Per-Ola Andersson

T-cell-mediated cytotoxicity toward platelets in chronic idiopathic thrombocytopenic purpura.

Chronic idiopathic thrombocytopenic purpura (ITP) is a bleeding disorder that is characterized by increased platelet destruction and is believed to be autoantibody mediated. In this study, CD3+ T cells from ITP patients had increased expression of genes involved in cell-mediated cytotoxicity. In addition, cytotoxic cell-mediated lysis of autologous platelets was shown in active ITP. Our data suggest that T-cell-mediated cytotoxicity is an alternative mechanism for platelet destruction in ITP.

Targeting p53 in Vivo: A First-in-Human Study With p53-Targeting Compound APR-246 in Refractory Hematologic Malignancies and Prostate Cancer

PURPOSE APR-246 (PRIMA-1MET) is a novel drug that restores transcriptional activity of unfolded wild-type or mutant p53. The main aims of this first-in-human trial were to determine maximum-tolerated dose (MTD), safety, dose-limiting toxicities (DLTs), and pharmacokinetics (PK) of APR-246. PATIENTS AND METHODS APR-246 was administered as a 2-hour intravenous infusion once per day for 4 consecutive days in 22 patients with hematologic malignancies and prostate cancer. Acute myeloid leukemia (AML; n = 7) and prostate cancer (n = 7) were the most frequent diagnoses. Starting dose was 2 mg/kg with dose escalations up to 90 mg/kg. RESULTS MTD was defined as 60 mg/kg. The drug was well tolerated, and the most common adverse effects were fatigue, dizziness, headache, and confusion. DLTs were increased ALT/AST (n = 1), dizziness, confusion, and sensory disturbances (n = 2). PK showed little interindividual variation and were neither dose nor time dependent; terminal half-life was 4 to 5 hours. Tumor cells showed cell cycle arrest, increased apoptosis, and upregulation of p53 target genes in several patients. Global gene expression analysis revealed changes in genes regulating proliferation and cell death. One patient with AML who had a p53 core domain mutation showed a reduction of blast percentage from 46% to 26% in the bone marrow, and one patient with non-Hodgkins lymphoma with a p53 splice site mutation showed a minor response. CONCLUSION We conclude that APR-246 is safe at predicted therapeutic plasma levels, shows a favorable pharmacokinetic profile, and can induce p53-dependent biologic effects in tumor cells in vivo.

A transforming growth factor-β1-mediated bystander immune suppression could be associated with remission of chronic idiopathic thrombocytopenic purpura

Abstract Bystander immune suppression has been demonstrated in experimental models of oral immune tolerance induction. This phenomenon is associated with expression of transforming growth factor (TGF)-β1 and T-helper cell (Th) 2 cytokines. We have studied serum levels of Th cytokines and B- and T-lymphocyte subsets in chronic idiopathic thrombocytopenic purpura (ITP), a disorder in which the production of platelet autoantibodies might be caused by a cytokine network dysregulation. Forty-six patients with ITP were separated into three groups depending on the platelet count (pltc): (1) <50×109/l, (2) 50–150×109/l and (3) >150×109/l. We found significantly elevated plasma levels of the Th3 cytokine TGF-β1 in patients with pltc >150×109/l (23.5±2.8 ng/ml), compared with patients with pltc <50×109/l (2.3±0.6 ng/ml;P<0.0001), patients with pltc 50–150×109/l (7.2±1.7 ng/ml;P<0.0001) and healthy volunteers (9.8±1.3 ng/ml;P<0.01). The serum levels of the Th1 cytokines interleukin (IL)-2 and interferon (IFN)-γ were below the detection limits of the assays. Likewise, the Th2 cytokine IL-4 was not detectable or was very low both in patients and controls. The serum levels of IL-10, a Th2 cytokine, were within the assay range and patients with pltc <50×109/l had significantly lower levels (0.6±0.1 pg/ml) than both patients with pltc 50–150×109/l (1.8±0.1 pg/ml;P<0.005) and healthy volunteers (1.4±0.1 pg/ml;P<0.005). Furthermore, patients with pltc <50×109/l and splenectomised patients had significantly higher levels of CD4+CD25+ activated T cells [26.2±14.8% (P<0.05) and 26.7±11.9% (P<0.005), respectively] than healthy controls (16.5±4.0%). Also, the number of natural killer (NK) cells among patients with pltc >150×109/l were significantly elevated (26.6±16.0%;P<0.05) compared with controls (17.4±7.6%). In conclusion, our data corroborate previous findings of elevated numbers of activated T cells in chronic ITP patients with active disease, but neither a clear-cut Th1 nor a Th2 serum cytokine profile could be established. However, ITP in remission was associated with elevated TGF-β1, which might be a part of a bystander immune suppression. We propose that the effect of possible expression of TGF-β1 by oral immune tolerance induction deserves to be explored in ITP patients with an active disease.

