[Pediatric aphereses (workshop SFGM-TC)]. / Cytaphérèses pédiatriques (atelier SFGM-TC).

Practice of pediatric aphereses - in particular when caring for low-weight children - differs from the practice of adult aphereses, since pediatric aphereses represent low numbers of procedures, which has practical implications in terms of practical training and retraining for involved healthcare personnel, as needed for habilitation and validation of ongoing competencies. A specific training is mandatory in order to ensure both the child and the staff safety during and after collection, as well as ensure high quality of the collected cell product and that its meets predefined specifications that depend on its intended use. Low and very low-weight children deserve a particular attention for a number of procedural and clinical aspects: the nature and quality of venous accesses to ensure proper operation of the cell separator, management of hemodynamic fluctuations in relation with the relative importance of the extracorporeal blood volume as compared to the total blood volume of the child, risks and clinical manifestations of citrate toxicity, minimization of stress during the procedure that may include but is not limited to pharmacological sedation. The full spectrum of competencies needed to deal with these aspects is rarely present within a single team of healthcare professionals; it most often requires the tight combination of expertise drawing from the collection facility, the pediatric department and possibly the pediatric intensive care unit ward, whether from the same or from different institutions. Interactions must be formalized in a document that accurately describes which category of actors is responsible for each category of acts (prescriptions, decisions), depending on their initial qualifications, specific competencies, and affiliations.

[Transfusion management and immuno-hematological follow-up after allogeneic hematopoietic cell transplantation: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Prise en charge transfusionnelle et suivi immunohématologique après allogreffe de cellules souches hématopoïétiques : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

The French High Authority of Health (HAS) and National Drug Safety (ANSM) agencies recommendations issued in 2014, the French General Direction of Health (DGS) instruction published in November 2021, the French National Blood Bank (EFS) guidelines and the data available in the literature globally define "good transfusion practices" but provide little information about the immuno-hematological and transfusion management of patients who have received an allogeneic hematopoietic stem transplantation (allo-HCT). The aim of this workshop was to harmonize these practices in situations for which there are currently no recommendations. In order to anticipate possible transfusion issues after allo-HCT, we recommend performing, before the transplantation, an extended red blood cell phenotyping of the donor and a detection of HLA alloimmunization in the recipient. We recommend to systematically perform for minor ABO mismatches: a direct antiglobulin test between D8 and D20, and for major ABO mismatches; a titration of anti-A/anti-B antibodies and an erythrocyte chimerism at D100. At one-year post-transplant, we recommend carrying out an erythrocyte chimerism to allow, if necessary, the update of transfusion counselling (RH phenotype, irradiation of packed red blood cells).

[Method and impact of allografts cryopreservation during the Covid-19 pandemic: guidelines from the SFGM-TC]. / Modalités et impact de la cryopréservation des greffons allogéniques en contexte pandémique : recommandations de la SFGM-TC.

The COVID-19 pandemic disorganized the allogeneic stem cell transplantation activities all over the world, with the necessity to cryopreserve allografts to secure the procedure for both the recipient and the donor. Cryopreservation, usually anecdotal, has been used by all the French speaking centers; data collected from 24 centers were assessed in order to determine the impact of cryopreservation on the quality of allografts. Our analysis clearly demonstrates that increasing transit time (more than 48hours) is deleterious for CD34+ recovery, legitimates the slight increase of the requested CD34+ cell dose with respect to the average recovery rate as well as the importance of the quality control on the infused product.

Study of a new device for washing and concentrating cryopreserved hematopoietic stem cells and mononuclear cells: a single center experience.

