected patients except after a fourth vaccination, which was effective for increasing antibodies in infection-naïve patients. Age, sex, body mass index (BMI), dialysis vintage, and presence of diabetes mellitus (DM) did not show a significant correlation with antibody levels. Four patients who experienced severe COVID-19 disease tended to have lower antibody levels prior to infection. A fourth dose of SARS-CoV-2 vaccine significantly elevated antibodies in infection-naïve HD patients and may be beneficial for HD patients who have not been previously infected with SARS-CoV-2 for protection against severe infection.

Two cases of nivolumab plus ipilimumab therapy for dialysis patients with advanced bone metastasis from renal cell carcinoma

Nivolumab and ipilimumab are immune checkpoint inhibitors. Combination therapy with these two drugs has been shown to improve the outcome of advanced renal cell carcinoma. However, data about the safety and the efficacy of combination therapy with these two drugs in hemodialysis patients are small. A 59-year-old male hemodialysis patient presented with bone metastasis from renal cell carcinoma, which was located at the right femur. He received nivolumab plus ipilimumab therapy. At 7 months after treatment, he was diagnosed with diabetes as an immune-related adverse event. He was managed with insulin therapy. At 11 months after treatment, CT revealed cytoreduction of metastasis. A 74-year-old male hemodialysis patient presented with bone metastasis of renal cell carcinoma located at the sacrum and left scapula. He received nivolumab plus ipilimumab therapy. At 6 months after treatment, CT showed no progression of metastasis. Nivolumab and ipilimumab therapy might be a viable treatment for hemodialysis patients with bone metastasis from renal cell carcinoma. However, close attention should be paid immune-related adverse events in such patients.

Serum Levels of α-Klotho, Inflammation-Related Cytokines, and Mortality in Hemodialysis Patients

It has been hypothesized that α-Klotho deficiency might contribute to chronic inflammation in patients with end-stage renal disease (ESRD), especially those on hemodialysis (HD). Serum Klotho levels by some authors are considered a potential predictor of cerebrovascular events. Therefore, we analyzed serum levels of α-Klotho with ELISA and inflammation-related cytokines in HD patients. Sixty-seven HD patients and 19 healthy people were recruited between November 2017 and June 2021. A Cytometric Bead Array (CBA) was used to determine the level of different cytokines: IL-12p70, TNF, IL-10, IL-6, IL-1β, and IL-8. A human Klotho ELISA kit was used to determine the level of α-Klotho in the plasma samples of HD patients. There was no difference in serum levels of α-Klotho between HD patients and healthy people. Patients had increased serum IL-6 and IL-8. Significant positive correlations existed between the concentration of α-Klotho and the serum concentrations of IL-12p70, IL-10, and IL-1β. However, in a multivariable linear regression analysis, only patients' age was associated independently with α-Klotho level. Serum α-Klotho was not associated with higher mortality risk in HD patients. While these results draw attention to potential relationships between α-Klotho proteins and inflammatory markers in HD patients, our cross-sectional study could not confirm the pathogenic link between α-Klotho, inflammation, and cardiovascular mortality.

Soluble uric acid inhibits β2 integrin-mediated neutrophil recruitment in innate immunity

Neutrophils are key players during host defense and sterile inflammation. Neutrophil dysfunction is a characteristic feature of the acquired immunodeficiency during kidney disease. We speculated that the impaired renal clearance of the intrinsic purine metabolite soluble uric acid (sUA) may account for neutrophil dysfunction. Indeed, hyperuricemia (HU, serum UA of 9-12 mg/dL) related or unrelated to kidney dysfunction significantly diminished neutrophil adhesion and extravasation in mice with crystal- and coronavirus-related sterile inflammation using intravital microscopy and an air pouch model. This impaired neutrophil recruitment was partially reversible by depleting UA with rasburicase. We validated these findings in vitro using either neutrophils or serum from patients with kidney dysfunction-related HU with or without UA depletion, which partially normalized the defective migration of neutrophils. Mechanistically, sUA impaired β2 integrin activity and internalization/recycling by regulating intracellular pH and cytoskeletal dynamics, physiological processes that are known to alter the migratory and phagocytic capability of neutrophils. This effect was fully reversible by blocking intracellular uptake of sUA via urate transporters. In contrast, sUA had no effect on neutrophil extracellular trap formation in neutrophils from healthy subjects or patients with kidney dysfunction. Our results identify an unexpected immunoregulatory role of the intrinsic purine metabolite sUA, which contrasts the well-known immunostimulatory effects of crystalline UA. Specifically targeting UA may help to overcome certain forms of immunodeficiency, for example in kidney dysfunction, but may enhance sterile forms of inflammation.

Secondary Immunodeficiency Related to Kidney Disease (SIDKD)-Definition, Unmet Need, and Mechanisms

Kidney disease is a known risk factor for poor outcomes of COVID-19 and many other serious infections. Conversely, infection is the second most common cause of death in patients with kidney disease. However, little is known about the underlying secondary immunodeficiency related to kidney disease (SIDKD). In contrast to cardiovascular disease related to kidney disease, which has triggered countless epidemiologic, clinical, and experimental research activities or interventional trials, investments in tracing, understanding, and therapeutically targeting SIDKD have been sparse. As a call for more awareness of SIDKD as an imminent unmet medical need that requires rigorous research activities at all levels, we review the epidemiology of SIDKD and the numerous aspects of the abnormal immunophenotype of patients with kidney disease. We propose a definition of SIDKD and discuss the pathogenic mechanisms of SIDKD known thus far, including more recent insights into the unexpected immunoregulatory roles of elevated levels of FGF23 and hyperuricemia and shifts in the secretome of the intestinal microbiota in kidney disease. As an ultimate goal, we should aim to develop therapeutics that can reduce mortality due to infections in patients with kidney disease by normalizing host defense to pathogens and immune responses to vaccines.

T cell subpopulations and cytokine levels in hemodialysis patients

HD patients have impaired adaptive immune responses, which might depend on the primary cause of chronic kidney disease (CKD). We analyzed percentages of T cells subpopulations with the expression of CD69, CD25, CD95, and HLA-DR antigens in HD patients to determine the status of T cell activation. Also, we determined serum levels of cytokines: IL12p70, TNF, IL-10, IL-6, IL-1β, IL-8. HD patients had increased percentages of CD4⁺CD25⁺, CD4⁺CD69⁺, CD4⁺HLA-DR⁺, CD8⁺CD69⁺, and CD8⁺HLA-DR⁺ cells compared to healthy people. Also, their IL-6 and IL-8 serum levels were higher. Changes in T cell subpopulations were seen in patients with diabetic nephropathy (DN) or ischemic nephropathy (IN) but not with glomerulonephritis (GN). HD patients dialyzed for more than six months had a lower percentage of CD4⁺CD69⁺, CD8⁺HLA-DR⁺, CD8⁺CD95⁺ cells, higher IL-12p70 levels, and lower IL-8 levels. Our results show that HD treatment and CKD cause influence T cell activation status.

End-stage kidney disease and COVID-19 in an urban safety-net hospital in Boston, Massachusetts

Introduction

End-stage kidney disease (ESKD) patients are at a high risk for Coronavirus Disease 2019 (COVID-19). In this study, we compared characteristics and outcomes of ESKD and non-ESKD patients admitted with COVID-19 to a large safety-net hospital.

Methods

We evaluated 759 adults (45 with ESKD) hospitalized with COVID-19 in Spring of 2020. We examined clinical characteristics, laboratory measures and clinical outcomes. Logistic regression analyses were performed to investigate the associations between ESKD status and outcomes.

Results

73% of ESKD and 47% of non-ESKD patients identified as Black (p = 0.002). ESKD patients were older and had higher rates of comorbidities. Admission ferritin was approximately 6-fold higher in ESKD patients. During hospitalization, the rise in white blood cell count, lactate dehydrogenase, ferritin and C-reactive protein, and the decrease in platelet count and serum albumin were all significantly greater in ESKD patients. The in-hospital mortality was higher for ESKD [18% vs. 10%; multivariable adjusted odds ratio 1.5 (95% CI, 0.48–4.70)], but this did not reach statistical significance.

Conclusions

Among hospitalized COVID-19 patients, ESKD patients had more co-morbidities and more robust inflammatory response than non-ESKD patients. The odds ratio point estimate for death was higher in ESKD patients, but the difference did not reach statistical significance.

