Pathogenesis Of Chronic Graft-versus-host Disease Research Articles

Murine Models Provide New Insights Into Pathogenesis of Chronic Graft-Versus-Host Disease in Humans.

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for hematologic malignancies, but its success is complicated by graft-versus-host disease (GVHD). GVHD can be divided into acute and chronic types. Acute GVHD represents an acute alloimmune inflammatory response initiated by donor T cells that recognize recipient alloantigens. Chronic GVHD has a more complex pathophysiology involving donor-derived T cells that recognize recipient-specific antigens, donor-specific antigens, and antigens shared by the recipient and donor. Antibodies produced by donor B cells contribute to the pathogenesis of chronic GVHD but not acute GVHD. Acute GVHD can often be effectively controlled by treatment with corticosteroids or other immunosuppressant for a period of weeks, but successful control of chronic GVHD requires much longer treatment. Therefore, chronic GVHD remains the major cause of long-term morbidity and mortality after allo-HCT. Murine models of allo-HCT have made great contributions to our understanding pathogenesis of acute and chronic GVHD. In this review, we summarize new mechanistic findings from murine models of chronic GVHD, and we discuss the relevance of these insights to chronic GVHD pathogenesis in humans and their potential impact on clinical prevention and treatment.

Anti-ICOS mAb Targets Pathogenic IL-17A-expressing Cells in Canine Model of Chronic GVHD.

Chronic graft-versus-host disease (GVHD) is a significant cause of morbidity and mortality in transplant patients. We have previously shown that 3 doses of an anti-inducible costimulator (ICOS) mAb transiently ameliorated symptoms and extended survival of dogs affected by chronic GVHD over that of control dogs. The purpose of this study was to specifically correlate changes in T-cell populations in the peripheral blood with anti-ICOS treatment and chronic GVHD progression and regression to reach a better understanding of the mechanism of the disease and prioritize future studies. Peripheral blood cells from canines transplanted with DLA-mismatched bone marrow and peripheral blood mononuclear cells to generate chronic GVHD were analyzed by flow cytometry using a panel of antibodies specific to helper and cytolytic T cells. Chronic GVHD was specifically associated with an increase in CD4+ICOS+ cells, ICOS+ cells expressing IL-17A, and CD8+ cells generating granzyme B. Treatment with anti-ICOS mAb at onset of chronic GVHD symptoms specifically targeted IL-17A+-expressing cells, transiently relieved symptoms, and lengthened survival but was unable to reduce the percentage of CD8+ T-cells expressing granzyme B. These studies suggested a role for both CD4+ and CD8+ T cells in pathogenesis of chronic GVHD in the canine model. We propose that future studies should focus on further extending survival by developing a treatment that would control both CD4+ and CD8+ T cells.

Dickkopf-related protein 3 is a novel biomarker for chronic GVHD after allogeneic hematopoietic cell transplantation

AbstractTo identify plasma biomarkers associated with fibrotic mechanisms of chronic graft-versus-host disease (GVHD), we used multiplex mass spectrometry with pooled samples for biomarker discovery in comparing proteomic profiles between patients with newly diagnosed sclerotic chronic GVHD (n = 21), those with newly diagnosed nonsclerotic chronic GVHD (n = 33), and those without chronic GVHD (n = 20). Immunoassay was used to measure protein concentrations of individual discovery samples and 186 independent verification samples. The discovery mass spectrometry analysis identified 2 candidate proteins with at least 1.5-fold difference in sclerotic GVHD: Dickkopf-related protein 3 (DKK3) and interleukin-1 receptor accessory protein (IL1RAP). Analysis of individual discovery samples by immunoassay showed that DKK3, a modulator of the Wnt signaling pathway, was a biomarker for both sclerotic and nonsclerotic chronic GVHD. Verification analysis of 186 patients confirmed that elevated plasma DKK3 concentrations were associated with chronic GVHD, regardless of the presence or absence of sclerosis, and that the area under the receiver operating characteristic curve was 0.85 for association of DKK3 concentrations with chronic GVHD. Multiple linear regression analysis showed that chronic GVHD with or without steroid treatment and patient age were independently associated with DKK3 concentrations. Patients with high DKK3 concentrations had a higher nonrelapse mortality than those with low concentrations. The lower IL1RAP concentrations in patients with sclerotic GVHD compared with other conditions in the discovery cohort were not confirmed in the verification cohort. DKK3 is a novel biomarker for chronic GVHD. Further studies are needed to determine the biological functions of DKK3 in the pathogenesis of chronic GVHD.

