WT1 and PRAME RNA-loaded dendritic cell vaccine as maintenance therapy in de novo AML after intensive induction chemotherapy.

Intensive induction chemotherapy achieves complete remissions (CR) in >60% of patients with acute myeloid leukemia (AML) but overall survival (OS) is poor for relapsing patients not eligible for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Oral azacytidine may be used as maintenance treatment in AML in first remission, but can be associated with substantial side effects, and less toxic strategies should be explored. Twenty AML patients in first CR (CR1) ineligible for allo-HSCT were treated with FDC101, an autologous RNA-loaded mature dendritic cell (mDC) vaccine expressing two leukemia-associated antigens (LAAs). Each dose consisted of 2.5-5 × 106 mDCs per antigen, given weekly until week 4, at week 6, and then monthly, during the 2-year study period. Patients were followed for safety and long-term survival. Treatment was well tolerated, with mild and transient injection site reactions. Eleven of 20 patients (55%) remained in CR, while 4 of 6 relapsing patients achieved CR2 after salvage therapy and underwent allo-HSCT. OS at five years was 75% (95% CI: 50-89), with 70% of patients ≥60 years of age being long-term survivors. Maintenance therapy with this DC vaccine was well tolerated in AML patients in CR1 and was accompanied by encouraging 5-year long-term survival.

Long-term first-in-man Phase I/II study of an adjuvant dendritic cell vaccine in patients with high-risk prostate cancer after radical prostatectomy.

BACKGROUND: Patients with high-risk prostate cancer (PC) can experience biochemical relapse (BCR), despite surgery, and develop noncurative disease. The present study aimed to reduce the risk of BCR with a personalized dendritic cell (DC) vaccine, given as adjuvant therapy, after robot-assisted laparoscopic prostatectomy (RALP). METHODS: Twelve weeks after RALP, 20 patients with high-risk PC and undetectable PSA received DC vaccinations for 3 years or until BCR. The primary endpoint was the time to BCR. The immune response was assessed 7 weeks after surgery (baseline) and at one-time point during the vaccination period. RESULTS: Among 20 patients, 11 were BCR-free over a median of 96 months (range: 84-99). The median time from the end of vaccinations to the last follow-up was 57 months (range: 45-60). Nine patients developed BCR, either during (n = 4) or after (n = 5) the vaccination period. Among five patients diagnosed with intraductal carcinoma, three experienced early BCR during the vaccination period. All patients that developed BCR remained in stable disease within a median of 99 months (range: 74-99). The baseline immune response was significantly associated with the immune response during the vaccination period (p = 0.015). For patients diagnosed with extraprostatic extension (EPE), time to BCR was longer in vaccine responders than in non-responders (p = 0.09). Among 12 patients with the International Society of Urological Pathology (ISUP) grade 5 PC, five achieved remission after 84 months, and all mounted immune responses. CONCLUSION: Patients diagnosed with EPE and ISUP grade 5 PC were at particularly high risk of developing postsurgical BCR. In this subgroup, the vaccine response was related to a reduced BCR incidence. The vaccine was safe, without side effects. This adjuvant first-in-man Phase I/II DC vaccine study showed promising results. DC vaccines after curative surgery should be investigated further in a larger cohort of patients with high-risk PC.

Thymectomy in Juvenile Myasthenia Gravis Is Safe Regarding Long Term Immunological Effects.

Thymectomy is an established treatment in adult MG and also recommended for the treatment of post-pubertal onset juvenile MG. Whether the youngest children should be thymectomized is still debated. Signs of premature aging of the immune system have been shown in studies on early perioperative thymectomy in children with congenital heart defect. In this retrospective cohort study the objective was to investigate the long-term effects of treatment related thymectomy on T cell subsets and T cell receptor rearrangement excision circles (TRECs) in peripheral blood of juvenile myasthenia gravis (MG) patients, as well as clinical occurrence of autoimmune disorders, malignancies and infectious diseases. Forty-seven patients with onset of myasthenia gravis before the age of 19 years were included; 32 (68.1%) had been thymectomized and 15 (31.8%) had not. They were studied at varying times after thymectomy (7-26 years). We found a significant lower number of naïve helper T cells (CD4+CD45RA+) with an increased proportion of memory helper T cells (CD4+CD45RO+), and a significant lower number of naïve cytotoxic T cells (CD8+CD27+CD28+) in the thymectomized patients. In addition they showed a significant reduction in the number of TRECs and proportion of recent thymic emigrants (RTE) compared to non-thymectomized patients. In none of them an increased frequency of malignancies or infections was found. Our findings indicate a premature aging of the immune system after thymectomy in juvenile MG, but associated clinical consequences could not be verified.

Erythrocytapheresis compared with whole blood phlebotomy for the treatment of hereditary haemochromatosis.

BACKGROUND: Hereditary haemochromatosis may result in severe organ damage which can be prevented by therapy. We studied the possible advantages and disadvantages of erythrocytapheresis as compared with phlebotomy in patients with hereditary haemochromatosis. MATERIALS AND METHODS: In a prospective, randomised, open-label study, patients with hereditary haemochromatosis were randomised to bi-weekly apheresis or weekly whole blood phlebotomy. Primary end-points were decrease in ferritin levels and transferrin saturation. Secondary endpoints were decrease in haemoglobin levels, discomfort during the therapeutic procedure, costs and technicians' working time. RESULTS: Sixty-two patients were included. Thirty patients were randomised to apheresis and 32 to whole blood phlebotomy. Initially, ferritin levels declined more rapidly in the apheresis group, and the difference became statistically highly significant at 11 weeks; however, time to normalisation of ferritin level was equal in the two groups. We observed no significant differences in decline of transferrin saturation, haemoglobin levels or discomfort. The mean cumulative technician time consumption until the ferritin level reached 50 µg/L was longer in the apheresis group, but the difference was not statistically significant. The cumulative costs for materials until achievement of the desired ferritin levels were three-fold higher in the apheresis group. CONCLUSION: Treatment of hereditary haemochromatosis with erythrocytapheresis instead of whole blood phlebotomy results in a more rapid initial decline in ferritin levels and a reduced number of procedures per patient, but not in earlier achievement of target ferritin level. The frequency of discomfort was equally low with the two methods. The costs and, probably, technician time consumption were higher in the apheresis group.

