Sophie Servais

Long-term immune reconstitution and infection burden after mismatched hematopoietic stem cell transplantation.

Mismatched unrelated donor (MMUD) or umbilical cord blood (UCB) can be chosen as alternative donors for allogeneic stem cell transplantation but might be associated with long-lasting immune deficiency. Sixty-six patients who underwent a first transplantation from either UCB (n = 30) or 9/10 MMUD (n = 36) and who survived beyond 3 months were evaluated. Immune reconstitution was prospectively assessed at sequential time points after transplantation. NK, B, CD4(+), and CD8(+) T cells and their naïve and memory subsets, as well as regulatory T cells (Treg), were studied. Detailed analyses on infections occurring after 3 months were also assessed. The 18-month cumulative incidences of infection-related death were 8% and 3%, and of infections were 72% and 57% after MMUD and UCB transplantation, respectively. Rates of infection per 12 patient-month were roughly 2 overall (1 for bacterial, .9 for viral, and .3 for fungal infections). Memory, naïve CD4(+) and CD8(+)T cells, naïve B cells, and Treg cells reconstitution between the 2 sources were roughly similar. Absolute CD4(+)T cells hardly reached 500 per μL by 1 year after transplantation and most B cells were of naïve phenotype. Correlations between immune reconstitution and infection were then performed by multivariate analyses. Low CD4(+) and high CD8(+)T cells absolute counts at 3 months were linked to increased risks of overall and viral (but not bacterial) infections. When assessing for the naïve/memory phenotypes at 3 months among the CD4(+) T cell compartment, higher percentages of memory subsets were protective against late infections. Central memory CD4(+)T cells protected against overall and bacterial infections; late effector memory CD4(+)T cells protected against overall, bacterial, and viral infections. To the contrary, high percentage of effector- and late effector-memory subsets at 3 months among the CD8(+) T cell compartment predicted higher risks for viral infections. Patients who underwent transplantation from alternative donors represent a population with very high risk of infection. Detailed phenotypic analysis of immune reconstitution may help to evaluate infection risk and to adjust infection prophylaxis.

Allogeneic stem cell transplantation for advanced cutaneous T-cell lymphomas: a study from the French Society of Bone Marrow Transplantation and French Study Group on Cutaneous Lymphomas

The treatment of advanced stage primary cutaneous T-cell lymphomas remains challenging. In particular, large-cell transformation of mycosis fungoides is associated with a median overall survival of two years for all stages taken together. Little is known regarding allogeneic hematopoietic stem cell transplantation in this context. We performed a multicenter retrospective analysis of 37 cases of advanced stage primary cutaneous T-cell lymphomas treated with allogeneic stem cell transplantation, including 20 (54%) transformed mycosis fungoides. Twenty-four patients (65%) had stage IV disease (for mycosis fungoides and Sézary syndrome) or disseminated nodal or visceral involvement (for non-epidermotropic primary cutaneous T-cell lymphomas). After a median follow up of 29 months, 19 patients experienced a relapse, leading to a 2-year cumulative incidence of relapse of 56% (95%CI: 0.38–0.74). Estimated 2-year overall survival was 57% (95%CI: 0.41–0.77) and progression-free survival 31% (95%CI: 0.19–0.53). Six of 19 patients with a post-transplant relapse achieved a subsequent complete remission after salvage therapy, with a median duration of 41 months. A weak residual tumor burden before transplantation was associated with increased progression-free survival (HR=0.3, 95%CI: 0.1–0.8; P=0.01). The use of antithymocyte globulin significantly reduced progression-free survival (HR=2.9, 95%CI: 1.3–6.2; P=0.01) but also transplant-related mortality (HR=10−7, 95%CI: 4.10−8−2.10−7; P<0.001) in univariate analysis. In multivariate analysis, the use of antithymocyte globulin was the only factor significantly associated with decreased progression-free survival (P=0.04). Allogeneic stem cell transplantation should be considered in advanced stage primary cutaneous T-cell lymphomas, including transformed mycosis fungoides.

Pre-transplant prognostic factors of long-term survival after allogeneic peripheral blood stem cell transplantation with matched related/unrelated donors