High immunohistochemical expression of p-AKT predicts inferior survival in patients with diffuse large B-cell lymphoma treated with immunochemotherapy

Chemotherapy and rituximab (R) is current standard therapy in diffuse large B‐cell lymphoma (DLBCL), but a substantial proportion of patients still fail to reach sustained remission. In vitro studies have indicated that rituximab resistance could be accompanied by dysregulated apoptotic pathways, such as the phosphatidylinositol 3‐kinase (PI3K)/AKT signaling pathway, which can be constitutively activated in DLBCL. In this retrospective, immunohistochemical study on 106 patients treated with R‐CHO(E)P (cyclophosphamide, doxorubicin, vincristine, prednisone, rituximab [+etoposide]), we investigated the prognostic role of proteins involved in different apoptotic pathways; phosphorylated AKT (p‐AKT), bcl‐2, MCL1, bcl‐xL, Bax and Bak. High p‐AKT expression (>108 cells/mm2, highest quartile, n = 27) predicted worse progression‐free (PFS) (P = 0·02) and overall (OS) (P = 0·01) survival, independent of International Prognostic Index and sex. Also bcl‐2+ (cut‐off 50%) predicted worse PFS (P = 0·005) and OS (P = 0·05) but after adjustment for clinical factors only the influence on PFS (P = 0·03) remained significant. The prognostic impact of p‐AKT overexpression was independent of bcl‐2 status. MCL1, bcl‐xL, Bax and Bak expression did not add any prognostic information. Our results suggest that high p‐AKT expression predicts worse outcome, possibly indicating that inhibition of the activated PI3K/AKT pathway could be of clinical interest in DLBCL patients. In addition, bcl‐2 status could have prognostic importance also in the era of immunochemotherapy.

Disturbed apoptosis of T-cells in patients with active idiopathic thrombocytopenic purpura

Idiopathic thrombocytopenic purpura (ITP) is an organ specific autoimmune disorder in which T-lymphocyte abnormalities have pathogenetic importance. In a DNA microarray screen of CD3+ T-lymphocytes from ITP patients and healthy controls we found an altered expression of genes associated with apoptosis, e.g. A20, caspase-8 and Bax. This together with our previous findings of increased gene expression of Fas, interferon-g and IL-2 receptor beta (IL2RB) indicated an altered activation induced cell death (AICD) of T-cells in ITP. Using a proliferation assay we found that CD3+ lymphocytes from ITP patients were significantly more resistant to dexamethasone induced suppression compared to normal lymphocytes. We also found that cultured CD3+ lymphocytes from ITP patients in remission were more susceptible to apoptosis both in the presence and absence of dexamethasone compared to cells from patient with active ITP and healthy controls, as indicated by increased staining of AnnexinV binding. Our findings suggest that apoptotic resistance of activated T-lymphocytes in patients with active ITP may lead to defective clearance of autoreactive T-lymphocytes through AICD, which might cause a continued immune destruction of platelets. Conversely, a loss of resistance to AICD in ITP patients in remission might be an important mechanism for the achievement of remission.

Expression of CD68+ tumor-associated macrophages in patients with diffuse large B-cell lymphoma and its relation to prognosis.

