Assessing immunologic function through CD4 T-lymphocyte ahenosine triphosphate levels by ImmuKnow assay in Chinese patients following renal transplantation

[Lymphocytes enzymatic status and peripheral blood neutrophils oxygen-dependent metabolism in patients with renal cancer]

The immune system, one of the most important homeostatic organism systems, is actively involved in the protection against malignant tumors. The earliest sighs of immune homeostasis disorders should be invetigated at the cellular level, because of cell functional manifestations depend on the state of intracellular metabolic reactions. The study of lymphocyte NAD(P)-dependent dehydrogenases activity and peripheral blood neutrophils oxygen-dependent metabolism in patients with renal cellular carcinoma (RCC) showed a decrease in the intensity of ribose-5-phosphate and NADH-dependent synthetic processes, inhibition of terminal reactions of glycolysis. Altered activities of the studied enzymes favor an increase in outflow of intermediates of the Krebs cycle on the reaction of amino acid metabolism in peripheral blood lymphocytes. Radical nephrectomy was accompanied by increased activity of glycolysis. The basal level chemiluminescent of peripheral neutrophils of RCC patients response was higher both before and after operations. Stimulation of neutrophils by opsonized zymosan in vitro leads to increase in oxidative metabolism activity, most in 14 days after surgery period. Before and 30 days after surgery, adaptive metabolic capabilities of neutrophilic granulocytes decreased.

[The immunological characteristics and enzymatic activity of lymphocytes from the peripheral blood of the children presenting with pharyngeal tonsillar hypertrophy]

The objective of the present work was to study the immunological characteristics and activity of NAD(P)-dependent dehydrogenases in peripheral blood lymphocytes in the young children presenting with pharyngeal tonsil hypertrophy (PTH). A total of 57 children at the age from 1 to 3 years with PTH were available for the examination. The control group was comprised of 35 age-matched practically healthy children. The amount of CD3+, CD4+, CD8+, CD16+/56-, and CD19+ cells in the peripheral blood was determined with the use of the cytoflowmetric technique. The activity of NAD(P)-dependent dehydrogenases in the peripheral blood lymphocytes was quantified by the method of A.A. Savchenko and co-workers ([14]. Serum IgA, IgM, and IgG levels were measured as described by G. Mancini and co-workers [12], and the levels of the circulating immune complexes (CIC) by the method of Haskova and co-workers [13]. The children presenting with pharyngeal tonsil hypertrophy were found to undergo changes in the immune-phenotypic spectrum of peripheral bloods lymphocytes, the decrease of serum IgA concentration, and the increase in the serum CIC level. The activity of riboso-5-phpsphate- and NADH-dependent reactions of the macromolecular synthesis was increased whereas the role of the malate-aspartate shunt in the cellular energy metabolism and activity of glycolysis decreased. On the contrary, the substrate flow in the tricarbonic acid cycle was rather high while glutathione reductase activity was low. The present study has shown that the children presenting with pharyngeal tonsil hypertrophy underwent changes in the immune and phenotypic spectrum of peripheral bloods lymphocytes, the decrease of serum IgA concentration, and the increase in the serum CIC level.

Umbilical Cord Mesenchymal Stromal Cell With Autologous Bone Marrow Cell Transplantation in Established Type 1 Diabetes: A Pilot Randomized Controlled Open-Label Clinical Study to Assess Safety and Impact on Insulin Secretion

OBJECTIVE

To determine the safety and effects on insulin secretion of umbilical cord (UC) mesenchymal stromal cells (MSCs) plus autologous bone marrow mononuclear cell (aBM-MNC) stem cell transplantation (SCT) without immunotherapy in established type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Between January 2009 and December 2010, 42 patients with T1D were randomized (n = 21/group) to either SCT (1.1 × 10(6)/kg UC-MSC, 106.8 × 10(6)/kg aBM-MNC through supraselective pancreatic artery cannulation) or standard care (control). Patients were followed for 1 year at 3-month intervals. The primary end point was C-peptide area under the curve (AUC(C-Pep)) during an oral glucose tolerance test at 1 year. Additional end points were safety and tolerability of the procedure, metabolic control, and quality of life.

