Serum levels of cytokines correlate to donor chimerism and acute graft-vs.-host disease after haematopoietic stem cell transplantation

Novel Biomarkers for Outcome After Allogeneic Hematopoietic Stem Cell Transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a well-established curative treatment for various malignant hematological diseases. However, its clinical success is substantially limited by major complications including graft-vs.-host disease (GVHD) and relapse of the underlying disease. Although these complications are known to lead to significant morbidity and mortality, standardized pathways for risk stratification of patients undergoing allo-HSCT are lacking. Recent advances in the development of diagnostic and prognostic tools have allowed the identification of biomarkers in order to predict outcome after allo-HSCT. This review will provide a summary of clinically relevant biomarkers that have been studied to predict the development of acute GVHD, the responsiveness of affected patients to immunosuppressive treatment and the risk of non-relapse mortality. Furthermore, biomarkers associated with increased risk of relapse and subsequent mortality will be discussed.

Prevention of acute graft-versus-host-disease by Withaferin a via suppression of AKT/mTOR pathway

Acute Graft versus Host Disease (aGVHD) is a frequent and serious complication in patients receiving allogeneic bone marrow transplantation (allo-BMT) and often requires rigorous prophylaxis. The current treatment regimens for aGVHD are associated with several side effects which necessitates the development of novel interventions that prevent aGVHD without precluding graft-versus-tumor effects. In the present study, we show that treatment of donor graft with plant steroidal lactone Withaferin A (WA) prior to transplantation markedly reduced aGVHD mediated damage in target organs without compromising the graft-versus.-tumor activity of the transplanted lymphocytes. WA abrogated post-transplant cytokine storm associated with allo-activation of donor lymphocytes. This was attributed to the ability of WA to inhibit early signaling events in T-cell activation including lymphoblast formation and activation of AKT/mTOR pathway. Mortality and morbidity related to allo-transplantation was significantly reduced in recipients of WA treated donor splenocytes compared to recipient of vehicle treated donor splenocytes. Further, WA treatment did not have any effect on reconstitution of lymphoid and myeloid lineages in recipients, resulting in stable and complete donor chimerism. In agreement with previous reports showing the effectiveness of WA in a mouse model of partial chimerism, our data further establishes that WA is able to attenuate aGVHD in an MHC-mismatched high dose chemo-conditioned murine model without compromising engraftment. This study provides compelling scientific basis for possible application of WA for prevention and treatment of aGVHD in patients receiving allo-BMT.

Biosimilar infliximab administration for the management of acute graft-versus-host disease

INTRODUCTION

Acute graft-versus-host disease (aGVHD) is a significant immune-mediated complication of allogeneic hematopoietic stem cell transplant (HSCT). Despite prophylactic immunosuppression, the incidence of grades II-IV aGVHD post-HSCT varies from 20 to 80%. Tumor necrosis factor (TNF) is an important cytokine involved in the pathogenesis of GVHD, and medications such as infliximab (Remicade®) have been utilized as second-line treatment options in patients with steroid-refractory GHVD. Infliximab-dyyb (Inflectra®) and infliximab-qbtx (Ixifi®) are biosimilars approved by the FDA for a variety of autoimmune disorders. This is the first case report documenting the utility of infliximab-dyyb and -qbtx for the management of steroid-refractory aGVHD.

CASE REPORT

We report the post-transplant course of three patients treated with infliximab biosimilars as a part of therapy for management of steroid-refractory aGVHD.

MANAGEMENT AND OUTCOME

Steroid-refractory aGVHD is associated with poor prognosis and its management, as highlighted in our three patient cases, and can be very diverse often requiring different therapeutic modalities which overlap in administration.

DISCUSSION

In these patients with steroid-refractory aGVHD, we were able to show that infliximab biosimilars could be used in lieu of the reference infliximab product. Although we had important limitations, this case report supports the use of anti-TNF agents in highly mortal steroid-refractory acute GI GVHD and that replacement of infliximab with its biosimilars is feasible.

Current Status and Future Directions in Graft-Versus-Host Disease Prevention Following Allogeneic Blood and Marrow Transplantation in Adults

Graft-versus-host disease (GvHD) in its acute and chronic forms continues to represent a significant barrier to the success and wide-applicability of blood and marrow transplantation as a potentially curative treatment modality for a number of benign and malignant blood conditions. Presently, calcineurin inhibitor (CNI)-based regimens remain the most commonly used prevention strategy, although post-transplant cyclophosphamide is emerging as an alternative approach, and is providing a backbone for innovative CNI-free combinations. In this paper, we review the current strategies used for the prevention of GvHD, and highlight some of the developing and promising combinations.

Investigation of TGFB1 -1347C>T variant as a biomarker after allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative therapeutic option for malignant hematopoietic diseases. Cytokines including transforming growth factor β1 (TGFβ1) play a pivotal role in immune reconstruction, and the development of graft versus host disease (GvHD) or infections. The aim of this study was to investigate the role of TGFB1 gene -1347C>T variant in the outcome of HSCT in a cohort of 409 adult recipient-donor pairs. TGFB1 variant was analysed from genomic DNA with LightCycler hybridisation probe method. In case of myeloablative conditioning, donor TGFB1 genotype correlated with overall survival (60-month OS for CC: 62.1 ± 4.8%; CT: 46.8 ± 4.8%; TT: 35.6 ± 9.3%; p = 0.032), which was independent of age, donor type and GvHD prophylaxis in multivariate analysis (HR:2.35, 95%CI:1.35-4.10, p = 0.003). The cumulative incidence of acute GvHD grade III-IV [CC:10%; CT:17%; TT:24%], and non-relapse mortality was higher in TT-carriers (24-month NRM: CC:24%; CT:26%; TT:46%, p = 0.035). We did not find any association between recipient TGFB1 -1347C>T polymorphism and HSCT outcome. Our results suggest that donor TGFB1 -1347C>T may exert an adverse influence on the outcome of myeloablative conditioning transplantation.

