Clinical outcome after conversion to FK 506 (tacrolimus) therapy for acute graft-versus-host disease resistant to cyclosporine or for cyclosporine-associated toxicities

Post-Transplantation Immunosuppression After TCRΑβ/CD19 Graft Depletion Does Not Improve HSCT Outcomes in Primary Immunodeficiency

We recently demonstrated that TCRαβ+/CD19+ graft depletion successfully prevents severe acute and chronic graft-versus-host disease (GVHD) in pediatric patients with primary immunodeficiencies (PID) receiving transplants from both matched unrelated and mismatched related donors. However, in all patients, short-term post-hematopoietic stem cell transplantation (HSCT) immunosuppressive therapy (IST) was used. There are limited data on TCRαβ+/CD19+ graft depletion with no post-HSCT IST implementation. In the current study 74 PID patients who underwent first HSCT from matched unrelated (n=51) or mismatched related donors (n=23) with TCRαβ+/CD19+ graft depletion were included. All received as a conditioning regimen a combination of treosulfan with fludarabine and either melphalan or thiotepa. In all, thymoglobulin 5 mg/kg (days -5, -4, -3) and rituximab at day -1 were used. In 48 patients, various approaches to short-term post-transplantation IST were used, and 26 patients received no post-HSCT IST. The rates of engraftment, acute and chronic GVHD, survival, and mortality were similar in those who received and did not receive IST, with a slightly higher incidence of graft rejection in patients not receiving IST: 19% in the non-IST group against 13% in the IST group (P = .41). The incidence of cytomegalovirus reactivation was 50% and 39% (P = .50) and Epstein-Barr virus reactivation 10% and 0 (P = .20) in the IST and non-IST groups, respectively. No grade 4 adverse events were seen in both groups, although in 19 of 40 (47.5%) patients receiving calcineurin inhibitors, the therapy was discontinued before day 45. More robust immune recovery with both T- and B-lymphocytes was observed in the non-IST group. To conclude, TCRαβ+/CD19+ in combination with particular serotherapy effectively prevents severe acute and chronic GVHD in PID. Regarding remaining risks of infectious complications and additional drug-related toxicity, there are no benefits to post-HSCT IST use in these patients.

Analyzing the clinical outcomes of switching from cyclosporine to tacrolimus in pediatric hematopoietic stem cell transplantation

OBJECTIVE

The selection of graft-vs. -host disease (GvHD) prophylaxis is vital for the success of hematopoetic stem cell transplantation (HSCT), and calcineurin inhibitors (CNI) have been used for decades as the backbone of GvHD prophylaxis. The aim of this study is to analyze the results of switching cyclosporine (CSA) to tacrolimus because of acute GvHD, engraftment syndrome (ES), persistent low level of CSA, or various CSA-associated adverse events in the first 100 days of pediatric HSCT.

MATERIALS AND METHODS

This is a retrospective analysis of 192 patients who underwent allogeneic hematopoietic stem cell transplantation at Medicalpark Göztepe and Antalya Hospitals between April 2014 and May 2019 had therapy switched from CSA to tacrolimus-based immunosuppression within 100 days of transplant.

RESULTS

The reasons for conversion to tacrolimus were low level of CSA (n = 70), aGvHD (n = 63), CSA-associated neurotoxicity (n = 15), CSA-associated nephrotoxicity (n = 10), hypertension (n = 10), allergic reactions (n = 9), ES (n = 7), CSA-associated hepatotoxicity (n = 5), and vomiting (n = 3). The median day after transplant for conversion to tacrolimus for all patients was day 20 (range 0-100 days). Response rates to conversion were 38% for GvHD, 86% for neurotoxicity, 50% for nephrotoxicity, 60% for hepatotoxicity, 80% for hypertension, 66% for vomiting, and 57% for ES. Twenty-nine patients (15%) experienced tacrolimus-associated toxicities after therapy conversion to tacrolimus. Neurotoxicity emerged as posterior reversible encephalopathy syndrome (PRES), which was the most common toxicity observed after conversion (18/29 patients).

CONCLUSION

Our data support the quick conversion to tacrolimus in the condition of persistent low CSA levels with acceptable efficacy and safety. Although both drugs are CNI and share a very similar mechanism of action, the conversion could be preferred especially in specific organ toxicities with special attention for neurotoxicity after conversion.

