Constantijn J.M. Halkes

The Y238X Stop Codon Polymorphism in the Human β-Glucan Receptor Dectin-1 and Susceptibility to Invasive Aspergillosis

BACKGROUND Dectin-1 is the major receptor for fungal β-glucans on myeloid cells. We investigated whether defective Dectin-1 receptor function, because of the early stop codon polymorphism Y238X, enhances susceptibility to invasive aspergillosis (IA) in at-risk patients. METHODS Association of Dectin-1 Y238X polymorphism with occurrence and clinical course of IA was evaluated in 71 patients who developed IA post hematopoietic stem cell transplantation (HSCT) and in another 21 non-HSCT patients with IA. The control group consisted of 108 patients who underwent HSCT. Functional studies were performed to investigate consequences of the Y238X Dectin-1 polymorphism. RESULTS The Y238X allele frequency was higher in non-HSCT patients with IA (19.0% vs 6.9%-7.7%; P < .05). Heterozygosity for Y238X polymorphism in HSCT recipients showed a trend toward IA susceptibility (odds ratio, 1.79; 95% CI, .77-4.19; P = .17) but did not influence clinical course of IA. Functional assays revealed that although peripheral blood mononuclear cells with defective Dectin-1 function due to Y238X responded less efficiently to Aspergillus, corresponding macrophages showed adequate response to Aspergillus. CONCLUSIONS Dectin-1 Y238X heterozygosity has a limited influence on susceptibility to IA and may be important in susceptible non-HSCT patients. This is partly attributable to redundancy inherent in the innate immune system. Larger studies are needed to confirm these findings.

Response to Rituximab-Based Therapy and Risk Factor Analysis in Epstein Barr Virus–Related Lymphoproliferative Disorder After Hematopoietic Stem Cell Transplant in Children and Adults: A Study From the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation

BACKGROUND  The objective of this analysis was to investigate prognostic factors that influence the outcome of Epstein-Barr virus (EBV)-related posttransplant lymphoproliferative disorder (PTLD) after a rituximab-based treatment in the allogeneic hematopoietic stem cell transplant (HSCT) setting. METHODS  A total of 4466 allogeneic HSCTs performed between 1999 and 2011 in 19 European Group for Blood and Marrow Transplantation centers were retrospectively analyzed for PTLD, either biopsy-proven or probable disease. RESULTS  One hundred forty-four cases of PTLD were identified, indicating an overall EBV-related PTLD frequency of 3.22%, ranging from 1.16% for matched-family donor, 2.86% for mismatched family donor, 3.97% in matched unrelated donors, and 11.24% in mismatched unrelated donor recipients. In total, 69.4% patients survived PTLD. Multivariable analysis showed that a poor response of PTLD to rituximab was associated with an age ≥30 years, involvement of extralymphoid tissue, acute GVHD, and a lack of reduction of immunosuppression upon PTLD diagnosis. In the prognostic model, the PTLD mortality increased with the increasing number of factors: 0-1, 2, or 3 factors being associated with mortality of 7%, 37%, and 72%, respectively (P < .0001). Immunosuppression tapering was associated with a lower PTLD mortality (16% vs 39%), and a decrease of EBV DNAemia in peripheral blood during therapy was predictive of better survival. CONCLUSIONS  More than two-thirds of patients with EBV-related PTLD survived after rituximab-based treatment. Reduction of immunosuppression was associated with improved outcome, whereas older age, extranodal disease, and acute graft-vs-host disease predicted poor outcome.

Sequential Combination of Gemtuzumab Ozogamicin and Standard Chemotherapy in Older Patients With Newly Diagnosed Acute Myeloid Leukemia: Results of a Randomized Phase III Trial by the EORTC and GIMEMA Consortium (AML-17)

PURPOSE This randomized trial evaluated the efficacy and toxicity of sequential gemtuzumab ozogamicin (GO) and standard chemotherapy in older patients with newly diagnosed acute myeloid leukemia (AML). PATIENTS AND METHODS Patients (n = 472) age 61 to 75 years were randomly assigned to induction chemotherapy with mitoxantrone, cytarabine, and etoposide preceded, or not, by a course of GO (6 mg/m(2) on days 1 and 15). In remission, patients received two consolidation courses with or without GO (3 mg/m(2) on day 0). The primary end point was overall survival (OS). RESULTS The overall response rate was comparable between the two arms (GO, 45%; no GO, 49%), but induction and 60-day mortality rates were higher in the GO arm (17% v 12% and 22% v 18%, respectively). With median follow-up of 5.2 years, median OS was 7.1 months in the GO arm and 10 months in the no-GO arm (hazard ratio, 1.20; 95% CI, 0.99 to 1.45; P = .07). Other survival end points were similar in both arms. Grade 3 to 4 hematologic and liver toxicities were greater in the GO arm. Treatment with GO provided no benefit in any prognostic subgroup, with the possible exception of patients age < 70 years with secondary AML, but outcomes were significantly worse in the oldest age subgroup because of a higher risk of early mortality. CONCLUSION As used in this trial, the sequential combination of GO and standard chemotherapy provides no benefit for older patients with AML and is too toxic for those age ≥ 70 years.