LST1: A multifunctional gene encoded in the MHC class III region

The LST1 gene is located in the MHC class III cluster between the MHC class I and II regions. While most genes in this cluster have been sufficiently characterised, a definitive function and expression pattern for LST1 still remains elusive. In the present review we describe its promotor, gene organisation, splice variants and expression in human tissues, cell lines and cancer. We focus on LST1 expression in inflammation and discuss known correlations with autoimmune diseases and cancer. Current data on LST1 polymorphisms and their known associations with pathologies are also discussed in detail. We summarize the potential functions that have been described for the full-length LST1 protein including its function as a transmembrane adaptor protein with inhibitory signal transduction and its role as a membrane scaffold facilitating the formation of tunnelling nanotubes. We also discuss further potential functions by compiling all known LST1-interacting proteins. Furthermore, we address knowledge gaps and conflictive issues regarding disease association, non-hematopoietic expression and the discrepancy between RNA and protein expression data.

Evaluation of Chimerism Dynamics after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Nonmalignant Diseases

It is recognized that chimerism following hematopoietic stem cell transplantation (HSCT) is a dynamic process. The aims of this study were to describe the evolution of chimerism in children with nonmalignant diseases who underwent allogeneic HSCT, and to analyze the risk factors influencing chimerism status. A total of 101 HSCTs were performed in 85 patients with nonmalignant diseases. The donor was unrelated in 62.4% of HSCTs. Reduced-intensity conditioning (RIC) regimen was administered in 48.5% of patients. Acute graft-versus-host disease (aGVHD) occurred in 51.7% and chronic GVHD (cGVHD) in 39.7% of patients. Analysis of chimerism was performed through amplification of 9 specific short tandem repeats by polymerase chain reaction at engraftment and 1, 6, and 12 months after HSCT. Upon first evaluation, complete chimerism (CC) was detected in 34.7% and mixed chimerism (MC) in 55.4%, whereas graft failure occurred in 9.9% of patients. Severe aGVHD was associated with CC (P = .031). The last chimerism evaluation showed CC in 72.1%, stable MC in 12.8%, and progressive MC in 3.5%. CC was associated with a higher incidence of aGVHD (P = .016) and cGVHD (P = .022), whereas the RIC regimen was associated with graft failure (P = .026). One- and 3-year overall survival (OS) was 87.4% and 80.5%, respectively, with a lower OS at 3 years in patients with CC compared with those with MC (P = .008). aGVHD and cGVHD represent factors favoring CC, thus close, careful follow-up of chimerism is recommended in patients affected by nonmalignant disease.

Association of cytokine gene polymorphisms with the complications of allogeneic haematopoietic stem cell transplantation

The purpose of our study was to confirm the prevalence of the association between single nucleotide polymorphisms present in genes encoding cytokines and the complications occurring after haematopoietic stem cell transplantation (HSCT). 108 recipients and 81 donors were typed for TNF-α (-308), TGF-β1 (codon 10, 25), IL-10 (-1082, -819, -592), IL-6 (-174) and INF-γ (+874). Our studies have shown a tendency toward association between the occurrence of acute form of graft versus host disease (aGVHD) and IL-6 genotype. Homozygote C/C was less likely to develop aGVHD (p=0,09). Genotype GCC/ATA in IL-10 recipient gene alone had protective effect against the occurrence of aGVHD (p=0,01). Furthermore, GCC/ATA protected the host against developing the disease in the clinically relevant grades (II-IV) (p=0,03). In addition, the recipient's T/T G/G genotype (TGF-β1) predisposed to the development of both acute (p=0,06 - trend) and chronic (p=0,04) GVHD and also severe aGVHD (p=0,004). We also observed a statistically significant association between the genotype of recipient and the risk of infection - the protective function of the G/C IL-6 in the bloodstream infections (p=0,001). Our results suggest that IL-6, IL-10 and TGF-β1 genotypes of recipient are the most associated with the risk of complications after HSCT.

Cytokine Profile of Engraftment Syndrome in Pediatric Hematopoietic Stem Cell Transplant Recipients

The biology of engraftment syndrome is poorly understood, and the degree of overlap with acute graft-versus-host disease (GVHD) is unclear. To understand engraftment syndrome better, plasma cytokine profiles were evaluated in 56 pediatric allogeneic bone marrow transplant recipients before transplant, on the day of stem cell infusion, and weekly until day +100. Patients were divided into 4 groups: those with isolated engraftment syndrome (n = 8), acute GVHD (n = 12), both engraftment syndrome and acute GVHD (n = 4), and neither engraftment syndrome nor acute GVHD (n = 32). Engraftment syndrome was observed a median of 13.5 days (range, 10 to 28) after transplant, whereas acute GVHD was diagnosed a median of 55 days (range, 19 to 95) after transplant. Four patients developed both engraftment syndrome at a median of 10.5 days (range, 10 to 11) and acute GVHD at a median of 35 days (range, 23 to 56) after stem cell infusion. Median plasma levels of IL-1β, IL-6, IL-12, IL-4, and IL-13 were significantly elevated in patients with isolated engraftment syndrome when compared with isolated acute GVHD. A rise of proinflammatory cytokines (IL-1β, IL-6, and IL-12) was followed by surge in anti-inflammatory cytokines (IL-4 and IL-13) in patients with isolated engraftment syndrome. The observation of elevated IL-1β suggests that engraftment syndrome could be an inflammasome mediated phenomenon.

