Key Points• Chronic graft-versus-host disease is associated with a global Breg defect.• This defect is particularly accentuated in the CD24 hi CD27 1 Breg compartment.Interleukin 10 (IL-10)-producing B cells (regulatory B cells [Bregs]) regulate autoimmunity in mice and humans, and a regulatory role of IL-10-producing plasma cells has been described in mice. Dysfunction of B cells that maintain homeostasis may play a role in the pathogenesis of chronic graft-versus-host disease (cGVHD) after allogeneic stem cell transplantation. Here, we found a relation between decreased Breg frequencies and cGVHD severity. An impaired ability of B cells to produce IL-10, possibly linked to poor signal transducer and activator of transcription 3 and extracellular signal-regulated kinase phosphorylation, was found in patients with active cGVHD. IL-10 production was not confined to a single B-cell subset, but enriched in both the CD24 hi CD27 1 and CD27 hi CD38 hi plasmablast B-cell compartments. In vitro plasmablast differentiation increased the frequency of IL-10-producing B cells. We confirmed that allogeneic transplant recipients had an impaired reconstitution of the memory B-cell pool. cGVHD patients had less CD24 hi CD27 1 B cells and IL-10-producing CD24 hi CD27 1 B cells. Patients with cGVHD had increased plasmablast frequencies but decreased IL-10-producing plasmablasts. These results suggest a role of CD24 hi CD27 1 B-cell and plasmablast-derived IL-10 in the regulation of human cGVHD. (Blood. 2015;125(11):1830-1839 IntroductionChronic graft-versus-host disease (cGVHD) is the leading cause of morbi-mortality after allogeneic hematopoietic stem cell transplantation (AHSCT). 1 GVHD prevention by means of adoptive transfer of regulatory T cells (Tregs) 2,3 and cGVHD treatment by in vivo induction of Tregs by low-dose interleukin 2 (IL-2) 4,5 may be effective. The exact role of IL-10-producing regulatory B cells (Bregs) in cGVHD is yet to be understood. Bregs have been shown to downmodulate adaptive 6 or innate immune responses 7 in mice and humans. In cGVHD, B cells are essentially recognized as positive regulators of inflammation. 1,8,9 Increased B-cell receptor responsiveness was found in cGVHD patients. 10 B-cell homeostatic defects were described in cGVHD, including elevated B-cell activating factor of the tumor necrosis factor (TNF) family (BAFF)/B-cell ratios, 11-15 expansion of CD21 lo B cells, 16 reduced CD5 1 B1-like cell numbers, 17 decreased CD27 1 memory B cells, and hypogammaglobulinemia. 18 BAFF concentrations correlated with increased circulating pre-germinal center (GC) B-cell and post-GC plasmablast cell counts in patients with cGVHD. 11 B-cell depletion with rituximab prevented cGVHD in humans. 19 Patients with cGVHD frequently have circulating antibodies reactive to recipient cells. 1,9,20 Besides their functions in antibody secretion, cytokine and chemokine production, and antigen presentation, B cells exhibit regulatory properties in several human autoimmune diseases including systemic lupus erythemat...

Response rate and overall survival after Eculizumab in our cohort compare favorably with previously published data in TMA after allogeneic HSCT. Prospective trials are warranted to confirm these results. Early initiation of Eculizumab may have a favorable effect on long-term renal function and further contribute to the prolongation of survival.

In patients referred for allogeneic hematopoietic stem cell transplantation (HSCT), iron overload is frequent and associated with increased morbidity and mortality. Both the evolution of iron overload after transplantation and its correlation with late posttransplantation events are unknown. We studied 290 patients undergoing myeloablative allogeneic HSCT between 2000 and 2009. Serum ferritin, transferrin saturation, transferrin, iron, and soluble transferrin receptor were determined regularly between 1 and 60 months after HSCT, and values were correlated with transplantation outcome. Ferritin levels peaked in the first 3 months posttransplantation and then decreased to normal values at 5 years. Transferrin saturation and iron behaved analogously, whereas transferrin and soluble transferrin receptor increased after an early nadir. Landmark survival analysis showed that hyperferritinemia had a detrimental effect on survival in all periods analyzed (0 to 6 months P < .001; 6 to 12 months P < .001; 1 to 2 years P = .02; 2 to 5 years P = .002). This effect was independent of red blood cell transfusion dependency and graft-versus-host disease. Similar trends were seen for other iron parameters. These data show the natural dynamics of iron parameters in the setting of allogeneic HSCT and provide evidence for a prognostic role of iron overload extending beyond the immediate posttransplantation period. Interventions to reduce excessive body iron might therefore be beneficial both before and after HSCT.