BACKGROUND AIMS: Cryopreserved cellular products, as parts of hematopoietic progenitor cell (HPC) transplants, mononuclear cell reinjections for donor lymphocyte infusion or extracorporeal photopheresis, can be washed before being reinjected into the patient or infused directly, depending on local practices. The aim of washing is to reduce the incidence and severity of adverse reactions (ARs) due to the dimethyl sulfoxide (DMSO) used as a cryoprotective agent and other factors, such as dead cell debris. At the authors' cell therapy laboratory (CTL) in Poitiers, France, as in 76% of Etablissement Français du Sang (EFS) CTLs, all cryopreserved products undergo thawing in a water bath followed by washing with the COBE 2991. As this device will soon cease to be available, an alternative process needs to be assessed. METHODS: The authors compared two closed systems: the authors' semi-automatic system using the traditional centrifugation method (COBE 2991) and an automated device using spinning membrane filtration (Lovo). A total of 72 HPC bags available for research were used. The authors first performed a paired comparison, processing one or two HPC bags washed by each device. A second study was carried out to compare two different washing solutions generally used by EFS CTLs along with variable storage conditions. Finally, the authors studied the efficiency of the Lovo with three or four thawed bags. The main parameters studied were viable CD34+ cell recovery and viability, CD3+ cell recovery, stability up to 6 h after washing, DMSO elimination and center feasibility. RESULTS: The Lovo device showed better CD34+ cell recovery compared with the COBE 2991 while maintaining CD34+ viability and stability over 6 h. Moreover, Lovo efficiency seemed to be independent of the number of thawed bags processed and washing solution used in the authors' study. CD3+ cell recovery met the authors' internal specifications (cell recovery >50%), with similar results seen when processing with either the COBE 2991 or Lovo. Additionally, on average, 97% of DMSO was removed after washing with Lovo, minimizing the risk of ARs. The storage conditions post-processing indicated preferred storage conditions of 7 ± 3°C. Finally, if processing time seemed shorter using COBE 2991 for one bag washed, the Lovo device required only one staff member regardless of the number of HPC bags processed. CONCLUSIONS: The Lovo device seems to provide an opportunity to standardize HPC processing, ensuring patient safety, with, on average, 97% of DMSO removed, while improving recovery of cells of interest and maintaining viability over time in case of delayed transplant. The Lovo device consequently seems to be a serious alternative to the COBE 2991.

Umbilical cord blood transplants facilitated by the French cord blood banks network. On behalf of the Agency of Biomedicine, Eurocord and the French society of bone marrow transplant and cell therapy (SFGM-TC).

The public French Cord Blood Banks Network was established in 1999 with the objective of standardizing the practices governing umbilical cord blood (UCB) banking in France. The Network adopted a strategy to optimize its inventory and improve the quality of its banked units based on a quality improvement process using outcome data regularly provided by Eurocord. This study aimed to describe the results, over 10 years, of UCBT facilitated by a national network that used the same criteria of UCB collection and banking and to assess how modifications of banking criteria and unit selection might influence transplant outcomes. Nine hundred and ninety-nine units (593 single-unit and 203 double-unit grafts) were released by the Network to transplant 796 patients with malignant (83%) and non-malignant (17%) diseases. Median cell dose exceeded 3.5 × 107 TNC/kg in 86%. There was a trend to select units more recently collected and with higher cell dose. Neutrophil engraftment was 88.2% (85.7-90.7) and 79.3% (72.6-86.5) respectively for malignant and non-malignant diseases with a trend to faster recovery with higher cell doses. The respective 3-year transplant-related mortality were 31.1% (27.5-35.1) and 34.3% (27.0-43.5). OS was 49% ± 4 in malignant and 62% ± 4 in non-malignant disorders. In multivariate analysis, cell dose was the only unit-related factor associated with outcomes. Our results reflect the benefit on clinical outcomes of the strategy adopted by the Network to bank units with higher cell counts.

Multidisciplinary management of anti-PP1Pk or anti-P alloimmunization during pregnancy: A new case with anti-P and a literature review.