Ferritin as an early marker of graft rejection after allogeneic hematopoietic stem cell transplantation in pediatric patients

Diagnosis of adverse events following hematopoietic stem cell transplantation (HSCT) is mainly assigned to clinical symptoms or biopsies and thus rather unspecific and/or invasive. Studies indicate a distinct role of serum ferritin in HSCT and its correlation with adverse events such as graft-versus-host disease (GvHD), veno-occlusive disease (VOD), or infections. However, published data on the relevance of ferritin as a prognostic marker for post-transplant adverse events is rare, especially in pediatric patients. The present study analyzes ferritin plasma concentrations of 138 pediatric patients after HSCT between 2007 and 2010 including the control group (n = 21). Given the initial results regarding ferritin as a significant predictor for acute graft rejection after allogeneic HSCT in 9 of the 138 pediatric patients, serum ferritin of all pediatric patients (n = 27) who experienced graft rejection between 2007 and 2014 was analyzed. In addition, laboratory parameters including C-reactive protein (CRP), lactate dehydrogenase (LDH), fibrinogen, and D-dimer as possible differentiation markers for graft rejection were determined. In 24 (88.9 %) of the 27 pediatric patients with graft rejection, a significant increase of ferritin levels was observed 1 to 7 days prior to (P < 0.0001) and at the time of graft rejection (P < 0.0001). Moreover, there was an increase of D-dimer, CRP, LDH, and fibrinogen 1-7 days before graft rejection. Ferritin increased significantly at time of VOD (P = 0.0067), at time of intestinal (P < 0.0001) and skin GvHD (P < 0.0001), and at time of sepsis (P = 0.0005) and bacteremia (P = 0.0029). Ferritin might serve as a readily available identification marker for differentiation and identification of adverse events after HSCT in combination with other laboratory markers.

Cytokine serum levels during post-transplant adverse events in 61 pediatric patients after hematopoietic stem cell transplantation

Background

Veno-occlusive disease, Graft-versus-Host disease, invasive or localized bacterial, viral and fungal infections are known as adverse events after hematopoietic stem cell transplantation representing the major cause for morbidity and mortality. Detection and differentiation of these adverse events are based on clinical symptoms and routine measurements of laboratory parameters.

Methods

To identify the role of cytokines as a possible complication-marker for adverse events, 61 consecutive pediatric patients with a median age of 7.0 years who underwent hematopoietic stem cell transplantation were enrolled in this single-center retrospective study. Interleukin-1 beta (IL-1β), soluble interleukin-2 receptor (sIL-2R), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10) and tumor necrosis factor-α serum (TNF-α) levels were regularly assessed after transplantation and during transplantation related adverse events.

Results

Veno-occlusive disease was accompanied by a significant increase in levels of IL-6, IL-8 and TNF-α.Graft-versus-Host disease was associated with a significant increase of IL-10, sIL-2R, IL-6 and TNF-α, depending on the respective stage or grade. Cytokine IL-6 enabled a significant differentiation between sepsis and fungemia, sepsis and viremia, and sepsis and bacteremia. Moreover, cytokine IL-8 enabled a significant differentiation between sepsis and viremia, sepsis and bacteremia, and bacteremia and viremia whereas IL-10 made a distinction between sepsis and viremia possible.

Conclusion

The data demonstrate that proinflammatory cytokines might be putative indicators for early detection and differentiation of post-transplant adverse events and may allow prompt and adequate clinical intervention. Prospective clinical trials are needed to evaluate these findings.

Rosiglitazone prevents graft-versus-host disease (GVHD)

The effect of rosiglitazone, an agonist of peroxisome proliferator-activated receptor-γ (PPARγ), was investigated in a mouse parent-to-F1 GVHD model. Rosiglitazone inhibited mixed lymphocyte reactions, inducing enhanced apoptosis in CD4+, CD8+, and B220+ cells, but not in NK1.1+, Mac-1+, CD4+/CD25+ and CD3+/NK1.1+ cells. Rosiglitazone administration prevented GVHD in the liver, skin, spleen and intestine. Rosiglitazone inhibited GVHD-induced increases in serum levels of tumor necrosis factor-alpha, interferon-gamma, interleukin (IL)-6, and IL-12, and the GVHD-induced decreases in transforming growth factor-beta and IL-10. Immunophenotyping of splenic leukocytes demonstrated that while rosiglitazone treatment increased the population percentages of both donor and host CD4+/CD25+ and CD3+/NK1.1+ cells, the treatment resulted in lower fractions of both donor and host CD8+ cells. Rosiglitazone inhibited the GVHD-induced decreases in the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN), as well as the GVHD-induced increase in the splenic p-Akt and nuclear factor-kappa B expression. These results indicate that rosiglitazone and PPARγ activation may be useful in protecting the host from GVHD.

Kinetics of T helper subsets and associated cytokines correlate well with the clinical activity of graft-versus-host disease

Background

CD4⁺interferon (IFN)-γ⁺ T cell (Th1) and CD4⁺interleukin (IL)-4⁺ T cell (Th2) polarizations are crucial in the pathogenesis of graft-versus-host disease (GVHD). However, this hypothesis is largely based on animal experiments of Parent-into-F1 GVHD model. The causal relationship between kinetics of Th1, Th2 and associated cytokines and the clinical activity of GVHD in a real world situation remains unknown.

Methodology

Peripheral blood was collected every week prospectively from Day 0 to Day 210 (patients without GVHD) or Day 300 (patients with chronic GVHD) after allogeneic peripheral blood stem cell transplantation in consecutive 27 patients. The frequencies of Th1 and Th2 within CD4⁺ T cells were determined by flow cytometry and pplasma IFN-γ, IL-12, IL-4, and IL-10 were determined by ELISA.

