Donor/recipient Rh-mismatched allogeneic hematopoietic stem cell transplantation: transfusion strategy and allo-immunization to red blood cell antigens.

In the case of donor/recipient rhesus (Rh)-incompatibility after allogeneic hematopoietic stem cell transplantation (alloHSCT), the transfusion policy in France is to transfuse red blood cells (RBC) in the donor's Rh phenotype from the day of transplantation, leading to a risk of allo-immunization, either of donor or recipient origin. In this single-center retrospective study, the incidence of donor/recipient Rh incompatibility was 7.1% over an 8-year period including 1012 alloHSCT. Six of 58 evaluable patients (10.3%) developed alloantibodies to RBC antigens within one year of alloHSCT. None of these allo-immunizations were directed against the donor-mismatched Rh antigens and none could have been prevented by the transfusion of recipient and donor Rh-compatible RBC units. None of these allo-immunizations led to immune-mediated hemolytic anemia. We observed a statistically significant higher incidence of chronic GVHD among patients with anti-RBC allo-immunization. In the context of donor/recipient Rh incompatibility, the transfusion of packed RBC units in the donor's Rh phenotype from the day of alloHSCT is feasible and not associated with a high risk of allo-immunization. The generalization of this strategy could be discussed even when donor and recipient Rh phenotypes could be respected, to allow the preservation of units of infrequent phenotypes for other indications.

Anti-PD-1 therapy triggers Tfh cell-dependent IL-4 release to boost CD8 T cell responses in tumor-draining lymph nodes.

Anti-PD-1 therapy targets intratumoral CD8+ T cells to promote clinical responses in cancer patients. Recent evidence suggests an additional activity in the periphery, but the underlying mechanism is unclear. Here, we show that anti-PD-1 mAb enhances CD8+ T cell responses in tumor-draining lymph nodes by stimulating cytokine production in follicular helper T cells (Tfh). In two different models, anti-PD-1 mAb increased the activation and proliferation of tumor-specific T cells in lymph nodes. Surprisingly, anti-PD-1 mAb did not primarily target CD8+ T cells but instead stimulated IL-4 production by Tfh cells, the major population bound by anti-PD-1 mAb. Blocking IL-4 or inhibiting the Tfh master transcription factor BCL6 abrogated anti-PD-1 mAb activity in lymph nodes while injection of IL-4 complexes was sufficient to recapitulate anti-PD-1 mAb activity. A similar mechanism was observed in a vaccine model. Finally, nivolumab also boosted human Tfh cells in humanized mice. We propose that Tfh cells and IL-4 play a key role in the peripheral activity of anti-PD-1 mAb.

A major role for CD4+ T cells in driving cytokine release syndrome during CAR T cell therapy.

Anti-CD19 chimeric antigen receptor (CAR) T cell therapy represents a breakthrough for the treatment of B cell malignancies. Yet, it can lead to severe adverse events, including cytokine release syndrome (CRS), which may require urgent clinical management. Whether interpatient variability in CAR T cell subsets contributes to CRS is unclear. Here, we show that CD4+ CAR T cells are the main drivers of CRS. Using an immunocompetent model of anti-CD19 CAR T cell therapy, we report that CD4+, but not CD8+, CAR T cells elicit physiological CRS-like manifestations associated with the release of inflammatory cytokines. In CAR T cell-treated patients, CRS occurrence and severity are significantly associated with high absolute values of CD4+ CAR T cells in the blood. CRS in mice occurs independently of CAR T cell-derived interferon γ (IFN-γ) but requires elevated tumor burden. Thus, adjusting the CD4:CD8 CAR T cell ratio to patient tumor load may help mitigate CAR T cell-associated toxicities.

Systematic review reveals urgent need to homogenize endpoints choices and definitions in marginal zone lymphomas trials.