BACKGROUND: Red blood cell alloimmunization is the first cause of fetal and neonatal anemia. Alloimmunizations with anti-PP1Pk or anti-P can cause recurrent miscarriages and hemolytic disease of the fetus and newborn in the 2nd and 3rd trimesters of pregnancy. We report on a pregnant patient immunized with anti-P and a history of recurrent miscarriages. CASE REPORT: This P2k (GLOB:-1; P1PK:-1,3) patient had a first pregnancy marked by a caesarean at 38 weeks of gestation (WG) for non-reassuring fetal heart rate. Then, she had three early spontaneous miscarriages. The fifth pregnancy began with a high titer of anti-P at 128. Early initiation of treatment with Intravenous Immunoglobulins (IVIg) and plasma exchanges (PE) starting at 5 WG permitted us to reduce the titer of anti-P below 32. A healthy infant was delivered by caesarean at 38 WG without anemia at birth and no exchange transfusion was required. DISCUSSION AND REVIEW OF THE LITERATURE: The P and Pk antigens are expressed on placental, trophoblastic, and embryonic cells. This explains why P1k (GLOB:-1; P1PK:1,3), P2k (GLOB:-1; P1PK:-1,3), or Tj(a-)/p (GLOB:-1; P1PK:-1,-3) patients are prone to recurrent abortions in the first trimester of pregnancy. A literature review demonstrated 87% (68/78) of miscarriages in p patients. However, publication biases are possible with the most severe cases being reported. CONCLUSION: Immunizations to P and PP1Pk antigens differ from others in their physiopathology and precocity. The association of PE and IVIg seems to be an effective treatment in the management of anti-PP1Pk or anti-P fetomaternal incompatibilities.

[Quality assessment of CAR T-cell activity: Recommendations of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Mutualisation des outils de qualité pour les cellules CAR-T : recommandations de la Société francophone de greffe de moelle et thérapie cellulaire (SFGM-TC).

CAR T-cells are anti-cancer immunocellular therapy drugs that involve reprogramming the patient's T-cells using a transgene encoding a chimeric antigen receptor (CAR). Although CAR T-cells are cellular therapies, the organization for manufacturing and delivering these medicinal products is in many ways different from the one for hematopoietic cell grafts or donor lymphocyte infusions. The implementation of this innovative therapy is recent and requires close coordination between clinical teams, the therapeutic apheresis unit, the cell therapy unit, the pharmaceutical laboratory, and pharmacy. Apart from the regulatory texts, which are regularly modified, and the specific requirements of each pharmaceutical laboratory, there is currently no guide to help the centers initiating their activity and there is no specific indicator to assess the quality of the CAR T-cell activity in each center. The purpose of the current harmonization workshop is to clarify the regulatory prerequisites warranted for a center to have a CAR T-cell activity and to propose recommendations for implementing quality tools, in particular indicators, and allowing their sharing.

Cost and efficacy of peripheral stem cell mobilization strategies in multiple myeloma.

Mobilization of peripheral blood stem cells (PBSC) can be performed using plerixafor, which is expensive, or high-dose cyclophosphamide (HDCy). We hypothesized that the overall cost of mobilization with plerixafor might not be greater if the cost of complication management was considered. We performed a cost analysis of these two strategies. This multicentric observational study recruited patients with myeloma who underwent a first PBSC mobilization. We considered direct medical costs, including hospitalization, mobilization agents, apheresis, and supportive treatments. We included 111 patients, 54 and 57 in the HDCy and plerixafor groups, respectively. Cost of mobilization with HDCy was 5097 ± 2982€ vs. 10958 ± 1789€ for plerixafor (p < 0.0001). Cost of agents used was 1287 ± 779€ vs. 6552 ± 509€, respectively (p = 0.0009). The mean number of days of hospitalization was 2 and 2.1 days, respectively (p = 0.035). All patients achieved the minimum PBSC collection target (p = 1.0); however, ASCT was performed with HDCy in 67% patients and with plerixafor in 86% (p = 0.02). Plerixafor mobilization incurred a greater cost, mostly due to the greater cost of the drug. Hospitalization length in the two groups was similar in our series. Interestingly, plerixafor appeared to be a very effective and safe mobilizing approach translating into a greater ASCT success.

