Steroid-refractory graft-vs.-host disease: past, present and future

Human amniotic epithelial stem cell is a cell therapy candidate for preventing acute graft-versus-host disease

Graft-versus-host disease (GVHD), an immunological disorder that arises from donor T cell activation through recognition of host alloantigens, is the major limitation in the application of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Traditional immunosuppressive agents can relieve GVHD, but they induce serious side effects. It is highly required to explore alternative therapeutic strategy. Human amniotic epithelial stem cells (hAESCs) were recently considered as an ideal source for cell therapy with special immune regulatory property. In this study, we evaluated the therapeutic role of hAESCs in the treatment of GVHD, based on our previous developed cGMP-grade hAESCs product. Humanized mouse model of acute GVHD (aGVHD) was established by injection of huPBMCs via the tail vein. For prevention or treatment of aGVHD, hAESCs were injected to the mice on day -1 or on day 7 post-PBMC infusion, respectively. We showed that hAESCs infusion significantly alleviated the disease phenotype, increased the survival rate of aGVHD mice, and ameliorated pathological injuries in aGVHD target organs. We demonstrated that hAESCs directly induced CD4+ T cell polarization, in which Th1 and Th17 subsets were downregulated, and Treg subset was elevated. Correspondingly, the levels of a series of pro-inflammatory cytokines were reduced while the levels of the anti-inflammatory cytokines were upregulated in the presence of hAESCs. We found that hAESCs regulated CD4+ subset polarization in a paracrine mode, in which TGFβ and PGE2 were selectively secreted to mediate Treg elevation and Th1/Th17 inhibition, respectively. In addition, transplanted hAESCs preserved the graft-versus-leukemia (GVL) effect by inhibiting leukemia cell growth. More intriguingly, hAESCs infusion in HSCT patients displayed potential anti-GVHD effect with no safety concerns and confirmed the immunoregulatory mechanisms in the preclinical study. We conclude that hAESCs infusion is a promising therapeutic strategy for post-HSCT GVHD without compromising the GVL effect. The clinical trial was registered at www.clinicaltrials.gov as #NCT03764228.

Acute and chronic Graft-versus-host disease after hematopoietic stem cell transplantation

graft-versus-host disease (GVHD) is one of the main complications of hematopoietic stem cell transplantation, affecting about 50% to 80% of the patients. Acute GVHD and its clinical manifestations are discussed in this article, as well as the new NIH criteria for the diagnosis and classification of chronic GVHD. Therapy for both chronic and acute GVHD is an important field of discussion, as there is no proven superiority for the majority of therapies used after primary treatment has failed. Hence, this review is meant to be a useful consultation tool for hematologists dealing with this complex transplantation procedure complication.

The quality of life of adult survivors of childhood hematopoietic cell transplant

Survival rates after myeloablative hematopoietic cell transplantation (HCT) in childhood have improved. We conducted a cross-sectional study evaluating the quality of life (QOL) of 214 adult survivors of a childhood HCT compared with controls using standardized self-report measures with strong psychometric properties to evaluate physical function, psychological function and cognitive symptoms. From these results we conducted a multivariate analysis of risk factors. This analysis for physical functioning showed poorer function among myeloid disease survivors compared with patients with all other diagnoses (P=0.02), men functioned better than women (P=0.05) and those >18 years after transplant functioned more poorly than those <18 years after transplant (P=0.05). Psychological functioning showed that those who received more therapy and females were more likely to be depressed (P=0.03) and (P=0.005). Perceived cognitive symptoms showed that female survivors had more symptoms than male survivors (P=0.01), and those receiving more preceding therapy compared with those with less preceding therapy (P=0.001) or cranial irradiation compared with those without cranial irradiation (P=0.002) had more perceived cognitive symptoms. Overall, these data indicate that the majority of adult survivors of a childhood transplant are functioning well, but some have problems that need to be addressed.