Principal Findings

Kinetics of Th1, Th2 frequency, and the plasma IL-10 and IFN-γ more commonly coincided with, rather than predicted, the activity of GVHD. These markers are significantly higher when acute or chronic GVHD developed. The kinetics of IL-10 is especially correlated well with the activity of GVHD during clinical course of immunosuppressive treatment. For patients with hepatic GVHD, there is a positive correlation between plasma IL-10 levels and the severity of hepatic injury. The frequency of Th2 is also significant higher in acute GVHD and tends to be higher in chronic GVHD. Interestingly, there is a very good positive correlation between the frequency of Th1 and Th2 (r = 0.951, p<0.001). The plasma level of IL-4 and IL-12 are not associated with the activity of GVHD.

Conclusions

The frequency of Th1, Th2 within CD4⁺ T cells and plasma IL-10 and IFN-γ are good biomarkers of GVHD. Plasma IL-10 can also be used to monitor the therapeutic responsiveness. Furthermore, both Th1 and Th2 likely contribute to the pathogenesis of GVHD.

Cytokine expression in tumors treated with donor lymphocyte infusions after allogeneic hematopoietic stem cell transplantation

AIMS

Risk factors for disease relapse are remaining tumor or leukemic cells or mixed chimerism (MC) following allogeneic hematopoietic stem cell transplantation. Donor lymphocyte infusion (DLI) after stem cell transplantation can contribute to complete donor chimerism and graft-versus-tumor/leukemia effect. We evaluate cytokine secretion at the single-cell level using ELISpot in relation to DLI effect on disease response.

PATIENTS & METHODS

Blood samples were collected from four patients with solid tumors and four with hematological malignancies before DLI, and 1 and 3 weeks after DLI. Tumor response was evaluated according to the international Response Evaluation Criteria In Solid Tumors (RECIST) method. Indications for DLI were stable disease or MC and/or progressive disease in solid tumors, and molecular or early relapse, or MC in hematological malignancies. ELISpot was performed for TNF-α, IFN-γ, IL-12, IL-4, IL-10 and IL-13 cytokines.

RESULTS

Depending on the disease response, patients were divided into two groups: responders and nonresponders. Responders were patients who achieved partial response (one renal cell cancer) or stable disease (one prostate cancer) or clinical remission (two acute myeloid leukemia). Patients who relapsed, progressed or rejected the graft were the nonresponders. DLI rescued the renal cell cancer patient, who has partial response, and two acute myeloid leukemia patients, who are in clinical remission. Patients who responded tended to have a higher expression of TNF-α, IFN-γ, IL-12 and IL-10 than those who did not respond.

CONCLUSIONS

DLI can act when the patients' mononuclear cells have normal or increased capacity to produce TNF-α, IFN-γ, IL-12 and IL-10. Assessment of these cytokines may be useful to predict those patients who will respond to DLI therapy.

Clinical implications of chimerism after allogeneic hematopoietic stem cell transplantation in children with non-malignant diseases

Background

The effects of chimerism on outcomes following allogeneic hematopoietic stem cell transplantation (HSCT) are unclear and may differ between diseases. We retrospectively evaluated the association between chimerism and transplant outcomes in children with nonmalignant diseases.

Methods

Chimerism was evaluated using short-tandem repeat polymerase chain reaction (STR-PCR) in 48 patients, with mixed chimerism (MC) defined as greater than 1% recipient cells.

Results

The only variable exerting a significant influence on patients' chimerism status was the number of infused CD34+ cells. MC was detected in 23 transplants (9 showing transient MC; 10 with sustained low levels [≤30%] of autologous cells; and 4 with high-level MC [>30%]). The degree of STR-PCR at 28 days after HSCT was significantly higher in patients with high-level MC than those with transient or low-level MC. All patients with transient or low-level MC successfully maintained engraftment and showed a clinical response to HSCT, whereas 2 of the 4 patients with high-level MC experienced graft failure. The incidences of grades II-IV acute and chronic graft-versus-host disease (GVHD) were significantly higher in patients with complete donor chimerism (CC) than MC. We observed no significant survival differences between CC and MC groups. However, the survival rate was lower in patients with high MC than those with low-level or transient MC (P=0.03).

Conclusion

In non-malignant diseases, MC may indicate a tolerant state with a decreased incidence of GVHD. However, high-level MC may signify an increased risk of graft failure and a lower survival rate.

Immunogenetics of hematopoietic stem cell transplantation: the contribution of microsatellite polymorphism studies

Polymorphisms of short tandem repeats of <10 nucleotides, or microsatellites (Msat), are largely used for post-transplant chimerism analyses in clinical hematopoietic stem cell transplantation (HSCT). Compared to single nucleotide polymorphisms (SNP), they have the advantage of a higher degree of allelic polymorphism and thus a potentially larger degree of informativity. Msat markers contribute to approximately 3% of the human genome and have been highly informative in disease association studies, population genetics, forensic medicine and organ and HSC transplantation. They allowed to expand our knowledge of the haplotypic structure of the HLA complex, including the noncoding sequences in the MHC, and to reach a better characterization of immunological phenotypes. Among the different immunogenetic studies in HSCT patients reviewed here, four Msat loci linked to cytokine genes have been analysed by a number of laboratories as potential candidates markers for HSCT outcome: IFNG, TNFd, IL-10(-1064) and IL-1RN. The low patient numbers and high diversity of clinical parameters account for some heterogeneity of the results. Among the trends starting to emerge from these studies, specific TNFd Msat alleles seem to be associated with acute graft-versus-host disease and mortality. Patient/donor Msat incompatibilities have also been used as surrogate markers to map biologically relevant polymorphisms, with a main focus on MHC-resident genetic variation. High throughput SNP typing and next-generation sequencing technologies will allow acquisition of large-scale genomic data and should allow refined analyses of clinically relevant genotypes in the transplantation settting, although the heterogeneity of the study cohorts will remain an issue. The analysis of Msat polymorphisms may still have a place in functional studies on the impact of Msat diversity in the control of immune response gene expression.