Tumor‐associated macrophages (TAM) have been ascribed both pro‐ and anti‐tumor properties, but the majority of clinical cancer studies have shown that the presence of a high number of TAM is related to poor prognosis, suggesting that TAM predominantly exert pro‐tumoral activity. The prognostic role of TAM in patients with diffuse large B‐cell lymphoma (DLBCL), however, is so far unknown. Therefore, TAM were immunohistochemically stained with a CD68 antibody in a retrospective, population‐based study including 176 DLBCL patients treated with curative intent. With the exception that patients >60 years of age had a larger number of CD68+ cells (1143 vs 1018 cells/mm2; P = 0.05), no significant differences were found between the number of CD68+ cells and other clinical factors. Similarly, germinal center B‐cell (GCB)/non‐GCB immunophenotype or low/high Ki‐67 percentage were not associated with CD68 expression. Finally, no significant correlation was found between the number of CD68+ cells and progression‐free survival (P = 0.34) or overall survival (P = 0.94). These data indicate that the pro‐tumor effect of TAM has limited clinical relevance in DLBCL patients, which could imply that therapeutic strategies aimed at enhancing their anti‐tumor activity are of continuous clinical interest.

The number of tumour‐infiltrating TIA‐1+ cytotoxic T cells but not FOXP3+ regulatory T cells predicts outcome in diffuse large B‐cell lymphoma

The prognostic significance of tumour‐infiltrating lymphocytes (TILs) in patients with diffuse large B‐cell lymphoma (DLBCL) remains controversial. Furthermore, the possible impact of regulatory T cells (Tregs) on survival in DLBCL is still unknown. We performed a retrospective study on the immunohistochemical expression of cytotoxic cells and Tregs, and their correlation with survival in 195 DLBCL patients. Patients with a small number of cytotoxic T‐cell intracytoplasmic antigen‐1 (TIA‐1)+ T cells (≤260 cells/mm2 tumour area; n = 52) had significantly better outcome than patients with a large number (>260 cells/mm2; n = 143); progression‐free survival (PFS) at 5 years was 67% vs. 50% (P = 0·03) and overall survival (OS) was 73% vs. 57% (P = 0·03). In multivariate analysis, the low TIA‐1+ group still had a better PFS (relative risk 0·75, 95% confidence interval 0·31–0·99; P = 0·05). The number of forkhead box protein 3 (FOXP3)+ Tregs had no influence on PFS (P = 0·89) or OS (P = 0·75). These results suggest that immunohistochemical analysis of cytotoxic T cells at time of diagnosis could provide additional prognostic information. The lack of correlation between the number of FOXP3+ cells and survival could possibly indicate that tumour‐infiltrating Tregs are of less clinical importance in DLBCL. However, these findings need to be explored in functional studies.

Reduced transforming growth factor-beta1 production by mononuclear cells from patients with active chronic idiopathic thrombocytopenic purpura.

Summary. Chronic idiopathic thrombocytopenic purpura (ITP) is an autoimmune disorder in which activated T‐helper (Th) cells and different Th‐cell cytokines might play an important role. We have recently reported that chronic ITP patients in remission had elevated plasma levels of the Th3 cytokine transforming growth factor‐β1 (TGF‐β1), possibly as a part of a bystander immune suppression. In the present study we found that, in ITP patients with active disease [platelet count (plc) < 50 × 109/l], mitogen‐stimulated peripheral blood mononuclear cells (PBMC) had a significantly reduced production of TGF‐β1 (444 ± 178 pg/ml; n = 6) compared with patients with plc 50–150 × 109/l (1293 ± 374 pg/ml; n = 9; P < 0·05), patients with plc > 150 × 109/l (1894 ± 244 pg/ml; n = 12; P < 0·005) and healthy controls (1698 ± 241 pg/ml; n = 10; P < 0·01). Nineteen per cent of ITP patients expressed a platelet‐induced PBMC proliferation. Surprisingly, 22% of the ITP patients had a PBMC proliferation below the normal range, i.e. a suppressed proliferation in the presence of platelets; five of these six patients had active disease. In summary, this study demonstrated that chronic ITP patients with active disease had reduced PBMC production of the Th3 cytokine TGF‐β1. This result gives further support to the theory that chronic ITP in active phase is associated with a downregulated Th3‐response.