Systematic serum ferritin measurements allowed an optimized management of ID in our donors and efficacious prevention of ID anemia.

3353 Iron store depletion is a common side effect of whole-blood donation. Iron loss may lead to iron deficiency symptoms such as fatigue, decreased physical and job performance then gradually result in iron deficiency anemia. As of 2004, routine serum ferritin testing was implemented at our Center. We analyzed the impact of this measure on our donor population with regard to hemoglobin level, anemia occurrence and donor deferral due to low hemoglobin. A total of 160'612 intended donations of 23'557 healthy blood donors at a single institution (Blutspendezentrum beider Basel, Basel, Switzerland) between 1996 and 2009 were analyzed. At each visit, complete blood counts were taken from fingerprick samples and donors were deferred if the capillary hemoglobin concentration proved <133 g/L (m) or <123 g/L (f). From 2004 on, serum ferritin was measured systematically. Upon detection of ferritin levels indicative of iron depletion or iron deficiency anemia, donors were contacted by a blood bank physician and received medical counseling. The further procedure of iron supplementation, donation interval extension or GP referral in the case of abnormal history remained at the physician and donor's discretion.Our donor population consisted of 10'893 males and 12'664 females, 8165 being women of childbearing age (age 18–45). Mean hemoglobin concentration of male donors rose from 151.7 g/L (before 2004) to 153.6 g/L after 2004 (difference 1.9 g/L, 95% CI 1.7 – 1.9 g/L). In women of all ages, the mean hemoglobin concentration increased from 135.7 to 138.3 g/L (difference 2.6 g/L, 95% CI 2.4 – 2.7 g/L) (Figure 1). The hemoglobin concentration of women of childbearing age was 134.2 g/L before 2004 and 137.0 g/L thereafter (difference 2.8 g/L, 95% CI 2.6 – 3.0 g/L). To rule out an alternative cause for the increase in hemoglobin, we assessed the evolution of hemoglobin levels in the periods of 1996–2003 and 2004–2009. In the former period, hemoglobin levels decreased at a mean rate of 0.22 g/L (95% CI -0.19 - -0.26 g/L) per year in male donors, whereas no significant change was seen in female donors (mean change 0.04 g/L, 95% CI -0.01 – 0.09 g/L). In the second period (2004 – 2009), mean hemoglobin levels increased in both male (mean increase per year 0.20 g/L, 95% CI 0.14 – 0.25 g/L) and female donors (mean increase per year 0.16 g/L, 95% CI 0.09 – 0.23 g/L). Before the introduction of routine ferritin measuring, 1.6% (95% CI 1.5 – 1.7%) of donors showed anemia according to WHO definitions (m: Hb<130; f: Hb<120). Anemia occurred in 1.1% of our donors after 2004 (95% CI 1.0 – 1.2%, difference before/after 2004 0.5%, 95% CI -0.6 – -0.3%). Frequency of anemia declined in both male donors (before 2004 0.7%, after 2004 0.5%) and in female donors (before 2004 3.6%, after 2004 2.2%). In the group of women of childbearing age, 4.9% (95% CI 4.6 – 5.3%) were anemic before and 3.1% (95% CI 2.7– 3.4%) after 2004 (difference before/after 2004 -1.8%, 95% CI -1.4 – -2.4%). In all visits to our center before 2004, 2.8% of donors (95% CI 2.7 – 2.9%) were not accepted for phlebotomy due to a hemoglobin count below the mandatory threshold. After 2004, the percentage of rejected donors due to a low hemoglobin count decreased to 1.9% (95% CI 1.8 – 2.0%, difference before/after 2004 -0.9%, 95% CI -0.7 – -1.0%). In particular in the group of women in childbearing age a clear reduction of the rejection rates was noted (before 2004: 7.6% CI 7.2 – 8.1%, thereafter: 4.8% CI 4.4 – 5.2%, difference before/after 2004 -2.8%, 95% CI -2.2 – -3.4%). In conclusion, the introduction of systematic serum ferritin measurements allowed an optimized management of donors with iron deficiency, with efficacious prevention of iron deficiency anemia. This resulted in an increase of mean hemoglobin levels in blood donors particularly in women of childbearing age, the population at highest risk for iron deficiency anemia. Both the incidence of pre-donation anemia and the frequency of donors rejected due to low hemoglobin decreased significantly. Disclosures: No relevant conflicts of interest to declare.

