Israel Medical Association Journal

Several novel strategies have emerged in the last decade as potential therapies for patients with chemorefractory lymphoproliferative diseases and acute leukemia. While these treatments include exciting drugs that dramatically change the landscape of treatment, the organ-toxicity profile associated with these therapies may be significant. This article focuses on cardiac disorders associated with chimeric antigen receptor T-cell (CAR-T) therapy, as well as with novel regimens for acute leukemia

Background: Tumor treating fields (TTFields) are low-intensity, intermediate frequency electric fields that affect proliferating cells. TTFields are FDA approved for treatment of newly diagnosed and recurrent glioblastoma. Combining TTFields with immunotherapy is a rational approach due to their different mechanisms of action (MOA) and to the ability of TTFields to induce immunogenic cell death. Conversely, TTFields may interfere with immune functions critical for effective T-cell responses.

Objectives: To evaluate the effects of TTFields on pivotal antitumoral T-cell functions.

Methods: T-cells from healthy donor peripheral blood (PB) or from viably dissociated human glioblastoma samples were cultured under normal or TTFields conditions, with or without superantigen stimulation. Multiparametric flow cytometry (8-color) was used to assess T-cell responses by monitoring select pivotal functions: proliferation (CFSE), IFNγ secretion, cytotoxic degranulation (CD107a), and activation/exhaustion (PD-1). Cellular viability was assessed in a dedicated assay. A chimeric antigen receptor (CAR) T-cell-based assay directly evaluated cellular cytotoxicity.

Results: Activated PB T-cells and tumor-infiltrating T-cells (TILs) preserved all monitored anti- tumoral functions under TTFields, apart from proliferation. This finding also applied specifically to PD-1 + TILs, comprised predominantly of tumor antigen-specific cells. Activated T-cells that attempted to proliferate under TTFields demonstrated decreased viability, in line with TTField MOA. Small or no reduction in viability was found in T-cells that did not attempt to proliferate, whether activated or resting.

Conclusions: All monitored anti-tumoral T cell functions, except for proliferation, were unhindered by TTFields. Our results support further investigation into combinations of TTFields with T-cell based immunotherapeutic approaches.

Objective: To assess the ability of TREC and KREC counts to identify patients with combined T and B cell immunodeficiency in a pilot study in Israel.

Methods: We studied seven children born in Israel during the years 2010–2011 and later diagnosed with SCID, and an additional patient with pure B cell immunodeficiency. TREC and KREC in peripheral blood upon diagnosis and in their neonatal Guthrie cards were analyzed using real-time quantitative polymerase chain reaction, as were Guthrie cards with dried blood spots from healthy newborns and from normal and SCID-like controls.

Results: The first features suggestive of SCID presented at age 3.1 ± 2.4 months in all patients. Yet, the diagnosis was made 4.1 ± 2.9 months later. Their TREC were undetectable or significantly low at their clinical diagnosis and in their originally stored Guthrie cards, irrespective of the amount of their circulating T cells. KREC were undetectable in six SCID patients who displayed B cell lymphopenia in addition to T cell lymphopenia. KREC were also undetectable in one patient with pure B cell immunodeficiency.

Conclusions: TREC and KREC quantification are useful screening tests for severe T and B cell immunodeficiency. Implementation of these tests is highly important especially in countries such as Israel where a high frequency of consanguinity is known to exist. 

Background: Survival in T cell lymphoblastic lymphoma has improved over the past 30 years, largely due to treatment protocols derived from regimens designed for children with acute lymphoblastic leukemia.

Objectives: To assess the outcome of the NHL-BFM-95 protocol in children and adolescents hospitalized during the period 1999–2006.

Methods: We conducted a retrospective multi-institutional, non-randomized study of children and adolescents up to age 21 with T cell lymphoma admitted to pediatric departments in six hospitals in Israel, with regard to prevalence, clinical characteristics, pathological characteristics, prognostic factors, overall survival (OS) and event-free survival (EFS). All patients had a minimal follow-up of one year after diagnosis. The study was based on the NHL[1]-BFM[2]-95 protocol.

Results: At a median follow-up of 4 years (range 1–9 years), OS and EFS for all patients was 86.5% and 83.8%, respectively. OS was 86.7% and 83.3% for patients with stage III and stage IV, respectively, and EFS was 83.3% and 83.3%, respectively. EFS was 62.5% for Arab patients and 89.7% for Jewish patients (P = 0.014). Patients who did not express CD45 antigen showed superior survival (P = 0.028). Five (13.5%) patients relapsed, four of whom died of their disease. Death as a consequence of therapy toxicity was documented in one patient while on the re-induction protocol (protocol IIA).

Conclusions: Our study shows that OS and EFS for all patients was 86.5% and 83.8%, respectively.

