Philipp Ivanyi

Circulating endothelial cells are an early predictor in renal cell carcinoma for tumor response to sunitinib

BackgroundTyrosine kinase inhibitors (TKI) have enriched the therapeutic options in patients with renal cell carcinoma (RCC), which frequently induce morphological changes in tumors. However, only little is known about the biological activity of TKI. Circulating endothelial cells (CEC) have been associated with endothelial damage and, hence, may serve as a putative marker for the biological activity of TKI. The main objective of our study was to evaluate the predictive value of CEC, monocytes, and soluble vascular endothelial growth factor receptor (sVEGFR)-2 in RCC patients receiving sunitinib treatment.MethodsAnalyses of CEC, monocytes, and sVEGFR-2 were accomplished for twenty-six consecutive patients with metastatic RCC who received treatment with sunitinib (50 mg, 4 wks on 2 wks off schedule) at our institution in 2005 and 2006.ResultsIn RCC patients CEC are elevated to 49 ± 44/ml (control 8 ± 8/ml; P = 0.0001). Treatment with sunitinib is associated with an increase in CEC within 28 days of treatment in patients with a Progression free survival (PFS) above the median to 111 ± 61 (P = 0.0109), whereas changes in patients with a PFS below the median remain insignificant 69 ± 61/ml (P = 0.1848). Monocytes and sVEGFR2 are frequently altered upon sunitinib treatment, but fail to correlate with clinical response, defined by PFS above or below the median.ConclusionsSunitinib treatment is associated with an early increase of CEC in responding patients, suggesting superior endothelial cell damage in these patients as a putative predictive biomarker.

Human regulatory T cells of G-CSF mobilized allogeneic stem cell donors qualify for clinical application.

Recent clinical studies demonstrate the high potency of regulatory T cells (Tregs) to control graft-versus-host disease in hematopoietic stem cell transplantation (SCT). However, the adoptive transfer of Tregs is limited by their low frequency in unstimulated donors and considerable concerns that G-CSF induced SC mobilization might have negative effects on the stability and function of Tregs. The isolation of Tregs from the G-CSF mobilized SC grafts would extend this novel strategy for tolerance induction to the unrelated setting and simplify global clinical application. We characterized CD4+CD25highCD127− Tregs from SC donors before and after G-CSF mobilization for their phenotype, function, and stability. After G-CSF application the Treg cell yield increased significantly. Donor Tregs retained their cytokine profile, phenotypic characteristics and in vitro expansion capacity after SC mobilization. Most importantly, in vivo G-CSF stimulated Tregs remained highly suppressive on the proliferation of effector T cells, also after in vitro expansion, and displayed a stable phenotype in epigenetic studies. The surface expression of CXCR3 is transiently reduced. However, donor-derived Tregs maintain their migratory properties after G-CSF stimulation. Therefore, the adoptive transfer of Tregs from G-CSF mobilized SC donors seems to be a feasible and safe strategy for clinical application in allogeneic SCT.

Inflammatory pseudotumor of the lung following invasive aspergillosis in a patient with chronic graft‐vs.‐host disease

Abstract:  Inflammatory myofibroblastic tumor (IMT) is an uncommon cause of solitary or multifocal lung nodules and can also be rarely found in various other extrapulmonary sites. Although this pseudotumor is benign, it can be locally very aggressive. The pathogenesis of IMT remains unclear; autoimmune or infectious origins have been hypothesized, so far. Here, we report a case of inflammatory pseudotumor of the lung secondary to invasive pulmonary aspergillosis in a patient with chronic graft‐vs.‐host disease. The 42‐year‐old patient presented with coughing and hemoptysis as major clinical signs 1 yr after successful HLA‐identical stem cell transplantation. Aspergillus fumigatus was cultured from the bronchoscopoic lavage, but intensive antifungal treatment could only initially improve the clinical situation. Diagnostic re‐evaluation by open‐chest biopsy surprisingly revealed an inflammatory pseudotumor responsible for clinical and radiographical deterioration. Both clinical and radiographical signs resolved under long‐term steroids and secondary antifungal prophylaxis.

