Soluble interleukin 2 receptor (sIL-2R) levels in renal transplant recipients

Soluble interleukin-2 receptor predicts acute kidney injury and in-hospital mortality in patients with acute myocardial infarction

BACKGROUND

Acute kidney injury (AKI) is the most common and critical complication in patients with acute myocardial infarction (AMI). This study aims to evaluate the significance of elevated soluble interleukin 2 receptor (sIL-2R) levels in predicting AKI and mortality.

METHODS

A total of 446 patients with AMI were enrolled between January 2020 and July 2022, including 58 patients with AKI and 388 without AKI. The sIL-2R levels were measured using a commercially available chemiluminescence enzyme immunoassay. Logistic regression analysis was used to examine the risk factors for AKI. Discrimination was assessed based on the area under the receiver operating characteristic curve. The model was internally validated using 10-fold cross-validation.

RESULTS

During hospitalization, 13% of patients developed AKI following AMI, with higher sIL-2R levels (0.61 ± 0.27 U/L vs. 0.42 ± 0.19 U/L, p = 0.003) and in-hospital all-cause mortality (12.1% vs. 2.6%, P < 0.001). The sIL-2R levels emerged as an independent risk factor for both AKI (OR = 5.08, 95% CI (1.04-24.84, p < 0.045) and in-hospital all-cause mortality (OR = 73.57,95% CI 10.24-528.41, p < 0.001) in AMI patients. The sIL-2R levels were found to be useful biomarkers in prediction of AKI and in-hospital all-cause mortality in patients with AMI (AUC: 0.771 and 0.894, respectively). The respective cutoff values for sIL-2R levels in predicting AKI and in-hospital all-cause mortality were determined to be 0.423 U/L and 0.615 U/L.

CONCLUSIONS

The level of sIL-2R was an independent risk factor and predictor for both AKI and in-hospital all-cause mortality in patients with AMI. These findings highlight the potential of sIL-2R as a valuable tool for identifying high-risk patients regarding AKI and in-hospital mortality.

Renal disease in sarcoidosis patients in a German multicentric retrospective cohort study

INTRODUCTION

Sarcoidosis is a systemic granulomatous disease potentially affecting every organ system. Renal involvement is reportedly rare, and the evidence consists of case reports and cohort studies. Systematic investigations are scarce and show a varying prevalence ranging from <1% to 30-50%.

METHODS

We retrospectively analyzed data from patients with a recent diagnosis of sarcoidosis from five tertiary care centers focusing on renal sarcoidosis.

RESULTS

We analyzed data from 327 patients with sarcoidosis between 2001 and 2021. Of 327 patients, 109 (33.3%) had probable or definite renal sarcoidosis. 90 (27.5%) had histopathologic confirmation. 57 (64%) had an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². The most prominent associated finding was an elevated soluble interleukin-2 receptor. Patients with renal sarcoidosis more frequently received glucocorticoids than other non-renal sarcoidosis patients (92% vs. 78%, p < 0.01). Also, azathioprine (38% vs. 16%, p < 0.001) and mycophenolate mofetil (5% vs. 1%, p < 0.05) were more frequently used in renal sarcoidosis compared to non-renal sarcoidosis, whereas methotrexate was used less frequently (7% vs. 17%, p < 0.05).

CONCLUSIONS

Our data of the largest cohort with biopsy-confirmed renal sarcoidosis demonstrate a higher prevalence (27.5% of all patients) than previously published with a relevant disease burden. The urinary findings in most cases were only mildly abnormal, and some patients did not have renal biopsy despite abnormal urinary results. A renal workup should be performed in all patients with a new diagnosis of sarcoidosis.

Soluble Interleukin-2 Receptor Predicts Treatment Outcome in Patients With Autoimmune Tubulointerstitial Nephritis. A Preliminary Study

Background

Autoimmune tubulointerstitial nephritis (TIN) is characterized by immune-mediated tubular injury and requires immunosuppressive therapy. However, diagnosing TIN and assessing therapeutic response are challenging for clinicians due to the lack of useful biomarkers. Pathologically, CD4⁺ T cells infiltrate to renal tubulointerstitium, and soluble interleukin-2 receptor (sIL-2R) has been widely known as a serological marker of activated T cell. Here, we explored the usefulness of serum sIL-2R to predict the treatment outcome in patients with autoimmune TIN.