Antileukemia and antitumor effects of the graft-versus-host disease: a new immunovirological approach

In leukemic mice, the native host's explicit and well-defined immune reactions to the leukemia virus (a strong exogenous antigen) and to leukemia cells (pretending in their native hosts to be protected "self" elements) are extinguished and replaced in GvHD (graft-versus-host disease) by those of the immunocompetent donor cells. In many cases, the GvHD-inducer donors display genetically encoded resistance to the leukemia virus. In human patients only antileukemia and anti-tumor cell immune reactions are mobilized; thus, patients are deprived of immune reactions to a strong exogenous antigen (the elusive human leukemia-sarcoma retroviruses). The innate and adaptive immune systems of mice have to sustain the immunosuppressive effects of leukemia-inducing retroviruses. Human patients due to the lack of leukemiainducing retroviral pathogens (if they exist, they have not as yet been discovered), escape such immunological downgrading. After studying leukemogenic retroviruses in murine and feline (and other mammalian) hosts, it is very difficult to dismiss retroviral etiology for human leukemias and sarcomas. Since no characterized and thus recognized leukemogenic-sarcomagenic retroviral agents are being isolated from the vast majority of human leukemias-sarcomas, the treatment for these conditions in mice and in human patients vastly differ. It is immunological and biological modalities (alpha interferons; vaccines; adoptive lymphocyte therapy) that dominate the treatment of murine leukemias, whereas combination chemotherapy remains the main remission-inducing agent in human leukemias-lymphomas and sarcomas (as humanized monoclonal antibodies and immunotoxins move in). Yet, in this apparently different backgrounds in Mus and Homo, GvHD, as a treatment modality, appears to work well in both hosts, by replacing the hosts' anti-leukemia and anti-tumor immune faculties with those of the donor. The clinical application of GvHD in the treatment of human leukemias-lymphomas and malignant solid tumors remains a force worthy of pursuit, refinement and strengthening. Graft engineering and modifications of the inner immunological environment of the recipient host by the activation or administration of tumor memory T cells, selected Treg cells and natural killer (NKT) cell classes and cytokines, and the improved pharmacotherapy of GvHD without reducing its antitumor efficacy, will raise the value of GvHD to the higher ranks of the effective antitumor immunotherapeutical measures. Clinical interventions of HCT/HSCT (hematopoietic cell/stem cell transplants) are now applicable to an extended spectrum of malignant diseases in human patients, being available to elderly patients, who receive non-myeloablative conditioning, are re-enforced by post-transplant donor lymphocyte (NK cell and immune T cell) infusions and post-transplant vaccinations, and the donor cells may derive from engineered grafts, or from cord blood with reduced GvHD, but increased GvL/GvT-inducing capabilities (graft-versus leukemia/tumor). Post-transplant T cell transfusions are possible only if selected leukemia antigen-specific T cell clones are available. In verbatim quotation: "Ultimately, advances in separation of GvT from GvHD will further enhance the potential of allogeneic HCT as a curative treatment for hematological malignancies" (Rezvani, A.R. and Storb, R.F., Journal of Autoimmunity 30:172-179, 2008 (see in the text)). It may be added: for cure, a combination of the GvL/T effects with new targeted therapeutic modalities, as elaborated on in this article, will be necessary.

Decrease of CD4(+)CD25(+) regulatory T cells and TGF-beta at early immune reconstitution is associated to the onset and severity of graft-versus-host disease following allogeneic haematogenesis stem cell transplantation

Graft-versus-host disease (GVHD) is a frequent and life threatening complication of allogeneic haematogenesis stem cell transplantation (aHSCT). The correlation of CD4(+)CD25(+) regulatory T cells (Tregs) in the patients after aHSCT to the occurrence and severity of acute and chronic GVHD (aGVHD and cGVHD) is not fully investigated. Here, we examined the levels of CD4(+)CD25(+) Tregs by assessment of CD4(+)CD25(high) and CD4(+)CD25(+)CD127(low) in peripheral blood, and the levels of serum TGF-beta and TNF-alpha in 56 patients at early immune reconstitution following aHSCT. Our data showed a significant reduction in the frequency of Tregs in patients with grades II-IV aGVHD and extensive cGVHD compared to healthy controls. Moreover, a decreased level of CD4(+)CD25(+) Tregs was correlated to increased severity of GVHD. The levels of CD4(+)CD25(+) Tregs in non-GVHD groups were however significantly higher than that in healthy controls. A significant decrease in the levels of TGF-beta and a significant increase the levels of TNF-alpha was also seen with increased severity of GVHD. This study suggested that measurement of CD4(+)CD25(+) Tregs along with serum TGF-beta and TNF-alpha at early immune reconstruction after aHSCT may indicate the onset and severity of both aGVHD and cGVHD.

Early onset of acute GVHD indicates worse outcome in terms of severity of chronic GVHD compared with late onset

Acute GVHD (aGVHD) is an important risk factor for predicting the incidence or severity of chronic GVHD (cGVHD). Transplant outcome can be influenced by the onset time of aGVHD in patients who have received allogeneic PBSC transplants (PBSCTs). The medical records of 134 patients who survived more than 3 months after myeloablative allogeneic PBSCT were retrospectively reviewed. In all, 38 patients (28.4%) developed grade II-IV aGVHD before day +28 (early aGVHD) and 25 patients (18.7%) after day +28 (late aGVHD). The 5-year cumulative incidence of cGVHD was 78.9% in the early-aGVHD group and 56.6% in the late-aGVHD group (P=0.034). The 5-year OS was 51.0% for the early-aGVHD and 80.8% for the late-aGVHD group (P=0.406). Infection was the primary cause of death for the early-aGVHD group (51.4 vs 16.7%, P=0.017), whereas relapse of the primary disease was higher among the patients with late aGVHD, although this was statistically insignificant (58.3 vs 25.7%, P=0.309). In a multivariate analysis, early aGVHD was identified as a risk factor for developing cGVHD (hazard ratio (HR) 2.278, P=0.004). The development of aGVHD early after allogeneic PBSCT increased the risk of cGVHD and infection-related death rate when compared with the late onset of aGVHD.