RESULTS

The treatment was well tolerated. At 1 year, metabolic measures improved in treated patients: AUCC-Pep increased 105.7% (6.6 ± 6.1 to 13.6 ± 8.1 pmol/mL/180 min, P = 0.00012) in 20 of 21 responders, whereas it decreased 7.7% in control subjects (8.4 ± 6.8 to 7.7 ± 4.5 pmol/mL/180 min, P = 0.013 vs. SCT); insulin area under the curve increased 49.3% (1,477.8 ± 1,012.8 to 2,205.5 ± 1,194.0 mmol/mL/180 min, P = 0.01), whereas it decreased 5.7% in control subjects (1,517.7 ± 630.2 to 1,431.7 ± 441.6 mmol/mL/180 min, P = 0.027 vs. SCT). HbA1c decreased 12.6% (8.6 ± 0.81% [70.0 ± 7.1 mmol/mol] to 7.5 ± 1.0% [58.0 ± 8.6 mmol/mol], P < 0.01) in the treated group, whereas it increased 1.2% in the control group (8.7 ± 0.9% [72.0 ± 7.5 mmol/mol] to 8.8 ± 0.9% [73 ± 7.5 mmol/mol], P < 0.01 vs. SCT). Fasting glycemia decreased 24.4% (200.0 ± 51.1 to 151.2 ± 22.1 mg/dL, P < 0.002) and 4.3% in control subjects (192.4 ± 35.3 to 184.2 ± 34.3 mg/dL, P < 0.042). Daily insulin requirements decreased 29.2% in only the treated group (0.9 ± 0.2 to 0.6 ± 0.2 IU/day/kg, P = 0.001), with no change found in control subjects (0.9 ± 0.2 to 0.9 ± 0.2 IU/day/kg, P < 0.01 vs. SCT).

CONCLUSIONS

Transplantation of UC-MSC and aBM-MNC was safe and associated with moderate improvement of metabolic measures in patients with established T1D.

Immunosuppression Modifications Based on an Immune Response Assay: Results of a Randomized, Controlled Trial

BACKGROUND

An immune function assay shows promise for identifying solid organ recipients at risk for infection or rejection. The following randomized prospective study was designed to assess the clinical benefits of adjusting immunosuppressive therapy in liver recipients based on immune function assay results.

METHODS

Adult liver recipients were randomized to standard practice (control group; n = 102) or serial immune function testing (interventional group; n = 100) performed with a commercially available in vitro diagnostic assay (ImmuKnow; Viracor-IBT Laboratories, Lee's Summit, MO) before transplantation, immediately after surgery and at day 1, weeks 1 to 4, 6, and 8, and months 3 to 6, 9, and 12. The assay was repeated within 7 days of suspected/confirmed rejection/infection and within 1 week after event resolution.

RESULTS

Based on immune function values, tacrolimus doses were reduced 25% when values were less than 130 ng/mL adenosine triphosphate (low immune cell response) and increased 25% when values were greater than 450 ng/mL adenosine triphosphate (strong immune cell response). The 1-year patient survival was significantly higher in the interventional arm (95% vs 82%; P < 0.01) and the incidence of infections longer than 14 days after transplantation was significantly lower among patients in the interventional arm (42.0% vs. 54.9%, P < 0.05). The difference in infection rates was because of lower bacterial (32% vs 46%; P < 0.05) and fungal infection (2% vs 11%; P < 0.05). Among recipients without adverse events, the study group had lower tacrolimus dosages and blood levels.

CONCLUSIONS

Immune function testing provided additional data which helped optimize immunosuppression and improve patient outcomes.