Methods

Study Design: Single-center retrospective observational study.

Participants

62 patients were diagnosed of TIN from 2005 to April 2018 at Hokkaido University Hospital. Among them, 30 patients were diagnosed with autoimmune TIN and treated with corticosteroids. We analyzed the association between baseline characteristics including sIL-2R and the change of estimated glomerular filtration rate (eGFR) after initiation of corticosteroids.

Results

The serum sIL-2R level in patients with autoimmune TIN was significantly higher than that in chronic kidney disease patients with other causes. Mean eGFR in autoimmune TIN patients treated with corticosteroids increased from 43.3 ± 20.4 mL/min/1.73 m² (baseline) to 50.7 ± 19.9 mL/min/1.73 m² (3 months) (ΔeGFR; 22.8 ± 26.0%). Multivariate analysis revealed that higher sIL-2R (per 100 U/mL, β = 1.102, P < 0.001) level was independently associated with the renal recovery. In ROC analysis, sIL-2R had the best area under the curve value (0.805) and the cutoff point was 1182 U/mL (sensitivity = 0.90, 1-specificity = 0.45).

Conclusions

Our study showed that elevated serum sIL-2R levels might become a potential predictive marker for therapeutic response in autoimmune TIN.

Hemophagocytic lymphohistiocytosis occurring after liver transplantation: A case series and review of the literature

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease characterized by excessive inflammation and tissue destruction due to a dysregulated immune response. Its secondary form is most commonly triggered by viral infection or malignancy. There have previously been 11 cases of acquired HLH described following liver transplantation in adult transplant recipients, most occurring within the first year following transplantation. Herein, we describe two cases of HLH in liver transplant recipients that both occurred remotely following transplantation. In the first case, HLH was thought to be triggered by the development of a post-transplant lymphoproliferative disorder in a patient who was initially diagnosed with recurrent autoimmune hepatitis. In the second, it was thought to be triggered by a newly acquired human herpesvirus-8 infection. In both cases, the syndrome was not recognized until treatment for the initial putative diagnoses was unsuccessful. Despite treatment, both patients unfortunately died from multiorgan failure. HLH in the post-liver transplant setting is likely under-recognized and has a high mortality; early diagnosis and intervention may lead to improved outcomes.

A retrospective matched cohort single-center study evaluating outcomes of COVID-19 and the impact of immunomodulation on COVID-19-related cytokine release syndrome in solid organ transplant recipients

This retrospective matched cohort study describes 30 solid organ transplant (SOT) patients with Coronavirus Disease 2019 (COVID-19) matched 1:2 to 60 non-SOT patients (control group) based on age, body mass index (BMI), and comorbidities (hypertension and diabetes mellitus with hemoglobin A1c > 8.0%). The SOT group had a higher proportion of cardiovascular disease (P < .05). During the index hospitalization, there were no significant differences with regard to disease severity or critical care needs (mechanical intubation, vasopressors, and renal replacement therapy). At 28 days, 4 (13%) patients died in the SOT group and 8 (13%) patients died in the control group (P = 1.0). Nineteen patients received tocilizumab in the SOT group compared to 29 patients in the control group. Among these patients, interleukin-6 (IL-6) and soluble interleukin-2 receptor (sIL2R) levels increased after tocilizumab and interleukin-10 (IL-10) levels decreased after tocilizumab. Overall, SOT patients had comparable mortality to non-SOT patients, although numerically more SOT patients received tocilizumab (63% vs 48%) and steroids (37% vs 20%). Larger, multi-center studies are needed to ascertain these findings. Lastly, the complex cytokine release syndrome in COVID-19 remains an area of intense research and the analysis of key interleukin levels (IL-6, IL-10, and sIL2R) in this study contributes to the understanding of this process.

The significance of serum levels of soluble interleukin-2 receptor in patients undergoing maintenance hemodialysis

Background

Elevated serum levels of sIL-2R are commonly observed in patients undergoing maintenance hemodialysis (MHD). However, the clinical implications in these subjects are unclear. This study is aimed to assess the significance of elevated sIL-2R levels in MHD patients.