Marginal zone lymphoma (MZL) is a heterogeneous disease and has various end-point measures. Our aim was to describe the endpoints used in trials involving patients with MZL. We searched over the last 35 years via PubMed, The Cochrane Library, clinicaltrials.govandclinicaltrialsregister.eu for published and registered clinical trials using the keyword "marginalzone lymphoma." We excluded studies focusing on pediatric populations, cutaneous MZL and on use of allogenic stem cell transplant. Endpoints were reviewed as well as their influencing factors and their definitions. Among 1192 references Q7 dentified by initial screening, 309 references were included (111 published, 198 registered), with 213 (69%) phase 2, 65 (21%) phase 1/2 and 31 (10%) phase 3 trials. The majority were open-label (n»295, 95%) non-randomized (n»256, 83%) trials, concerned all subtypes of MZLs at once (n»239, 77%), and were often merged with non-MZL patients (n»232, 75%). Among phase 1/2 and 2 trials, Overall/complete response rate (ORR/CRR) (n»196, 70.5%) and progression-free survival (PFS,n»28, 10.1%) were the most used primary endpoints; in phase 3 trials PFS was the most used primary endpoint (n»18, 58.1%; ORR/CRR n»6, 19.4%, p<0.001). Overall, the most frequent secondary endpoints were overall survival (OS, n»153, 50%), PFS (n»142, 46%) and ORR/CRR (n»116, 38%). Distribution was similar when considering trials with only patients with MZL. Endpoints definitions were inconsistent across published trials (up to 9 definitions per endpoint). Trials involving patients with MZL showed marked heterogeneity both in the choice and definitions of primary and secondary endpoints, thus hampering comparability between trials.

Should Transplantation Still Be Considered for Ph1-Negative Myeloproliferative Neoplasms in Transformation?

BCR-ABL-negative myeloproliferative neoplasms (MPNs) in transformation have a dismal prognosis, and allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered the sole curative therapeutic option. We retrospectively analyzed 53 molecularly annotated patients treated at Saint Louis Hospital, Paris, diagnosed with MPN in transformation between 2008 and 2018. The median patient age was 65 years, and the median interval between MPN diagnosis and MPN transformation was 46 months. The median overall survival (OS) of the entire cohort after transformation was 7.1 months. OS was better for patients treated with hypomethylating agents (HMAs) or with chemotherapy compared than for those treated by best supportive care or single-agent targeted therapy (median, 9.1 months versus 1.5 months; P < .001). Patients treated with chemotherapy more often achieved complete remission compared with those treated with HMAs (68% versus 29%; P = .02), and were more often candidates for transplantation (59% versus 14%; P = .02), but the median OS was similar in the 2 groups. We then compared the outcomes in transplant recipients and nonrecipients using the Mantel-Byar methodology and found that allo-HSCT did not improve survival. In multivariate analysis, independent factors in prognosis were performance status at transformation (P < .01), initial treatment with HMAs or chemotherapy (P = .02), and the ability to achieve complete remission during follow-up (P < .01). Our data demonstrate that the indication for allo-HSCT for high-risk MPN should be discussed before transformation, because transplantation rescues few patients after transformation.

Impact of hyperoxia on patients hospitalized in an intensive care unit for acute heart failure.

BACKGROUND: Oxygen therapy remains a cornerstone of treatment for acute heart failure in patients with pulmonary congestion. While avoiding hypoxaemia has long been a goal of critical care practitioners, less attention has been paid to the potential hazard related to excessive hyperoxia. AIM: To evaluate the impact of early hyperoxia exposure among critically ill patients hospitalized in an intensive care unit for acute heart failure. METHODS: In this preliminary study conducted in a Parisian intensive care unit, we assessed patients with acute heart failure admitted with pulmonary congestion and treated with oxygen therapy from 1 January 2015 to 31 December 2016. The hyperoxia group was defined by having at least one partial pressure of oxygen measurement>100mmHg on the first day following admission to the intensive care unit. The primary endpoint was 30-day all-cause mortality. Secondary endpoints were 30-day unplanned hospital admissions, occurrence of infections and intensive care unit and hospital lengths of stay. RESULTS: Seventy-five patients were included. Forty-three patients (57.3%) presented hyperoxia, whereas 32 patients (42.7%) did not (control group). The baseline clinical characteristics did not differ between the two groups. The primary endpoint was not statistically different between the two groups (14.0% in the hyperoxia group vs 18.8% in the control group; P=0.85). The secondary endpoints were also not significantly different between the two groups. In the multivariable analysis, hyperoxia was not associated with increased 30-day mortality (odds ratio 0.77, 95% confidence interval 0.24-2.41). CONCLUSION: In patients referred to an intensive care unit for acute heart failure, we did not find any difference in outcomes according to the presence of hyperoxia.