Clinical features, management, and outcome of hemodialysis patients with SARS-CoV-2

The aim of the study was to evaluate the clinical features of the patients on HD with COVID‐19 and determine the prognostic factors. In this single‐center prospective study, a total of 58 chronic renal failure patients on HD and diagnosed COVID‐19 infection were enrolled in the study. The patients were divided into two groups according to their need for intensive care unit referral. Demographic features of the patients, clinical manifestations, laboratory data, treatments, and clinical outcome were evaluated. The mean age of 58 HD patients was 63.2 ± 13.8 (30–93) years and female–male ratio was 0.34. SARS‐CoV2‐PCR positivity rate was 32.8%. 85.2% of patients (n = 46) had bilateral lesions and 14.8% (n = 8) had unilateral one lesion in chest CT. The most common symptoms were fatigue (in 44 patients, 80%) and dyspnea (in 31 patients, 56.4%). The most common comorbidity was HT (in 37 patients, 67.3%). The patients who need intensive care and died were older (p = 0.015). We observed lower platelet and eosinophil counts, potassium levels, higher AST, troponin and CRP levels in the group of patients who need intensive care and died than the group who survived (p = 0.043, 0.005, 0.033, 0.007, 0.001, <0.001, respectively). 15.5% of the patients (n = 9) were transferred to intensive care unit. Among them, two were discharged with cure and seven patients died. Mortality rate was 12.1%. Older age, lower platelet and eosinophil counts and higher AST, troponin and CRP levels were prognostic risk factors in our HD patients who needed intensive care.

Risk factors for losing hepatitis B virus surface antibody in patients with HBV surface antigen negative/surface antibody positive serostatus receiving biologic disease-modifying anti-rheumatic drugs: a nested case-control study

BACKGROUND

Hepatitis B virus (HBV) reactivation consequent to immunosuppressive therapy is an increasingly prevalent problem with serious clinical implications. Treatment with biologic agents conduces to the loss of protective antibody to HBV surface antigen (anti-HBs), which significantly increases the risk of HBV reactivation. Hence, we investigated the risk factors for losing anti-HBs in patients with rheumatic diseases and HBV surface antigen negative/anti-HBs positive (HBsAg-/anti-HBs+) serostatus during treatment with biologic disease-modifying anti-rheumatic drugs (DMARDs).

METHODS

Using a nested case-control design, we prospectively enrolled patients with rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis/psoriasis, or juvenile idiopathic arthritis, who were treated with biologic DMARDs at Changhua Christian Hospital, Taiwan, from January 2013 to June 2019 and had HBsAg-/anti-HBs+ serostatus; the analytic sample excluded all patients with HBsAg+ or anti-HBs- serostatus. Anti-HBs titers were monitored 6-monthly and cases were defined as anti-HBs < 10 mIU/ml during follow-up. Cases were matched one-to-all with controls with anti-HBs ≥ 10 mIU/ml on the same ascertainment date and equivalent durations of biologic DMARDs treatment (control patients could be resampled and could also become cases during follow-up). Between-group characteristics were compared and risk factors for anti-HBs loss were investigated by conditional logistic regression analyses.

RESULTS

Among 294 eligible patients, 23 cases were matched with 311 controls. The incidence of anti-HBs loss was ~ 2.7%/person-year during biologic DMARDs treatment. Besides lower baseline anti-HBs titer (risk ratio 0.93, 95% CI 0.89-0.97), cases were significantly more likely than controls to have diabetes mellitus (risk ratio 4.76, 95% CI 1.48-15.30) and chronic kidney disease (risk ratio 14.00, 95% CI 2.22-88.23) in univariate analysis. Risk factors remaining significantly associated with anti-HBs loss in multivariate analysis were lower baseline anti-HBs titer (adjusted risk ratio 0.93, 95% CI 0.88-0.97) and chronic kidney disease (adjusted risk ratio 45.68, 95% CI 2.39-871.5).

CONCLUSIONS

Besides lower baseline anti-HBs titer, chronic kidney disease also strongly predicts future anti-HBs negativity in patients with HBsAg-/anti-HBs+ serostatus who receive biologic DMARDs to treat rheumatic diseases. Patients with low anti-HBs titer (≤ 100 mIU/ml) and/or chronic kidney disease should be monitored during biologic DMARDs therapy, to enable timely prophylaxis to preempt potential HBV reactivation.

Microbiome, Immunosenescence, and Chronic Kidney Disease

The gut microbiome is known as an important predictive tool for perceiving characteristic shifts in disease states. Multiple renal diseases and pathologies seem to be associated with gut dysbiosis which directly affects host homeostasis. The gastrointestinal-kidney dialogue confers interesting information about the pathogenesis of multiple kidney diseases. Moreover, aging is followed by specific shifts in the human microbiome, and gradual elimination of physiological functions predisposes the microbiome to inflammaging, sarcopenia, and disease. Aging is characterized by a microbiota with an abundance of disease-associated pathobionts. Multiple factors such as the immune system, environment, medication, diet, and genetic endowment are involved in determining the age of the microbiome in health and disease. Our present review promotes recently acquired knowledge and is expected to inspire researchers to advance studies and investigations on the involved pathways of the gut microbiota and kidney axis.

Lipid microsphere-coated PGE1 improves peritoneal transport and reduces inflammation in peritoneal dialysis: A randomized clinical pilot trial

OBJECTIVE

To evaluate the effects of lipid microspheres coated with prostaglandin E1 (lipo-PGE1) on peritoneal transport function and inflammation in patients with end-stage renal disease undergoing continuous ambulatory peritoneal dialysis (CAPD).

METHODS

In total, 89 patients were randomly allocated to the lipo-PGE1 and control groups. All the patients received conventional treatment, and those in the lipo-PGE1 group received lipo-PGE1 intravenously for 2 weeks. The levels of β2-microglobulin (β2-MG), cystatin C, albumin, urea, creatinine, interleukin-6 (IL-6), matrix metalloproteinase-2 (MMP-2), and high-sensitivity C-reactive protein (hs-CRP) were measured before and at 1 and 2 weeks after treatment.

RESULTS

In the lipo-PGE1 group, the peritoneal clearance rates of β2-MG, cystatin C, and albumin were significantly increased comparing with pre-treatment values, and the IL-6 appearance rate (AR) in the peritoneal dialysate and the serum levels of IL-6 and hs-CRP were markedly decreased (p < 0.05). The lipo-PGE1 group had significantly higher peritoneal clearance rates of β2-MG and cystatin C and lower IL-6 AR in the peritoneal dialysate than the control group (p < 0.05).

CONCLUSIONS

Lipid microspheres coated with prostaglandin E1 may increase the peritoneal clearance of moderately sized molecules and macromolecules with insignificant effect on the clearance of small molecules. The reduction in IL-6 level following treatment with lipo-PGE1 may alleviate inflammation.

Protein-Bound Uremic Toxins and Immunity

Protein-bound uremic toxins (PBUTs) are bioactive microbiota metabolites originated exclusively from protein fermentation of the bacterial community resident within the gut microbiota, whose composition and function is profoundly different in the chronic kidney disease (CKD) population. PBUTs accumulate in the later stages of CKD because they cannot be efficiently removed by conventional hemodialysis due to their high binding affinity for albumin, worsening their toxic effects, especially at the cardiovascular level. The accumulation of uremic toxins, along with oxidative stress products and pro-inflammatory cytokines, characterizes the uremic status of CKD patients which is increasingly associated to a state of immune dysfunction including both immune activation and immunodepression. Furthermore, the links between immune activation and cardiovascular disease (CVD), and between immunodepression and infection diseases, which are the two major complications of CKD, are becoming more and more evident. This review summarizes and discusses the current state of knowledge on the role of the main PBUTs, namely indoxyl sulfate and p-cresyl sulfate, as regulators of immune response in CKD, in order to understand whether a microbiota modulation may be useful in the management of its main complications, CVD, and infections. Summarizing the direct effects of PBUT on immune system we may conclude that PCS seemed to be associated to an immune deficiency status of CKD mainly related to the adaptative immune response, while IS seemed to reflect the activation of both innate and adaptative immune systems likely responsible of the CKD-associated inflammation. However, the exact role of IS and PCS on immunity modulation in physiological and pathological state still needs in-depth investigation, particularly in vivo studies.