Mobilized peripheral blood has become the predominant stem cell source for allogeneic hematopoietic cell transplantation. In this retrospective single center study of 442 patients with hematologic malignancies, we analyzed prognostic factors for long-term survival after peripheral blood stem cell transplantation from HLA-matched related or unrelated donors. To account for disease/status heterogeneity, patients were risk-stratified according to the Disease Risk Index. Five-year overall survival was similar after transplants with matched related and unrelated donors (45% and 46%, respectively; P=0.49). Because donor age ≥60 years impacted outcome during model building, we further considered 3 groups of donors: matched unrelated (aged <60 years by definition), matched related aged <60 years and matched related aged ≥60 years. In multivariate analysis, the donor type/age group and the graft CD34+ and CD3+ cell doses impacted long-term survival. Compared with matched unrelated donor transplant, transplant from matched related donor <60 years resulted in similar long-term survival (P=0.67) while transplant from matched related donor ≥60 years was associated with higher risks for late mortality (hazard ratio (HR) 4.41; P=0.006) and treatment failure (HR: 6.33; P=0.009). Lower mortality risks were observed after transplant with CD34+ cell dose more than 4.5×106/kg (HR: 0.56; P=0.002) and CD3+ cell dose more than 3×108/kg (HR: 0.61; P=0.01). The Disease Risk Index failed to predict survival. We built an “adapted Disease Risk Index” by modifying risks for myeloproliferative neoplasms and multiple myeloma that improved stratification ability for progression-free survival (P=0.04) but not for overall survival (P=0.82).

Darbepoetin-alfa and intravenous iron administration after autologous hematopoietic stem cell transplantation : A prospective multicenter randomized trial

We conducted a randomized study analyzing the impact of darbepoetin alfa (DA) administration with or without intravenous (i.v.) iron on erythroid recovery after autologous hematopoietic cell transplantation (HCT). Patients were randomized between no DA (Arm 1), DA 300 μg every 2 weeks starting on Day 28 after HCT (Arm 2), or DA plus i.v. iron 200 mg on Days 28, 42, and 56 (Arm 3). The proportion achieving complete hemoglobin (Hb) response within 18 weeks (primary end point) was 21% in Arm 1 (n = 24), 79% in Arm 2 (n = 25), and 100% in Arm 3 (n = 23; P < 0.0001). Erythropoietic response was shown to be significantly higher in Arm 3 (n = 46) than in Arm 2 (n = 50; P = 0.008), resulting in lower DA use, reduced drug costs, and improved quality of life scores, but the effect on transfusions was not significant. In multivariate analysis, DA administration (P < 0.0001), i.v. iron administration (P = 0.0010), high baseline Hb (P < 0.0001), and low baseline creatinine (P = 0.0458) were independently associated with faster achievement of complete Hb response. In conclusion, DA is highly effective to ensure full erythroid reconstitution after autologous HCT when started on Day 28 post‐transplant. I.v. iron sucrose further improves erythroid recovery. Am. J. Hematol. 88:990–996, 2013.

Allogeneic hematopoietic stem cell transplantation (HSCT) after reduced intensity conditioning

Allogeneic hematopoietic stem cell transplantation (HSCT) following myeloablative (conventional) conditioning regimen is associated with a high incidence of transplant-related morbidity and mortality, limiting its use to younger patients without medical co-morbidities. Over the past few years, it has become more evident that the alloreactivity of transplanted donor immunocompetent cells against host tumor cells (graft-versus-tumor effects, GVT effects) plays a major role in eradicating malignancies after allogeneic HSCT. Based on these observations, several groups of investigators have developed reduced intensity conditioning (RIC) regimens allowing patients who are ineligible for conventional HSCT to benefit from the potentially curative GVT effects of allogeneic transplantation. Retrospective studies have suggested that, in comparison with myeloablative allogeneic HSCT, in patients aged 40-60 years, RIC HSCT was associated with a higher risk of relapse but a lower incidence of transplant-related mortality leading to similar progression-free and overall survivals. Prospective studies are ongoing to define which patients might most benefit from RIC HSCT, and to increase the anti-tumoral activity of the procedure while reducing the incidence and the severity of acute graft-versus-host disease (GVHD). In this article, we review the current status and perspectives of RIC HSCT.

Enteroviral meningoencephalitis as complication of Rituximab therapy in a patient treated for diffuse large B-cell lymphoma

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Immune Recovery after Allogeneic Hematopoietic Stem Cell Transplantation following Flu-TBI versus TLI-ATG Conditioning

Purpose: A conditioning regimen for allogeneic hematopoietic cell transplantation (HCT) combining total lymphoid irradiation (TLI) plus anti-thymocyte globulin (ATG) has been developed to induce graft-versus-tumor effects without graft-versus-host disease (GVHD). Experimental Design: We compared immune recovery in 53 patients included in a phase II randomized study comparing nonmyeloablative HCT following either fludarabine plus 2 Gy total body irradiation (TBI arm, n = 28) or 8 Gy TLI plus ATG (TLI arm, n = 25). Results: In comparison with TBI patients, TLI patients had a similarly low 6-month incidence of grade II-IV acute GVHD, a lower incidence of moderate/severe chronic GVHD (P = 0.02), a higher incidence of CMV reactivation (P < 0.001), and a higher incidence of relapse (P = 0.01). While recovery of total CD8+ T cells was similar in the two groups, with median CD8+ T-cell counts reaching the normal values 40 to 60 days after allo-HCT, TLI patients had lower percentages of naïve CD8 T cells. Median CD4+ T-cell counts did not reach the lower limit of normal values the first year after allo-HCT in the two groups. Furthermore, CD4+ T-cell counts were significantly lower in TLI than in TBI patients the first 6 months after transplantation. Interestingly, while median absolute regulatory T-cell (Treg) counts were comparable in TBI and TLI patients, Treg/naïve CD4+ T-cell ratios were significantly higher in TLI than in TBI patients the 2 first years after transplantation. Conclusions: Immune recovery differs substantially between these two conditioning regimens, possibly explaining the different clinical outcomes observed (NCT00603954). Clin Cancer Res; 21(14); 3131–9. ©2015 AACR.