Adenosine triphosphate production by peripheral blood CD4⁺T cells in clinically stable renal transplant recipients

Previous studies have shown that intracellular adenosine triphosphate (iATP) in activated CD4 T cells in vitro may identify patients at risk of infection or rejection post-transplantation. In this study, we evaluated whether this test could identify the level of risk in 656 renal transplant recipients (RTRs) with good and stable graft function. Therefore, 1095 blood samples from RTRs and 200 from healthy blood donors (normal controls [NCs]) were collected in 2 years and analyzed using the Cylex(®) ImmuKnow™ assay (Cylex, Inc., Columbia, MD, USA). The classification of T cell responses into strong, moderate, and low revealed significant differences between patients and NCs in low and strong responses (P < .001 and P = .021, respectively). The majority of patient samples exhibited moderate immune response (72.2%) in comparison with NC (75%). One hundred twenty-eight patients had fluctuated T cell responses between the three response zones. All patients were clinically stable for at least 1 month after the test. T cell response was increased after time post-transplantation (P < .001) and was found higher in protocols using azathioprine versus other immunosuppression (P < .001) and cyclosporine instead of tacrolimus (P = .012). According to the results of this study, we are not able to support this assay as an immune monitoring test post-transplantation in clinically stable RTRs. In contrast, measuring of iATP in CD4 T cells is a valuable tool for estimating T cell activation capacity. Because T cell activation is mainly affected by immunosuppression, this test may give information regarding the strength of different immunosuppressive protocols or the strength of immunosuppression as it is associated with longer follow-up periods.

Comparison of several functional methods to evaluate the immune response on stable kidney transplant patients

The introduction of new immunosuppressive drugs in the last two decades has been associated with a significant decline in the prevalence of acute rejection and a huge improvement of graft survival. Monitoring blood levels of immunosuppressive drugs is the most common way to control drug doses in renal transplant patients. This approach is useful and widely used but doesn't give accurate information about the immune status of the patient. For this goal, there are many "in house" protocols which give more information, but cannot be standardized, limiting their applicability to compare results between different laboratories. In this study we compare three classical functional methods to evaluate the immune response: Mixed lymphocyte reaction (MLR), phytohemagglutinin stimulated peripheral blood lymphocytes (PBLs), and anti-CD3 monoclonal antibodies (mAbs) against PBL with the only FDA-labeled assay to measure the patient immune status: Cylex ImmuKnow® that measures the intracelullar ATP in CD4+ lymphocytes. We used n=111 stable renal transplant patients, all the patients with more than one year functioning grafts. We referred the results to a control population of healthy blood donors (n=125).

RESULTS

Measurement of intracellular ATP in CD4+ lymphocytes is able to differentiate immunosuppressed populations in renal transplant patients from health controls (242.30±21.62 vs. 386.43±25.12, p 0.0001). By contrary, there were no differences between controls and renal recipients when functional response was measured by MLR, PHA and anti-CD3 mAbs (2.48±0.45 vs. 2.37±0.41; 2.84±0.76 vs. 2.37±0.32; 2.32±0.34 vs. 1.89±0.38 respectively). In summary, our results show that the measurement of ATP in CD4+ lymphocytes gives more accurate information in comparison to the classical methods.

Immunologic monitoring in kidney transplant recipients

Transplant biopsy has always been the gold standard for assessing the immune response to a kidney allograft (Chandraker A: Diagnostic techniques in the work-up of renal allograft dysfunction-an update. Curr Opin Nephrol Hypertens 8:723-728, 1999). A biopsy is not without risk and is unable to predict rejection and is only diagnostic once rejection has already occurred. However, in the past two decades, we have seen an expansion in assays that can potentially put an end to the "drug level" era, which until now has been one of the few tools available to clinicians for monitoring the immune response. A better understanding of the mechanisms of rejection and tolerance, and technological advances has led to the development of new noninvasive methods to monitor the immune response. In this article, we discuss these new methods and their potential uses in renal transplant recipients.

Significance of CD4 T-cell adenosine triphosphate levels monitoring in elderly renal transplant recipients

OBJECTIVES

To find the significance of CD4 T-cell adenosine triphosphate (ATP) levels in elderly renal recipients in correlation with drug doses, levels, and clinical parameters.

METHODS

Drug doses and levels, CD4 T-cell ATP level (162 sequential samples), and other clinical data were collected and assessed among 31 elderly renal recipients who underwent transplantations from November 2007 to March 2011.