Oncogenic mechanisms in renal insufficiency

The prevalence of both cancer and end-stage renal disease is increasing. In addition, medical advances have meant increased survival rates for both diseases. Many chemotherapeutics are renally excreted, and conversely, renal insufficiency promotes a pro-neoplastic state, including genitourinary and other cancers. Dialysis prolongs life while increasing cancer risk. Proposed oncogenic mechanisms include immune dysfunction, chronic inflammation, changes in gut microbiota and stimulation of the renin-angiotensin system. This review summarizes current concepts in the relationship between cancer and renal insufficiency.

Immune response to influenza vaccination in ESRD patients undergoing hemodialysis vs. hemodiafiltration

BACKGROUND

On-line hemodiafiltration (HDF) clears more azotemic toxins compared to high-flux hemodialysis (HD). The response to vaccination is impaired in dialysis patients. We wished to determine whether the immune responses to influenza vaccine in dialysis patients treated by HDF were stronger than those treated by HD.

MATERIALS AND METHODS

We conducted a prospective cohort study in chronic dialysis patients during the 2016 and 2017 influenza seasons. All participants received a single standard dose of trivalent influenza vaccine, and we studied the elicited humoral immune response by hemagglutination inhibition test, and cell-mediated immune response by enumeration of lymphocyte cellular markers and proliferation assays.

RESULTS

We immunized 60 end-stage renal disease (ESRD) patients: 42 (70%) treated with HD and 18 patients (30%) with HDF. The median (interquartile range) age was 65.0 (55.0-74.5) years. All patients developed seroprotection to at least one influenza vaccine strain at one month post-vaccination, and did not differ between groups. By logistic regression, age was the only factor independently associated with seroconversion to all vaccine strains (odds ratio 0.89, 95% confidence interval 0.80-0.98; p = 0.022). Seroprotection to all vaccine strains was sustained for longer in patients treated with HDF, and the results remained the same after age adjustment. For cellular immune response, patients who seroconverted to all vaccine strains had higher CD38+ T cell subpopulations pre-vaccination. Patients treated by HDF had higher lymphocyte proliferation to circulating influenza A strains.

CONCLUSIONS

Seroconversion to all influenza vaccine strains was associated with age. Patients treated with HDF demonstrated seroprotection was sustained for longer compared to those treated by HD and greater lymphocyte proliferation to circulating influenza A strains. These encouraging results for HDF require confirmation in a larger dialysis population.

TRIAL REGISTRATION

ClinicalTrial.gov, NCT04122222.

Assessment of variation in B-cell receptor heavy chain repertoire in patients with end-stage renal disease by high-throughput sequencing

Background/Aims: End-stage renal disease (ESRD), characterized by progressive loss of rental function during the disease course, has been reported to be correlated with immune dysregulation. To date, a majority of previous studies on immune response to ESRD have been focused on the T-cell response. This prospective study was to assess the B-cell receptor (BCR) heavy chain repertoire in ESRD patients.Materials and methods: A total of 10 ESRD patients and six healthy controls were prospectively enrolled in this study. BCR immunoglobulin heavy chain (IGH) repertoire in the peripheral blood from ESRD patients and healthy individuals were analyzed by means of next generation sequencing (NGS) in combination with multiplex PCR, Illumina sequencing, and the international ImMunoGeneTics database (IMGT).Results: Abnormal BCR complementary-determining region 3 (CDR3) sequences were identified in relation to ESRD. We also found that the degree of the B-cell clonal expansion in the ESRD group was significantly greater than that in the control group (p < .05), whereas the distributions of BCR CDR3, V, D, J, and V-J gene segments were comparable between the ESRD and control groups. T-test for analysis of the distribution ratio of the V, D, J, and V-J genes revealed five up-regulated genes and nine down-regulated genes associated with ESRD, and there were significant differences between the ESRD and control groups (p < .05).Conclusions: We have provided a successful approach to analyzing peripheral B-cell repertoire in ESRD patients, and the results suggest a direct correlation between the BCR repertoire and ESRD. The ESRD-specific BCR CDR3 sequences may hold promise for potentially therapeutic benefit.

Infectious Disease Risk in Dialysis Patients: A Transdisciplinary Approach

Purpose of review:

Infections are a major contributor to morbidity and mortality in end-stage renal disease (ESRD) patients. A better understanding of the interplay between infectious processes and ESRD may eventually lead to the development of targeted treatment strategies aimed at lowering overall disease morbidity and mortality. Monogenic causes are a major contributor to the development of adult chronic kidney disease (CKD). Recent studies identified a genetic cause in 10% to 20% of adults with CKD. With the introduction of whole-exome sequencing (WES) into clinical mainstay, this proportion is expected to increase in the future. Once patients develop CKD/ESRD due to a genetic cause, secondary changes, such as a compromised immune status, affect overall disease progression and clinical outcomes. Stratification according to genotype may enable us to study its effects on secondary disease outcomes, such as infectious risk. Moreover, this knowledge will enable us to better understand the molecular interplay between primary disease and secondary disease outcomes.

Sources of information:

We conducted a literature review using search engines such as PubMed, PubMed central, and Medline, as well as cumulative knowledge from our respective areas of expertise.

Methods:

This is a transdisciplinary perspective on infectious complications in ESRD due to monogenic causes, such as autosomal dominant polycystic kidney disease (ADPKD), combining expertise in genomics and immunology.

Key findings:

In ADPKD, infection is a frequent complication manifesting primarily as lower urinary tract infection and less frequently as renal infection. Infectious episodes may be a direct consequence of a specific underlying structural abnormality, for example the characteristic cysts, among others. However, evidence suggests that infectious disease risk is also increased in ESRD due to secondary not-well-understood disease mechanisms. These disease mechanisms may vary depending on the underlying nature of the primary disease. While the infectious disease risk is well documented in ADPKD, there are currently insufficient data on the risk in other monogenic causes of ESRD. WES in combination with novel technologies, such as RNA sequencing and single-cell RNA sequencing, can provide insight into the molecular mechanisms of disease progression in different monogenic causes of CKD/ESRD and may lead to the development of novel risk-stratification profiles in the future.

Limitations:

This is not a systematic review of the literature and the proposed perspective is tainted by the authors’ point of view on the topic.

Implications:

WES in combination with novel technologies such as RNA sequencing may enable us to fully unravel underlying disease mechanisms and secondary disease outcomes in monogenic causes of CKD and better characterize individual risk profiles. This understanding will hopefully facilitate the development of novel targeted therapies.

Patients with immunological diseases or on peritoneal dialysis are prone to false positive flow cytometry crossmatch

Despite implementation of virtual crossmatches, flow cytometry crossmatches (FCXM) are still used by many transplant centers to determine immunological risk before kidney transplantation. To determine if common profiles of patients prone to false positive FCXM exist, we examined the demographics and native diseases of kidney patients tested with autologous FCXM (n = 480). Improvements to FCXM and cell isolation methods significantly reduced the positive rate from 15.1% to 5.3%. Patients with native diseases considered 'immunological' (vasculitis, lupus, IgA nephropathy) had more positive autologous FCXM (OR = 3.36, p = 0.003) vs. patients with all other diseases. Patients who were tested using our updated method (n = 321) still showed that these immunological diseases were a significant predictor for positive autologous FCXM (OR = 4.79, p = 0.006). Interestingly, patients on peritoneal dialysis (PD) also had significantly more positive autologous FCXM than patients on hemodialysis or waiting for pre-emptive kidney transplants (OR = 3.27, p = 0.02). These findings were confirmed in patients who had false positive allogeneic FCXM. Twenty of 24 (83.3%) patients with false positive allogeneic FCXM tested with updated method either had immunological diseases originally or were on PD. Our findings are helpful when interpreting an unexpected positive FCXM, especially for transplantation from deceased donors.

The influence of a single hemodialysis procedure on human T lymphocytes

At the moment it is unknown to what extent the impaired function of T lymphocytes in ESRD patients depends on uremia, and to what extent on hemodialysis (HD) procedure. Therefore, the purpose of the study was to evaluate percentages of T lymphocyte subpopulations ex vivo, plasma concentrations of IL12p70, TNF, IL-10, IL-6, IL-1β, IL-8 cytokines and selected proliferation parameters of in vitro activated T lymphocytes in HD patients before and after single HD procedure using flow cytometry. We demonstrated that the percentage of CD8⁺ cells ex vivo was decreased while the CD4⁺/CD8⁺ ratio was increased after HD procedure. Also, there was significant decrease in the percentage of CD8⁺HLA-DR⁺, CD8⁺CD69⁺ and CD8⁺CD95⁺ cells after HD. At the same time, an increase in the percentage of CD4⁺CD95⁺ cells was observed after HD. From all analyzed cytokines, only the concentration of IL-8 was significantly decreased after HD procedure. A single HD session enhanced proliferation capacity of CD4⁺ cells but not CD8⁺ cells in vitro by increasing number of cell divisions and percentage of dividing cells. Our results show that a single hemodialysis can have immunomodulatory effect on HD patients and may contribute to the state of immune deficiency observed in patients with ESRD.