Identification of novel regulators in T-cell differentiation of aplastic anemia patients

BackgroundAplastic anemia (AA) is a bone marrow failure syndrome mostly characterized by an immune-mediated destruction of marrow hematopoietic progenitor/stem cells. The resulting hypocellularity limits a detailed analysis of the cellular immune response. To overcome this technical problem we performed a microarray analysis of CD3+ T-cells derived from bone marrow aspirates and peripheral blood samples of newly diagnosed AA patients and healthy volunteers. Two AA patients were additionally analyzed after achieving a partial remission following immunosuppression. The regulation of selected candidate genes was confirmed by real-time RT-PCR.ResultsAmong more than 22.200 transcripts, 583 genes were differentially expressed in the bone marrow of AA patients compared to healthy controls. Dysregulated genes are involved in T-cell mediated cytotoxicity, immune response of Th1 differentiated T-cells, and major regulators of immune function. In hematological remission the expression levels of several candidate genes tend to normalize, such as immune regulators and genes involved in proinflammatory immune response.ConclusionOur study suggests a pivotal role of Th1/Tc1 differentiated T-cells in immune-mediated marrow destruction of AA patients. Most importantly, immune regulatory genes could be identified, which are likely involved in the recovery of hematopoiesis and may help to design new therapeutic strategies in bone marrow failure syndromes.

Reconstitution and Phenotype of Tregs in CMV Reactivating Patients Following Allogeneic Hematopoietic Stem Cell Transplantation

In experimental and clinical settings Tregs prevent graft-versus-host disease (GvHD) by inhibiting the proliferation and function of conventional T cells (Tconv). The suppressive potency of Tregs might also lead to the inhibition of protective antiviral T cell responses. As the control of CMV reactivation is important to improve the clinical outcome in allogeneic HSCT, we analyzed the Treg reconstitution in CMV reactivating patients with and without GvHD (n=47) in the first 6 months following transplantation. Most importantly, CMV reactivation does not correlate with the numerical reconstitution of CD4+CD25highCD127− Tregs. During CMV reactivation the proportion of Tregs within the CD4+ T cell population decreased significantly independent of GvHD manifestation. A comprehensive FACS analysis was performed in order to characterize the phenotype of Tregs and Tconv cells in greater detail for activation, co-stimulation, proliferation, suppressive function and migratory capability. Interestingly, Tregs of patients with CMV reactivation showed a significantly higher CXCR3 expression. CD4+ Tconv cells expressed significantly higher protein levels of the proliferation marker Ki67 correlating with a numerical increase of CD4+ T cells. Our results indicate that Tregs are not inhibiting pathogen clearance by Tconv following HSCT, which is of high relevance for future Treg cell-based clinical trials in allogeneic HSCT.

Confusion of therapeutic approaches.

Schlitt et al. in their review article focused on cardiotoxic oncological treatments (1). Adequate management of adverse effects of cardiotoxic treatments ensures optimal results of oncological treatment. In the article by Schlitt et al., an algorithm was proposed for monitoring, prevention, and treatment in the context of cardiotoxicity, including the VEGFR inhibitors sunitinib and sorafenib. Schmidinger et al. postulated direct cardiotoxicity for sunitinib and sorafenib on the basis of a retrospective analysis (2). However, prospective clinical studies did not confirm this suspicion (Haas et al, ASCO Annual Meeting Proceedings, J Clin Oncol 2012; 30[suppl 18; abstr 4500]; Michel MS et al., ASCO Genitourinary Cancers Symposium, J Clin Oncol 2014; 32[suppl 4; abstr 393]). Rather, the discussion concerns cardiac events as a consequence of uncontrolled, treatment-associated, arterial hypertension, a class-specific adverse drug effect of the VEGFR inhibitors (3). Accordingly, monitoring and regulation of blood pressure in patients taking VEGFR inhibitors are essential in order to prevent secondary cardiac events (4). For cytotoxic drugs, such as doxorubicin, the monitoring measures for identifying cumulative myocardial injury described by Schlitt et al may be adequate, but this approach is not \sufficient for VEGFR inhibitors. In sum, my main criticism of the proposed algorithm is the confusion of curative and palliative treatments, as well as the lack of discrimination between acute, sporadically occurring, and cumulative cardiotoxicity, which as a rule have different underlying pathomechanisms. A blanket recommendation to monitor cardiac function often does not do justice to the individual therapeutic scenario and requires an understanding of the class of substance administered. At least for the use of VEGFR inhibitors there is hardly any rationale for the proposed algorithm; instead, the priority should be to proactively regulate and monitor blood pressure during treatment.