Emerging drugs for acute graft-versus-host disease

The number of allogeneic hematopoietic cell transplantations (HCT) continues to increase. More than 15,000 allogeneic transplantations are performed annually. The graft-versus-leukemia/tumor effect during allogeneic HCT effectively eradicates many hematological malignancies. The development of novel strategies that use donor leukocyte infusions, nonmyeloablative conditioning and umbilical cord blood transplantation have helped expand the indications for allogeneic HCT over the past several years, especially among older patients. Yet the major complication of allogeneic HCT, graft-versus-host disease, remains lethal and limits wider application of allogeneic HCT. In this article, we review current practice and recent advances made in prevention and treatment of graft-versus-host disease.

Daclizumab therapy for children with corticosteroid-resistant acute graft-vs.-host disease

MAbs such as daclizumab have shown promising results in the treatment of corticosteroid-resistant aGVHD. Data describing the efficacy of MAbs in children are limited. We describe the efficacy of daclizumab in children with corticosteroid-resistant aGVHD. Seventeen children (0.4-16.2 yr) received daclizumab for aGVHD. Safety was evaluated in all 17. Response was evaluated in the 15 children who received a full course of daclizumab. A PR was defined as improvement of aGVHD symptoms in at least one organ without worsening in other organs. We observed an overall response rate (CR plus PR) of 40% (6/15). Four children had a CR and two had a PR. aGVHD involving the gut had the highest response rate (five of 10; 50%). Adverse effects attributed to daclizumab were limited to an episode of reactive arthritis. Mortality was high (47%; eight of 17) though five of the six responders to daclizumab survived. The mean length of follow-up in the surviving nine patients was 32 months (range seven to 48). We conclude that daclizumab is effective in the treatment of children with corticosteroid-resistant aGVHD, especially in patients with gut involvement.

Current and novel therapies in acute GVHD

Despite improvements in our understanding of transplant immunology and clinical and supportive care, acute graft-versus-host disease (GVHD) remains a clinical challenge and a major cause of morbidity and mortality for patients after allogeneic hematopoietic stem-cell transplantation. While systemic corticosteroid is standard primary therapy for acute GVHD, there is no established standard treatment in the steroid-refractory setting. New generations of monoclonal antibodies, biologics, and chemotherapeutics with immunomodulatory effects have been developed over the past decade, and are being tested as novel therapies in this disease. Many of these agents - including, among others, mycophenolate mofetil, anti-tumor necrosis factor-alpha antibodies, denileukin diftitox, and anti-interleukin-2Ralpha-chain antibodies - have demonstrated promising activity in steroid-refractory acute GVHD. Despite the high response rates, however, long-term survival remains poor due to a high incidence of infections. The key to improving acute GVHD outcomes may, in fact, rest upon successful initial therapy, and timely taper of corticosteroids to promote healthier immune reconstitution. Clinical trials combining these newer agents with systemic corticosteroids as initial treatment are under way, and will determine whether fortifying initial therapy will indeed reduce the development of steroid-refractory GVHD and improve long-term outcomes. In this article, we review current and novel agents available for acute GVHD, and discuss newer investigational approaches - such as phototherapy and cellular therapies - in the management of this common transplant complication.

Therapeutic options in acute severe ulcerative colitis

Ulcerative colitis is a relapsing-remitting inflammatory disease affecting the colon and is associated with considerable morbidity. In acute severe attacks, there continues to be an associated mortality rate of 1-2%, even in specialist units. During an acute severe exacerbation, approximately two-thirds of patients will respond to intravenous corticosteroid therapy, the accepted first-line therapy in such cases. For steroid-refractory patients, options are limited to surgery (colectomy) or second-line agents, such as ciclosporin or infliximab, used in an attempt to salvage the colon. Considerable debate exists over the optimal management of such patients. During the last decade, an increased understanding of the pathogenesis of inflammatory bowel disease has led to the rapid development of other biological agents, such as basiliximab and visilizumab. Novel methods, such as leucopheresis, have been studied and other established immunomodulatory agents, such as tacrolimus, have also been suggested. The purpose of this review is to highlight some of the areas of recent development in the treatment of acute severe ulcerative colitis and review important safety data, with a particular emphasis on biological agents.