A mechanistic rationale for combining alemtuzumab and rituximab in the treatment of ALL.

B-lineage acute lymphoblastic leukemia (ALL) may express CD52 and CD20. Alemtuzumab (ALM) and rituximab (RTX) are therapeutic antibodies directed against CD52 and CD20, respectively, but showed limited activity against ALL in clinical trials. The mechanisms for the impaired responses remained unclear. We studied expression of CD52 and CD20 on ALL cells and found that most cases coexpressed CD52 and CD20. However, distinct CD52-negative (CD52(-)) subpopulations were detected in most cases as the result of defective glycophosphatidyl-inositol anchoring. Although ALM efficiently eradicated CD52-positive (CD52(+)) cells in NOD/scid mice engrafted with primary human ALL, CD52(-) subclones escaped therapy. In the same model, RTX showed limited activity resulting from occurrence of CD20 down-modulation. However, CD52(-) cells concurrently lacked the glycophosphatidyl-inositol-anchored complement regulators CD55 and CD59 and showed increased susceptibility to RTX-mediated complement-dependent cytotoxicity in vitro. At the same time, ALM was shown to inhibit down-modulation of CD20 in response to RTX by depleting the trogocytic capacity of phagocytic cells. Probably because of these complementary mechanisms, combined administration of ALM and RTX induced complete responses in vivo. Based on these data, we propose a mechanistic rationale for combined application of RTX and ALM in ALL.

Effective Treatment of Refractory CMV Reactivation After Allogeneic Stem Cell Transplantation With In Vitro-generated CMV pp65-specific CD8+ T-cell Lines

To treat patients with refractory cytomegalovirus (CMV) reactivation after allogeneic stem cell transplantation, a phase I/II clinical study on adoptive transfer of in vitro-generated donor-derived or patient-derived CMV pp65-specific CD8+ T-cell lines was performed. Peripheral blood mononuclear cells from CMV seropositive donors or patients were stimulated with HLA-A*0201-restricted and/or HLA-B*0702-restricted CMV pp65 peptides (NLV/TPR) and 1 day after stimulation interferon-&ggr;)-producing cells were enriched using the CliniMACS Cytokine Capture System (interferon-&ggr;), and cultured with autologous feeders and low-dose interluekin-2. After 7–14 days of culture, quality controls were performed and the CMV-specific T-cell lines were administered or cryopreserved. The T-cell lines generated contained 0.6–17×106 cells, comprising 54%–96% CMV pp65-specific CD8+ T cells, and showed CMV-specific lysis of target cells. Fifteen CMV-specific T-cell lines were generated of which 8 were administered to patients with refractory CMV reactivation. After administration, no acute adverse events and no graft versus host disease were observed and CMV load disappeared. In several patients, a direct relation between administration of the T-cell line and the in vivo appearance of CMV pp65-specific T cells could be documented. In conclusion, administration of CMV pp65-specific CD8+ T-cell lines was found to be feasible and safe, and enduring efficacy of administered CMV pp65-specific CD8+ T-cell lines could be demonstrated.

Selective graft-versus-leukemia depends on magnitude and diversity of the alloreactive T cell response

Patients with leukemia who receive a T cell–depleted allogeneic stem cell graft followed by postponed donor lymphocyte infusion (DLI) can experience graft-versus-leukemia (GVL) reactivity, with a lower risk of graft-versus-host disease (GVHD). Here, we have investigated the magnitude, diversity, and specificity of alloreactive CD8 T cells in patients who developed GVL reactivity after DLI in the absence or presence of GVHD. We observed a lower magnitude and diversity of CD8 T cells for minor histocompatibility antigens (MiHAs) in patients with selective GVL reactivity without GVHD. Furthermore, we demonstrated that MiHA-specific T cell clones from patients with selective GVL reactivity showed lower reactivity against nonhematopoietic cells, even when pretreated with inflammatory cytokines. Expression analysis of MiHA-encoding genes showed that similar types of antigens were recognized in both patient groups, but in patients who developed GVHD, T cell reactivity was skewed to target broadly expressed MiHAs. As an inflammatory environment can render nonhematopoietic cells susceptible to T cell recognition, prevention of such circumstances favors induction of selective GVL reactivity without development of GVHD.