Methods

A total of 382 MHD patients were followed-up from September 2016 to December 2019. Patients were divided into two groups: high sIL-2R, with sIL-2R levels ≥2-fold of the upper limit of normal (710 U/ml); and low sIL-2R, with sIL-2R levels < 2-fold the upper limit of normal. The relationships between sIL-2R levels and other clinical parameters, as well as patient prognosis were both assessed.

Results

The median concentration of sIL-2R was 1268 U/mL. A total of 372 (97.38%) patients exhibited sIL-2R levels higher than the upper limit of the normal range. Multiple linear regression analysis revealed that monocyte count (β = 0.1571, p = 0.01), and β₂-MG (β = 0.2635, p < 0.0001), hemoglobin (β = −0.1610, p = 0.001), SCr (β = −0.3471, p < 0.0001), and HDL-C (β = −0.1091, p = 0.029) levels were independent factors influencing serum concentrations of sIL-2R. High sIL-2R was significantly correlated with non-cardiovascular-related mortality (OR 2.97 [95% CI 1.59–5.56; p = 0.001), of which 39 (82.98%) were attributed to infection and/or cancer.

Conclusions

Elevated sIL-2R is prevalent in MHD patients and related with several unfavorable parameters. sIL-2R appears to have no ability to predict cardiovascular mortality, which accounts for approximately one-half of all deaths. However, sIL-2R may be beneficial in predicting noncardiovascular mortality.

Human Articular Chondrocytes Induce Interleukin-2 Nonresponsiveness to Allogeneic Lymphocytes

Introduction We previously showed that articular chondrocytes (ACs) have immune privilege and immunomodulatory functions like those of mesenchymal stem cells. To elucidate these mechanisms, we focused on interleukin-2 (IL-2), which plays critical roles in lymphocyte mitogenic activity. The purpose of this study was to explore whether ACs affect the role of IL-2 underlying immunomodulatory functions. Material and Methods Irradiated human ACs from osteoarthritis donors were used. Third-party ACs were added to the mixed lymphocyte reaction (MLR) with or without recombinant human IL-2 (rhIL-2), and the levels of IL-2 and the soluble form of the IL-2 receptor α (sIL-2Rα) protein in supernatant were measured by enzyme-linked immunosorbent assay. Recombinant human IL-2 (rhIL-2) was also added to the MLR. To detect the expression of IL-2 receptor α (CD25) on lymphocytes in the MLR, flow cytometric analysis was performed. Last, ACs and allogeneic activated CD4⁺ T cell were co-cultured, and the expression of CD25 on activated T cells was examined by flow cytometry. Results Third-party ACs significantly inhibited the MLR and reduced the level of sIL-2Rα in a dose-dependent manner, but did not affect the concentration of IL-2. Exogenous rhIL-2 accelerated MLR but did not rescue the inhibitory effect of ACs. ACs inhibited the expression of CD25 on activated CD4⁺ T cells. Discussion Our results showed that third-party ACs inhibited the proliferation of allogeneic activated lymphocytes, thereby inhibiting production sIL-2Rα, although ACs did not affect IL-2 secretion from lymphocytes. Also, ACs inhibited CD25 expression on activated CD4⁺ T cells. Thus, ACs inhibited the immune response of allogeneic lymphocytes by inducing IL-2 nonresponsiveness.

Sleep influences the immune response and the rejection process alters sleep pattern: Evidence from a skin allograft model in mice

INTRODUCTION

Sleep generally regulates immune functions in a supportive manner and can affect parameters that are directly involved in the rejection process.

STUDY OBJECTIVES

The first objective was to assess whether sleep deprivation (SD) or sleep restriction (SR) affects the allograft rejection process in mice. The second objective was to investigate whether the rejection process itself modulates the sleep pattern of allografted mice.