Background: Adenoviral infection in children undergoing stem cell transplantation is associated with significant morbidity and mortality. Identification of adenoviral infection by polymerase chain reaction from blood facilitates accurate and rapid diagnosis and surveillance. The incidence of adenoviral infection among children undergoing SCT[1] in Israel is not known.

Objective: To estimate the incidence of adenoviral infection in pediatric SCT patients and to characterize the morbidity associated with proven infection.

Methods: Blood samples obtained weekly from children who underwent allogeneic SCT were retrospectively tested for adenovirus using standard PCR[2]. A total of 657 samples collected from 32 patients were examined. Correlation was made between the presence of adenovirus in samples and clinical records.

Results: Of the 32 patients 4 had adenoviral infection by PCR (12.5%). Clinical disease was present in all four patients concurrent with positive PCR. Gastrointestinal complaints and abnormal hepatocellular enzymes were uniformly present. One patient died due to disseminated disease. T cell depletion was a significant risk factor for adenoviral infection (P = 0.03).

Conclusions: In the patient population studied, the incidence of adenoviral infection in children undergoing SCT was 12.5%. The combination of gastrointestinal symptoms and abnormal hepatocellular enzymes should raise the suspicion of adenoviral infection, especially when occurring during the first few months after SCT. 

Tumor necrosis factor-associated fever syndrome is an autosomal dominant disorder caused by mutations of the TNFRSF 1A gene encoding the 55 kD TNF receptor (p55 TNF-RI).

Background: Superantigens produced by Staphylococcus aureus and Streptococcus pyogenes are among the most lethal of toxins. Toxins in this family trigger an excessive cellular immune response leading to toxic shock.

Objectives: To design an antagonist that is effective in vivo against a broad spectrum of superantigen toxins.

Methods: Short peptide antagonists were selected for their ability to inhibit superantigen-induced expression of human genes for cytokines that mediate shock. The ability of these peptides to protect mice against lethal toxin challenge was examined.

Results: Antagonist peptide protected mice against lethal challenge with staphylococcal enterotoxin B and toxic shock syndrome toxin-1, superantigens that share only 6% overall amino acid homology. Moreover, it rescued mice undergoing toxic shock. Antagonist peptides show homology to a β-strand/hinge/a-helix domain that is structurally conserved among superantigens, yet remote from known binding sites for the major histocompatibility class II molecule and T cell receptor that function in toxic T cell hyperactivation.

Conclusions: The lethal effect of superantigens can be blocked with a peptide antagonist that inhibits their action at the top of the toxicity cascade, before activation of T cells occurs. Superantigenic toxin antagonists may serve not only as countermeasures to biologic warfare but may be useful in the treatment of staphylococcal and streptococcal toxic shock, as well as in some cases of septic shock.
 

Background: Cell-mediated immunity is impaired in uremia. Cell-matrix interactions of immune cells such as CD4+T lymphocytes with extracellular matrix are an important requirement for an intact immune response. The adherence of CD4+T cells of healthy subjects (normal T cells) to ECM components is inhibited in the presence of uremic serum. Such decreased adhesive capacity is also found in T cells of dialysis patients. Various chemokines and cytokines affect the attachment of CD4+T cells to ECM.

Objective: To evaluate chemokine (MIP-1β and RANTES) and tumor necrosis factor α-induced adhesion of CD4+T cells to ECM in a uremic milieu.

Methods: We examined adhesion of normal CD4+T cells (resting and activated) to intact ECM in response to soluble or bound chemokines (MIP-1β and RANTES) and to TNF-α following incubation in uremic versus normal serum. Thereafter, we evaluated the adhesion of resting CD4+T cells from dialysis patients in a similar fashion and compared it to that obtained from a healthy control group.

Results: Addition of uremic serum diminished soluble and anchored chemokine-induced attachment of normal resting and activated CD4+T cells to ECM compared to a normal milieu (a peak response of 10–11% vs. 24–29% for soluble chemokines, P<0.001; 12–13% vs. 37–39% for bound chemokines on resting cells, P<0.01; and 18–20% vs. 45–47% for bound chemokines on activated cells, P<0.02). The same pattern of response was noted following stimulation with immobilized TNF-α (7 vs. 12% for resting cells, P<0.05; 17 vs. 51% for activated cells, P<0.01).  Adherence of dialysis patients’ cells to ECM following stimulation with both bound chemokines was reduced compared to control T cells (15–17% vs. 25–32%, P<0.0000). In contrast, adherence following stimulation by TNF-α was of equal magnitude.

Conclusions: Abnormal adhesive capacity of T lymphocytes to ECM in uremia may, in part, be related to a diminished response to MIP-1β, RANTES and TNF-α. However, whereas reduced adhesion to chemokines was present in both normal CD4+T cells in a uremic environment and in dialysis patients’ T cells, TNF-α-induced adhesion was found to be inhibited only in normal cells in a uremic milieu.

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ECM = extracellular matrix

TNF-α = tumor necrosis factor-a