Utility and Safety of Liver Biopsy in Patients with Undetermined Liver Blood Test Anomalies after Allogeneic Hematopoietic Stem Cell Transplantation: A Monocentric Retrospective Cohort Study.

Liver blood test anomalies are common after allogeneic hematopoietic stem cell transplantation (allo-HSCT), but their cause often remains difficult to identify. Our objective was to evaluate the safety and utility of liver biopsies in patients who underwent allo-HSCT. In a retrospective single-center cohort study, we reviewed all cases of patients who underwent liver biopsy between June 2005 and July 2017. During this period, 54 biopsies were performed in 45 patients, in which 38 patients underwent allo-HSCT for malignant and 7 for nonmalignant hematological disorders. Median time between allo-HSCT and liver biopsy was 213 days. Seven biopsies were percutaneous, and 47 were transjugular. No adverse event related to the biopsy procedure occurred; 94.5% biopsies (51 of 54) led to a histological diagnosis. Cholestatic graft-versus-host disease was histologically demonstrated in 16 biopsies (30%); hepatitis-like graft-versus-host disease in 9 biopsies (17%); nonalcoholic steatohepatitis in 6 biopsies (9%); regenerative nodular hyperplasia in 4 biopsies (5%); and drug-induced liver injury, sinusoidal obstruction syndrome, and viral hepatitis each in 3 biopsies (5%). Association between clinical, laboratory, imaging and pathological features was poor. Only 34% of physicians' prebiopsy hypotheses were confirmed by pathological findings. Patient management was influenced by liver biopsy results in 65% of cases, allowing us to identify a new diagnosis (n = 13), rule out a differential diagnosis (n = 14), or confirm the main hypothesis (n = 6). In conclusion, liver biopsy is a safe and useful technique to investigate liver blood test anomalies following allo-HSCT.

Azacytidine in combination with tyrosine kinase inhibitors induced durable responses in patients with advanced phase chronic myelogenous leukemia.

Although the tyrosine kinase inhibitor (TKI) era has brought great improvement in outcome in chronic myelogenous leukemia (CML), prognosis of accelerated phase or myeloid blast crisis patients or of de novo Philadelphia chromosome-positive acute myeloid leukemia remains poor. We conducted a retrospective study on patients with advanced phase disease treated with a TKI and azacytidine. Sixteen patients were eligible. Median age was 64.9 years, the median number of previous therapies was 2.5 lines, and median follow-up was 23.1 months. Hematologic response (HR) rate was 81.3%. Median overall survival (OS), event free survival and relapse-free survival (RFS) were 31.5, 23.3, and 32.2 months, respectively. All except one patient were treated as out-patients after the first cycle. Five patients were bridged to allogenic hematopoietic stem cells transplant. The combination of a TKI and azacytidine is a safe and efficient regiment for patients with CML patients in advanced phases.

Case report: Central nervous system involvement of human graft versus host disease: Report of 7 cases and a review of literature.

