Monitoring of T-cell subsets in patients treated with anti-CD 25 antibody

Donor-Derived CD123-Targeted CAR T Cell Serves as a RIC Regimen for Haploidentical Transplantation in a Patient With FUS-ERG+ AML

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) following chemotherapy is part of standard treatment protocol for patients with acute myeloid leukemia (AML). FUS-ERG+ AML is rare but has an extremely poor prognosis even with allo-HSCT in remission, possibly due to its a leukemia stem cell (LSC)-driven disease resulting in chemotherapy resistance and a novel therapy is urgently required. It has been reported that FUS-ERG-positive AML expresses CD123, a marker of LSC, in some cases. CD123-targeted CAR T cell (CART123) is promising immunotherapy, but how to improve the complete remission (CR) rate and rescue potential hematopoietic toxicity still need to explore.

Case Presentation: We used donor-derived CART123 as part of conditioning regimen for haploidentical HSCT (haplo-HSCT) in a patient with FUS-ERG+ AML who relapsed after allogeneic transplantation within 3 months, resists to multi-agent chemotherapy and donor lymphocyte infusion (DLI) and remained non-remission, aiming to reduce these chemotherapy-resistant blasts and rescue potential hematopoietic toxicity. The blasts in BM were reduced within 2 weeks and coincided with CAR copies expansion after CART123 infusion. The patient achieved full donor chimerism, CR with incomplete blood count recovery, and myeloid implantation.

Conclusion: Our results hints that CART123 reduces the chemotherapy-resistant AML blasts for FUS-ERG+ AML without affecting the full donor chimerism and myeloid implantation.

NFAT-regulated cytokine gene expression during tacrolimus therapy early after renal transplantation

AIMS

Despite pharmacokinetic monitoring of calcineurin inhibitors, the long-term outcome after transplantation (Tx) is still hampered by the side effects of these drugs. The aim of the present study was to characterize nuclear factor of activated T cells (NFAT)-regulated gene expression as a potential pharmacodynamic biomarker for further individualization of tacrolimus (Tac) therapy.

METHODS

In 29 renal allograft recipients, samples were drawn once pre-Tx, and before and 1.5 h after Tac dosing at approximately 1 week, 6 weeks and 1 year post-Tx. Tac concentrations were measured by immunoassay, while the expression of genes encoding NFAT-regulated cytokines [interleukin 2 (IL2), interferon gamma (IFNG), colony stimulating factor 2 (CSF2)] and cytochrome P450 3A5 (CYP3A5) genotyping were determined by real-time polymerase chain reaction.

RESULTS

The cytokine response after Tac dosing varied up to 46-fold between patients and changed significantly with time post-engraftment. Tac concentrations 1.5 h postdose (C_1.5 ) >15 μg l^-1 were associated with strong cytokine inhibition and residual gene expression (RGE) ≤10%, while lower Tac C_1.5 resulted in more variable responses (RGE 2.5-68.7%). Patients with ongoing subclinical acute rejection (n = 5) demonstrated limited cytokine inhibition (RGE 39.7-72.6%), while patients with polyoma virus viraemia (n = 3) had relatively strong inhibition of cytokines (RGE 2.5-32.5%). By contrast, there was no association between Tac exposure and rejection or viraemia.

CONCLUSIONS

The findings of our study support the potential of NFAT-regulated gene expression measurements as a pharmacodynamic tool for additional monitoring of Tac therapy, especially in the context of overimmunosuppression and viraemia.

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.

Serum acute phase protein and inflammatory cytokine network correlations: comparison of a pre-rheumatoid arthritis and non-rheumatoid arthritis community cohort

Serum concentrations of acute phase proteins, inflammatory cytokines, and other immunological components were individually assayed using high-sensitivity ELISA in a com-munity-based cohort of preclinical rheumatoid arthritis (pre-RA) and matched non-RA control (CN) subjects. Bivariate correlations of the biomarker panel concentrations were compared in pre-RA versus CN and female versus male subjects. Clinically elevated CRP levels (8+ mg/l) occurred in a higher (p = 0.010) frequency in 46 pre-RA (n = 8, 17.4%) subjects than in 179 CN (n = 9, 5.0%), and were independent of age, gender, smoking behaviors, and serum rheumatoid factor. Selected age and gender differences were found in levels of the immunological network factors. In each study group, the ratio of sTNF-RI to IL-2sRα mean concentrations was 2-fold higher in men than in women. Aging correlated positively with CRP, ASAA, and TNF-α levels, but negatively with IL-1β. Bivariate correlations were similar in pre-RA subjects versus CN and by gender, with few exceptions. Factor loadings in principal component analysis of the total subjects indicated that age- and gender-related variables constituted the two main components. Using multiple regression analyses, an integrative working model of all variable interrelations was generated. The tentative, directional model supports a concept of gender dimorphism of the ratio of sTNF-RI to IL-2sRα serum concentrations and displays differing effects of age on TNF-α versus IL-1β levels. These findings indicate complex age, gender, and cytokine interrelations in control of the immune systems network. Future research in testing such inflammatory pathways promises a better understanding of predisposition to diseases, like RA.