DESIGN

Adult BALB/c and C57BL/6J male mice were used as the donors and recipients, respectively, except for the syngeneic group (ISOTX), which received skin from mice of the same strain (C57BL/6J). The recipients were randomly assigned to either one of two control groups - TX (allogenic) or ISOTX (syngeneic) - which underwent stereotaxic surgery to enable sleep recording prior to the allograft but were not sleep deprived; one of two paradoxical sleep deprived groups - SDTX and TXSD - which underwent 72h of continuous SD either before or after the allograft respectively, and one of two sleep restricted groups - SRTX and TXSR - which underwent 21h of SD and 3h of sleep for 15days either before or after the allograft respectively.

INTERVENTIONS

The skin allograft was inspected daily to determine the survival time, expected as 8.0±0.4days in this transplant model under no treatment. The sleep pattern was controlled throughout the rejection process in the SD and SR groups. Draining lymph nodes, spleen, blood and skin grafts were harvested on the 5th day after transplantation for evaluation of the immune parameters related to allograft rejection.

MEASUREMENTS AND RESULTS

In the control groups, we observed a reduction in paradoxical sleep throughout the entire allograft rejection process. Acute and chronic experimental sleep loss in the SD and SR groups produced marked alterations in the immune response. Both SD and SR prolonged allograft survival compared to the non-sleep-deprived group. There were reductions in the following parameters involved in the allograft rejection under sleep loss: CD4⁺ and CD8⁺ T cell subpopulations in the peripheral lymph organs and spleen, circulating sIL-2R levels, graft-infiltrating CD4⁺ T cells and skin allograft global gene expression.

CONCLUSIONS

We provide, as far as we are aware, the first evidence in vivo that the immune response can alter the normal sleep pattern, and that sleep loss can conversely affect the immune response related to graft rejection.

Barcelona Consensus on Biomarker-Based Immunosuppressive Drugs Management in Solid Organ Transplantation

With current treatment regimens, a relatively high proportion of transplant recipients experience underimmunosuppression or overimmunosuppression. Recently, several promising biomarkers have been identified for determining patient alloreactivity, which help in assessing the risk of rejection and personal response to the drug; others correlate with graft dysfunction and clinical outcome, offering a realistic opportunity for personalized immunosuppression. This consensus document aims to help tailor immunosuppression to the needs of the individual patient. It examines current knowledge on biomarkers associated with patient risk stratification and immunosuppression requirements that have been generally accepted as promising. It is based on a comprehensive review of the literature and the expert opinion of the Biomarker Working Group of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology. The quality of evidence was systematically weighted, and the strength of recommendations was rated according to the GRADE system. Three types of biomarkers are discussed: (1) those associated with the risk of rejection (alloreactivity/tolerance), (2) those reflecting individual response to immunosuppressants, and (3) those associated with graft dysfunction. Analytical aspects of biomarker measurement and novel pharmacokinetic-pharmacodynamic models accessible to the transplant community are also addressed. Conventional pharmacokinetic biomarkers may be used in combination with those discussed in this article to achieve better outcomes and improve long-term graft survival. Our group of experts has made recommendations for the most appropriate analysis of a proposed panel of preliminary biomarkers, most of which are currently under clinical evaluation in ongoing multicentre clinical trials. A section of Next Steps was also included, in which the Expert Committee is committed to sharing this knowledge with the Transplant Community in the form of triennial updates.

Lymphocyte surface molecules as immune activation biomarkers

Immunosuppression is mandatory after solid organ transplantation between HLA mismatched individuals. It is a lifelong therapy that needs to be closely monitored to avoid under- and over-immunosuppression. For many drugs, pharmacokinetic monitoring has been proven to be beneficial. However, the therapeutic ranges are statistically derived surrogate markers for the effects that cannot predict the individual response of single patients. Better tailored immunosuppression biomarkers are needed that indicate immune activation. T cells are critically involved in organ rejection, and the means to assess their activation state may be promising to individualize immunosuppressive therapies. Activated T cells can be monitored with flow cytometry based on surface molecules that are typically up regulated or with molecules that are cleaved off the cell surface. Among these molecules are the interleukin-2 receptor (CD25); transferrin receptor (CD71); the T cell co-stimulatory molecules CD28, CD69, and CD154 and sCD30, which is a member of the TNF-alpha family. The effect of immunosuppressive drugs on T cell activation can be recorded with indirect cell function assays or by directly monitoring activated T cells in whole blood. Soluble proteins can be measured with immunoassays. This review provides a summary of the experimental and clinical studies investigating the potential of surface molecules as a tool for immune monitoring. It critically discusses the obstacles and shortcomings from an analytical and diagnostic perspective that are currently preventing their use in multicenter trials and clinical routine monitoring of transplant patients.