Different Immune Reconstitution between Cord Blood and unrelated Bone Marrow Transplantation with Relation to Chronic Graft-versus-Host Disease

Background: Advances of allogeneic hematopoietic cell transplantation (allo-HCT) have brought long-term survival to the patients with hematologic malignancies. Chronic graft-versus-host disease (GVHD) is one of major problems for the long- term survivors after allo-HCT. Dysregulation of immune reconstitution has been reported to be involved in the pathogenesis of chronic GVHD. Differences of immune reconstitution between cord blood transplantation (CBT) and unrelated bone marrow transplantation (UBMT) remain unclear in long-term survivors. We investigated immune reconstitution in patients surviving for more than 2 years after CBT (n=21) or UBMT (n=20) without relapse of underlying disease. Materials and Methods: Using flow cytometric analysis of peripheral blood, we investigated immune reconstitution of T cells, B cells, and NK cells between CBT and UBMT patients. We collected clinical data regarding allo-HCT and examined the relation of immune reconstitution to the development of chronic GVHD. Results: Between CBT and UBMT patients, we found significant differences in absolute cell number of CD8+ as well as CD19+ cell and CD4/CD8 ratio even more than 2 years after allo-HCT. Among UBMT patients, absolute cell number of naive CD4+ cell was significantly lower in patients with chronic GVHD. In addition, we found significant differences in absolute cell number of CD19+ cell, especially naive B cell between patients with and without chronic GVHD in both CBT and UBMT patients. Conclusion: These results suggest that differences of immune recovery between CBT and UBMT patients may exist even in patients surviving for more than 2 years and might be related to the development of chronic GVHD.

Mixed Chimerism: Good News or Bad News?

Mixed Chimerism: Good News or Bad News?

Administration Of Anti-CD20 Mab Is Highly Effective In Preventing But Ineffective In Treating Chronic GVHD While Preserving A Strong GVL Effect

Donor T cell-mediated graft versus leukemia/lymphoma (GVL) effect plays a critical role in preventing tumor relapse in leukemia/lymphoma patients treated with allogeneic hematopoietic cell transplantation (HCT). However, these same donor T cells also induce acute and chronic graft versus host disease (GVHD), which remains a major obstacle for allogeneic HCT as a curative therapy for hematological malignancies. Chronic GVHD is a systemic lupus- and scleroderma-like autoimmune syndrome. We and others reported that donor B cells play important roles in augmenting pathogenesis of chronic GVHD in mouse models and humans. Rituxan (an anti-CD20 mAb) has been used in the clinic for the treatment of ongoing chronic GVHD, but the effect is variable and minimum in some reports, and the mechanisms for this ineffectiveness remains unclear. In the current studies, we evaluated the effect of in vivo administration of a depleting anti-CD20 mAb in preventing and treating autoimmune-like chronic GVHD as well as the impact on GVL effect. With the mouse chronic GVHD model of DBA/2 donor to MHC-matched BALB/c recipient established in our lab (Blood, 2006, J. Immunol 2012), we found that one intravenous injection of anti-CD20 (50mg/kg) immediately after HCT effectively prevented induction of autoimmune-like chronic GVHD. While all (12/12) recipients treated with control IgG developed chronic GVHD with proteinuria and hair-loss and died by 30 days, none (0/12) of the anti-CD20-treated recipients developed proteinuria or hair-loss and all survived for more than 50 days after HCT without signs of chronic GVHD. In addition, the anti-CD20-treated recipients eliminated BCL1 leukemia/lymphoma cells without signs of chronic GVHD. The preventative anti-CD20 treatment had little impact on donor CD8+ T cell activation and expansion in the periphery and allowed for the strong CD8+ T cell-mediated GVL effect. The effective prevention of chronic GVHD by anti-CD20 was associated with significant changes in donor B and CD4+ T cells as well as associated with protection of host thymus. Preventive anti-CD20 treatment depleted IL-6-producing donor B cells and increased IL-10-producing B cells. In addition, the treatment also significantly reduced donor CD4+ T cell expansion, the percentage of IFN-g-producing CD4+ T as well as CD4+ T cells expressing CD8αα, the latter of which has recently been reported to represent over-activated pathogenic CD4+ T cells, such that the host thymus was protected from donor T-cell-mediated damage. Anti-CD20 or control IgG treatment of recipients with ongoing chronic GVHD 15-20 days after HCT did not show any difference in disease progress, and all (8/8) in each group died within 30 days after HCT. The ineffectiveness of anti-CD20 therapy was associated with little reduction of CD19+ B or CD4+ T cells, as the majority of CD19+ B cells became CD20- in the recipients with ongoing chronic GVHD. These results indication that anti-CD20 can effectively prevent induction of autoimmune-like chronic GVHD while preserving the GVL effect, but anti-CD20 is ineffective in treating ongoing chronic GVHD. (This study is supported by the Nesvig Lymphoma Foundation). Disclosures:Chan:Genentech Inc.: Employment.

