Appraisal of immune response in lymphoproliferative syndromes: A systematic review

The emerging role of anti-CD25 directed therapies as both immune modulators and targeted agents in cancer

CD25 (also termed IL2RA) forms one component of the high-affinity heterotrimeric interleukin 2 (IL2) receptor on activated T cells. Its affinity for IL2 and cellular function are tightly regulated and vary in different cell types. The high frequency of CD25 on the surface of many different haematological tumour cells is now well established and, apart from its prognostic significance, CD25 may be present on leukaemic stem cells and enable oncogenic signalling pathways in leukaemic cells. Additionally, high CD25 expression in activated circulating immune cells and Tregs is a factor that has already been exploited by IL2 immunotherapies for treatment of tumours and autoimmune disease. The relative clinical safety and efficacy of administering anti-CD25 radioimmunoconjugates and immunotoxins in various haematological tumour indications has been established and clinical trials of a novel CD25-directed antibody drug conjugate are underway.

Ratios of T-cell immune effectors and checkpoint molecules as prognostic biomarkers in diffuse large B-cell lymphoma: a population-based study

BACKGROUND

Risk-stratification of diffuse large B-cell lymphoma (DLBCL) requires identification of patients with disease that is not cured, despite initial treatment with R-CHOP. The prognostic importance of the revised International Prognostic Index (R-IPI) and cell of origin of the malignant B cell are established in DLBCL. We aimed to develop a novel, easily applicable, tissue-based prognostic biomarker based on quantification of the tumour microenvironment that is independent of and additive to the R-IPI and cell of origin.

METHODS

We performed digital hybridisation on the NanoString platform to assess the relation between immune effector and inhibitory (checkpoint) genes in 252 formalin-fixed, paraffin-embedded DLBCL tissue specimens obtained from patients treated with R-CHOP. We used a tree-based survival model to quantify net antitumoral immunity (using ratios of immune effector to checkpoint genes) and to generate a cutoff as an outcome predictor in 158 of the 252 patients. We validated this model in tissue (n=233) and blood (n=140) samples from two independent cohorts treated with R-CHOP.

FINDINGS

T-cell and NK-cell immune effector molecule expression correlated with tumour-associated macrophage and PD-1/PD-L1 axis markers, consistent with malignant B cells triggering a dynamic checkpoint response to adapt to and evade immune surveillance. The ratio of CD4*CD8 to (CD163:CD68[M2])*PD-L1 was better able to stratify overall survival than was any one immune marker or combination, distinguishing groups with disparate 4-year overall survival. 94 (59%) of 158 patients had a score above the cutoff and 4-year overall survival of 92·1% (95% CI 82·9-96·7), and the remaining 64 (41%) patients had a score below the cutoff and 4-year overall survival of 47·0% (32·8-60·5; hazard ratio [HR] 8·3, 95% CI 4·3-17·3; p<0·0001). The CD4*CD8:M2*PD-L1 immune ratio was independent of and added to the R-IPI and cell of origin. Tissue findings in the independent tissue cohort accorded with those in our initial tissue cohort. 139 (60%) of 233 patients had a score above the cutoff and 4-year overall survival of 75·6% (95% CI 64·6-83·6), with the remaining 94 (40%) patients having a score below the cutoff (63·5% [52·5-72·7]; HR 1·9, 95% CI 1·1-3·3; p=0·0067).

INTERPRETATION

Ratios of immune effectors to checkpoints augment the cell of origin and R-IPI in DLBCL and are applicable to paraffin-embedded biopsy specimens. These findings might have potential implications for selection of patients for checkpoint blockade within clinical trials.

FUNDING

Leukaemia Foundation of Queensland, Kasey-Anne Oklobdzijato Memorial Fund, the Australasian Leukaemia and Lymphoma Group (Malcolm Broomhead Bequest), the Australian Cancer Research Foundation, and the Cancer Council of Queensland.