Pre-transplant immune state defined by serum markers and alloreactivity predicts acute rejection after living donor kidney transplantation

Acute rejection (AR) remains a major cause for long-term kidney allograft failure. Reliable immunological parameters suitable to define the pre-transplant immune state and hence the individual risk of graft rejection are highly desired to preferably adapt the immunosuppressive regimen in advance. Donor and third party alloreactivities were determined by mixed lymphocyte cultures. Soluble forms of CD25, CD30, and CD44 were detected in patients' serum by ELISA. Various lymphocyte subpopulations were measured using flow cytometry. All patients received triple immunosuppression (tacrolimus/mycophenolate mofetil/steroids) and were grouped according to biopsy results within the first year: rejection-free (RF, n = 13), borderline (BL, n = 5), or acute rejection (AR, n = 7). Patients with AR showed the highest pre-transplant alloreactivities and serum levels (sCD25/sCD30/sCD44) according to the pattern RF < BL < AR. Relying on serum analysis only, multivariate logistic regression (logit link function) yielded a prognostic score for prediction of rejection with 75.0% sensitivity and 69.2% specificity. Patients with rejection showed markedly higher pre-transplant frequencies of CD4(+) /CD8(+) T cells lacking CD28, but lower numbers of CD8(+) CD161(bright) T cells and NK cells than RF individuals. Pre-transplant immune state defined by alloreactivity, serum markers, and particular lymphocyte subsets seems to correlate with occurrence of graft rejection after kidney transplantation. A prognostic score based on pre-transplant serum levels has shown great potential for prediction of rejection episodes and should be further evaluated.

Array-based methods for diagnosis and prevention of transplant rejection

DNA microarray is a microhybridization-based assay that is used to simultaneously study the expression of thousands of genes, thus providing a global view of gene expression in a tissue sample. This powerful technique has been adopted by many biomedical disciplines and will likely have a profound impact on the diagnosis, treatment and prognosis of human diseases. This review article presents an overview of the application of microarray technology to the field of solid-organ transplantation.

Immune reactivity of renal transplant recipients receiving interleukin-2 receptor antagonists during the early posttransplant period

PURPOSE

There is a need for methods that would enable monitoring of the effects of immunosuppression on the recipient's immune system to avoid rejection, immunodeficiency-related complications and non-immune toxicities of the drugs used in therapy.

METHODS

This prospective trial included thirty patients who underwent renal transplantation in our center. All patients received an interleukin-2 receptor (IL-2R) antagonist in combination with mycophenolate, corticosteroid and calcineurin inhibitor. During the first 6 weeks after transplantation, the anti-CD3-stimulated proliferative response of peripheral blood T lymphocytes (PBTL) was studied by cell cycle analysis. The proportion of PBTL in different phases of the cell cycle and expression of IL-2R were determined by flow cytometry.

RESULTS

As an effect of quadruple immunosuppressive therapy including IL-2R antagonists, cell cycle analysis showed an incremental decrease in the proliferative response of PBTL during the first 6 weeks after renal transplantation. A sudden drop in the proportion of IL-2R-positive cells was observed immediately after the first dose of the IL-2R antagonist and a significant antiproliferative effect on PBTL after the second dose. In vitro, IL-2R antagonists showed a dose-dependent inhibition of the anti-CD3-stimulated proliferation of PBTL of healthy blood donors.

CONCLUSIONS

Cell cycle analysis of the immune reactivity of renal allograft recipients may represent a valuable tool for the immunological posttransplant follow-up and optimization of the immunosuppressive therapy.

Human papillomavirus typing and soluble interleukin-2 receptor levels in female sex workers with a negative cervical smear result

OBJECTIVE

To investigate the association between high-risk human papillomavirus (HPV) types and soluble interleukin-2 receptor (sIL-2R) levels in female sex workers with a negative cervical smear result, and to determine the effectiveness of using sIL-2R levels to screen for high-risk strains of HPV.