Inhibition of inositol kinase B controls acute and chronic graft-versus-host disease

T-cell activation releases inositol 1,4,5-trisphosphate (IP3), inducing cytoplasmic calcium (Ca2+) influx. In turn, inositol 1,4,5-trisphosphate 3-kinase B (Itpkb) phosphorylates IP3 to negatively regulate and thereby tightly control Ca2+ fluxes that are essential for mature T-cell activation and differentiation and protection from cell death. Itpkb pathway inhibition increases intracellular Ca2+, induces apoptosis of activated T cells, and can control T-cell-mediated autoimmunity. In this study, we employed genetic and pharmacological approaches to inhibit Itpkb signaling as a means of controlling graft-versus-host disease (GVHD). Murine-induced, Itpkb-deleted (Itpkb-/-) T cells attenuated acute GVHD in 2 models without eliminating A20-luciferase B-cell lymphoma graft-versus-leukemia (GVL). A highly potent, selective inhibitor, GNF362, ameliorated acute GVHD without impairing GVL against 2 acute myeloid leukemia lines (MLL-AF9-eGFP and C1498-luciferase). Compared with FK506, GNF362 more selectively deleted donor alloreactive vs nominal antigen-responsive T cells. Consistent with these data and as compared with FK506, GNF362 had favorable acute GVHD and GVL properties against MLL-AF9-eGFP cells. In chronic GVHD preclinical models that have a pathophysiology distinct from acute GVHD, Itpkb-/- donor T cells reduced active chronic GVHD in a multiorgan system model of bronchiolitis obliterans (BO), driven by germinal center reactions and resulting in target organ fibrosis. GNF362 treatment reduced active chronic GVHD in both BO and scleroderma models. Thus, intact Itpkb signaling is essential to drive acute GVHD pathogenesis and sustain active chronic GVHD, pointing toward a novel clinical application to prevent acute or treat chronic GVHD.

Eye Movement Disorders Following Allogeneic Bone Marrow Transplantation on FK506 (Tacrolimus) and Ganciclovir

FK506 (tacrolimus) is an immunosuppressive drug and more potent than cyclosporine. FK506 is widely used for immunosuppression in the prevention and treatment of graft-versus-host disease after allogeneic bone marrow transplantation and solid organ transplantation. Neurotoxicity is a recognized complication of FK506 therapy, but ptosis and weakness of eye abduction unilaterally has not been reported in association with FK506 administration to date. We discuss a 13-year-old male patient who developed ptosis and weakness of eye abduction unilaterally 90 days after transplantation with bone marrow from an unrelated donor, for acute lymphoblastic leukemia in this case report. FK506 therapy was administered for graft-versus-host disease prophylaxis and CMV infection was treated with ganciclovir. The physical examination findings completely resolved 72 to 96 hours after concomitant FK506 and ganciclovir treatment were terminated.

Calcineurin inhibitor-free strategies for prophylaxis and treatment of GVHD in children with posterior reversible encephalopathy syndrome after stem cell transplantation

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is a distinct clinico-radiologic entity that can occur following allogeneic hematopoietic stem cell transplantation, often in the context of treatment with calcineurin inhibitors (CNIs).

PROCEDURE

We describe the results of CNI-free management of 14 children with PRES and review the clinical and radiologic manifestations of their presentation.

RESULTS

Discontinuation of CNIs usually resulted in remission of PRES, but patients with established graft versus host disease (GVHD) at the time when treatment was changed often experienced progressive GVHD despite administration of immune suppressive and modulating treatments. All but three patients experienced full neurologic recovery. Nine children died as a result of either GVHD, disease relapse, or severe infection.

CONCLUSIONS

Discontinuation of CNIs results in neurologic improvement in most cases, but superior alternative immune modulatory treatment is needed to prevent progression of established GVHD.

Is complement blockade an acceptable therapeutic strategy for hematopoietic cell transplant-associated thrombotic microangiopathy?