Immune Responses of HLA Highly Sensitized and Nonsensitized Patients to Genetically Engineered Pig Cells

BACKGROUND

We investigated in vitro whether HLA highly sensitized patients with end-stage renal disease will be disadvantaged immunologically after a genetically engineered pig kidney transplant.

METHODS

Blood was drawn from patients with a calculated panel-reactive antibody (cPRA) 99% to 100% (Gp1, n = 10) or cPRA 0% (Gp2, n = 12), and from healthy volunteers (Gp3, n = 10). Serum IgM and IgG binding was measured (i) to galactose-α1-3 galactose and N-glycolylneuraminic acid glycans by enzyme-linked immunosorbent assay, and (ii) to pig red blood cell, pig aortic endothelial cells, and pig peripheral blood mononuclear cell from α1,3-galactosyltransferase gene-knockout (GTKO)/CD46 and GTKO/CD46/cytidine monophosphate-N-acetylneuraminic acid hydroxylase-knockout (CMAHKO) pigs by flow cytometry. (iii) T-cell and B-cell phenotypes were determined by flow cytometry, and (iv) proliferation of T-cell and B-cell carboxyfluorescein diacetate succinimidyl ester-mixed lymphocyte reaction.

RESULTS

(i) By enzyme-linked immunosorbent assay, there was no difference in IgM or IgG binding to galactose-α1-3 galactose or N-glycolylneuraminic acid between Gps1 and 2, but binding was significantly reduced in both groups compared to Gp3. (ii) IgM and IgG binding in Gps1 and 2 was also significantly lower to GTKO/CD46 pig cells than in healthy controls, but there were no differences between the 3 groups in binding to GTKO/CD46/CMAHKO cells. (iii and iv) Gp1 patients had more memory T cells than Gp2, but there was no difference in T or B cell proliferation when stimulated by any pig cells. The proliferative responses in all 3 groups were weakest when stimulated by GTKO/CD46/CMAHKO pig peripheral blood mononuclear cell.

CONCLUSIONS

(i) End-stage renal disease was associated with low antipig antibody levels. (ii) Xenoreactivity decreased with increased genetic engineering of pig cells. (iii) High cPRA status had no significant effect on antibody binding or T-cell and B-cell response.

Plasma levels of Th1/Th2 Type Cytokine are Associated with Change of Prolactin and GH/IGF-I in Hemodialysis Patients

Patients undergoing chronic hemodialysis (HD) have an impaired immune system involving both B and T cell-mediated immune responses. Since T helper type 1 (Th1) and type 2 (Th2) cytokines are implicated in regulating the immune responses, while the pituitary hormones, prolactin (PRL) and growth hormone (GH) are known to be involved in the regulation of the immune response, all of them may, therefore, be involved in impaired status. The aims of the present study were to estimate the serum concentrations of Th1-Th2 cytokine, GH, insulin-like growth factor-I (IGF-I) and PRL, and to determine whether there are any correlations between the release of T-cell cytokines and disturbance of hormones in a group of patients on maintenance hemodialysis (MHD). The study included 35 HD patients (23 males and 12 females, mean age 56.8±12.8 years) and a control group of 20 age-matched healthy subjects. Baseline serum concentrations of GH/IGF-I, PRL, IL-2, sIL-2R, IFN-γ, IL-4 and IL-10 were measured in all patients and control subjects. Our results demonstrate that the fasting serum concentration of IGF-I, PRL, sIL-2R and Th1-type cytokine, including IL-2 and IFN-γ, were significantly higher in HD patients compared to the healthy subjects. GH and Th2-type cytokine including IL-4 and IL-10 levels were slightly reduced, but no significant differences were observed between HD patients and the control group. In the group of HD patients, PRL correlated directly with IFN-γ and correlated inversely with IL-10; IFN-γ correlated inversely with IL-4; and GH also correlated inversely with IGF-I and IL-4. However, IGF-I correlated directly with IL-2 and IL-10. These data suggest that the Th1/Th2 imbalance in HD patients with an increase of Th1 type cytokines, associated with the altered GH/IGF-I axis and prolactin and immuno-endocrine dysfunction, probably plays a role in an impaired immune system in HD patients.

Comparison of QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for diagnosis of latent tuberculosis in haemodialysis (HD) patients: a meta-analysis of κ estimates

Diagnosis of latent tuberculosis infection (LTBI) is a concern in haemodialysis (HD) patients. Many studies have compared QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for detecting LTBI and reported the κ statistic of agreement between QFT-GIT and TST in HD patients. The present study aimed to systematically review this literature and conduct meta-analysis of individual studies that estimated the κ between QFT-GIT with TST among HD patients. All relevant published studies that were available as full-text were obtained by searching Medline (1950), Web of Sciences (1945), Scopus (1973) through May 2016. The κ was re-estimated from the individual studies and pooled using random effect meta-analysis. Subgroup analysis and meta-regression were applied to evaluate the effect of Bacillus Calmette-Guérin (BCG) vaccination, TST cut-off points, quality of studies, sample size and age on variation of κ estimate. Eight studies involving 901 HD patients were included in meta-analysis. The pooled κ estimate was 0·28 (I 2 = 18·4%, P = 0·239, 95% confidence intervals 0·22-0·34). The discordance of TST-/QFT-GIT+ was more than TST+/QFT-GIT-. History of BCG vaccination, TST cut-off points and age are related to variation of κ estimates. TST and QFT-GIT are not comparable in detecting LTBI in HD patients. The higher TST-/QFT-GIT+ ratio compared with TST+/QFT-GIT- ratio, may indicate the superiority of QFT-GIT over TST for detection LTBI in HD patients.

Effect of Different Dialysis Methods on Cellular Immunity Function of Maintenance Haemodialysis Patients

Background

The study of the effect of different dialysis methods on cellular immune function of maintenance haemodialysis (MHD) patients should provide theoretical support for deciding on the best method of blood purification that effectively improves cellular immune function of haemodialysis patients.

Subjects and Method

Sixty MHD patients were randomly divided into three groups that respectively received treatment of haemodialysis (HD), high flux haemodialysis (HFHD) and haemodiafiltration (HDF). Peripheral blood T lymphocyte subsets [CD4+, CD8+, CD25+ (mIL-2R) and CD4+/CD8+ ratio] and serum interleukin (IL)-2 and soluble IL-2 receptor (sIL-2R) levels were detected before dialysis and 4, 24 and 48 hours after dialysis in all cases.

Results

Compared with the HD group, CD4+ and CD25+ cells, CD4+/CD8+ ratio and IL-2 level increased but sIL-2R level decreased in the HFHD and HDF groups at four hours without statistical significance (p > 0.05) and at 24 and 48 hours after dialysis with statistical significance (p < 0.05), while CD8+ cells had no change after dialysis (p > 0.05). Compared with the HFHD group, CD4+ and CD25+ cells, CD4+/CD8+ ratio, and IL-2 level increased but sIL-2R level decreased in the HDF group at four and 24 hours without statistical significance (p > 0.05) and at 48 hours after dialysis with statistical significance (p < 0.05), while CD8+ cells had no change after dialysis (p > 0.05).

Conclusion

The results indicate that HD can briefly improve the cellular immune function of MHD patients, while MHD and HFHD can improve it continuously, with HDF having the best effect.