[Modalities of mobilization and hematopoietic stem cells objectives in autologous transplantation: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Modalités de mobilisation des cellules souches hématopoïétiques autologues et objectifs cellulaires en cellules CD34+ : recommandations de la Société francophone de greffe de mœlle et de thérapie cellulaire (SFGM-TC).

The modalities of mobilization of hematopoietic stem cells in autologous transplantation have evolved in recent years. The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 9th hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2018 in Lille, France, to conduct a review of current practices of the society centers and of international recommendations. The cell dose objectives have been revised. The modalities of mobilization including the use of plerixafor have been specified allowing reaching the objectives of collection while limiting the number of apheresis. Collections failures have become exceptional.

[Transfusion in autologous and allogenic hematopoietic stem cell transplant: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Transfusion dans l'autogreffe et l'allogreffe de cellules souches hématopoïétiques chez l'adulte et l'enfant : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

The recommendations of the French Health and Drug Safety Authorities (HAS/ANSM-Haute Autorité de santé/Agence nationale de sécurité du médicament) are known, but there are always new developments underway. With regards to CMV suppression, there is the introduction of platelet glycoprotein Ia and the Intercept (Amotosalem+UVA) inactivation method which addresses bacterial risk. The irradiation of platelets is included in the recommendations to ensure HEV-negative plasma post allograft. In terms of blood transfusion safety, these measures as well as the broader spectrum of Ia, particularly for arboviruses, are a real breakthrough. The survey conducted in clinical services and the services providing blood products for transfusion along with a literature review have shown that several improvements need to be made. The first is a reduction of transfusions of concentrated red blood cells with introduction at a threshold of 7g/dL during hospitalization of patients without a fragile clinical status. The second improvement would address transfusion of refractory thrombocytopenia, encouraging an increase in discussion between clinicians and those conducting the transfusion in order to consider different etiologies and to identify appropriate care protocols. Third would be the need for the transmission of information between the transplantation doctors and blood transfusion specialists in order to define an approach to transfusion care adapted to the patient's situation. It is important to inform and educate patients about transfusion protocols post allotransplant or autotransplant. It must be clearly communicated to patients that they should always have on their person their blood group documentation. This is especially true when receiving care for a hemopathy or an autologous transplant. If undergoing an allogeneic transplant, patients should also carry transfusion guidelines post autotransplant or post allotransplant along with the phone numbers for the stem cell transplantation department and the blood transfusion center responsible for their care.

[Management of the chronic graft versus host disease: Guidelines from the Francophone society of bone marrow transplantation and cellular therapies (SFGM-TC)]. / Prise en charge de la maladie du greffon contre l'hôte chronique : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

The Francophone society of bone marrow transplantation and cellular therapy (SFGM-TC) organized the 7th allogeneic hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2016 in Lille, France. The objective of our workshop is to discuss chronic graft versus host disease and to provide recommendations for the indications and treatment of this condition.

High-Dose Proton Beam-Based Radiation Therapy in the Management of Extracranial Chondrosarcomas.

PURPOSE: Radiation therapy (RT) improves local tumor control in axial chondrosarcomas (CS). It is, however, often difficult to safely deliver the high doses (range, 70.2-77.4 Gy) required for achieving a high likelihood of local control, especially in the spine, using photons. This, however, can be achieved with proton beam therapy (PBT) due to its unique physical characteristics. The main goal of our study is to evaluate the outcomes of CS patients treated with passive scattered PBT. MATERIALS AND METHODS: Forty-four patients (N = 44) were identified who received PBT as part of their treatment from 1990 to 2012. A retrospective review of their medical and RT treatment records was conducted. Multivariate analyses were performed to identify patient- and tumor-related factors predicting for improved local control and overall survival. RESULTS: Median age was 45.5 years and 55% were female. Median tumor size was 13 cm. Most common anatomical location was the spine (80%). Median follow-up was 29.1 months. Median external beam RT dose was 70.2 Gy relative biological effectiveness (RBE) at 1.8 Gy (RBE) per fraction typically administered using a combination of photon RT + PBT (77%) or PBT alone (23%). Local control was 76% and 57%, and overall survival was 90% and 68% at 2 and 5 years, respectively. Toxicity was acceptable, with the most frequent being wound complications (16%). On multivariate analyses, grade III tumors were significantly associated with decreased local control (P = 0.019), while female sex (P = 0.037) and grade III tumors (P = 0.005) were associated with a poorer overall survival. CONCLUSIONS: High-dose proton-based RT in combination with surgery resulted in local tumor control in most of these high-risk CS patients. Female sex was predictive for decreased survival, while higher tumor grade (grade III) was predictive of decreased local control and survival. Proton beam therapy is an attractive treatment modality for these challenging tumors.