Evaluation of significance of lymphocyte subpopulations and non-specific serologic markers in B-cell non-Hodgkin's lymphoma patients

The use of rituximab brought attention to the hosts' immune system and to the microenvironment in non-Hodgkin's lymphoma cases. Our aim was to identify prognostic factors that can be measured easily to indicate the current state of the patient's immune status and possible reaction against malignant cells. In the retrospective analysis (2000-2008), 66 patients diagnosed with B-cell non-Hodgkin's lymphomas were enrolled (40 women, 26 men; mean age: 51 years). White blood cells, lymphocytes, CD3 +; CD4 +; CD8 + T-cells, immunoglobulin types A; G; M, anti-cardiolipin antibody isotypes A; G; M; and levels of beta-2-microglobulin were measured before the initiation of the first cycle of chemotherapy, during and after 4-weeks treatment. As for CD 3+ T-lymphocytes, the absolute CD 3+ T -lymphocyte numbers were higher before (0.78 × 10(9)/L) versus during (0.27 × 10(9)/L) treatment, and increased percentages were detected in pre- (66.57 %) and post-treatment (75.32 %). Absolute numbers of CD 8+ T-lymphocyte levels showed reduction before (0.26 × 10(9)/L) versus during (0.10 × 10(9)/L) therapy, but were elevated after (0.28 × 10(9)/L) treatment, while increased percentage before (21.99 %) versus after (29.85 %), and during (24.56 %) versus after (29.85 %) therapy were seen. Average white blood cell numbers were increased before (9.71 × 10(9)/L) versus during (12.07 × 10(9)/L) treatment, while decreased numbers could be observed, after (5.47 × 10(9)/L) treatment. IgA levels were decreased before (2.51 g/L) versus after (1.63 g/L) therapy. IgG levels were higher before (12.25 g/L) vs. after (8.64 g/L) treatment. IgM levels were decreased before (1.76 g/L) and after (0.83 g/L) as well as before (1.76 g/L) versus during (0.73 g/L) treatment. Anti-cardiolipin antibody type A level were decreased before (2.76 U/ml) versus after (2.49 U/ml) treatment. Decreased level of beta-2-microglobulin could be observed before (2.91 mg/L) versus post (2.28 mg/L) chemotherapy. Findings may provide better insight into the effects of immuno-chemotherapy on the hosts' immune system.

Utilisation of search filters in systematic reviews of prognosis questions

BACKGROUND

Search filters are designed to increase efficiency of information retrieval and can be particularly useful in limiting the large numbers of articles retrieved for systematic reviews (SRs). Existing published prognosis search filters (or hedges) have lower sensitivity and precision values than their therapy counterparts.

OBJECTIVES

Taking into account the relatively poor performance of prognosis filters, this study seeks to identify which methods of limiting search results to prognostic studies are most often used by SR teams.

METHODS

One hundred and three SRs of prognostic studies published in 2009 and indexed in MEDLINE were retrieved. Each review's search strategy was reviewed and prognosis-related search terms were extracted.

RESULTS

Forty-seven of 103 studies used prognosis-related terms to limit the search. Six SRs of 103 did not specify their search terms, and the remaining 50 SRs used content terms only (no terms related to methodology or prognosis). Of the 47 strategies using prognosis-related terms, only six used a published filter. Many SRs used few or poorly selected prognosis-related search terms which are unlikely to provide the sensitivity generally sought for SRs.

CONCLUSIONS

Published prognosis search filters are used in only a small minority of prognosis SRs.