Diagnosis and management of hematopoietic cell transplant-associated thrombotic microangiopathy (TA-TMA) are very complex and controversial, given multiple ongoing issues and comorbidities in sick transplant recipients. Complement activation via classic and alternative pathways is emerging as a potential pathogenetic mechanism in the development of TA-TMA. Complement-centric diagnostic strategy using functional and genetic tests may possibly support diagnosis, enhance molecular understanding and direct drug development. Complement blockade using eculizumab has shown some promising rates of hematologic responses, however, survival may still be poor. Early discontinuation of calcineurin inhibitor where feasible, use of eculizumab, aggressive infection prophylaxis, close monitoring and early treatment of potential complications including GvHD and organ failure may improve outcomes. A number of complement inhibitors are in the development and may change treatment paradigm. Future studies are important to better understand TA-TMA as a disease process and may aim to confirm the role of complement activation in TA-TMA, enhance diagnostic strategy, determine therapeutic approaches and strategies to reduce the risk of other complications particularly infection and GvHD.

Thrombomodulin blocks calcineurin inhibitor-induced vascular permeability via inhibition of Src/VE-cadherin axis

Recombinant human soluble thrombomodulin (rTM) counteracted capillary leakage and alleviated edema in individuals with sinusoidal obstruction syndrome and engraftment syndrome after hematopoietic stem cell transplantation. We previously showed that rTM increased levels of antiapoptotic protein Mcl-1 and protected endothelial cells from calcineurin inhibitor cyclosporine A (CsA)-induced apoptosis. However, the molecular mechanisms by which rTM enhances barrier function in vascular endothelial cells remain unknown. Here we show that exposure of vascular endothelial EA.hy926 cells to CsA induced phosphorylation of Src/vascular endothelial cadherin (VE-cadherin) and translocation of VE-cadherin from cell surface to cytoplasm, resulting in an increase in vascular permeability. In addition, CsA increased production of inflammatory cytokines, including interleukin (IL)-1β and IL-6, associated with an increase in nuclear levels of nuclear factor-κB (NF-κB) which also enhanced vascular permeability. Importantly, the fourth and fifth regions of epidermal growth factor-like domain of TM (TME45) attenuated CsA-induced p-Src/VE-cadherin and vascular permeability in parallel with a decrease in nuclear levels of NF-κB and cytokine production in EA.hy926 cells. In conclusion, TM, especially TME45, maintains vascular integrity, at least in part, via Src signaling.

Hematopoietic Stem Cell Transplant-Associated Thrombotic Microangiopathy

Hematopoietic stem cell transplant-associated thrombotic microangiopathy (TA-TMA) is a fatal, multifactorial disorder, which may present with thrombocytopenia, hemolysis, acute renal failure, mental status changes and involvement of other organs. The pathogenesis of TA-TMA is complex and includes multiple risk factors such as certain conditioning regimens, calcineurin inhibitors (CNIs), graft-versus-host disease (GVHD), human leukocyte antigen mismatch, and opportunistic infections. The end result of these insults is endothelial injury in the kidney and other organs. Recent studies also indicate a role of complement activation in tissue damage. The lack of sensitive and specific diagnostic tests for TA-TMA often results in delayed diagnosis. Biopsy is not always possible for diagnosis because of the risk of complications such as bleeding. Recently, an emerging role of renal-centered screening approach has been demonstrated, which utilize the monitoring of blood pressure, urine protein, serum lactate dehydrogenase and hemogram for early detection. Therapeutic options are limited, and plasma exchange plays a minor role. Withdrawal of offending agent such as CNIs and the use of rituximab can be effective in some patients. However, the current treatment strategy is suboptimal and associated with high mortality rate. Recently, eculizumab has been utilized in a few patients with good outcomes. Patients, who develop TA-TMA, are also at an increased risk of GVHD, infection, renal, cardiovascular, and other complications, which can contribute to high mortality. Better understanding of molecular pathogenesis, improvement in posttransplant management, leading to early diagnosis, and management of TA-TMA are required to improve outcomes of this fatal entity.