Association of CD30 transcripts with Th1 responses and proinflammatory cytokines in patients with end-stage renal disease

High serum sCD30 levels are associated with inflammatory disorders and poor outcome in renal transplantation. The contribution to these phenomena of transcripts and proteins related to CD30-activation and -cleavage is unknown. We assessed in peripheral blood of end-stage renal disease patients (ESRDP) transcripts of CD30-activation proteins CD30 and CD30L, CD30-cleavage proteins ADAM10 and ADAM17, and Th1- and Th2-type immunity-related factors t-bet and GATA3. Additionally, we evaluated the same transcripts and release of sCD30 and 32 cytokines after allogeneic and polyclonal T-cell activation. In peripheral blood, ESRDP showed increased levels of t-bet and GATA3 transcripts compared to healthy controls (HC) (both P<0.01) whereas levels of CD30, CD30L, ADAM10 and ADAM17 transcripts were similar. Polyclonal and allogeneic stimulation induced higher levels of CD30 transcripts in ESRDP than in HC (both P<0.001). Principal component analysis (PCA) in allogeneic cultures of ESRDP identified two correlation clusters, one consisting of sCD30, the Th-1 cytokine IFN-γ, MIP-1α, RANTES, sIL-2Rα, MIP-1β, TNF-β, MDC, GM-CSF and IL-5, and another one consisting of CD30 and t-bet transcripts, IL-13 and proinflammatory proteins IP-10, IL-8, IL-1Rα and MCP-1. Reflecting an activated immune state, ESRDP exhibited after allostimulation upregulation of CD30 transcripts in T cells, which was associated with Th1 and proinflammatory responses.

Spanish multicentre PIBHE study: Prevalence and immunization of chronic hepatitis B in haemodialysis patients in Spain

INTRODUCTION

The PIBHE study, promoted by the Spanish Liver and Kidney Association and the Dialysis Virus Group of the Spanish Society of Nephrology, is the first study to determine the status of haemodialysis patients with chronic HBV infection and the immunisation against the vaccine.

METHOD

The study has a national multicentre, observational, cross-sectional design and was carried out between January 2013 and 2014. A data collection folder was sent to all the nephrology departments and outpatient haemodialysis units in Spain, to be completed based on patient medical files after informed consent. The data were recorded in a central database.

RESULTS

A total of 215 centres participated (15,645 patients), with an HBV prevalence of 1.03%. HCV or HIV was present in 7.2% of the HBV(+) patients. Viral load was below 2,000 IU/ml in 80%. GOT and GPT levels were 19.1±10.1 and 15.9±9.6 IU/ml, respectively. Liver biopsy was performed in 7.1%. Antiviral treatment was prescribed in 30% and suspended in 12.5%: entecavir (13.3%), lamivudine (10%), adefovir and tenofovir (6.7%), and interferon (3.3%). A total of 34.5% were candidates for renal transplantation and 6.9% had not been evaluated; 64.3% were followed up by a gastroenterologist; 27.2% of HBV(-) patients without immunisation had not been vaccinated. Fourteen different immunisation schedules had been used, with an immunisation rate of 58.8%. Mean anti-HBs stood at 165.7±297.8mIU/ml. A total of 72.7% of patients had received a vaccination course; 26.4%, 2 cycles; 1.0%, 3 cycles; and 11.6%, a booster dose. A total of 28.3% had a poor response (anti-HBs 10-99mIU/ml); 22.4%, an optimal response (anti-HBs 100-999mIU/ml); and 7.9%, an excellent response (anti-HBs ≥ 1,000mIU/ml). Age was significantly associated with response to vaccination; the mean age of nonresponders was significantly higher than patients who had a response of any kind (P<.05). The highest probability of an immune response was achieved with 4 doses of 40 mcg of adjuvanted vaccine (OR: 7.3; 95% CI 3.4 to 15.7), for the same age and number of cycles and boosters. Age, adjuvanted vaccine, dose and vaccination schedule influenced the immune response and the anti-HBs titres reached (P<.05).

CONCLUSION

The prevalence of chronic HBV infection in haemodialysis in Spain is low and so are the rates of immunisation against the virus. The vaccination schedules used are very diverse and have been observed to correlate with the immune response. It would therefore be necessary to establish a protocol for the most effective vaccination schedule to increase immunisation in these patients.

A case of mediastinal abscess in a hemodialysis patient

An asymptomatic mediastinal abscess was incidentally found in a 68-year-old male patient with a long history of hemodialysis. He had never had any symptoms but complained of chest pain only after the abscess ruptured into the right thoracic cavity. The abscess was discovered incidentally, when computed tomography was performed to determine the cause of his increasing ascites. Video-assisted thoracic surgery was performed to facilitate sufficient drainage and safe debridement. After the operation, we administered adequate antibiotics and continued irrigation of the thoracic cavity. The origin of his abscess was still unknown, but we have to consider that immunocompromised patients including those undergoing hemodialysis can develop severe infectious conditions even with minor causes. This case is clinically suggestive of the need to focus on the immunocompromised condition of hemodialysis patients. Furthermore, our case reveals video-assisted thoracic surgery to be a safe and less invasive procedure for patients in poor general condition.

Study of peripheral blood natural killer cells, T-cell helper/T-cell suppressor ratio and intercurrent infection frequency in hepatitis C seropositive prevalent hemodialysis patients

Hemodialysis (HD) may adversely affect the immune system. It is established that intercurrent infection rate and severity may be increased in prevalent HD patients. Moreover, hepatitis C viral infection, a common infection in many HD centers, may further inhibit the immune system. To our knowledge, no previous study in the literature has attempted to investigate the possible effects of hepatitis C seropositivity on rate and severity of intercurrent infection in prevalent HD patients. The aim of this study was to assess the peripheral blood CD16-natural killer cells, CD4/CD8 ratio, as well as rate of intercurrent infection in hepatitis C seropositive prevalent HD patients as compared with hepatitis C seronegative prevalent HD patients. Twenty hepatitis C seropositive stable prevalent HD patients (group A), as well as another twenty hepatitis C seronegative stable prevalent HD patients (group B), were randomly selected from our HD unit and enrolled in the study. Both groups were similar in age, sex, body mass index, and duration of HD. Diabetics, smokers, and cases with advanced liver disease (Child classification stages B and C) were excluded from the study. A third group (group C) of 10 apparently healthy subjects (of similar age, sex, and body mass index), was also enrolled in the study. All subjects were investigated by complete blood count, routine chemistry, assessment of peripheral lymphocytes CD3,CD16, CD4, CD8, CD4/CD8 ratio by flow cytometer, as well assessment of intercurrent infection frequency retrospectively (since the start of HD therapy and seroconversion in HD patients, and prospectively for a period of six months. Although we detected statistically significant higher frequency of intercurrent infection in both HD groups compared with the healthy group, we did not detect significant differences between hepatitis C seropositive and seronegative groups regarding frequency or severity of intercurrent infection. Moreover, we did not detect significant differences among the three studied groups regarding levels of CD16, CD3, CD4, CD8, CD4/CD8 ratio in peripheral lymphocytes. It may be concluded that hepatitis C seropositive prevalent HD patients are not at increased risk of intercurrent infection as compared with hepatitis C seronegative prevalent HD patients, contrary to what is reported in hepatitis C seroconverted organ transplant candidates.

Serum vitamin D levels are positively associated with varicella zoster immunity in chronic dialysis patients

Uremia results in a relatively immunocompromised status, and patients under chronic dialysis have an elevated risk of developing herpes zoster (HZ). We sought to investigate the relationship between vitamin D status and immunity to varicella-zoster virus (VZV). A multicenter prevalent hemodialysis cohort was assembled between 2012 and 2013. We assayed the biochemical parameters, 25-hydroxy- (25-OH-D) and 1,25-dihydroxyvitamin D, vitamin D-binding protein levels in the sera. VZV immunity was quantitated using VZV-specific glycoprotein IgG and IgM titers. Eighty-eight patients were enrolled and their sera were analyzed. Chronic hemodialysis patients with 25-OH-D < 30 ng/ml (insufficiency or deficiency) had significantly lower VZV-IgG than those with sufficient 25-OH-D (p = 0.04). This discrepancy became more prominent if active vitamin D users alone were analyzed (p = 0.01). Generalized additive modeling showed that those with 25-OH-D higher than 27.8 ng/ml or bioavailable 25-OH-D higher than 3.88 ng/ml had significantly higher VZV-IgG levels than those with lower values. Linear regression suggested that both total and bioavailable 25-OH-D were significantly associated with higher VZV-IgG levels (p = 0.003 [total] and 0.01 [bioavailable]), whereas patients with cancer had lower VZV-IgG. Vitamin D may therefore be a potentially useful choice for raising VZV immunity in chronic dialysis patients.