A phase III study of infliximab and corticosteroids for the initial treatment of acute graft-versus-host disease

Anti-Tumor Necrosis Factor Alpha (TNF-alpha) therapy with infliximab has shown to be effective for patients with steroid-refractory acute graft-versus-host disease (aGVHD). An open-labeled, phase III trial was conducted to determine if the addition of infliximab to steroids could improve results for patients with newly diagnosed grade II-IV aGVHD. A total of 63 patients were randomized either to 2 mg/kg/day methylprednisolone (MP) or infliximab+ MP. Average age was 47 years (range: 20-70 years); 64% were male. Fifty-three percent and 51% of patients received a matched-sibling and/or bone marrow (BM) graft. Sixty-seven percent had grade II, 33% grade III-IV aGVHD; 62% had skin, 53% gastrointestinal (GI), and 7% had liver involvement. At days 7 and 28, the response rate for infliximab+ MP versus MP was 52% versus 78%, P=.03 and 62% versus 58%, P=.7, respectively. Cumulative incidences of GVHD-related mortality, nonrelapse mortality (NRM), and overall survival (OS) were not significantly different between the 2 groups (GVHD-related mortality: 38% versus 32%, P=.6; NRM: 52% versus 36%, P=.3; OS: 17% and 28%, P=.4 for infliximab+ MP versus MP, respectively). Patients with newly diagnosed aGVHD derive no benefit from the addition of anti-TNF-alpha therapy with infliximab when compared to corticosteroids alone.

Haematopoietic stem cell transplantation: can our genes predict clinical outcome?

Haematopoietic stem cell transplantation (HSCT) is currently the only curative treatment for many patients with malignant and non-malignant haematological diseases. The success of HSCT is greatly reduced by the development of complications, which include graft-versus-host disease (GVHD), relapse and infection. Human leukocyte antigen (HLA) matching of patients and donors is essential, but does not completely prevent these complications; non-HLA genes may also have an impact upon transplant outcome. Polymorphisms within genes that are associated with an individual's capability to mount an immune response to alloantigen and infectious pathogens and/or response to drugs (pharmacogenomics) are all currently being studied for their association with HSCT outcome. This review summarises the potential role of non-HLA polymorphisms in predicting HSCT outcome, from studies on retrospective transplant cohorts of HLA-identical siblings and matched unrelated donors. The clinical relevance and interpretation of non-HLA genetics, and how these could be used alongside clinical risk factors in HSCT, are also discussed.

Absence of Cutaneous TNFα-Producing CD4+ T Cells and TNFα may Allow for Fibrosis Rather than Epithelial Cytotoxicity in Murine Sclerodermatous Graft-Versus-Host Disease, a Model for Human Scleroderma

Graft-versus-host disease (GVHD) is a complication of hematopoietic cell transplantation and is a major source of morbidity and mortality. Two main forms of GVHD occur: cytotoxic GVHD (Cyt GVHD), in which TNFalpha is a critical cytokine in epithelial injury, and sclerodermatous GVHD (Scl GVHD), in which TGFbeta plays a major role in fibrosis. To understand the critical early events in GVHD and scleroderma, we are studying a murine model that uses differences in minor histocompatibility antigens to generate Scl GVHD. We asked the question: what is the immune environment in this model that promotes fibrosis rather than the epithelial injury of Cyt GVHD? We found that in Scl GVHD, cutaneous CD4+ T cells produced IFNgamma and IL-2 but not TNFalpha, also absent by gene array analysis. The role of cutaneous CD4+ T cells in Scl GVHD may not be an active process through production of TGFbeta, but may rather be a passive one due to lack of antigen-presenting cell (APC) support for CD4+ T cells and failure to produce TNFalpha, a potent inhibitor of TGFbeta-induced fibrosis as well as inducer of keratinocyte apoptosis. These APC-T cell interactions and the cytokine environment promote fibrosis rather than cytotoxic epithelial injury in skin in Scl GVHD.

Cyclosporine A (CsA) 2-h concentrations vary between patients without correlation to graft-versus-host disease after allogeneic haematopoietic stem cell transplantation

Cyclosporine A (CsA) therapy based on 2-h concentrations (C2) after oral administration has demonstrated low acute rejection rates after solid organ transplantation. We analysed the correlation between C2 and trough (C0) levels of oral CsA therapy in samples obtained twice in consecutive weeks from 58 patients during their first admission for allogeneic haematopoietic stem cell transplantation. Also 8-h concentration curves were obtained from 23 patients. The mean (range) CsA dose was 332 (167-763) and 255 (113-575) mg/day for patients with matched unrelated donor (MUD) and human leukocyte antigen identical sibling donor (Sib), respectively. Median (range) C0 and C2 were 254 (145-332) and 898 (419-1466) ng/ml in MUD patients, and 130 (93-265) and 554 (196-988) ng/ml in Sib patients. In MUD patients with either aGVHD grade < II or > or = II, the median C2 were 915 (419-1466) and 890 (519-1399) ng/ml, respectively. In Sib patients with aGVHD grade < II or grade > or = II, the median C2 were 552 (404-718) and 539 (196-988) ng/ml, respectively. The median C2 levels were comparable in patients with or without severe infections. Interindividual variations in CsA uptake and metabolism may explain the wide variation of C2 levels without prediction for increased risk for severe aGVHD or infectious complication when C0 guided the CsA dosing.