Graft-versus-host Disease Confined Solely to Intestine after Allogeneic Peripheral Blood Stem Cells Transplantation in a Patient with Chronic Myelogenous Leukemia

We describe a patient with chronic myelogenous leukemia who developing severe intestinal bleeding after allogeneic peripheral blood stem cells transplantation (allo-PBSCT). PBSC were obtained from an HLA one-locus mismatch sibling donor. On day 26 after PBSCT, although there was no sign of graft-versus-host disease (GVHD) in either the skin or the liver, diarrhea and severe intestinal bleeding occurred. The histopathological examination of the colon revealed complete denudation of the epithelial cells of the mucosa and no obvious apoptosis. Neither red cell fragments nor hemorrhagic diathesis was seen during this episode and the patient was diagnosed as having GVHD. Methylpredonisolone followed by FK506 may be effective in controlling intestinal bleeding and was used in our patient. Acute GVHD involving only the intestine has rarely been described but when using HLA-mismatched PBSCs, acute GVHD may occur severely and atypically.

Phase-1 study of siplizumab in the treatment of pediatric patients with at least grade II newly diagnosed acute graft-versus-host disease

In a phase-1 study, siplizumab, a humanized anti-CD2 monoclonal antibody, was administered (0.012 or 0.04 mg/kg) to 10 pediatric patients with > or = grade-II newly diagnosed, non-steroid-refractory aGvHD after BMT or PBSCT. SAEs and other AEs including infections, and GvHD staging changes (overall, skin, liver, gut) were evaluated over 364 days. Patients reported a total of 121 AEs (19 grade-3, 5 grade-4 0.012 mg/kg group; 17 grade-3, 17 grade-4 0.04 mg/kg group) and 14 SAEs (five grade-3, three grade-4, 0.012 mg/kg group; three grade-3, 0.04 mg/kg group); 15 AEs in five patients and four SAEs in three patients (fever, PTLD, adenoviral infection, and EBV lymphoma) were considered siplizumab-related. Six deaths occurred (study days 17-267); two were considered siplizumab-related: one from EBV-associated PTLD (0.012 mg/kg) and one from adenoviral infection (0.04 mg/kg); the other four deaths could potentially be attributed in part to study drug Three patients (one, 0.012 mg/kg group; two, 0.04 mg/kg group) developed PTLD. By study day 12, GvHD grade decreased in 3/5 and 2/5 patients in the 0.012 and 0.04 mg/kg groups, respectively; remission (grade 0) occurred in one patient in each group. Four of five patients (0.012 mg/kg group) and one of four patients (0.04 mg/kg group) achieved grade 0 GvHD during the first 100 study days (55.6% response). While treatment with siplizumab was associated with improvement of GvHD and remission in some pediatric patients, the overall high morbidity, mortality, and occurrence of PTLD is of safety concern, not warranting further development of siplizumab for the treatment of aGvHD in children.

Should methotrexate plus calcineurin inhibitors be considered standard of care for prophylaxis of acute graft-versus-host disease?

In a rapidly developing field, one can always anticipate that different interpretations of similar data will coexist. Stem cell transplanters can be a contentious lot, especially in the absence of controlled randomized trials. Thus, although improvements in the basic understanding of acute graft-versus-host disease (aGVHD) has led to many testable hypotheses in the management of GVHD, there remains little consensus regarding the most effective and least toxic approach to GVHD prevention. In the 1980s, the comparison would have been between cyclosporine-based regimens and ex vivo T cell depletion (TCD). Although ex vivo TCD is still used in some settings, pharmacologic-based therapy and in vivo TCD with serotherapy now predominate. This review is meant to highlight the advantages and disadvantages of the "standard of care" and assess the prospects for future regimens that may be more effective.

Incidence and predictors of delayed chronic kidney disease in long-term survivors of hematopoietic cell transplantation

BACKGROUND

The authors investigated the risk of delayed chronic kidney disease (CKD) in 1190 adult hematopoietic cell transplantation (HCT) survivors who underwent HCT for hematologic malignancies or aplastic anemia between 1976 and 1997 and survived for at least 1 year.

METHODS

CKD was defined as a sustained elevation of serum creatinine that indicated a glomerular filtration rate of <60 mL per minute per 1.73 m2 for > or =3 months. The median age at HCT was 35 years (range, 18.1-68.6 years), and the median length of follow-up was 7.1 years after HCT (range, 1-24.3 years).