Risk of pneumonia among patients with chronic kidney disease in outpatient and inpatient settings: a nationwide population-based study

Patients with chronic kidney disease (CKD) are more at risk for pneumonia than the general population. Patients with pneumonia are usually treated as outpatients. However, previous studies were conducted on the basis of inpatient pneumonia. This method may underestimate the risk of pneumonia in patients with CKD. Therefore, we investigated the risk of pneumonia among CKD patients in both outpatient and inpatient settings. A total of 15,562 patients with CKD and 62,109 individuals without CKD (matched for age and gender) were taken as subjects in the Longitudinal Health Insurance Database of Taiwan National Insurance from 1996 to 2010. The incidence density rates of inpatient and outpatient pneumonia were calculated. The risk factors associated with pneumonia were analyzed using Cox proportional hazard models with adjustments for confounders. The incidence density rate of pneumonia was 65.6 per 1000 person-years in patients with CKD and 28.4 per 1000 person-years in individuals without CKD. The incidence density rate of inpatient pneumonia was 43.3 per 1000 person-years in patients with CKD and 16.6 per 1000 person-years in individuals without CKD. CKD was associated with increased risk of pneumonia (adjusted hazard ratio [aHR], 1.97; 95% confidence interval [CI], 1.89-2.05; P < 0.001), outpatient pneumonia (aHR, 1.40; 95% CI, 1.31-1.49), and inpatient pneumonia (aHR, 2.17; 95% CI, 2.07-2.29, P < 0.001). Patients' comorbidities, including diabetes, cardiovascular disease (CVD), asthma, and chronic obstructive pulmonary disease (COPD), were independently associated with increased risk of pneumonia.CKD is associated with the increased risk of both outpatient and inpatient pneumonia. This association is independent of comorbid diabetes, CVD, asthma, and COPD.

Association of CTLA-4 gene polymorphism with end-stage renal disease and renal allograft outcome

Cytotoxic T-lymphocyte antigen 4 (CTLA-4) is upregulated in effector-T-cells after activation that may alter signal transduction and subsequently cytokine production. The present study was designed to investigate the impact of CTLA-4+49 A>G (rs231775), -318 C>T (rs5742909), -658 C>T (rs11571317), -1147 C>T (rs16840252), -1661 A>G (rs4553808), +6230 A>G (rs3087243) SNPs, and microsatellite (AT)n repeat polymorphism among end-stage renal disease (ESRD), acute allograft rejection (AR), and delayed graft function (DGF) cases. In this regard, 350 ESRD patients and 350 controls were included. Polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis method was used for genotyping of CTLA-4 SNPs, while PCR-polyacrylamide gel electrophoresis method was adopted for studying CTLA4 (AT)n polymorphism. The mutant genotype GG of CTLA-4+49A>G,+6230 A>G, and longer alleles of (AT)n repeats polymorphisms were risk associated with ESRD, AR, and DGF cases. The distribution of haplotype+49G:+6230G and GCTTGG (constructed by using 6 studied SNPs) showed risk association for ESRD, DGF, and AR cases. Further, linkage analysis demonstrated strong to moderate linkage disequilibrium in our study populations. The meta-analysis also revealed risk associations for AR cases against GG genotype of CTLA-4+49A>G SNP, while CTLA-4 -318C>T polymorphism showed no correlation against TT genotype among AR cases. Subsequently, no correlation was established against the CTLA-4 -318C>T, -658 C>T, -1147 C>T, and -1661 A>G SNPs in the promoter region. Survival analysis revealed risk associations against GG genotype of CTLA-4+49A>G, +6230 A>G SNP's with overall survival (OS), and higher hazard for the OS. These results suggested that CTLA-4 variants might be involved in susceptibility to ESRD, AR, and DGF.

Uremic toxin indoxyl 3-sulfate regulates the differentiation of Th2 but not of Th1 cells to lessen allergic asthma

Immune system dysfunctions including the increased Th1/Th2 ratio are common in chronic kidney disease (CKD) patients, and a wide variety of skin diseases including Th1-mediated uremic pruritis are associated with CKD. Although there are more than 90 uremic toxins reported, it is yet to be known which uremic solute is associated with the unbalanced Th1/Th2 ratio and how it works. Indoxyl 3-sulfate (I3S), one of uremic toxins and a potent aryl hydrocarbon receptor (AhR) ligand, accumulates in blood and tissues, increasing up to 81.04 μM in CKD patients, compared with 1.03 μM in healthy subjects. I3S activates NF-κB and AhR. Thus, we investigated roles of I3S in the differentiation of Th1 and Th2 cells. I3S inhibited Th2 differentiation but showed little or no effect on Th1 differentiation. I3S suppressed Th2-mediated ovalbumin-induced allergic asthma in mice and decreased the frequency of IL-4 producing CD4 T cells in the lungs. I3S inhibited phosphorylation of STAT5 and STAT6, transcription factors associated with Th2 differentiation. Effects of I3S on Th2 differentiation were suppressed by α-naphtoflavone, an AhR antagonist, indicating that I3S regulates Th2 differentiation AhR-dependently.

Effects of intestinal bacteria-derived p-cresyl sulfate on Th1-type immune response in vivo and in vitro

Protein fermentation by intestinal bacteria generates various compounds that are not synthesized by their hosts. An example is p-cresol, which is produced from tyrosine. Patients with chronic kidney disease (CKD) accumulate high concentrations of intestinal bacteria-derived p-cresyl sulfate (pCS), which is the major metabolite of p-cresol, in their blood, and this accumulation contributes to certain CKD-associated disorders. Immune dysfunction is a CKD-associated disorder that frequently contributes to infectious diseases among CKD patients. Although some studies imply pCS as an etiological factor, the relation between pCS and immune systems is poorly understood. In the present study, we investigated the immunological effects of pCS derived from intestinal bacteria in mice. For this purpose, we fed mice a tyrosine-rich diet that causes the accumulation of pCS in their blood. The mice were shown to exhibit decreased Th1-driven 2, 4-dinitrofluorobenzene-induced contact hypersensitivity response. The concentration of pCS in blood was negatively correlated with the degree of the contact hypersensitivity response. In contrast, the T cell-dependent antibody response was not influenced by the accumulated pCS. We also examined the in vitro cytokine responses by T cells in the presence of pCS. The production of IFN-γ was suppressed by pCS. Further, pCS decreased the percentage of IFN-γ-producing Th1 cells. Our results suggest that intestinal bacteria-derived pCS suppressesTh1-type cellular immune responses.

Maternal immune stimulation during pregnancy shapes the immunological phenotype of offspring

Epidemiological studies have associated infection during pregnancy with increased risk of neurodevelopmental disorders in children, which is modeled in rodents by stimulating the immune system of pregnant dams with microorganisms or their mimics, such as poly(I:C) or LPS. In two prenatal mouse models, we show that in utero exposure of the fetus to cytokines/inflammatory mediators elicited by maternal immune stimulation with poly(I:C) yields offspring that exhibit a proinflammatory phenotype due to alterations in developmental programming of their immune system. Changes in the innate and adaptive immune elements of these pro-inflammatory offspring result in more robust responses following exposure to immune stimuli than those observed in control offspring from PBS-injected pregnant dams. In the first model, offspring from poly(I:C)-injected immunologically naïve dams showed heightened cellular and cytokine responses 4 h after injection of zymosan, a TLR2 agonist. In the second model, using dams with immunological memory, poly(I:C) injection during pregnancy produced offspring that showed preferential differentiation toward Th17 cell development, earlier onset of clinical symptoms of EAE, and more severe neurological deficits following immunization with MOG35-55. Such "fetal programming" in offspring from poly(I:C)-injected dams not only persists into neonatal and adult life, but also can have profound consequences on health and disease.

Influence of cholecalciferol supplementation in hemodialysis patients on monocyte subsets: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND/AIMS

Although most hemodialysis patients share a significant 25-hydroxyvitamin D [25(OH)D] deficiency, supplementation is controversially discussed. A potential influence on monocyte and T lymphocyte dysfunction advocates blood level-adapted supplementation as recommended by K/DOQI guidelines. This was a prospective double-blind randomized placebo controlled trial examining immune effects of 12 weeks of cholecalciferol supplementation.

METHODS

We initiated serum level-adapted de novo cholecalciferol supplementation in 38 hemodialysis patients. Outcome measures were: monocyte subset cell counts (CD14+CD16++ vs. CD14++CD16+ vs. CD14++CD16-), lymphocyte Th1/Th2 differentiation frequencies, serum inflammatory proteins CRP and TNFα, parathyroid hormone (PTH), FGF-23, and α-Klotho.