Immunosuppression armamentarium in 2010: mechanistic and clinical considerations

Effective immunosuppression is the key to successful organ transplantation, with success being defined as minimal rejection risk with concomitant minimal drug toxicities. Despite the general recognition of this fact, a paucity of appropriate clinical trials in children has contributed to lack of standardization of clinical management regimens, resulting in an extensive diversity of favored approaches. Nonetheless, although consensus has not been reached on the ideal approach to immunosuppression in pediatric transplantation, new drug therapies have contributed to a continuing improvement in graft and patient survival. Future clinical research must focus on diminishing the extensive burden of toxicities of these therapeutic agents in children.

Inflammatory bowel disease following solid organ transplantation

Inflammatory bowel disease (IBD) is a T cell driven inflammatory condition of the gut. Following solid organ transplantation (SOT), de novo IBD has been reported despite anti-T cell therapy for the prevention of organ rejection. This paradox is illustrated with a case report, highlighting the difficult diagnostic criteria, the potential role of Damage or Pathogen Associated Molecular Pattern Molecules [DAMPs and PAMPs] that drives aspects of ongoing inflammation within the transplanted organ as well as the intestine, and the therapeutic strategies applied. Recurrent IBD is more common than de novo IBD following transplantation, with cumulative risks ten years after orthotopic liver transplantation of 70% and 30%, respectively. Furthermore, the annual incidence of de novo IBD following solid organ transplantation has been estimated to be 206 cases/100,000 or ten times the expected incidence of IBD in the general population (approximately 20 cases/100,000). The association of IBD with other autoimmune conditions such as primary sclerosing cholangitis and autoimmune hepatitis, both common indications for liver transplantation, may play a contributory role, particularly in view of the observation that IBD is more common following liver transplant than other solid organ transplants. Recurrent IBD following transplant appears to run a more aggressive course than de novo IBD, with a higher proportion requiring colectomy for medically refractory disease. Risk factors that have been associated with development of post-transplant IBD include acute CMV infection and the use of tacrolimus.

Clinicopathological evaluation of renal allograft treated with anti-CD25 monoclonal antibody

Twenty-seven living-donor kidney recipients were treated with the antibody against CD25 as the induction immunosuppressive agent. They did not develop acute rejection within 1 month after transplantation, and mean serum creatinine level at 1 month was 1.0 +/- 0.4 mg/dL. There were no findings of acute rejection or drug-induced nephrotoxicity in protocol biopsies at 1 month following transplantation. After 1 month had passed, acute rejection occurred in three cases. The pathological grade of acute rejection varied from borderline to grade III by Banff classification. The careful inspection is necessary to find out the occurrences of acute rejection more than 2 months after transplantation because immunological situation has been changing around this period.

Pharmacological and functional characterization of endothelin receptors in bovine trabecular meshwork and ciliary muscle

To clarify the potential role of endothelin-1 (ET-1) in the pathogenesis of glaucoma, the endothelin receptors expressed in bovine trabecular meshwork (TM) and ciliary muscle (CM) were identified. TM and CM strips were subjected to ET-1 as well as to specific endothelin receptor antagonists. In both tissues BQ123, a specific ET-A receptor antagonist, substantially inhibited ET-1-induced contraction. BQ788, a specific ET-B receptor antagonist, showed only moderate effects. Both ET receptor types were detected in bovine TM and CM using Western blot analysis. ET-1 produced an increase in intracellular calcium in cultured TM cells. This effect was inhibited by BQ123, but not by BQ788. Thus, although both receptors are present, the ET-A receptor appears to play the predominant role in mediating contraction in both the TM and CM, while the ET-B receptor seems to contribute little to the overall ET-1 effect.