The purpose of this study was to examine changes in haematopoietic stem cell transplant (HSCT) characteristics and outcome in our combined paediatric and adult programme over the past four decades, since its implementation in 1973. The total number of transplant procedures rose from 109 in the first decade (1973-82) to 939 in the last decade (2003-12). Transplant characteristics changed significantly over time: patient age increased, peripheral blood largely replaced bone marrow as stem cell source, unrelated donors became an alternative to matched siblings, and patients are increasingly transplanted in more advanced disease stages. Advances such as improved supportive care and histocompatibility typing resulted in a steady decrease of transplant-related mortality after allogeneic HSCT (43% in the first decade, 22% in the last decade). Despite this, unadjusted survival rates were stable in the last three decades for allogeneic HSCT (approximately 50% 5-year survival) and in the last two decades for autologous HSCT (approximately 60% 5-year survival). After adjustment for covariates such as donor type, age and stage, the relative risk of treatment failure continuously dropped (for allogeneic HSCT: first decade 1.0, second decade 0.58, third decade 0.51, last decade 0.41). Collectively, these data suggest that improvements in peri- and post-transplant care have allowed considerable extension of transplant indications without having a negative impact on outcome.

In a previous study, the fecal biomarkers calprotectin and α1-antitrypsin (α1-AT) at symptom onset were reported to be significantly associated with the response to steroids in gastrointestinal GvHD (GI-GvHD). The purpose of this trial was to evaluate the dynamics of the fecal biomarkers calprotectin and α1-AT throughout the course of GvHD. Patients who were refractory to steroids had initially higher biomarker levels and in the course of GvHD demonstrated a continuous increase in fecal biomarkers. In contrast, the dynamics of calprotectin and α1-AT demonstrated low and decreasing levels in cortico-sensitive GvHD. In steroid-refractory patients who received a second line of treatment, the biomarker levels at the beginning of second-line treatment did not predict the subsequent response. Nevertheless, calprotectin levels progressively decreased in subsequent responders, whereas non-responders demonstrated continuously high levels of calprotectin. α1-AT values correlated to a lesser extent with the response to second-line treatment and remained elevated in both non-responders and responders. In conclusion, calprotectin monitoring can be of use in the management of immunosuppressive treatment in GI-GvHD.

Risk factors for deferral from red blood cell (RBC) donation due to low hemoglobin are not well defined. We analyzed in a large cohort of returning donors the prognostic value of RBC parameters and serum ferritin regarding low hemoglobin levels at the subsequent visit. Between 2004 and 2009, RBC indices and serum ferritin were recorded in 45,533 visits by 7,994 donors. In 689 instances, donation was deferred at the subsequent visit due to low hemoglobin levels (<123 g/l for female donors, <133 g/l for male donors). Pre-donation hemoglobin at the current visit correlated best with hemoglobin at the subsequent visit (R (2) = 0.63), whereas other RBC indices and serum ferritin correlated only poorly (R (2) ≤ 0.15). Similar results were obtained in ROC curve analysis and in multivariable binary logistic regression. A pre-donation hemoglobin within 5 g/l from the deferral threshold (<128 g/l for female, <138 g/l for male donors) predicted below-threshold hemoglobin levels at the subsequent visit with a sensitivity of 52% and a specificity of 94%. In conclusion, pre-donation hemoglobin is a useful marker identifying donors at risk of developing low hemoglobin levels. Diagnostic and therapeutic interventions should be aimed at donors presenting with hemoglobin levels near the threshold of donor deferral.