[Modalities for preparation, cryopreservation, thawing of hematopoietic stem cells and precautions for infusion to patient: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)]. / Modalités de préparation, cryopréservation, décongélation des cellules souches hématopoïétiques et précautions pour infusion au patient : recommandations de la Société francophone de greffe de moelle et de thérapie cellulaire (SFGM-TC).

To date, despite an existing regulatory framework and standards, there are no true technical recommendations. A survey of 23 cell processing facilities (France, Belgium and Switzerland) has allowed to overview current practices according to cellular products specifications upon arrival at the facility, with modalities for their preparation prior to cryopreservation, storage, thawing and finally for infusion to patient. Data analysis shows great variability of collected volumes and cell concentrations in cellular products. Despite homogeneous practices for handling cells at the facility, methods vary between centers, especially for the choice of cryoprotective solutions and thawing methods. During the workshop, practices have been discussed and summarized to write of recommendations about the following topics: processing and cryopreservation, thawing, bedside precautions (for infusion). This work identifies some improvements in terms of collection, choice of wash solution of thawed cells and validation of the conditions of carriage.

The Hypothesis of the Human iNKT/Innate CD8(+) T-Cell Axis Applied to Cancer: Evidence for a Deficiency in Chronic Myeloid Leukemia.

We recently identified a new human subset of NK-like [KIR/NKG2A(+)] CD8(+) T cells with a marked/memory phenotype, high Eomesodermin expression, potent antigen-independent cytotoxic activity, and the capacity to generate IFN-γ rapidly after exposure to pro-inflammatory cytokines. These features support the hypothesis that this new member of the innate T cell family in humans, hereafter referred to as innate CD8(+) T cells, has a role in cancer immune surveillance analogous to invariant natural killer T (iNKT) cells. Here, we report the first quantitative and functional analysis of innate CD8(+) T cells in a physiopathological context in humans, namely chronic myeloid leukemia (CML), a well-characterized myeloproliferative disorder. We have chosen CML based on our previous report that IL-4 production by iNKT cells was deficient in CML patients at diagnosis and considering the recent evidence in mice that IL-4 promotes the generation/differentiation of innate CD8(+) T cells. We found that the pool of innate CD8(+) T cells was severely reduced in the blood of CML patients at diagnosis. Moreover, like iNKT and NK cells, innate CD8(+) T cells were functionally impaired, as attested by their loss of antigen-independent cytotoxic activity and IFN-γ production in response to innate-like stimulation with IL-12 + IL-18. Remarkably, as previously reported for IL-4 production by iNKT cells, both quantitative and functional deficiencies of innate CD8(+) T cells were at least partially corrected in patients having achieved complete cytogenetic remission following tyrosine kinase inhibitor therapy. Finally, direct correlation between the functional potential of innate CD8(+) T and iNKT cells was found when considering all healthy donors and CML patients in diagnosis and remission, in accordance with the iNKT cell-dependent generation of innate CD8(+) T cells reported in mice. All in all, our data demonstrate that CML is associated with deficiencies of innate CD8(+) T cells that are restored upon remission, thereby suggesting their possible contribution to disease control. More generally, our study strongly supports the existence of an innate iNKT/innate CD8(+) T-cell axis in humans and reveals its potential contribution to the restoration of tumor immune surveillance.