New directions in the genomics of allogeneic hematopoietic stem cell transplantation

Despite optimal supportive care and high-resolution HLA matching, complications such as GVHD and infection remain major barriers to the success of allogeneic HCT (allo-HCT). This has led to growing interest in the non-HLA genetic determinants of complications after allo-HCT. Most studies have examined genetic predictors of GVHD, relapse, and mortality and have focused on 3 main areas: minor histocompatibility antigen (miHAs), inflammatory mediators of GVHD, and more recently NK cell-mediated allorecognition. The genetic basis of other outcomes such as infection and drug toxicity are less well studied but are being actively investigated. High-throughput methodologies such as single nucleotide polymorphism arrays are enabling the study of hundreds of thousands of genetic markers throughout the genome and the interrogation of novel genetic variants such as copy number variations. These data offer the opportunity to better predict those at risk of complications and to identify novel targets for therapeutic intervention. This review examines the current data regarding the non-HLA genomics of allo-HCT and appraises the promises and pitfalls for integration of this new genetic information into clinical transplantation practice.

Association of TNFd and IL-10 polymorphisms with mortality in unrelated hematopoietic stem cell transplantation

BACKGROUND

Non-HLA immunogenetic polymorphisms may influence outcome of hematopoietic stem cell transplantation (HSCT). In this study, we have determined the role of TNFa, TNFd, IL-10, IL-1, IL-1Ra, and IL-4R polymorphisms in patients transplanted with HSC of an unrelated donor.

METHODS

The allelic variants of four SNPs (IL-10-1082, IL-1beta-511, IL-4R-3223, IL-4R-1902) and four microsatellites (TNFa, TNFd, IL-10-1064, IL-1Ra) were determined in 131 unrelated patient/donor pairs typed for HLA-A/B/C/DR/DQ (four digits).

RESULTS

The allelic distribution of the polymorphisms was similar to that previously reported in Caucasoid populations. Patient and donor TNFd and patient IL-10-1064 polymorphisms correlated with mortality in univariate analysis. Patients with TNFd1/d2/d3 genotypes had 3-year survival rates of 65%. A gradual decrease in survival rates was observed for patients with TNFd3/d3 genotypes (50%, p=n.s.), TNFd4 (46%, P=0.08), and TNFd5 (33%, P=0.03). A multivariate analysis of 10/10 matched patients revealed that the following patient genotypes correlated with lower survival: TNFd3/d3 (RR 4.08, P=0.026) TNFd4 (RR 3.78, P=0.032) and TNFd5 (RR 6.69, P=0.021) all compared to TNFd1/d2/d3 genotypes. Patient IL-10 (12, 14, 15) microsatellite alleles correlated with lower 3-year survival (28%) when compared to IL-10 (<12) (56%, P=0.052) and to Il-10 (13) alleles (60%, P=0.0023). In multivariate analysis this correlation remained significant only in recipients of HSCT of 10/10 HLA matched donors (RR=2.96, P=0.038).

CONCLUSION

The data demonstrate a significant correlation of the TNFd and IL-10-1064 microsatellite polymorphisms with mortality after unrelated HSCT. They support the hypothesis that simple genomic tests, in addition to precise HLA matching, may contribute to determine prognosis in patients undergoing unrelated HSCT.

Inflammatory cytokines predominate in cases of tumor regression after hematopoietic stem cell transplantation for solid cancer

Allogeneic hematopoietic stem cell transplantation (SCT) has recently been presented as promising immunotherapy against renal cell, colon, ovarian, breast, and primary liver cancer. Because clinical results demonstrate a variable effect on metastases, we studied whether there is an association between the clinical response and free cytokines in serum. Two patients with metastatic colorectal and 4 with renal cell cancer underwent allogeneic SCT. Conditioning included fludarabine (30 mg/m2) for 3 or 5 days, using sibling or matched unrelated donors, respectively, followed by 2 Gy total body irradiation (n=5) or cyclophosphamide (60 mg/kg) for 2 days (n=1). Antithymoglobuline (4 mg/kg) was given to patients with matched unrelated donors (n=3). Immunosuppression was cyclosporin A, combined with mycophenolate mofetil (n=5) or methotrexate (n=1). The tumor load was examined by computer tomography of the thorax and abdomen before and 3, 6, 9, and 12 months after SCT. Free cytokines in serum were analyzed using enzyme-linked immunosorbent assay. In each patient, the ratio between inflammatory (I) and anti-I cytokines was calculated. No statistical significance was found between the cytokine ratio in correlation to the tumor load according to international response evaluation criteria in solid tumors criteria. In contrast, tumor regression was found to correlate with dominating I cytokine levels in 5/7 occasions, compared with 1/12 of cases with anti-I cytokines using our local method focusing on metastases in lungs, lymph nodes, and liver (P=.01). Thus, an increased level of I cytokines possibly mirrors tumor killing induced by type 1 T-cell response. Furthermore, anti-I cytokines might inhibit cytotoxic cells from exerting the antitumor effect of allogeneic SCT.

Cytokine Gene Expression in Peripheral Blood Mononuclear Cells and Alloreactivity in Hematopoietic Cell Transplantation with Nonmyeloablative Conditioning