Treatment of chronic graft-versus-host disease in 2011

This article summarizes recent reports on the risks, pathogenesis and treatment of chronic graft-versus-host disease (GVHD). Chronic GVHD remains an elusive disorder to characterize and to treat. Recent evidence on tolerance induction by regulatory T-cells and on B-cell involvement shed some insights into the pathogenesis of chronic GVHD. In a recent large comparative study, the overall risk profiles for acute and for chronic GVHD were similar, but risk factors were not changed after adjustment for prior acute GVHD, supporting the concept that chronic GVHD is not an end stage of acute GVHD. Glucocorticoids remain the standard initial treatment of chronic GVHD, but the outcomes are not satisfactory, particularly for patients with high-risk features. Many treatments for chronic GVHD including extracorporeal photopheresis, rituximab, sirolimus, mycofenolate mofetil, imatinib, pentostatin and infusion of mesenchymal stem cells have been reported in several retrospective and relatively small phase I/II studies with a wide range of overall responses. No current therapies used for chronic GVHD have been approved by the US Food and Drug Administration. Large well designed prospective studies are warranted to establish better treatments. Targeted therapies based on the pathogenesis of chronic GVHD may lead to better outcomes.

Progress in chronic graft-versus-host disease

The National Institute of Health (NIH) consensus conference on criteria for clinical trials in chronic graft-versus-host disease (GvHD) brought fresh attention to a problem that is all too familiar to clinicians involved in hematopoietic stem cell transplantation. The series of 6 papers published in 2005 proposed new diagnostic criteria for the disease, summarized information regarding biomarkers and pathologic features associated with the disease, and offered recommendations for supportive care, measurement of response to treatment and the conduct of clinical trials.(1-6) Subsequent publications have focused on efforts to validate the diagnostic criteria through retrospective studies and some additional work has been done to elucidate the significance of biomarkers, especially those indicating a possible role for B cells in the pathogenesis of the disease. In the United States, Dr. Stephanie Lee organized a consortium of investigators in multiple centers to collect prospective data from a large cohort of incident and prevalent cases. These data are now being used to address several important questions, including the optimal methods for measuring ocular and oral involvement, the association of disease severity with quality of life and risk of mortality, and the prognostic significance of acute GvHD manifestations including cutaneous erythema and gastrointestinal and hepatic involvement. Ultimately, the results of these studies will be used to refine and validate recommendations that emerged from the NIH consensus conference, which were mostly based on expert opinion. In this issue of the Revista Brasileira de Hematologica e Hemoterapia, Vigorito and colleagues describe the initial results of work by a group of Brazilian investigators to develop a platform for collaboration in clinical trials related to chronic GvHD.(7) These investigators translated the US prospective data forms into Portuguese and then tested their use in five Brazilian centers. To date, the study has enrolled 34 patients with chronic GvHD. The Brazilian group and their colleagues in the US are to be congratulated for this first demonstration that international collaborations in the field of chronic GvHD are feasible in an academic setting. Much work lies ahead. The authors emphasize the theme that the Brazilian consortium is intended to serve as a platform for future collaboration in clinical trials. Better insight into the pathogenesis of chronic GvHD is needed in order to select treatments that are most likely to be effective and safe. Further discussion is needed in order to standardize eligibility criteria, organ and overall response criteria, and assessment time points in studies of secondary treatment for chronic GvHD. The shared language emerging from this standardization will facilitate informative comparisons of results between different studies. Even more importantly, benchmarks of success should be established from both retrospective and prospective cohorts so that adequately powered, rigorous phase II studies can be conducted with one-sample statistical methods to identify the most promising agents for testing in future phase III trials. The case-report forms used by the US and Brazilian consortiums will benefit from further refinement, since their current length and complexity is likely to discourage physicians from enrolling patients in clinical trials. The analysis of data from the forms will help to identify the most reliable and useful items that should be retained in shorter and less complex report forms to be used for future clinical trials. Members of the Brazilian consortium are in a good position to suggest how the forms can be improved since they were not involved in the design. As a more important contribution, however, the current members should celebrate the success illustrated in this report as a way of recruiting additional Brazilian colleagues to join in this new international effort to improve the treatment of patients with chronic GvHD.

Treatment Outcome of Steroid-Refractory Chronic Graft-Versus-Host Disease with Weekly Rituximab Followed by Maintenance Rituximab: a KSBMT Multicenter Phase II Study.