Evidence for eomesodermin-expressing innate-like CD8(+) KIR/NKG2A(+) T cells in human adults and cord blood samples.

Polyclonal CD8(+) T cells, with a marked innate/memory phenotype, high eomesodermin (Eomes) expression, and the capacity to generate IFN-γ rapidly without prior exposure to antigen, have been described in mice. However, even though a pool of human CD8(+) T cells expressing killer Ig-like receptors (KIRs) was recently documented, the existence of a human equivalent of murine innate/memory CD8(+) T cells remains to be established. Here, we provide evidence for a population of KIR/NKG2A(+) CD8(+) T cells in healthy human adults sharing the same features, namely increased Eomes expression, prompt IFN-γ production in response to innate-like stimulation by IL-12+IL-18, and a potent antigen-independent cytotoxic activity along with a preferential terminally differentiated effector memory phenotype. None of the above functional characteristics applied to the KIR/NKG2A(-) fraction of the Eomes(+) CD8(+) T-cell population, thereby underlining the ability of KIR/NKG2A to distinguish between "innate/memory-like" and "conventional/memory" pools of CD8(+) T cells. Remarkably, KIR/NKG2A(+) Eomes(+) CD8(+) T cells with innate-like functions and a memory/terminally differentiated effector memory phenotype were also identified in human cord blood, suggesting that their development did not depend on cognate antigens. Taken together, our results support the conclusion that CD8(+) T cells co-expressing Eomes and KIR/NKG2A may represent a new, functionally distinct "innate/memory-like" subset in humans.

Impact of LDL apheresis on aortic root atheroma in children with homozygous familial hypercholesterolemia.

BACKGROUND: Homozygous familial hypercholesterolemia (HFH) is a rare genetic disease leading to early onset atherosclerosis, due to high concentrations of LDL-C in the blood. Aortic root atheromas may be complicated by obstruction to left ventricle outflow or coronary stenosis. The aim of this study was to describe the progression of aortic root atheroma in patients requiring lipoprotein apheresis before 16 years of age and to examine the requirement of these patients for aortic surgery. METHOD: Clinical reports, lipid profiles and echocardiogram results were obtained retrospectively for patients with HFH from three French hemapheresis centers. Data are presented as group medians. RESULTS: Twenty patients were included, of which 53% had aortic root atheroma (as assessed by echocardiogram) before starting lipoprotein apheresis. These patients began lipoprotein apheresis later than children without aortic root atheroma (10.3 years old [range 5.6-15.9 years] vs. 5.0 years old [range 4.5-11.6 years], respectively, p < 0.05). After 16.4 years (range 2.2-22.8 years) of lipoprotein apheresis treatment, aortic root atheroma had progressed in 64% of patients. Five patients needed surgery for aortic stenosis, which was associated with a coronary artery by-pass for two of them. There were significantly more operations among patients with an aortic root atheroma at the beginning of lipoprotein apheresis than among patients without preexisting lesions (p < 0.01). One patient died after aorta replacement surgery during this period. CONCLUSION: Our results suggest that the initiation of lipoprotein apheresis before the onset of aortic root atheroma should reduce the requirement for aortic surgery.

Role of post-operative radiation boost for soft tissue sarcomas with positive margins following pre-operative radiation and surgery.