Cytokines are thought to play an important role in the pathophysiology of graft-versus-host disease (GVHD). To study the relationship between cytokines and GVHD, we obtained peripheral blood mononuclear cells (MNCs) from 21 patients with hematologic malignancies and their HLA-identical sibling donors before and sequentially after hematopoietic cell transplantation (HCT) with nonmyeloablative conditioning. The MNCs were cultured for 72 hours either alone or in mixed lymphocyte cultures with irradiated MNCs of recipient, donor, or HLA-mismatched third-party origin. The gene expression of interleukin (IL)-2, IL-4, IL-10, IL-18, tumor necrosis factor alpha, and transforming growth factor beta in each culture was then measured by real-time quantitative reverse transcriptase-polymerase chain reaction. The composition of the responder MNCs differed between patients and donors and changed after HCT, with a possible influence on the results. Early after transplantation (day +14), the IL-10 messenger RNA (mRNA) level in response to recipient or donor antigens was higher in patients who did not develop clinically significant acute GVHD when compared with the level in patients who subsequently developed acute GVHD grades II to IV (P = .005 and P = .004, respectively). The IL-10 mRNA level on day +14 was highly correlated with the pretransplantation mRNA level of the recipient MNCs but not with the level of the donor MNCs; this suggests that the IL-10 mRNA detected on day +14 originated from responder cells of recipient origin. A higher IL-10 mRNA level was found in MNCs obtained before transplantation from recipients whose disease progressed or relapsed after the transplantation when compared with the level in patients whose disease did not progress or relapse (P = .03). In conclusion, a high IL-10 gene expression in the recipient MNCs may be related to a reduced incidence of acute GVHD grades II to IV and a reduced graft-versus-tumor effect after HCT with nonmyeloablative conditioning.

Molecular monitoring of T-cell chimerism early after allogeneic stem cell transplantation may predict the occurrence of acute GVHD grades II-IV

Mixed chimerism (MC) within CD4+ and CD8+ T cell days 7 and 10 after allogeneic stem cell transplantation (SCT) was compared with the occurrence of acute graft-vs.-host disease (GVHD) in 34 patients after SCT. Acute GVHD was diagnosed in 22 patients within the first 3 months after SCT, 15 of these developed acute GVHD grades II-IV. The difference in the clearance rate of host T cell between the two days were compared. We found a significantly higher risk (p = 0.005) for developing acute GVHD grades II-IV in patients with complete donor CD4+ T-cell chimerism day 7 after SCT together with patients who increased 50% or more in donor CD4+ T cells between days 7 and 10 after SCT. Our data suggest that molecular monitoring of MC early after transplantation may be useful as a diagnostic tool in predicting the occurrence of moderate to severe acute GVHD after SCT.

Genomic screening and complications of hematopoietic stem cell transplantation: has the time come?

The occurrence of toxic complications following hematopoietic stem cell transplantation (HSCT) is highly variable and dependent on a multitude of host, donor, and treatment factors. The increasingly broad indications for HSCT and the need to provide this treatment option to older and/or more debilitated patients emphasizes the importance of refining our methods of predicting and ameliorating these toxicities. Late complications (occurring after day 100) also pose a threat to quality of life after HSCT. Genetic polymorphisms in key molecular pathways in the host are likely to contribute significantly to the observed variability in the development HSCT-associated complications. Hepatic veno-occlusive disease and acute lung injury, two of the most serious organ toxicities that occur, represent useful paradigms for the identification of genetic polymorphisms in enzyme systems that modulate local and systemic responses to oxidant stress during transplant conditioning therapy. Ongoing studies in this area are providing clues to the prevention of adverse clinical outcomes based on the genetic milieu. This review of studies in HSCT that explore genetic risk factors for transplant complications indicates that significant progress is being made in this rapidly evolving area. However, further large-scale clinical and translational studies are needed before genomic screening can be widely used to individualize treatment.

A possible association between the presence of interleukin-4–secreting cells and a reduction in the risk of acute graft-versus-host disease

OBJECTIVE

We monitored cytokine-secreting cells using an enzyme-linked immunospot (ELISPOT) assay in a prospective study to assess the cytokine network after transplantation.

PATIENTS AND METHODS

Peripheral blood mononuclear cells were collected from 23 patients who received allogeneic stem cell transplantation, from before the preconditioning regimen to 56 days after transplantation. The number of interleukin-4 (IL-4), interferon-gamma (IFN-gamma), and tumor necrosis factor-alpha (TNF-alpha)-secreting cells were measured by ELISPOT assay. For IL-4 and IFN-gamma, in vitro stimulation with phorbol 12-myristate 13-acetate and phytohemagglutinin was performed.

RESULTS

The frequency of IL-4-secreting cells was significantly higher in five patients receiving peripheral blood stem cell transplantation (PBSCT) than that in 18 patients who received bone marrow transplantation (BMT). Based on IFN-gamma and TNF-alpha release, there was a trend toward a decrease in the number of cytokine-secreting cells in PBSCT compared with BMT. Furthermore, patients who did not develop acute graft-vs-host disease (GVHD, n=5) showed a significantly higher number of IL-4-secreting cells compared with those who developed acute GVHD (n=18). Both IFN-gamma-secreting cells and TNF-alpha-secreting cells showed a trend to increase in number in patients with acute GVHD. In patients who received reduced-intensity stem cell transplantation (n=7) compared with conventional stem cell transplantation (n=16), there was a large number of cytokine-secreting cells detected by IL-4 and IFN-gamma release.

CONCLUSIONS

These results are consistent with the hypothesis that IL-4-producing cells inhibit the development of acute GVHD. In addition, the increased percentage of IL-4-secreting cells may be responsible for the unexpected low incidence of acute GVHD in PBSCT, despite the presence of large numbers of mature T cells in the donor infusion.

Acute graft-versus-host disease: Pathophysiology, clinical manifestations, and management

Hematopoietic stem cell transplantation has evolved as a central treatment modality in the management of different hematologic malignancies. Despite adequate posttransplantation immunosuppressive therapy, acute graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality in the hematopoietic stem cell transplantation setting, even in patients who receive human leukemic antigen (HLA) identical sibling grafts. Up to 30% of the recipients of stem cells or bone marrow transplantation from HLA-identical related donors and most patients who receive cells from other sources (matched-unrelated, non-HLA-identical siblings, cord blood) will develop > Grade 2 acute GVHD despite immunosuppressive prophylaxis. Thus, GVHD continues to be a major limitation to successful hematopoietic stem cell transplantation. In this review, the authors summarize the most current knowledge on the pathophysiology, clinical manifestations, and management of this potentially life-threatening transplantation complication.