Abstract 1151Poster Board I-173 IntroductionThe mainstay of treatment for chronic graft-versus-host disease (GVHD) is steroid. However, there is limited treatment option for steroid-refractory chronic GVHD. Although the pathogenesis of chronic GVHD is still uncertain, the possible relation of auto-antibodies with chronic GVHD (Patriarca F, et al. Exp Hematol 389-96, 2006) and the result from a previous pilot study (Cutler C, et al. Blood 756-762, 2006) suggested that a treatment strategy targeting against B cells might become another effective therapy for chronic GVHD. Thus, we performed a study to determine the efficacy of rituximab (Mabthera®, Roche), an anti-CD20 monoclonal chimeric antibody in patients with steroid-refractory chronic GVHD. Patients and methodsThis is a multicenter, open-labeled prospective phase II study performed by the Korean Society of Blood and Marrow Transplantation (NCT00472225). Patients should be diagnosed as chronic GVHD according to the criteria for clinical trials in chronic GVHD proposed by National Institutes of Health Consensus Development Project (Filipovich AH, et al. Biol Blood Marrow Transplant 945-56, 2005). The steroid-refractoriness was defined as the same severity during the last one month while patients received the equivalent of prednisone ≥0.5mg/kg per day or 1mg/kg every other day at least for 30 days or longer. The treatment schedule consists of induction (rituximab 375mg/m2 weekly IV for 4 consecutive weeks) and maintenance (rituximab 375mg/m2 monthly IV for 4 consecutive months). The response and the quality of life (SF36 questionnaire) were evaluated during the follow-up. Results37 patients (20 male, 17 female) were evaluated, and their median age was 29 years (range 8-57 years, 7 patients from pediatrics and 30 from internal medicine). The time interval between transplantation and rituximab treatment was from 4.0 to 45.7 months. The most commonly involved organs were skin, oral cavity, eyes and lungs. The average number of involved organ per each patient was three and their average severity was grade 2-3. The median potential follow-up was 12.3 months (95% confidence interval: 12.06-12.54 months). The maximum response during follow-up was as follows: 8 complete response (21.6%), 22 partial response (59.5%), 6 no response (16.2%), and 1 disease progression (2.7%). Thus, the overall response rate was 81.1%. The dosage of steroid was reduced in all responders including complete withdrawal of steroid. The quality of life was improved in terms of physical health and mental/emotional health after treatment. However, 5 responders showed the progression of disease activity during follow-up, and infectious complications were life-threatening, thus, 8 patients died due to infections including pneumonia. The involvement of skin and oral cavity showed better response than the involvement of lungs and eyes. ConclusionThe weekly administration of rituximab followed by monthly maintenance rituximab may be an effective treatment for steroid-refractory chronic GVHD, however, the active prophylaxis against infection should be considered. DisclosuresNo relevant conflicts of interest to declare.

Single Nucleotide Polymorphism (SNP) Approach of Multiple Candidate Pathways Predicting the Risk of Acute / Chronic Graft-Versus-Host Disease or Transplant Outcomes Following Allogeneic Hematopoietic Stem Cell Transplantation: Potential Involvement of Nuclear Factor Kappa-B (NFKB), Platelet-Derived Growth Factor (PDGF) and Transforming Growth Factor-Beta (TGF-β) Pathway with Chronic Graft-Versus-Host Disease Graft-Versus-Host Disease.