One week of multifactorial high-stress military ranger training affects Gram-negative signalling.

BACKGROUND: Toll-like receptor 4 (TLR4), especially expressed on monocytes/macrophages, connects microbial and sterile innate immune activation. Lipopolysaccharide (LPS) from Gram-negative bacteria and several endogenous molecules, among others saturated fatty acids (SFAs), are able to induce signalling through this receptor. Downstream inflammatory cytokines orchestrate the immune response. Our aim was to investigate how long-lasting multifactorial stress affects Gram-negative signalling and search for possible correlations between cytokine production and TLR4 expression or SFA concentration. METHODS: Eight healthy males were studied during a 7-day ranger-training course with semi-continuous physical strain, together with energy and sleep restrictions. Blood drawn on days 0, 3, 5 and 7 was incubated ex vivo for 6 h with or without LPS 10 ng/mL, whereupon surface expression of TLR4 on CD14⁺ monocytes and supernatant concentrations of inflammatory cytokines (TNF-α, IL-1ß and IL-6) were measured. In addition, plasma free fatty acids were quantified. RESULTS: Monocyte TLR4 expression was elevated throughout the course (p < 0.05 vs. baseline). Corresponding results were found for SFAs. The concentration of TNF-α increased significantly on day 3 and thereafter normalized, and a similar pattern was seen for IL-1ß. No correlations were found between cytokine concentrations and monocyte TLR4 expression or plasma SFAs. CONCLUSION: Multifactorial stress significantly affected ex vivo production of TNF-α and monocyte surface expression of TLR4. In addition, mobilization of fat resulted in increased plasma concentrations of SFAs. No associations between inflammatory cytokines and monocyte TLR4 expression or SFAs were found.

Moderate temperature alterations affect Gram-negative immune signalling in ex vivo whole blood.

BACKGROUND: Alterations in body temperature may influence immune system function and consequently affect the risk of infection and inflammatory diseases. Lipopolysaccharide (LPS) from gram-negative bacteria induces production of inflammatory cytokines after ligand binding to Toll-like receptor 4 (TLR4) on immune cells (especially monocytes/ macrophages). Our aim was to explore how clinically relevant hypo- and hyperthermia affect this signalling in an ex vivo whole blood model, and investigate if the cytokine response was correlated with monocyte TLR4 expression level. METHODS: Blood from 11 healthy volunteers was incubated with LPS 10 ng/ml for 6 h at 33, 37 or 40°C. The concentrations of selected pro-inflammatory (tumour necrosis factor-α (TNF-α) and interleukin (IL)-1ß) and anti-inflammatory (IL-10) cytokines were measured in plasma, and the surface expression of TLR4 was quantified on CD14 + monocytes. RESULTS: Monocyte TLR4 expression and plasma IL-1ß were inversely related to temperature. The TNF-α production was unaffected by hypothermia but increased significantly during hyperthermia, whereas plasma IL-10 was significantly reduced during both hypo- and hyperthermic incubation. No correlation was found between TLR4 expression and cytokine concentrations. During hypothermia, the TNF-α/IL-10 and IL-1ß/IL-10 ratios increased seven and nine times, respectively. Hyperthermia increased the TNF-α/IL-10 ratio, but to a lesser extent (doubling), whereas the IL-1ß/IL-10 ratio remained unchanged. CONCLUSION: Hypothermia significantly changed the cytokine ratios in the pro-inflammatory direction. In comparison, the effect of hyperthermia was sparse, with a modest increase in the TNF-α/IL-10 ratio only. No association was found between LPS-stimulated cytokine production and TLR4 expression on CD14 + monocytes.

Reduced chemokine receptor 9 on intraepithelial lymphocytes in celiac disease suggests persistent epithelial activation.

BACKGROUND & AIMS: Celiac disease is caused by an inappropriate immune response to dietary gluten, with increased epithelial lymphocyte infiltration in the duodenum/jejunum as a hallmark. The chemokine receptor 9 (CCR9) is a small intestinal homing receptor normally found on most mucosal T cells in this organ. Because CCR9 expression appears to be activation dependent, we examined CCR9 on duodenal T cells from untreated and treated (gluten-free diet) patients with celiac disease and healthy controls. METHODS: Duodenal biopsy specimens and blood samples were obtained for histologic analysis and flow-cytometric CCR9 analysis of isolated lymphocytes. CCR9 expression after activation was studied in peripheral blood T cells from healthy volunteers. RESULTS: The median number of CCR9(+) cells among CD3(+) T cells in epithelium and lamina propria, respectively, was 56% and 48% in controls, 11% and 40% in treated patients, and 1% and 8% in untreated patients. Significant differences occurred between controls and treated or untreated patients in the epithelium but only between controls and untreated patients in the lamina propria (P=.008, all comparisons). No such differences were seen in peripheral blood, but stimulation with phorbol myristate acetate and ionomycin and, to a lesser extent, stimulation via NKG2D reduced the CCR9 expression on blood T cells. CONCLUSIONS: CCR9 expression is reduced on epithelial and lamina propria T cells in untreated celiac disease. Down-regulation of CCR9 persists in intraepithelial T cells from well-treated patients. This suggests ongoing immune activation preferentially within the epithelium.