Real-world results of ibrutinib in patients with relapsed or refractory chronic lymphocytic leukemia: data from 95 consecutive patients treated in a compassionate use program. A study from the Swedish Chronic Lymphocytic Leukemia Group

Ibrutinib, a Bruton’s tyrosine kinase inhibitor is approved for relapsed/refractory and del(17p)/TP53 mutated chronic lymphocytic leukemia. Discrepancies between clinical trials and routine health-care are commonly observed in oncology. Herein we report real-world results for 95 poor prognosis Swedish patients treated with ibrutinib in a compassionate use program. Ninety-five consecutive patients (93 chronic lymphocytic leukemia, 2 small lymphocytic leukemia) were included in the study between May 2014 and May 2015. The median age was 69 years. 63% had del(17p)/TP53 mutation, 65% had Rai stage III/IV, 28% had lymphadenopathy ≥10cm. Patients received ibrutinib 420 mg once daily until progression. At a median follow-up of 10.2 months, the overall response rate was 84% (consistent among subgroups) and 77% remained progression-free. Progression-free survival and overall survival were significantly shorter in patients with del(17p)/TP53 mutation (P=0.017 and P=0.027, log-rank test); no other factor was significant in Cox proportional regression hazards model. Ibrutinib was well tolerated. Hematomas occurred in 46% of patients without any major bleeding. Seven patients had Richter’s transformation. This real-world analysis on consecutive chronic lymphocytic leukemia patients from a well-defined geographical region shows the efficacy and safety of ibrutinib to be similar to that of pivotal trials. Yet, del(17p)/TP53 mutation remains a therapeutic challenge. Since not more than half of our patients would have qualified for the pivotal ibrutinib trial (RESONATE), our study emphasizes that real-world results should be carefully considered in future with regards to new agents and new indications in chronic lymphocytic leukemia.

Infections With the Tick-Borne Bacterium “Candidatus Neoehrlichia mikurensis” Mimic Noninfectious Conditions in Patients With B Cell Malignancies or Autoimmune Diseases

BACKGROUND Candidatus Neoehrlichia mikurensis is a newly discovered noncultivatable bacterium spread among ticks and rodents in Europe and Asia that can infect humans, particularly immunocompromised patients. METHODS We compiled clinical and laboratory data from 11 patients with hematological malignances or autoimmune diseases who were diagnosed with Candidatus N. mikurensis infection in Europe 2010-2013. Both published (6) and unpublished cases (5) were included. RESULTS The patients had a median age of 67, were mostly male (8/11), and resided in Sweden, Switzerland, Germany, and the Czech Republic. All but one had ongoing or recent immune suppressive treatment and a majority were splenectomized (8/11). Less than half of them recalled tick exposure. The most frequent symptoms were fever (11/11), localized pain afflicting muscles and/or joints (8/11), vascular and thromboembolic events (6/11), that is, deep vein thrombosis (4), transitory ischemic attacks (2), pulmonary embolism (1), and arterial aneurysm (1). Typical laboratory findings were elevated C-reactive protein, leukocytosis with neutrophilia, and anemia. Median time from onset of symptoms to correct diagnosis was 2 months. In at least 4 cases, the condition was interpreted to be due to the underlying disease, and immunosuppressive therapy was scheduled. All patients recovered completely when doxycycline was administered. CONCLUSIONS Candidatus N. mikurensis is an emerging tick-borne pathogen that may give rise to a systemic inflammatory syndrome in persons with hematologic or autoimmune diseases that could be mistaken for recurrence of the underlying disease and/or unrelated arteriosclerotic vascular events. Awareness of this new pathogen is warranted among rheumatologists, hematologists, oncologists, and infectious disease specialists.