Abstract 2221Poster Board II-198 Background:Acute graft-versus-host disease (GVHD) was known to be involved in the Th1 cytokine activation and alloreactive T-cell cytotoxicity, while the pathogenesis of chronic GVHD is yet revealed fully although in which Th2 cytokine activation or transforming growth factor (TGF) mediated pathway was suggested to be involved. The current study is a hypothesis generating study in order to identify potential predictive surrogate associated with the risk of acute or chronic GVHD in addition with transplant outcomes after allogeneic hematopoietic stem cell transplantation (HSCT). Methods:The current study was performed to identify genetic surrogates predicting the risk of acute / chronic GVHD, relapse free survival, non-relapse mortality and overall survival in 394 pairs transplanted at the Princess Margaret Hospital, Toronto, ON, Canada. In addition, the predictive markers for organ specific incidence of acute / chronic GVHD were also evaluated (i.e. for skin/liver/gut acute GVHD or skin, eye, oral, lung or liver chronic GVHD). Total of 261 single nucleotide polymorphisms (SNPs) in 56 genes were determined for donor/recipients' genotypes using MALDI-TOF based platform, involving in the pathways of 1) cytokines (i.e. IL1A, IL1B and its receptor, IL1R1, IL2 & IL2RA, IL4 & IL4R, IL6 & IL6R, IL8, IL10 & IL10RA, RB, IL12A/BandIL12RB1, IFNG & IFNGR1/2, TNFTI/II/II), 2) NFKB (NFKB1/2/A, NFKBIA/B, IKB, IKK1, IKBKB, RelB), 3) apoptosis (FAS, TRAIL & TRAILR1), 4) endothelium nitric oxide regulation (EDN1, NOS1/2A/3), 5) PDGF (PDGFB/C/D & PDGFRA/B), 6) TGF-β (TGFB1/2 & TGFBR1/2/3, TGFRB1), 7) Toll-like receptor (TLR4/5), 8) NOD2/CARD15 and 9) prostaglandin-endoperoxide synthase (PTGS1/2). The candidate genotypes have been selected by choosing the SNPs in non-synonymous SNPs in exon region with minor allele frequency of > 0.05 to 0.1. Results:Followings are the lists of recipients' and donors' genotypes with p-value<0.05 thus associating with clinical outcomes following allogeneic HSCT:Clinical outcomesRecipients' genotypeDonors' genotypeAcute GVHDFAS, EDN, TGFB1, TNFRI, NFKBIATNFRIChronic GVHD-IL1R, FCRG2AChronic GVHD, skinPDGFCNFKBA, PDGFCChronic GVHD, eyeIL6R, PDGFRTGFBR1Chronic GVHD, oralIL12RFCRG2AChronic GVHD, lungTGFB1, FAS, RelBIL4R, FAS, TGFB1, IL12B3Relapse free survivalIL6RNOD2/CARD15, IL6RNon-relapse mortalityIL2NOS2, TGFB2Overall survivalIL2NOS2, TGFB2, IL1BSteroid responsivenessIL4R, PDGFRIn summary, the risk of chronic GVHD was significantly associated with SNP of the genes involved in the pathway of NFKB, PDGF, TGF-β, and some of cytokines (esp. type II, IL6 & IL4), while that of acute GVHD associates with the genotypes in the pathway of TNF and apoptosis. In addition, survival after allogeneic transplantation was associated with the genotypes in NOS (nitric oxide synthase, endothelial nitric oxide synthesis pathway), IL-2 and TGF pathway. Conclusion:Because of complex nature of GVHD pathogenesis, multiple candidate pathway SNPs has been explored targeting SNPs in the pathway of cytokines, NFKB, apoptosis, endothelium nitric oxide regulation, NOD2/CARD15, PDGF, PTGS1/2, TGF-β and TLR. Different involvements were noted of TGF-β, PDGF or NFKB with chronic GVHD versus TNF and apoptosis-associated SNPs with acute GVHD. Further study will help us to reach more clear conclusion which genotype is the predictor of the risk of GVHD. Disclosures:No relevant conflicts of interest to declare.

IgG Antibodies against Human Cytomegalovirus Late Protein UL94 in the Pathogenesis of Scleroderma-Like Skin Lesions in Chronic Graft Versus Host Disease