BACKGROUND AND OBJECTIVES: The role of a radiation therapy (RT) boost for positive margins following pre-operative RT and surgery in extremity soft tissue sarcomas (STS) is unclear. We assessed the contribution of a boost to local control (LC), disease-free survival (DFS), and overall survival (OS). METHODS: We identified 67 patients treated from 1987 to 2011 with pre-operative RT and surgery with positive margin(s). Select patients received a boost delivered as peri-operative Iridium-192 brachytherapy (BRT), intra-operative electrons (IORT), or post-operative external beam RT (EBRT). RESULTS: Ten patients received no RT boost, 10 received a BRT or IORT boost, and 47 received an EBRT boost. Five-year LC rates for no boost, BRT/IORT boost, and EBRT boost were 100%, 78%, and 71% (P = 0.5). On multivariate analysis, there were no significant predictors for LC. Variables associated with improved DFS rates were single positive margin (P = 0.007) and low tumor grade (P = 0.03). Tumor size <5 cm (P = 0.003), low grade (P = 0.001), and boost (P = 0.02) were associated with longer survival. CONCLUSIONS: We did not identify a LC advantage for an RT boost. Given the unidentified selection factors for delivery of boost and its potential toxicities, its role in this setting remains unproven.

BCR-ABL-induced deregulation of the IL-33/ST2 pathway in CD34+ progenitors from chronic myeloid leukemia patients.

Although it is generally acknowledged that cytokines regulate normal hematopoiesis in an autocrine/paracrine fashion, their possible role in chronic myelogenous leukemia (CML) and resistance to imatinib mesylate treatment remain poorly investigated. Here, we report that CD34(+) progenitors from patients with CML at diagnosis are selectively targeted by the cytokine/alarmin interleukin (IL)-33. Indeed, CML CD34(+) progenitors upregulate their cell surface expression of the IL-33-specific receptor chain ST2, proliferate and produce cytokines in response to IL-33, conversely to CD34(+) cells from healthy individuals. Moreover, ST2 overexpression is normalized following imatinib mesylate therapy, whereas IL-33 counteracts in vitro imatinib mesylate-induced growth arrest in CML CD34(+) progenitors via reactivation of the STAT5 pathway, thus supporting the notion that IL-33 may impede the antiproliferative effects of imatinib mesylate on CD34(+) progenitors in CML. Clinically, the levels of circulating soluble ST2, commonly considered a functional signature of IL-33 signaling in vivo, correlate with disease burden. Indeed, these elevated peripheral concentrations associated with a high Sokal score predictive of therapeutic outcome are normalized in patients in molecular remission. Finally, we evidenced a facilitating effect of IL-33 on in vivo maintenance of CD34(+) progenitors from patients with CML by using xenotransplant experiments in immunodeficient NOG mice, and we showed that engraftment of mouse BCR-ABL-transfected bone marrow progenitors was less efficient in IL-33-deficient mice compared with wild-type recipients. Taken together, our results provide evidence that IL-33/ST2 signaling may represent a novel cytokine-mediated mechanism contributing to CML progenitor growth and support a role for this pathway in CML maintenance and imatinib mesylate resistance.

MRI surveillance following treatment of extremity soft tissue sarcoma.

BACKGROUND AND OBJECTIVES: Local recurrence (LR) following limb-sparing surgery and radiation therapy (RT) for extremity soft tissue sarcoma (STS) is rare. The current study investigates the utility of surveillance nuclear magnetic resonance imaging (MRI) for detection of asymptomatic LRs. METHODS: The study cohort consisted of 168 adult patients with extremity STS treated with limb-sparing surgery and RT with curative intent between October 2001 and January 2011. Follow-up surveillance MRIs and history and physical examinations were performed per the NCCN guidelines with additional MRIs as clinically indicated. The method of LR detection and MRI number and indication were determined. RESULTS: After a median follow-up of 4.7 years (range: 0.6-10.5) 11 (6.5%; 11/168) patients developed LRs. Five hundred two MRIs were obtained, 429 (85.5%; 429/502) for surveillance and 73 (14.5%; 73/502) as clinically indicated. One hundred fourteen patients underwent ≥1 surveillance MRI. The median surveillance MRI interval was 6.4 months (range 1.4-68.9). Surveillance MRI detected an asymptomatic LR in 1 (0.9%; 1/114) patient with a complex reconstruction. CONCLUSIONS: Surveillance MRI infrequently detects asymptomatic LRs following limb-sparing surgery and RT for extremity STS and should be limited to patients whose primary tumor sites are not easily assessed by history and physical examination.