Role of immune escape mechanisms in Hodgkin's lymphoma development and progression: a whole new world with therapeutic implications

Hodgkin's lymphoma represents one of the most frequent lymphoproliferative syndromes, especially in young population. Although HL is considered one of the most curable tumors, a sizeable fraction of patients recur after successful upfront treatment or, less commonly, are primarily resistant. This work tries to summarize the data on clinical, histological, pathological, and biological factors in HL, with special emphasis on the improvement of prognosis and their impact on therapeutical strategies. The recent advances in our understanding of HL biology and immunology show that infiltrated immune cells and cytokines in the tumoral microenvironment may play different functions that seem tightly related with clinical outcomes. Strategies aimed at interfering with the crosstalk between tumoral Reed-Sternberg cells and their cellular partners have been taken into account in the development of new immunotherapies that target different cell components of HL microenvironment. This new knowledge will probably translate into a change in the antineoplastic treatments in HL in the next future and hopefully will increase the curability rates of this disease.

Cellular immunotherapy for high-grade glioma

The outcome for patients with the most common primary brain tumor, glioblastoma multiforme (GBM), remains poor. Several immunotherapeutic approaches are actively being pursued including antibodies and cell-based therapies. While the blood-brain barrier protects brain tumor cells from therapeutic antibodies, immune cells have the ability to traverse the blood-brain barrier and migrate into GBM tumors to exert their therapeutic function. Results of Phase I clinical studies with vaccines to induce GBM-specific T cells are encouraging and Phase II clinical trials are in progress. Nonvaccine-based cell therapy for GBM has been actively explored over the last four decades. Here we will review past clinical experience with adoptive cell therapies for GBM and summarize current strategies on how to improve these approaches.

Both CD4+ FoxP3+ and CD4+ FoxP3- T cells from patients with B-cell malignancy express cytolytic markers and kill autologous leukaemic B cells in vitro

Cytotoxic CD4(+) T cells have been found in patients with chronic lymphocytic leukaemia (CLL) and seem to be involved in the regulation of malignant B cells. The CD4(+) T regulatory cells (Tregs) can regulate various immune cells, including B cells, by inducing their apoptosis. Hence, different subgroups of CD4(+) T cells may be involved in the regulation of malignant B cells. In this study, the cytotoxic phenotype and function of various CD4(+) T-cell subgroups were investigated in patients with B-cell malignancies. Peripheral blood was collected from patients with CLL, various B-cell lymphomas, healthy adult donors, children with precursor B-cell acute lymphoblastic leukaemia (pre-B ALL) and from healthy children. CD4(+) T cells (CD3(+) CD4(+)  FoxP3(-)), Tregs (CD3(+) CD4(+) CD127(low) FoxP3(+)) and CD127(high) FoxP3(+) T cells (CD3(+) CD4(+) CD127(high) FoxP3(+)) were analysed for their expression of the cytolytic markers CD107a and Fas ligand. Patients with CLL had increased CD107a expression on all tested T-cell subgroups compared with healthy donors. Similar results were found in patients with B-cell lymphomas whereas the CD107a expression in children with pre-B ALL was no different from that in healthy controls. Fas ligand expression was similar between patient cells and cells of healthy donors. CD4(+) T cells and Tregs from patients with CLL and healthy donors were subsequently purified and cultured in vitro with autologous B cells. Both subgroups lysed B cells and killing was confirmed by granzyme ELISAs. In conclusion, cytotoxic populations of CD4(+) T cells, including Tregs, are present in patients with B-cell malignancy and may be an important factor in immune-related disease control.

Tumor microenvironment and immune effects of antineoplastic therapy in lymphoproliferative syndromes

Lymphomas represent a wide group of heterogenic diseases with different biological and clinical behavior. The underlying microenvironment-specific composition seems to play an essential role in this scenario, harboring the ability to develop successful immune responses or, on the contrary, leading to immune evasion and even promotion of tumor growth. Depending on surrounding lymphoid infiltrates, lymphomas may have different prognosis. Moreover, recent evidences have emerged that confer a significant impact of main lymphoma's treatment over microenvironment, with clinical consequences. In this review, we summarize these concepts from a pathological and clinical perspective. Also, the state of the art of lymphoma's anti-idiotype vaccine development is revised, highlighting the situations where this strategy has proven to be successful and eventual clues to obtain better results in the future.