Patients undergoing allogeneic cell transplantation (HCT), who develop chronic Graft versus Host Disease (GVHD), can show a cutaneous involvement similar to that of patients with systemic sclerosis (SSc). Human Cytomegalovirus (hCMV) has been shown to be implicated in the pathogenesis of SSc, since a subset of anti-hCMV antibodies directed against the late viral protein UL94, cross-react with the cell surface tetraspanin NAG-2, and induce the vascular and fibrotic damage observed in the disease. HCMV infection and/or its reactivation have also been associated with the increased risk to develop GVHD and with the worsening of clinical manifestations. Immunosuppressive treatment for GVHD can be intuitively correlated to the viral reactivation, however, the pathogenetic link between hCMV infection and chronic GVHD is still lacking. In this study we wanted first to evaluate the presence of anti-hCMV antibodies directed against the viral protein UL94 in the plasma of HCT patients and second to study their possible role in the pathogenesis of chronic GVHD. Eighteen patients undergone allogeneic HCT for hematological malignancies (16 with nonmyeloablative conditioning regimen and 2 with myeloablative), between 2003 and 2006, with a median follow-up of 7.35 months (range 1.2–55.7), were retrospectively studied. Five of them were anti-hCMV antibodies negative but their donors were anti-hCMV IgG positive. Twelve patients experienced hCMV reactivation evaluated by pp65 and PCR and they needed either Gancyclovir or Valgancyclovir or Foscavir as preemptive therapy. Interestingly, almost all patients (11/12) with hCMV reactivation developed chronic GVHD, and six of the eleven had acute GVHD. All GVHD patients showed skin involvement, and some of them had evidence of diffuse skin fibrosis remarkably similar to that of SSc. None of the patients nor of the donors were suffering from autoimmune diseases. Five of 18 are still alive and in complete remission, included the 2 patients with a skin involvement similar to diffuse SSc. One patient with diffuse skin involvement was lost to the follow-up. Thirteen patients died: 8 for progression of disease, 4 because of steroid resistant GVHD, 1 for sepsis and multi-organ failure. Patients who died before day 100 were not suitable for chronic GVHD evaluation. Patients who developed chronic GVHD showed the presence of anti-hCMV derived late viral protein UL94. Remarkably, the 3 patients with chronic GVHD who developed a diffuse SSc-like skin involvement, had antibodies directed against NAG-2, a cell surface tetraspanin that forms complexes with integrins, already reported to play a pivotal role in the pathogenesis of SSc. Such antibodies bound endothelial cells and fibroblasts and were able to induce endothelial cell apoptosis and fibroblast proliferation, as already shown in patients with SSc (Methods as previously published by Lunardi C. et al. on Nat Med. 2000 Oct; 6(10):1183–6 and PLoS Med. 2006 Jan; 3(1 e 2): 94–108). These findings sustain the involvement of hCMV infection in the pathogenesis of chronic skin GVHD through a mechanism of molecular mimicry between the viral late protein UL94 and the cell surface molecule NAG-2. Moreover, these data provide a previously unknown pathogenetic mechanism by which hCMV infection contributes to the development of chronic skin GVHD resembling SSc. Perspective studies with a larger number of patients are needed to further support these results. [Display omitted]

Donor Bone Marrow Derived IL-17 Expressing Cells Exacerbate Chronic Graft-Versus-Host Disease in a Murine Bone Marrow Transplantation.

Th17 is a newly identified T cell lineage that secretes the proinflamatory cytokine IL-17. Th17 cells have been shown to play a crucial role in mediating autoimmune diseases such as experimental autoimmune encephalomyelitis (EAE), arthritis, and colitis. However, recent study showed that donor Th17 cell ameliorated acute graft-versus-host disease (GVHD) due to the downregulation of Th1 differentiation in a murine BMT model. The role of IL-17 on developing chronic GVHD, which is pathologically similar to autoimmue diseases, remains unanswered. To this end, we compared the development of chronic GVHD between the lethally irradiated mice (Balb/c, H-2d) given IL-17 knockout(IL- 17KO, C57BL/6 background, H-2b) bone marrow (BM) cells and wild type BM cells with low dose WT splenocytes to induce sublethal acute GVHD and chronic GVHD subsequently. Up to day 60 after BMT no significant differences in clinical symptoms of GVHD including body weight changes were observed between the mice co-injected with IL-17 KO BM cells plus WT splenocytes and WT BM cells plus WT splenocytes. After day 60 the mice receiving WT BM cells plus WT splenocytes experienced weight loss accompanied by skin inflammatory changes, while mice receiving IL-17KO BM plus WT splenocytes showed minimal signs of GVHD as well as mice receiving IL-17 KO BM or WT BM alone. Recovery of body weight on day 160 after BMT was statistically different between two groups (p=0.035). Taken together, IL-17 was exacerbation factor of chronic GVHD, but not acute GVHD. Next we further evaluated the percentage of Th17 cells derived from BM cells (not from infused splenocytes) in the spleen on day 160 after BMT. Percentages of IL-17 expressing cells in the mice receiving WT BM plus WT splenocytes in spleen were significantly higher than those of WT BM alone receiving mice in CD4 (p=0.03) subpopulations. In conclusion, Th17 cells critically involved in the pathogenesis of chronic GVHD. Neutralizing IL-17 would be potent strategy for preventing chronic GVHD. [Display omitted]

Association of autoimmune disease‐related gene polymorphisms with chronic graft‐versus‐host disease

Chronic graft-versus-host disease (GVHD) is the most common cause of poor outcomes after haematopoietic stem cell transplantation (HSCT), while the pathophysiology of chronic GVHD remains poorly understood. As both chronic GVHD and autoimmune disease share clinical features, we speculated that autoimmune disease-related genes might be candidate chronic GVHD-related genes. Recent large-scale cohort studies showed that Fc receptor-like 3 gene (FCRL3) single nucleotide polymorphism (SNP) and peptidylarginine deiminases citrullinating enzymes 4 gene (PADI4) haplotype were associated with autoimmune disease. The present study investigated the association between polymorphisms of these two genes and the incidence of chronic GVHD. We analysed 123 cases of Japanese human leucocyte antigen-matched sibling recipients and their donors who underwent HSCT. Although PADI4, which is the rheumatoid arthritis-specific related gene, was not associated with the occurrence of chronic GVHD, the recipient FCRL3-169C/C genotype was significantly less frequent in chronic GVHD patients than in those without chronic GVHD (P = 0.0086). There was no relationship between FCRL3 polymorphism and acute GVHD. As FCRL3 is expressed by B cells and might have an important role in immunoregulation, this significant protective genetic effect raises the question of whether FCRL3 might also be involved in the pathogenesis of chronic GVHD.