METHOD

A negative cervical smear result and a blood sample were obtained from 68 women: 43 female sex workers and 25 women acting as controls. HPV DNA genotyping was performed and sIL-2R levels were assessed.

RESULTS

Female sex workers had significantly higher sIL-2R levels than women in the control group (318.37+/-239.7 vs 114.4+/-56.5 U/mL, respectively P<0.001). In addition, female sex workers with high-risk strains of HPV had significantly higher sIL-2R levels than those who did not have high-risk strains of HPV (736.7+/-251.5 vs 250.5+/-156.1 U/mL, respectively; P=0.001).

CONCLUSION

High sIL-2R levels may be useful in screening for high-risk strains of HPV in female sex workers who have a negative cervical smear result.

CD25 as an immune regulatory molecule expressed on myeloid dendritic cells

CD25 (alpha-chain of IL-2 receptor) on dendritic cells (DC) has been previously regarded as an activation marker. DC that concomitantly express surface CD25 and co-stimulatory molecules were considered to be fully mature. While both murine and human DC can express CD25, they do not express the beta-chain of the IL-2 receptor, which is indispensable for the execution of IL-2 signaling. The biological function of CD25 during the DC maturation therefore still remains undefined. In this review we focus on recent findings, describing CD25 expression and secretion by human myeloid regulatory DC. These DC co-express CD25 and the immunoregulatory enzyme indoleamine 2,3-dioxygenase (IDO) and inhibit T-cell function. CD25, expressed and secreted by such DC may capture IL-2 and thereby suppress T-cell proliferation, by this means providing an accessory mechanism of DC-mediated immune suppression. We also discuss the implication of DC-derived CD25 for human disease in both cancer and chronic infection.

Serum soluble interleukin 2 receptor alpha in human cancer of adults and children: a review

Cancer growth and development is associated with the stimulation of the innate immune system, including enhanced interleukin 2 receptor (IL-2R) expression in immune cells and its shedding into the circulation in a soluble form of sIL-2Ralpha. In most haematological malignancies, including different types of leukaemias and lymphomas, sIL-2Ralpha has been found to be released directly from the surface of neoplastic cells thus reflecting the tumour bulk, turnover and activity. Several studies have proved that not only lymphoid cancer cells, but also some non-lymphoid cancer cells, express IL-2R on their surface. They include malignant melanoma and carcinomas of the kidney, head and neck, oesophagus and lung. It is suggested that in most malignant solid tumours, elevated levels of sIL-2Ralpha are likely to be the product of normal peripheral mononuclear cells activated in response to the neoplasm's growth or that they are released from activated lymphoid cells infiltrating neoplastic tissues. This latter hypothesis has been proved by discovering the high expression of CD25 on the cell surface of most of these cells. Although the precise source and biological role of sIL-2Ralpha has not been clarified definitively, pretreatment serum levels of sIL-2Ralpha have been shown to reflect the activity, advancement and biological aggressiveness of many types of cancer in adults and children as well as to correlate with prognosis and overall survival. The possibility of enriching the diagnostic tools of oncologists with a new biochemical marker of activity of neoplasms resulted in numerous studies and reports concerning the clinical usefulness of sIL-2Ralpha measurements in adult and, less frequently, in paediatric malignancies. This article presents the actual knowledge concerning the structure, source and biological function of sIL-2Ralpha in patients with haematological and non-haematological malignancies. The authors review the published data on clinical applicability of soluble IL-2Ralpha determination in terms of diagnostics, prognosis and treatment monitoring of particular types of malignant disorders both in adults and in children. They also provide an insight into the clinical usefulness of sLL-2Ralpha-blocking antibodies in patients with cancer, and in those who reject organ transplants, develop graft-versus-host disease after allogeneic bone marrow transplantation and are affected with autoimmune disorders.