RESULTS

At baseline, the mean 25(OH)D serum level in the study population was 31.7 ± 14.3 nmol/l, and only 3% of patients had levels within the normal range. At 12 weeks, 25(OH)D levels were normalized in the verum group (87.8 ± 22.3 vs. placebo 24.6 ± 8.0 nmol/l, p < 0.0001). In parallel, 1,25(OH)2D levels increased in the verum group. Monocyte subset cell counts as well as Th1 and Th2 lymphocyte frequencies did not change significantly after 12 weeks of cholecalciferol supplementation. There was also no significant difference in PTH, alkaline phosphatase, calcium, phosphate, TNFα, FGF-23, α-Klotho and CRP levels.

CONCLUSIONS

Oral cholecalciferol supplementation according to the K/DOQI recommendations normalizes 25(OH)D levels without relevant side effects such as hyperphosphatemia or hypercalcemia. However, beneficial pleiotropic effects on monocyte subset cell counts, T cell differentiation, or cytokine production could not be confirmed at least at the used dosage. PTH and FGF23 levels were not affected during cholecalciferol administration.

Serial influenza-vaccination reveals impaired maintenance of specific T-cell memory in patients with end-stage renal failure

To investigate correlates for the well-known impaired response of haemodialysis-patients to a variety of recommended vaccinations, the induction of antigen-specific cellular and humoral immunity was characterised after influenza-vaccination in two following seasons where the identical vaccine-composition was used. Influenza-specific T-cells were flow-cytometrically characterised from whole blood of 24 healthy controls and 26 haemodialysis-patients by proliferation-assays, induction of IFN-γ and TNF-α, and maturation markers. Antibody-titres were quantified using ELISA and hemagglutination-inhibition test. Influenza-specific CD4 T-cells were recently activated CD45RO+/CD27+ Th1-cells. Specific T-cell frequencies significantly increased 1-2 weeks after the first vaccination in both controls (mean increase by 0.50±0.64%, max: 3.01%) and haemodialysis-patients (by 0.55±0.71%, max: 3.44%). Thereafter, T-cell levels continuously decreased to pre-vaccination levels within approximately 7 weeks, whereas antibody-titres were more stable over time. By 6 months, haemodialysis-patients had significantly lower precursor-frequencies of proliferating influenza-specific memory T-cells (p=0.006). In the following season, memory-maintenance in immunocompetent individuals led to a significantly less pronounced increase in cellular immunity after re-vaccination (by only 0.12±0.09%, p=0.003), whereas the vaccine induced a strong increase in a second group of vaccination-naïve controls. Of note, haemodialysis-patients responded like vaccination-naïve individuals, as they showed a strong increase in cellular immunity after re-vaccination that was as pronounced as in the year before. In conclusion, the less pronounced T-cell increase after re-vaccination in controls may indicate maintenance of sufficient immunological memory. In contrast, the more rapid loss of proliferating cells in haemodialysis-patients may represent a sign of relative immunodeficiency and contribute to an increased incidence of recurrent infectious complications.

Serum levels and activity of indoleamine2,3-dioxygenase and tryptophanyl-tRNA synthetase and their association with disease severity in patients with chronic kidney disease

OBJECTIVE

This study aims to test the serum levels and activity of indoleamine2,3-dioxygenase(IDO) and tryptophanyl-tRNA synthetase (TTS) in patients with chronic kidney disease (CKD) and to evaluate their association with disease severity.

METHOD

Serum concentrations of IDO and TTS in 61 patients with CKD and 16 healthy volunteers were tested by ELISA. Tryptophan and kynurenine concentrations were measured by high-performance liquid chromatography (HPLC).

RESULTS

Patients with CKD showed higher serum levels of IDO and TTS in comparison to healthy controls (p = 0.001). Patients with CKD showed lower serum levels of tryptophan and higher serum levels of kynurenine in comparison to healthy controls (p < 0.001). The kyn/Trp ratio significantly correlated with the disease severity in CKD patients (r = 0.721; p < 0.001).

CONCLUSIONS

IDO and TTS may play critical roles in the immune pathogenesis of CKD. The activity of IDO correlated with the disease severity of CKD.

Indoxyl 3-sulfate stimulates Th17 differentiation enhancing phosphorylation of c-Src and STAT3 to worsen experimental autoimmune encephalomyelitis

Although AhR activation regulates CD4T cell differentiation, how it works has yet to be elucidated. In the present study, using in vitro Th17 differentiation model, we examined effects of AhR activation by indoxyl 3-sulfate (I3S), a uremic toxin, on Th17 differentiation and investigated underlying mechanisms. I3S increased expression of RORγt, the master transcription factor for Th17 differentiation, and stimulated Th17 differentiation, in a comparative manner as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a prototypical AhR ligand. Activation of STAT3, which is phosphorylated by the IL-6 signaling pathways and thus is necessary for Th17 differentiation, was strongly stimulated by I3S and TCDD. Phosphorylation of c-Src, which was shown to be activated by AhR ligands, was also increased by I3S and TCDD, and blocking of c-Src activity by 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo[3,4-d]pyrimidine (PP2) inhibited phosphorylation of both c-Src and STAT3, raising a possibility that stimulatory activities of I3S and TCDD on Th17 differentiation could be exerted via increased phosphorylation of c-Src, which in turn stimulates STAT3 activation. Finally, we found that I3S worsened experimental autoimmune encephalomyelitis (EAE), which is primarily mediated by Th17 cells, enhancing the frequency of IL-17-producing cells in draining lymph nodes.

Comparison of regulatory T cells in hemodialysis patients and healthy controls: implications for cell therapy in transplantation

BACKGROUND AND OBJECTIVES

Cell-based therapy with natural (CD4(+)CD25(hi)CD127(lo)) regulatory T cells to induce transplant tolerance is now technically feasible. However, regulatory T cells from hemodialysis patients awaiting transplantation may be functionally/numerically defective. Human regulatory T cells are also heterogeneous, and some are able to convert to proinflammatory Th17 cells. This study addresses the suitability of regulatory T cells from hemodialysis patients for cell-based therapy in preparation for the first clinical trials in renal transplant recipients (the ONE Study).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Healthy controls and age- and sex-matched hemodialysis patients without recent illness/autoimmune disease on established, complication-free hemodialysis for a minimum of 6 months were recruited. Circulating regulatory T cells were studied by flow cytometry to compare the regulatory T cell subpopulations. Regulatory T cells from members of each group were compared for suppressive function and plasticity (IL-17-producing capacity) before and after in vitro expansion with and without Rapamycin, using standard assays.

RESULTS

Both groups had similar total regulatory T cells and subpopulations I and III. In each subpopulation, regulatory T cells expressed similar levels of the function-associated markers CD27, CD39, HLA-DR, and FOXP3. Hemodialysis regulatory T cells were less suppressive, expanded poorly compared with healthy control regulatory T cells, and produced IL-17 in the absence of Rapamycin. However, Rapamycin efficiently expanded hemodialysis regulatory T cells to a functional and stable cell product.

CONCLUSIONS

Rapamycin-based expansion protocols should enable clinical trials of cell-based immunotherapy for the induction of tolerance to renal allografts using hemodialysis regulatory T cells.

Impact of non-dialysis chronic kidney disease on survival in patients with septic shock

BACKGROUND

Chronic kidney disease (CKD) is known to expose the patient to a high risk of death due to cardiovascular and infective causes. In parallel, septic shock is a major challenge for cardiovascular and immune system. Therefore we tried to determine whether non-dialysis CKD, defined as a baseline estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2, for three months prior to the onset of septic shock is an independent risk factor for death.

METHODS

All patients treated in a teaching hospital medical ICU for septic shock between January 2007 and December 2009 were retrospectively analyzed. Patients in whom baseline eGFR could not be determined (n=14) or patients treated by chronic dialysis (n=21) or kidney transplantation (n=14) were excluded. A total of 163 patients were included. The population was divided according to baseline eGFR ≥ 60 ml/min/1.73 m2 (non-CKD group, n=107) and < 60 ml/min/1.73 m2 (CKD group, n=56). Twenty-eight-day and 1-year survival curves were plotted. Prognostic factors were determined using Cox proportional hazards models.