Biological agents for ulcerative colitis: hypes and hopes

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colonic mucosa. Over the last decade, the increasing knowledge on the pathogenic mechanisms underlying intestinal inflammation has led to the development of a number of biological agents, mainly addressed to molecules and/or pathways demonstrated to have a pathogenic role in UC. In UC, clinical course and therapeutic decisions mainly depend on disease activity and extent. While therapeutic approach to mild-to-moderate UC by using aminosalicylates and corticosteroids has been well established, treatment of severe UC is far from being satisfactory. A severe attack of UC remains a challenge to be managed jointly by gastroenterology, surgery, and intensive care units. However, the recent introduction of biological therapies has led to promising changes in the management of UC patients. Aim of this paper is to review the recent advances and future perspectives for the use of biological agents in UC.

Allogeneic stem cell transplantation in children with leukemia using human leukocyte antigen-mismatched unrelated donors

Allogeneic HSCT is a curative treatment, when chemotherapy fails, for certain malignant diseases. In Europe, only 15% of the indicated children have an HLA-matched sibling available; in 65-70% of others, HLA allele-matched (9-10/10) UDs can be identified. For the rest, it is necessary to identify other alternative donors (HLA-mismatched family or unrelated cord blood). We present our data of HSCT using HLA partially allele-mismatched (7-8/10) UDs in 24 children with leukemia. Uniform GvHD prophylaxis was used (rATG, CsA and MTX). Acute GvHD grade II was diagnosed in 70.8% of the patients and grade III-IV in 12.5%. Overall incidence of chronic GvHD was 38.7% (extensive in 30%). The probability of EFS was 60.3% (95% CI 35.5-78.1) and OS was 74.9 (95% CI 49.1-88.9). No difference in survival between PBSC and BM recipients was observed. TRM at day + 100 was 4%, and overall was 12.5%. We conclude that used combination of drugs for GvHD prophylaxis is efficient even for patients transplanted with grafts from a HLA-mismatched UDs. It enables stable engraftment, good control of GvHD, full reconstitution of immunity, and is not connected with unacceptable transplant-related mortality.

Anti-tumor necrosis factor-a for the treatment of steroid-refractory acute graft-versus-host disease

Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD) occurs in 9 to 50% of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximab)for the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6) for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5). Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600) after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.

Calcineurin inhibitors and rapamycin: cancer protection or promotion?

Since the introduction of cyclosporin A (CsA) in the early 1980s, the use of immunosuppressants has markedly increased. Already established drugs have proved effective in the treatment of a wide range of diseases outside transplantation medicine and new immunosuppressants have been developed for more specific indications such as psoriasis and atopic dermatitis. Patients in transplantation medicine as well as in dermatology have benefited significantly from systemic and topical application of both new and established drugs. But are these drugs without risks? Cancer-protecting effects have been reported for some of the available immunosuppressants. Conversely, other publications and the issue of a black box warning by the US Food and Drug Administration have increased concerns about cancer-promoting effects. Knowledge of the specific effects as well as adverse effects is paramount to ensure an application that is safe and beneficial for the patient. Here we review the mechanisms of action and therapeutic potential, and critically review recent literature with respect to possible carcinogenic side effects of systemic and topical CsA, tacrolimus, pimecrolimus and rapamycin.

How I treat refractory acute GVHD

Graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT) is associated with considerable morbidity and mortality, particularly in patients who do not respond to primary therapy, which usually consists of glucocorticoids (steroids). Approaches to therapy of acute GVHD refractory to "standard" doses of steroids have ranged from increasing the dose of steroids to the addition of polyclonal or monoclonal antibodies, the use of immunotoxins, additional immunosuppressive/chemotherapeutic interventions, phototherapy, and other means. While many pilot studies have yielded encouraging response rates, in most of these studies long-term survival was not improved in comparison with that seen with the use of steroids alone. A major reason for failure has been the high rate of infections, including invasive fungal, bacterial, and viral infections. It is difficult to conduct controlled prospective trials in the setting of steroid-refractory GVHD, and a custom-tailored therapy dependent upon the time after HCT, specific organ manifestations of GVHD, and severity is appropriate. All patients being treated for GVHD should also receive intensive prophylaxis against infectious complications.