Transplant results in adults with Fanconi anaemia

The outcomes of adult patients transplanted for Fanconi anaemia (FA) have not been well described. We retrospectively analysed 199 adult patients with FA transplanted between 1991 and 2014. Patients were a median of 16 years of age when diagnosed with FA, and underwent transplantation at a median age of 23 years. Time between diagnosis and transplant was shortest (median 2 years) in those patients who had a human leucocyte antigen identical sibling donor. Fifty four percent of patients had bone marrow (BM) failure at transplantation and 46% had clonal disease (34% myelodysplasia, 12% acute leukaemia). BM was the main stem cell source, the conditioning regimen included cyclophosphamide in 96% of cases and fludarabine in 64%. Engraftment occurred in 82% (95% confidence interval [CI] 76–87%), acute graft‐versus‐host disease (GvHD) grade II–IV in 22% (95% CI 16–28%) and the incidence of chronic GvHD at 96 months was 26% (95% CI 20–33). Non‐relapse mortality at 96 months was 56% with an overall survival of 34%, which improved with more recent transplants. Median follow‐up was 58 months. Patients transplanted after 2000 had improved survival (84% at 36 months), using BM from an identical sibling and fludarabine in the conditioning regimen. Factors associated with improved outcome in multivariate analysis were use of fludarabine and an identical sibling or matched non‐sibling donor. Main causes of death were infection (37%), GvHD (24%) and organ failure (12%). The presence of clonal disease at transplant did not significant impact on survival. Secondary malignancies were reported in 15 of 131 evaluable patients.

Mismatched Hla-drb3 can induce a potent immune response after Hla 10/10 matched stem cell transplantation.

Background Donors for allogeneic stem cell transplantation are preferentially matched with patients for HLA-A, -B, -C, and -DRB1. Mismatches between donor and patient in these alleles are associated with an increased risk of graft-versus-host disease (GVHD). In contrast, HLA-DRB3, 4 and 5, HLA-DQ and HLA-DP are usually assumed to be low expression loci with limited relevance, although mismatches in HLA-DQ and HLA-DP can result in alloimmune responses. Mismatches in HLA-DRB3, 4, and 5 are usually not taken into account in donor selection. Methods Conversion of chimerism in the presence of GVHD after CD4 donor lymphocyte infusion was observed in a patient, HLA 10/10 matched, but mismatched for HLA-DRB3 and HLA-DPB1 compared with the donor. Alloreactive CD4 T cells were isolated from peripheral blood after CD4 donor lymphocyte infusion and recognition of donor-derived target cells transduced with the mismatched patient variant HLA-DRB3 and HLA-DPB1 molecule was tested. Results A dominant polyclonal CD4 T cell response against patients mismatched HLA-DRB3 molecule was found in addition to an immune response against patient’s mismatched HLA-DPB1 molecule. CD4 T cells specific for these HLA class II molecules recognized both hematopoietic target cells as well as GVHD target cells. Conclusions In contrast to the assumption that mismatches in HLA-DRB3, 4, and 5 are not of immunogenic significance after HLA 10/10 matched allogeneic stem cell transplantation, we show that in this matched setting not only mismatches in HLA-DPB1, but also mismatches in HLA-DRB3 may induce a polyclonal allo-immune response associated with conversion of chimerism and severe GVHD.

Mutation in PIGA Results in a CD52-Negative Escape Variant in a Sézary Syndrome Patient during Alemtuzumab Treatment

ted skin on UVR-blood flow doseresponse (Young et al., 1985; Flanagan et al., 2001). In view of an encouraging report, we also explored the possibility of using a* (‘redness’), a hemoglobin (Hb) index, and Hb oxygen (HbO2) saturation gained with a standard spectrophotometer (CM-600D; Konica Minolta) to describe erythemal responses (Kollias et al., 1994). However, we found that they by no means reached the level of reliability of the MFD in assessing minimal sunburn in pigmented skin (Supplementary Figure 1a–d online). MFD permits objective assessment of UVR-vasodilatation response, which is transferable between laboratories. Although our data suggest that 30% flux increase is a good threshold for MFD, this should be verified in a larger study with more extensive MED and MFD assessments. Laser speckle contrast imaging appears to be more sensitive and more reliable compared with other available objective methods, such as determining oxyhemoglobin levels from reflectance spectra. Hence, we find 785 nm laser speckle contrast imaging excellently suited to assess robustly a minimal sunburn reaction (by vasodilatation) even in heavily pigmented skin. Influence of skin pigmentation on UVR responses is an area of substantial current interest and controversy (Brenner and Hearing, 2008; Bogh et al., 2010; Farrar et al., 2011), and this technique will assist its further exploration.

Short-term efficacy and safety of antithymocyte globulin treatment in elderly patients with acquired aplastic anaemia.

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