RESULTS

Baseline eGFR was significantly higher in the non-CKD group than in the CKD group (81 (67-108) vs. 36 (28-44) ml/min/1.73 m2, respectively; p=0.001). Age, SAPS II, serum creatinine on admission and the number of patients with a history of diabetes, hypertension, heart failure, peripheral artery disease, coronary artery disease and statin medication were significantly higher in the CKD group than in the non-CKD group. The mortality rate was lower in the non-CKD group than in the CKD group after 28 days (50% vs. 70%, respectively; p=0.03) and 1 year (64% vs. 82%, respectively; p=0.03). On multivariate analysis, the dichotomous variable CKD (eGFR < 60 ml/min/1.73 m2) remained significantly associated with the 28-day and 1-year mortality.

CONCLUSIONS

Non-dialysis CKD appears to be an independent risk factor for death after septic shock.

Uremia and chronic kidney disease: the role of the gut microflora and therapies with pro- and prebiotics

Uremia is an illness that accompanies kidney failure and chronic kidney disease (CKD). Uremic illness is considered to be due largely to the accumulation of organic waste products that are normally cleared by the kidneys. However, uremic retention solutes are generated in part in the gastrointestinal tract (GIT), with the gut microbiota and the ensuing micro-biometabolome playing a significant role in the proliferation of uremic retention solutes. Toxins generated in, or introduced into the body via the intestine, such as advanced glycation end products, phenols, and indoles, all may contribute to the pathogenesis of CKD. Hence, it is biologically plausible, but not well recognized, that an important participant in the toxic load that contributes to CKD originates in the GIT. The microbiota that colonize the GIT perform a number of functions that include regulating the normal development and function of the mucosal barriers; assisting with maturation of immunological tissues, which in turn promotes immunological tolerance to antigens from foods, the environment, or potentially pathogenic organisms; controlling nutrient uptake and metabolism; and preventing propagation of pathogenic micro-organisms. Here, we develop a hypothesis that probiotics and prebiotics have a therapeutic role in maintaining a metabolically balanced GIT, and reducing progression of CKD and associated uremia.

The intestinal microbiota, a leaky gut, and abnormal immunity in kidney disease

Chronic kidney disease (CKD) and end-stage renal disease (ESRD) are associated with systemic inflammation and acquired immunodeficiency, which promote cardiovascular disease, body wasting, and infections as leading causes of death. This phenomenon persists despite dialysis-related triggers of immune deregulation having been largely eliminated. Here we propose a potential immunoregulatory role of the intestinal microbiota in CKD/ESRD. We discuss how the metabolic alterations of uremia favor pathogen overgrowth (dysbiosis) in the gut and an increased translocation of living bacteria and bacterial components. This process has the potential to activate innate immunity and systemic inflammation. Persistent innate immune activation involves the induction of immunoregulatory mediators that suppress innate and adaptive immunity, similar to the concept of 'endotoxin tolerance' or 'immune paralysis' in advanced sepsis or chronic infections. Renal science has largely neglected the gut as a source of triggers for CKD/ESRD-related immune derangements and complications and lags behind on the evolving microbiota research. Interdisciplinary research activities at all levels are needed to unravel the pathogenic role of the intestinal microbiota in kidney disease and to evaluate if therapeutic interventions that manipulate the microbiota, such as pre- or probiotics, have a therapeutic potential to correct CKD/ESRD-related immune deregulation and to prevent the associated complications.

Association of response to hepatitis B vaccination and survival in dialysis patients

Background

The status of immunocompromised patients is well recognized in end stage renal disease (ESRD). As described recently, this acquired immune dysfunction in the uremic milieu may be one of the main pathogenic factors for mortality in ESRD. The aim of this study was to determine the relationship between the immune response following a hepatitis B vaccination (HBV vaccination) and the survival of maintenance dialysis patients.

Methods

A total of 156 patients (103 on hemodialysis and 53 on continuous ambulatory peritoneal dialysis) were recruited. After receiving a full dose of the HBV vaccination, all patients were followed up for to 5 years to evaluate the association of patient survival, cause of mortality, and immune response.

Results

The response rate to the hepatitis B vaccination was 70.5%. There was no significant association between the immune response and the 5-year survival rate (p =0.600) or between the post-vaccination anti-HBs titers and the 5-year survival rate (p = 0.201). The logistic prediction model with the coefficient as non-response following HBV vaccination, diabetes mellitus, old age, and low albumin level could significantly predict infection-cause mortality (sensitivity = 0.842, specificity = 0.937).

Conclusion

There was no significant association between the immune response to HBV vaccination and the 5-year survival rate. However, non-response following HBV vaccination might be associated with infection-cause mortality in dialysis patients.

Antibodies to hepatitis B virus surface antigen and interleukin 12 and interleukin 18 gene polymorphisms in hemodialysis patients

BACKGROUND

The interleukin (IL)18 rs360719 CC genotype is associated with the development of antibodies to hepatitis B virus surface antigen (anti-HBs) in hemodialysis (HD) patients. IL18 shares biological properties with IL12 in promoting the T-hepler 1 (Th1) system. We studied whether polymorphisms in the IL12A 3` untranslated region (UTR) and IL12B 3`UTR may contribute to anti-HBs development (titre ≥ 10 IU/L) in HD patients either individually or jointly with the IL18 polymorphism.

METHODS

In 518 HD patients and 240 controls the IL12A rs568408 3'UTR G > A polymorphism was genotyped by high-resolution melting curve analysis. Polymerase chain reaction restriction fragment length polymorphism was used to detect the IL12B rs3212227 3'UTR A > C and IL18 -1297 T > C rs360719 polymorphisms. The associations between the IL12A, IL12B and IL18 genotypes and the risk of impaired anti-HBs development were estimated by computing the odds ratios and their 95% confidence intervals using logistic regression analysis.

RESULTS

In the logistic regression analysis, the higher frequency of rs360719 CC individually (2.9% in 207 patients without anti-HBs development vs 8.0% in 311 patients with anti-HBs development, p = 0.009) and of rs360719 CC combined with rs568408 GG (p = 0.048), rs568408 GA (p = 0.035), rs568408 GG/AA (p = 0.034) or rs3212227 AA (p = 0.046) was associated with an increased chance for the development of anti-HBs in HD patients. Patients bearing both rs568408 AA and rs360719 TT had a 10.9-fold or 8.9-fold lower chance, respectively, to develop anti-HBs compared with those carrying any other genotype (p = 0.005) or those who had both wild-type rs568408 GG and rs360719 TT (p = 0.011). Carriers of both rs3212227 CC and rs360719 TC had a 4.6-fold lower chance for anti-HBs development than carriers of any other genotype (p = 0.042).

CONCLUSION

Development of anti-HBs in HD patients is associated with gene polymorphisms of interleukins involved in the Th1 system.

Iron sucrose impairs phagocytic function and promotes apoptosis in polymorphonuclear leukocytes

BACKGROUND

With the recent implementation of bundling reimbursement policy, the use of intravenous (IV) iron preparations for the management of anemia in the end-stage renal disease (ESRD) population has dramatically increased. Iron overload increases the risk of infections in individuals with or without kidney disease. IV iron administration in ESRD patients impairs bacteriocidal capacity of polymorphonuclear leukocytes (PMNs) against Escherichia coli. These preparations consist of an elemental iron core and a carbohydrate shell. In addition to the iron core, the carbohydrate shell may affect PMNs. We therefore examined the effect of iron sucrose, a commonly used preparation, on phagocytic capacity of PMNs from a group of normal individuals against Gram-positive (Staphylococcus aureus) and Gram-negative (E. coli) bacteria.

METHODS

Iron sucrose was added to heparinized blood samples at pharmacologically-relevant concentrations and incubated for 4 and 24 h at 37°C to simulate in vivo condition. Blood samples mixed with equal volume of saline solution served as controls. To isolate the effects of the carbohydrate shell, blood samples were co-treated with the iron chelator, desferrioxamine.

RESULTS

Iron sucrose caused significant PMN apoptosis and dose-dependent suppression of phagocytic function against both Gram-positive and Gram-negative bacteria. These abnormalities were prevented by desferrioxamine which precluded contribution of the carbohydrate shell to the PMN dysfunction.

CONCLUSIONS

At pharmacologically-relevant concentrations, iron sucrose promotes apoptosis and inhibits phagocytic activities of PMNs. The deleterious effect of iron sucrose is mediated by its elemental iron core, not its carbohydrate shell, and as such may be shared by other IV iron preparations.