Diagnosis and clinical management of chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) occurs in approximately 60% of patients who survive for more than 100 days after receiving an allogeneic marrow or peripheral blood stem cell transplant without T-cell depletion of the graft. Chronic GVHD represents a major cause of morbidity and mortality among hematopoietic stem cell transplant recipients. Risk factors for the development of chronic GVHD and for mortality among patients who develop this complication have been defined, but the pathogenesis of chronic GVHD is not well understood. This review discusses the clinical manifestations that lead to a diagnosis of chronic GVHD and outlines an approach for therapy with glucocorticoids and extended administration of a calcineurin inhibitor. The judicious use of glucocorticoids at the lowest effective dose and alternate-day administration can minimize steroid-related side effects. Antibiotic prophylaxis to prevent infection and supportive care to minimize morbidity and prevent disability are critically important components in the management of patients with chronic GVHD. Approximately 50% of patients with chronic GVHD are able to discontinue immunosuppressive treatment within 5 years after the diagnosis, and 10% require continued treatment beyond 5 years. The remaining 40% die or develop recurrent malignancy before the chronic GVHD resolves. An improved understanding of the pathogenesis of the disease is needed to develop more effective therapy.

Treatment of chronic graft-versus-host disease with anti-CD20 chimeric monoclonal antibody

We reviewed the clinical outcome of 8 patients with steroid-refractory chronic graft-versus-host disease (GVHD) who received an anti-CD20 chimeric monoclonal antibody (rituximab). Rituximab was given by intravenous infusion at a weekly dose of 375 mg/m 2 for 4 weeks. All patients had received extensive treatment with various immunosuppressive agents; 6 patients had also received extracorporeal photopheresis. All patients had extensive chronic GVHD with diffuse or localized sclerodermoid GVHD and xerophthalmia. Other extracutaneous involvements included cold agglutinin disease with the Raynaud phenomenon, membranous glomerulonephritis, and restrictive or obstructive lung disease. Four patients responded to treatment with ongoing resolution or improvement ranging from 265 to 846 days after therapy, despite recovery of B cells in 3 patients. Rituximab seems to have significant activity in the treatment of refractory chronic GVHD and should be considered for further study in patients with early disease. This study suggests a participating role of B cells in the pathogenesis of chronic GVHD.

Chronic intestinal graft-versus-host disease: clinical, histological and immunohistochemical analysis of 17 children.

Graft-versus-host disease (GVHD) can be acute or chronic. The pathogenesis of chronic GVHD is unclear. Chronic GVHD affects mainly skin, liver and digestive tract. Intestinal involvement is uncommon and histological features are poorly described. We report here the clinical, histological and immunohistochemical features of chronic GVHD with intestinal involvement. Intestinal biopsies from children with chronic GVHD (n=17) were compared to control children (n=21: 10 non-transplant cases, four non-GVHD transplant cases, seven acute GVHD). We evaluated clinical outcome, histological features and characterized immunohistochemically the immune cells involved locally. Chronic GVHD with intestinal involvement was usually multisystemic (88.2%) and preceded by acute GVHD in 88.2% of cases. The outcome was severe with complete recovery in only 58.8% of cases, and death related to chronic GVHD in 17.6% of cases. Histological features were characterized by (1) villous atrophy and (2) glandular lesions, mainly apoptotic with variable intensity and (3) lamina propria infiltrate with cytotoxic T lymphocytes (CD3+, CD8+, TiA1+, granzyme B-) which were significantly (P<0.001) increased compared to non-GVHD transplant and non-transplant controls. Therefore in chronic intestinal GVHD, the apoptotic process could be related to cytotoxic T lymphocytes.

Chronic graft-versus-host disease.

Chronic graft-versus-host disease (GVHD) continues to be the major problem in the long-term survivors of allogeneic hematopoietic stem cell transplants. Because of its similarities to autoimmune disease, the pathogenesis of chronic GVHD has been thought to differ from acute GVHD. Autoreactive T lymphocytes are an important effector mechanism with interferon gamma playing a central role in the increased collagen deposition that is the central histopathologic feature of chronic GVHD. Therapies that prevent the development of acute GVHD have been unsuccessful in the prevention of chronic GVHD. None of the present therapies for established chronic GVHD are successful in the majority of patients.