A humanized monoclonal antibody against interleukin-2 that can inactivate the cytokine/receptor complex

Inhibition of the interleukin-2 (IL-2) pathway has potent immunosuppressive activity in humans as is evident from the broad therapeutic utility of cyclosporine, rapamycin, tacrolimus, and monoclonal antibodies blocking the high-affinity subunit of the IL-2 receptor (CD25). Here we describe a humanized antibody, MT204, interfering with IL-2 signaling by a novel mechanism. Although MT204 did not prevent IL-2 from binding to CD25, it potently antagonized downstream signaling events of IL-2 at sub-nanomolar concentrations, such as STAT3 tyrosine phosphorylation, expression of CD124, production of gamma-interferon and cell proliferation. While MT204 and the anti-CD25 mAb daclizumab were equally effective in inhibiting autocrine growth of human CD4(+) T cells, MT204 was far superior in preventing proliferation of NKL lymphoma cells, production of gamma-interferon by natural killer (NK) cells and proliferation of primary NK cells. MT204 has potential as a novel immunosuppressive and anti-proliferative therapy with an apparently broader spectrum of activities than anti-CD25 antibodies.

Is the Determination of the Soluble Interleukin-2 Receptor after Application of Interleukin-2 Receptor Antibodies Still Appropriate for Immunological Monitoring after Renal Transplantation?

INTRODUCTION

The use of monoclonal antibodies against the alpha-chain of the membrane-bound interleukin-2 receptor (IL-2Ralpha) as immune suppressants causes characteristic changes in the levels of soluble interleukin-2 receptor (sIL-2R) in serum and urine.

METHODS

38 kidney transplant patients were included in this study. 28 of them received an induction therapy with the IL-2R antibody basiliximax (Simulect) in addition to standard immunosuppression, 10 patients constituted the control group.

RESULTS

Time courses of sIL-2R levels of Simulect patients with and without complications after transplantation have been compared. It turned out that of a total of 18 cases with complications 15 cases could be identified by their elevated sIL-2R levels, which corresponds to a sensitivity of 83%.

CONCLUSION

Acute rejection, CMV infection, extrarenal bacterial infection and pyelonephritis in the transplant all cause a significant increase of the sIL-2R level even after application of Simulect.

Functional assessment of immune markers of graft rejection: a comprehensive study in live-related donor renal transplantation

A better understanding of the immunobiological processes and predictors of graft rejection holds promise for the development of potential therapeutic strategies and also individualization of immunosuppression. The objective of this study is to analyze the clinical relevance of immune parameters such as antidonor antihuman leukocyte antigen (anti-HLA) antibodies, monitoring of cytokines and their receptors on the graft outcome following live-related donor renal transplantation. Flow cytometry-based methods were used to detect antidonor antibodies (flow cytometry crossmatch, FCXM) and intracellular cytokines. Enzyme-linked immunosorbent assay (ELISA) methods were employed to detect anti-HLA class I and class II antibodies and quantitative serum-soluble interleukin-2 receptor (sIL-2R) levels. The data revealed that patients with HLA class I-specific IgG antibody experienced higher acute rejection (AR) episodes at 1 yr in comparison to the antibody negative group (82% vs. 56%, p = 0.01). On the contrary, donor-specific class II antibodies (B+) did not have any influence on the graft survival. However, 15 recipients having both T- and B-cell antidonor antibodies (T+B+) had significantly poor graft survival (60%) as compared to the antibody-negative group (T-B-, 82%, p = 0.05). Additionally, patients having non-donor but HLA-specific antibodies (FCXM-/ELISA+) had poor graft survival as compared to the antibody-negative group (64% vs. 88%, p < 0.05). Further, patients undergoing AR episodes had significantly higher expression of IFN-gamma-producing T cells (19.16 +/- 7.4% median 17.50) as compared to their pre-transplant levels (5.68 +/- 1.63%, Median 5.20) and the non-rejecter group (5.97 +/- 4.39%, median 4.3, p = 0.0004). Similarly sIL-2 was significantly increased in AR episodes during the first month of transplantation (292 +/- 131.5 pmol/L) as compared to those with well-functioning grafts (p = 0.01) and healthy controls (p = 0.001). Evaluation of antidonor antibodies by flow cytometry is found to be relatively more sensitive and a better predictor of graft outcome. Further monitoring of cytokine expression profile of primed peripheral T-helper cells and quantitative analysis of sIL-2R offer additional valuable diagnostic and prognostic tools for follow-up of transplant subjects and a better alternative for functional assessment of immunosuppression.