Low mortality of children undergoing hematopoietic stem cell transplantation from 7 to 8/10 human leukocyte antigen allele-matched unrelated donors with the use of antithymocyte globulin

Human leukocyte antigen (HLA)-matched sibling donor hematopoietic stem cell transplantation (HSCT) is available for only approximately 30% patients needing HSCT. Use of alternative donors is associated with a high incidence and severity of graft-versus-host disease (GVHD). Here we report our experience with GVHD prophylaxis using pre-transplant rabbit antithymocyte globulin (rATG), in addition to post transplant cyclosporin A and methotrexate. Seventy-five children received unmanipulated grafts from 7 to 10/10 HLA allele-matched unrelated donors. Median follow-up was 25 months (range, 6-65 months). Only 2/75 patients (2.5%) developed acute GVHD grades III-IV, and 17/75 (25%) developed extensive chronic GVHD. Overall survival was 79%. It was similar in patients receiving grafts from 7 or 8/10 to 9 or 10/10 allele-matched donors, and similar in patients receiving peripheral blood stem cells and marrow. Six (11%) patients died owing to relapse, and 10 (13%) due to transplant-related complications. The addition of rATG appears to result in a low incidence of severe GVHD and overall mortality.

Technology insight: ECP for the treatment of GvHD--can we offer selective immune control without generalized immunosuppression?

Hematopoietic stem-cell transplantation remains an important curative therapy for many conditions and its use is increasing annually. Graft-versus-host disease (GvHD) is the major cause of mortality and suffering following allogeneic hematopoietic stem-cell transplantation. Conventional treatments are associated with multiple side effects and are often ineffective. New therapeutic approaches for the control of GvHD are desperately required. Extracorporeal photochemotherapy (ECP) was developed in the 1970s for the treatment of cutaneous T-cell lymphoma and was approved by the FDA as the first selective immunotherapy for a cancer. ECP has also proved an effective therapy for immune-related conditions, particularly GvHD, even in patients refractory to conventional therapies. The treatment involves the mechanical separation of circulating white cells, which are exposed to psoralen and UVA light and then returned to the patient. ECP is extremely well tolerated with minimal side effects and is not associated with the increased rates of infection or relapse of malignant disease typical of conventional immunosuppressive agents. Thus, ECP appears to offer selective immune modulation without generalized immunosuppression, but its mechanism of action remains poorly understood. This review discusses the development of ECP, its use in the treatment of GvHD, as well as current theories of its mechanism of action.

Macromolecular immunosuppressants

Recombinant immunosuppressants have come of age and represent a significant class of quite diverse drugs. They target extracellular molecules, and either label or inhibit them. Those targets are soluble factors or membrane proteins almost all of which are components of a very complex molecular network of communication and amplification. Notably, many recombinant immunosuppressants have been developed in a rather short period of time. This is due to the fact that developing the actual drug is left to nature, so to speak; either it is a human protein as is the case for Anakinra or it is an antibody or antibody derivative "developed" by the immune system of mice or rats following exposure to the antigen. The challenge for developing recombinant immunosuppressants is to identify relevant targets. It is no longer very difficult to generate proteins to targets, once those are identified. The clinical use of recombinant immunosuppressants has yet to show which targets are truly relevant and which drugs prove effective.

Lymphocytes treated by extracorporeal photopheresis can down-regulate cytokine production in untreated monocytes

BACKGROUND

Pro-inflammatory cytokines are actively involved in graft-versus host-disease (GvHD) aetiology. Treatment of GvHD, using extracorporeal photopheresis (ECP), has demonstrated clinical efficacy. ECP rapidly reduces the number of T cells that produce tumour necrosis factor alpha (TNFalpha), interferon gamma (IFNgamma) and interleukin (IL)2. ECP-treated cells are re-infused immediately after completion of treatment. This study attempted to determine the influence that ECP-treated cells would have on untreated cells following re-infusion.