RATIONALE: Central nervous system (CNS) involvement of graft versus host disease (GvHD) is a rare cause of CNS disorders after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Chronic CNS GvHD symptoms are heterogeneous and include cerebrovascular manifestations, demyelinating disease and immune-mediated encephalitis. CNS-Acute GvHD is not formally defined in literature. PATIENTS CONCERNS AND DIAGNOSES: We report 7 cases of CNS-GvHD among which two had histological-proven disease. We reviewed 32 additional cases of CNS GvHD published in literature since 1990. In this cohort, 34 patients were transplanted for hematologic malignancies, and 5 for non-malignant hematopoiesis disorders. Of these patients, 25 had a history of chronic GvHD and immunosuppressive treatment had been decreased or discontinued in 14 patients before neurological symptoms onset. Median neurological disorder onset was 385 days [7-7320]. Patients had stroke-like episodes (n = 7), lacunar syndromes (n = 3), multiple sclerosis-like presentations (n = 7), acute demyelinating encephalomyelitis-like symptoms (n = 4), encephalitis (n = 14), mass syndrome (n = 1), and 3 had non-specific symptoms. Median neurological symptoms onset was 81.5 days [7-1095] for patients without chronic GVHD history versus 549 days [11-7300] for patients with chronic GVHD (P = 0.001). Patients with early involvement of CNS after allo-HSCT and no chronic GVHD symptoms were more frequently suffering from encephalitis (64% versus 28%, P = 0.07), whereas stroke-like episodes and lacunar symptoms were less frequent (9% versus 36%, P = 0.13). INTERVENTIONS: 34 patients with CNS-GvHD were treated with immunosuppressive therapy, including corticosteroids for 31 of them. Other treatments were intravenous immunoglobulin, plasmapheresis, cyclophosphamide, calcineurin inhibitors, mycophenolic acid, methotrexate and etoposide. OUTCOMES: 27 patients achieved a response: 10 complete responses, 15 partial responses and 2 transient responses. Of 25 patients with sufficient follow-up, 7 were alive and 18 patients deceased after CNS-GvHD diagnosis. LESSONS: CNS-related GvHD is a rare cause of CNS disorders after allo-HSCT and is associated with a poor prognosis.

Transcriptomic analysis of mouse limb tendon cells during development.

The molecular signals driving tendon development are not fully identified. We have undertaken a transcriptome analysis of mouse limb tendon cells that were isolated at different stages of development based on scleraxis (Scx) expression. Microarray comparisons allowed us to establish a list of genes regulated in tendon cells during mouse limb development. Bioinformatics analysis of the tendon transcriptome showed that the two most strongly modified signalling pathways were TGF-ß and MAPK. TGF-ß/SMAD2/3 gain- and loss-of-function experiments in mouse limb explants and mesenchymal stem cells showed that TGF-ß signalling was sufficient and required via SMAD2/3 to drive mouse mesodermal stem cells towards the tendon lineage ex vivo and in vitro. TGF-ß was also sufficient for tendon gene expression in late limb explants during tendon differentiation. FGF does not have a tenogenic effect and the inhibition of the ERK MAPK signalling pathway was sufficient to activate Scx in mouse limb mesodermal progenitors and mesenchymal stem cells.

Transcription factor EGR1 directs tendon differentiation and promotes tendon repair.

Tendon formation and repair rely on specific combinations of transcription factors, growth factors, and mechanical parameters that regulate the production and spatial organization of type I collagen. Here, we investigated the function of the zinc finger transcription factor EGR1 in tendon formation, healing, and repair using rodent animal models and mesenchymal stem cells (MSCs). Adult tendons of Egr1-/- mice displayed a deficiency in the expression of tendon genes, including Scx, Col1a1, and Col1a2, and were mechanically weaker compared with their WT littermates. EGR1 was recruited to the Col1a1 and Col2a1 promoters in postnatal mouse tendons in vivo. Egr1 was required for the normal gene response following tendon injury in a mouse model of Achilles tendon healing. Forced Egr1 expression programmed MSCs toward the tendon lineage and promoted the formation of in vitro-engineered tendons from MSCs. The application of EGR1-producing MSCs increased the formation of tendon-like tissues in a rat model of Achilles tendon injury. We provide evidence that the ability of EGR1 to promote tendon differentiation is partially mediated by TGF-ß2. This study demonstrates EGR1 involvement in adult tendon formation, healing, and repair and identifies Egr1 as a putative target in tendon repair strategies.