Treatment of graft versus host disease (GVHD) by photopheresis?

Graft versus host disease (GVHD), whether acute or chronic, is a frightening complication of bone marrow allografts-indeed in many cases it can be life threatening. In chronic GVHD, the symptoms are less serious, but they can nevertheless be alarming. The mechanism of this reaction is very complex and the pathogenesis of chronic GVHD seems to be slightly different from that of acute GVHD. However, there is no doubt about the immune mechanisms. The production of numerous cytokines plays an important part and has also been des-cribed. Until the use of photopheresis, the only treatments that were effective to any degree have been immunosuppressive treatments. Extracorporeal photopheresis (ECP), a technique recently proposed in chronic GVHD, is promising and is believed to attack the actual cause of the disease (the role of cytotoxic T lymphocytes is now recognized). ECP is believed to have a complex mechanism of action, the explanation of an anti-T lymphocyte action of ECP seems too simple. We report the results of three patients suffering from chronic GVHD, refractory to the usual treatments. The schedule for ECP was a cycle of two treatments every 2 weeks. We recorded a complete remission for patient No. 1 (grade 1) with no relapse for now 3 years. In patient No. 2 (grade 2-3) a progressive improvement was observed in the various symptoms with, however, several episodes of aggravation. In patient No. 3 (grade 2-3), the skin symptoms improved and the lichen planus lesions healed after only 15 months of treatment (interrupted by two infectious episodes during which ECP was stopped). Although the study population was small, we may be justified in thinking that ECP can cause an improvement in chronic GVHD refractory to immunosuppressive treatment. These results should be confirmed by a rigorously designed multicentre study.

Treatment of graft versus host disease (GVHD) by photopheresis?

Graft versus host disease (GVHD), whether acute or chronic, is a frightening complication of bone marrow allografts — indeed in many cases it can be life threatening. In chronic GVHD, the symptoms are less serious, but they can nevertheless be alarming. The mechanism of this reaction is very complex and the pathogenesis of chronic GVHD seems to be slightly different from that of acute GVHD. However, there is no doubt about the immune mechanisms. The production of numerous cytokines plays an important part and has also been des-cribed. Until the use of photopheresis, the only treatments that were effective to any degree have been immunosuppressive treatments. Extracorporeal photopheresis (ECP), a technique recently proposed in chronic GVHD, is promising and is believed to attack the actual cause of the disease (the role of cytotoxic T lymphocytes is now recognized). ECP is believed to have a complex mechanism of action; the explanation of an anti-T lymphocyte action of ECP seems too simple. We report the results of three patients suffering from chronic GVHD, refractory to the usual treatments. The schedule for ECP was a cycle of two treatments every 2 weeks. We recorded a complete remission for patient No. 1 (grade 1) with no relapse for now 3 years. In patient No. 2 (grade 2–3) a progressive improvement was observed in the various symptoms with, however, several episodes of aggravation. In patient No. 3 (grade 2–3), the skin symptoms improved and the lichen planus lesions healed after only 15 months of treatment (interrupted by two infectious episodes during which ECP was stopped). Although the study population was small, we may be justified in thinking that ECP can cause an improvement in chronic GVHD refractory to immunosuppressive treatment. These results should be confirmed by a rigorously designed multicentre study.

Correlation between donor cytomegalovirus immunity and chronic graft-versus-host disease after allogeneic bone marrow transplantation.

Chronic graft-versus-host disease (GvHD) in bone marrow allograft recipients is frequently preceded by a cytomegalovirus (CMV) infection. To elucidate whether an immune reaction of transplanted donor cells against CMV was involved in the pathogenesis of chronic GvHD, the effect of donor pretransplant CMV immune status on chronic GvHD incidence was analyzed. In 43 bone marrow recipients at risk, the 2-yr cumulative chronic GvHD probability was 55% when the donor was immune, in contrast to 16.5% when the donor was non-immune (p less than 0.002). No correlation between recipient pretransplant CMV immunity and chronic GvHD was observed. Donor CMV immunity did not correlate with acute GvHD or posttranplant CMV infection and seemed to predispose for chronic GvHD regardless of donor and recipient age. However, the proportion of CMV immune donors increased with increasing donor and recipient age. This may account for the higher incidence of chronic GvHD in older patients. The present study suggests that chronic GvHD may be mediated by a reaction of immune donor cells against CMV infected recipient cells.