METHODS

Heparinized samples were taken from 10 chronic GvHD patients, pre-ECP and immediately prior to re-infusion (post-ECP). Lymphocytes and monocytes were isolated using magnetic separation. The post-ECP lymphocytes were mixed with pre-ECP monocytes, while the post-ECP monocytes and pre-ECP lymphocytes were combined. After suitable stimulation, the T cells were tested for intracellular TNFalpha, IFNgamma and IL2, while the monocytes were evaluated for TNFalpha, IL1alpha, IL1beta, IL6 and IL8.

RESULTS

Although cytokine secretion is decreased in T cells exposed to ECP, pre-ECP T cells were unaffected by post-ECP monocytes. Post-ECP monocytes demonstrated a reduction in cytokine secretion. Furthermore, untreated monocytes down-regulated cytokine production following exposure to ECP-treated lymphocytes.

CONCLUSION

ECP has both a direct and indirect immunosuppressive action, both of which may be beneficial in the treatment of GvHD.

Low-dose Thoracoabdominal Irradiation for the Treatment of Refractory Chronic Graft-versus-Host Disease

BACKGROUND

Half of the patients with chronic graft-versus-host disease (GvHD) do not achieve a complete remission with first-line therapy. No clear recommendations are available regarding second-line treatments.

METHODS

We retrospectively report our single-center experience of low-dose thoracoabdominal irradiation (1-Gy TAI) in 41 patients with refractory extensive chronic GvHD from 1983 to 2000. Median time from extensive chronic GvHD to TAI was one year (median GvHD episodes before TAI, n = 4).

RESULTS

Eighty-two percent of the patients achieved a clinical response at a median of 34 days after TAI (range, 15-180). Best response rates were observed in fasciitis (79%), and oral GvHD lesions (73%). A complete clinical response was achieved in 11 patients by 2 years postTAI. Fifty-seven percent of the patients had at least a 50% reduction of their corticosteroid daily dose by 6 months postTAI. Probability of corticosteroid discontinuation was 38% by 2 years postTAI (95% CI, 23-56%). Two-year chronic GvHD relapse incidence was 34%. Ten-year survival from irradiation was 57% (95% CI, 42-78%); patients with fasciitis, lymphocytes >1.0 x 10/L, and platelets >200 x 10/L had a better outcome.

CONCLUSIONS

TAI is a safe and efficient option in patients with refractory chronic GvHD, leading to a significant tapering of systemic corticosteroid dose in most cases.

Role of extracorporeal photochemotherapy in patients with refractory chronic graft-versus-host disease

Recent studies suggest that extracorporeal photochemotherapy (ECP) may be beneficial in patients with steroid-refractory chronic graft-versus-host disease (cGvHD). However, it is not yet clear whether certain conditions, such as age, mode of onset of cGvHD etc., influence clinical response and whether certain affected organs are more sensitive to ECP than others. We analysed the main clinical and laboratory parameters related to evolution of the disease in 32 steroid-refractory cGvHD patients, to identify any useful response predictors to ECP. ECP affected the course of the disease positively in 78% (25/32) of our cases.

The predominant mechanism by which ribavirin exerts its antiviral activity in vitro against flaviviruses and paramyxoviruses is mediated by inhibition of IMP dehydrogenase

It is not yet clear to what extent depletion of intracellular GTP pools contributes to the antiviral activity of ribavirin. Therefore, the antiviral activities of (i) ribavirin, (ii) its 5-ethynyl analogue, 5-ethynyl-1-beta-D-ribofuranosylimidazole-4-carboxamide (EICAR), and (iii) mycophenolic acid (MPA) (a compound that inhibits only cellular IMP dehydrogenase activity) were studied on the replication of flaviviruses and paramyxoviruses. In addition, the effects of these three compounds on intracellular GTP pools were assessed. A linear correlation was observed over a broad concentration range between the antiviral activities of ribavirin, EICAR, and MPA and the effects of these compounds on GTP pool depletion. When the 50% effective concentrations (EC50s) for the antiviral activities of ribavirin, EICAR, and MPA were plotted against the respective EC50 values for GTP pool depletion, a linear correlation was calculated. These data provide compelling evidence that the predominant mechanism of action of ribavirin in vitro against flavi- and paramyxoviruses is based on inhibition of cellular IMP dehydrogenase activity.