RESULTS

Among subjects with stable clinical status, the main ATP levels pretransplantation were not significantly different from those posttransplantation: 302.4 ± 97.5 ng/mL versus 288.8 ± 102.6 ng/mL (P > .05). There was no relationship between ATP levels and tacrolimus concentrations or doses. In 12 patients experiencing infection, the ATP levels were significantly lower then those of subjects showing a stable clinical status: 127.3 ± 92.8 versus 288.8 ± 102.6 ng/mL (P < .01). Six patients with biopsy-proven acute rejection episodes did not show significantly higher ATP levels compared with those who were clinically stable: 26.2 ± 224.8 versus 288.8 ± 102.6 (P > .05).

CONCLUSIONS

CD4 T-cell ATP levels were valuable to monitor immunosuppression among elderly renal transplant recipients.

Use of the ImmuKnow assay to evaluate the effect of alemtuzumab-depleting induction therapy on cell-mediated immune function after renal transplantation

BACKGROUND

Good outcomes after renal transplantation are dependent on effective immunosuppression while minimizing infection. Alemtuzumab (Campath or Campath-1H) is an anti-CD52 humanized monoclonal IgG1 antibody which induces rapid and sustained depletion of circulating lymphocytes and has been effectively used as an immunosuppressant in post-transplant induction therapy.

METHODS

We used the ImmuKnow assay to compare cell-mediated immune function in renal transplant patients treated with alemtuzumab or with conventional immunosuppressive tri-therapy. The ImmuKnow method determines the levels of adenosine triphosphate (ATP) released from CD4 cells following stimulation with a mitogen.

RESULTS

We showed a statistically significant difference in the distribution of outcome after transplantation between the conventional and the Campath groups (P = 0.010). A significantly higher number of patients treated with alemtuzumab induction therapy were stable after transplantation compared to those treated with conventional immunosuppressive tri-therapy (96.6 vs. 75.7 %). ATP values were significantly higher in the conventional group compared to the Campath group at 180 days after transplantation (P < 0.001). ATP levels did not change significantly over time in clinically stable kidney recipients treated with alemtuzumab induction therapy (P = 0.554).

CONCLUSIONS

The ImmuKnow assay is a useful tool for evaluating the global immune response in alemtuzumab-treated renal transplant patients. Alemtuzumab-depleting induction therapy remains effective for at least 180 days.

Can immune cell function assay identify patients at risk of infection or rejection? A meta-analysis

BACKGROUND

The Cylex ImmuKnow cell function assay (CICFA) is being considered as a possible tool for identification of infection and rejection in transplant recipients. However, the predictive capability of CICFA is still unclear.

METHODS

Herein, we performed a meta-analysis to assess the efficacy of CICFA in identifying risks of infection and rejection posttransplantation. After a careful review of eligible studies, sensitivity, specificity, and other measures of the accuracy of CICFA were pooled. Summary receiver operating characteristic curves were used to represent the overall test performance.

RESULTS

Nine studies met the inclusion criteria. The pooled estimates for CICFA in identification of infection risk were poor, with a sensitivity of 0.58 (95% confidence interval [CI]: 0.52-0.64), a specificity of 0.69 (95% CI: 0.66-0.70), a positive likelihood ratio of 2.37 (95% CI: 1.90-2.94), a negative likelihood ratio of 0.39 (95% CI: 0.16-0.70), and a diagnostic odds ratio of 7.41 (95% CI: 3.36-16.34). The pooled estimates for CICFA in identifying risk of rejection were also fairly poor with a sensitivity of 0.43 (95% CI: 0.34-0.52), a specificity of 0.75 (95% CI: 0.72-0.78), a positive likelihood ratio of 1.30 (95% CI: 0.74-2.28), a negative likelihood ratio of 0.96 (95% CI: 0.85-1.07), and a diagnostic odds ratio of 1.19 (95% CI: 0.65-2.20).

CONCLUSION

The current evidence suggests that CICFA is not able to identify individuals at risk of infection or rejection. Additional studies are still needed to clarify the usefulness of this test for identifying risks of infection and rejection in transplant recipients.