High cut-off dialysis as a salvage therapy option in high-dose methotrexate chemotherapy?

Dear Editor,High-dose methotrexate (HD-MTX) is a standard chemother-apy for a variety of malignancies [1]. Despite intensive pre-cautions, 2–10 % of the patients experience MTX-relatednephrotoxicity due to intratubular crystal precipitation andinduction of acute tubular necrosis (ATN) [2]. Acute kidneyinjury (AKI) leads to delayed MTX clearance and sustainedelevated MTX plasma levels, requiring prompt institution ofintensifiedleucovorinrescuetoavoidfataltoxicity[3].MTX-eliminating procedures, such as carboxypeptidase-G

Pre T-cell receptor alpha (pTα) expression patterns and functional analysis in human T-cell lymphoblastic leukemia

Background: The pTα/preTCR regulates the β-selection, a crucial T-cell developmental checkpoint, providing a most potent survival advantage to thymocytes mediated by the src-kinase p56Lck. Methods: To define the relevance of pTα in human T-cell lymphoblastic leukemia (T-ALL), we analyzed in T-ALL cell lines (n=14) pTα and p56Lck mRNA and protein expression as also the tyrosine-phosphorylation. The p56Lck specific src-protein-tyrosine kinase inhibitor (PTK-I) PP1 was used in growth inhibition assays. IC50 value determination, cell cycle- and apoptosis analyses were performed in T-ALL-, non-T-ALL- and murine transgenic cell lines. Results: pTα expression patterns were markedly different in T-ALL cell lines as compared to those reported for normal lymphoid counterparts. PP1 induced in 6/11 T-ALL cell lines a survival disadvantage resulting from a cell cycle arrest in the G1/0 phase in thymic lymphoblastic cells and apoptosis induction in the immature cell line HSB-2, respectively. PP1 sensitive cell lines expressed the target protein p56Lck and showed a corresponding P-Tyr signal. Conclusions: Sensitivity of thymic T-ALLs to PP1 clearly underlines the impact of pTα mediated proliferation in this leukemic sub-type. In addition, p56Lck represents also independently of pTα a promising therapeutical target for the src-kinase inhibitors in neoplastic lymphoid diseases.

Prognostic impact of PD-1 and its ligands in renal cell carcinoma

Programmed death-1 receptor (PD-1) and programmed death-1 receptor-ligand (PD-L1) have been suggested to play a role as prognostic markers in clear cell renal cell carcinoma (ccRCC). The association between PD-L1 and prognosis seems to be more robust than for PD-1. Further, preliminary analyses suggest that neither PD-1 nor its ligands play a role as prognostic markers in non-clear cell RCC, while the prognostic role of PD-L2 in ccRCC as well as in non-clear cell RCC remains unclear.

Predictive Factors for Second-Line Therapy in Metastatic Renal Cell Carcinoma: A Retrospective Analysis

Currently, about 50% of patients with metastatic renal cell carcinoma (mRCC) receive a second-line therapy. Therefore, the choice at each subsequent treatment line remains an important issue. In this retrospective study, we sought to identify pretreatment clinical parameters that could predict the likelihood of a patient receiving a second-line therapy. One hundred and sixty-one mRCC patients who received targeted therapy were evaluated. Descriptive statistics, Kaplan–Meier overall survival (OS), Cox regression, and binary logistic regression models were used for data analysis. Second-line therapy was given to 105 patients (65%). Patients with grade 1 tumor received second-line therapy more frequently than those with grade 2/3 tumors (P = 0.03). Only tumor grade was significantly different between patients receiving, or not receiving, second-line treatment. Median OS was significantly superior in patients receiving second-line therapy (32 versus 14 months; P = 0.007; hazard ratio [HR], 1.75; P = 0.008), patients with grade 1 tumors (130 versus 29 months in G2/3 tumors; HR, 3.85; P = 0.009), and in patients without early tumor progression (41 versus 11 months; HR, 5.04; 95% confidence interval [CI], 3.06–8.31; P < 0.001). In binary logistic regression, we identified early progression to be significantly associated with a higher probability of not receiving a second-line therapy (HR, 2.50; 95% CI, 1.01–6.21; P = 0.048). This study hypothesizes that pretreatment grade and early progression are predictive parameters for the selection of patients for second-line therapy.