Impact of Pre-Transplant Anti-T Cell Globulin (ATG) on Immune Recovery after Myeloablative Allogeneic Peripheral Blood Stem Cell Transplantation.

Background Pre-transplant infusion of rabbit anti-T cell globulin (ATG) is increasingly used as prevention of graft-versus-host disease (GVHD) after allogeneic peripheral blood stem cell transplantation (PBSCT). However, the precise impact of pre-transplant ATG on immune recovery after PBSCT is still poorly documented. Methods In the current study, we compared immune recovery after myeloablative PBSCT in 65 patients who either received (n = 37) or did not (n = 28) pre-transplant ATG-Fresenius (ATG-F). Detailed phenotypes of circulating T, B, natural killer (NK) and invariant NKT (iNKT) cells were analyzed by multicolor flow cytometry at serial time-points from day 40 to day 365 after transplantation. Thymic function was also assessed by sjTREC quantification. Serious infectious events were collected up to 2 years post-transplantation. Results Pre-transplant ATG-F had a prolonged (for at least up to 1-year) and selective negative impact on the T-cell pool, while it did not impair the recovery of B, NK nor iNKT cells. Among T cells, ATG-F selectively compromised the recovery of naïve CD4+, central memory CD4+ and naïve CD8+ cells, while it spared effector memory T and regulatory T cells. Levels of sjTRECs were similar in both cohorts at 1-year after PBSCT, suggesting that ATG-F unlikely impaired thymopoiesis at long-term after PBSCT. Finally, the incidence and rate of serious infections were similar in both groups, while ATG-F patients had a lower incidence of grade II-IV acute graft-versus-host disease. Conclusions Pre-transplant ATG-F induces long-lasting modulation of the circulating T-cell pool after myeloablative PBSCT, that may participate in preventing graft-versus-host disease without deeply compromising anti-pathogen defenses.

Circadian and circannual variations in cord blood hematopoietic cell composition

Several previous studies have demonstrated that cord blood unit composition is an important factor that may predict outcomes after cord blood transplantation, with higher doses of transplanted nucleated cells and hematopoietic stem and progenitor cells being associated with faster engraftment and better overall survival. In the setting of this study involving 3 University centers, we analyzed factors potentially influencing cord blood cell composition. In accordance with the results of several previous publications, we observed that gestational age, birth weight and babys gender impacted concentrations of nucleated and hematopoietic progenitor cells in cord blood. We also showed that uses of epidural anesthesia and of oxytocin were associated with higher concentrations of hematopoietic progenitor cells. Interestingly, we observed that nucleated cell and progenitor cell concentrations were also determined by time of day and month of delivery. Recent studies have suggested chronological rhythmic egress of hematopoietic stem and progenitor cells from the bone marrow to the peripheral blood in adult individuals. Our findings suggest that such physiological rhythm may not be restricted to post-natal life. We think our study may have practical implications for cord blood banking strategies and also raises questions about chronological rhythm in hematopoietic cell trafficking during fetal life.

Novel approaches for preventing acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

ABSTRACT Introduction: Allogeneic hematopoietic stem cell transplantation (alloHSCT) offers potential curative treatment for a wide range of malignant and nonmalignant hematological disorders. However, its success may be limited by post-transplant acute graft-versus-host disease (aGVHD), a systemic syndrome in which donor’s immune cells attack healthy tissues in the immunocompromised host. aGVHD is one of the main causes of morbidity and mortality after alloHSCT. Despite standard GVHD prophylaxis regimens, aGVHD still develops in approximately 40–60% of alloHSCT recipients. Areas covered: In this review, after a brief summary of current knowledge on the pathogenesis of aGVHD, the authors review the current combination of a calcineurin inhibitor with an antimetabolite with or without added anti-thymocyte globulin (ATG) and emerging strategies for GVHD prevention. Expert opinion: A new understanding of the involvement of cytokines, intracellular signaling pathways, epigenetics and immunoregulatory cells in GVHD pathogenesis will lead to new standards for aGVHD prophylaxis allowing better prevention of severe aGVHD without affecting graft-versus-tumor effects.