RESULTS

Sixty patients with CKD were identified, resulting in a cumulative incidence of 4.4% at 5 years (autologous HCT, 3.8%; matched-sibling HCT, 4.5%; unrelated donor HCT, 10%; P = .09 compared with autologous HCT). Older age at HCT (relative risk [RR] per 5-year increment, 1.33; 95% confidence interval [CI], 1.2-1.5), exposure to cyclosporine without tacrolimus (RR, 1.90; 95% CI, 1.1-3.4) or with tacrolimus (RR, 4.59; 95% CI, 1.8-11.5), and a primary diagnosis of multiple myeloma (RR, 2.51; 95% CI, 1.1-5.6) were associated with an increased risk of delayed CKD.

CONCLUSIONS

In this study, the authors identified a subpopulation of patients who underwent HCT and remained at increased risk for CKD. The current findings set the stage for appropriate long-term follow-up of vulnerable patients.

Posterior reversible encephalopathy syndrome, part 1: fundamental imaging and clinical features

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state coupled with a unique CT or MR imaging appearance. Recognized in the setting of a number of complex conditions (preeclampsia/eclampsia, allogeneic bone marrow transplantation, organ transplantation, autoimmune disease and high dose chemotherapy) the imaging, clinical and laboratory features of this toxic state are becoming better elucidated. This review summarizes the basic and advanced imaging features of PRES, along with pertinent features of the clinical and laboratory presentation and available histopathology. Many common imaging/clinical/laboratory observations are present among these patients, despite the perception of widely different associated clinical conditions.

Posterior reversible encephalopathy syndrome after solid organ transplantation

BACKGROUND AND PURPOSE

Posterior reversible encephalopathy syndrome (PRES) is known to occur after solid organ transplantation (SOT), potentially associated with cyclosporine and tacrolimus. In this study, we assess the frequency and clinical and imaging characteristics of PRES after SOT.

MATERIALS AND METHODS

We identified 27 patients (13 men and 14 women; age range, 22-72 years) who developed PRES after SOT. Features noted included SOT subtype, incidence and timing of PRES, infection and rejection, mean arterial pressure (MAP), and toxicity brain edema.

RESULTS

PRES developed in 21 (0.49%) of 4222 patients who underwent transplantation within the study period (no significant difference among SOT subtypes). Transplantation was performed in 5 patients before the study period, and 1 patient underwent transplantation elsewhere. In consideration of all 27 patients, PRES typically developed in the first 2 months in patients who had SOT of the liver (9 of 10 patients) and was associated with cytomegalovirus (CMV), mild rejection, or systemic bacterial infection. PRES also typically developed after 1 year in patients who had SOT of the kidney (8 of 9 patients) and was associated with moderate rejection or bacterial infection. Toxicity MAP was significantly lower (P < .001) in liver transplants (average MAP, 104.8 +/- 16 mm Hg) compared with that in kidney transplants (average MAP, 143 +/- 20 mm Hg). Toxicity brain edema was significantly greater (P < .001) in patients who had liver transplants and developed PRES compared with patients who had undergone kidney transplants despite severe hypertension in those who had the kidney transplants.

CONCLUSION

Patients who had undergone SOTs have a similar low incidence of developing PRES. Differences between those who have had liver and kidney transplants included time after transplant, toxicity MAP, and PRES vasogenic edema noted at presentation. In patients who have undergone kidney transplants, severely elevated MAP was associated with reduced, not greater, brain edema.

Diagnostic and therapeutic implications of neurological complications following paediatric haematopoietic stem cell transplantation

Neurological complications are a relevant cause of morbidity and mortality after haematopoietic stem cell transplantation (SCT). We retrospectively analysed neurological complications of 165 paediatric patients who underwent SCT between 1996 and 2003. In all, 111 (67%) transplantations were allogeneic and 54 (33%) transplantations were autologous. Post-SCT neurological complications were seen in 24% of patients. They were seen in six children after autologous SCT and in 11 and 23 cases after allogeneic-related and -unrelated SCT. Neurological symptoms occurred between day +22 and +912 after transplantation and were classified into two groups. The first group (n=21) offered non-repetitive symptoms lasting less than 24 h without any cerebral imaging and cerebrospinal fluid(CSF) abnormalities. The second group (n=19) was characterized by progressive neurological symptoms, pathological MRI findings and/or abnormal results in CSF. Those with a progressive clinical course resulted from infections (n=10), drug toxicity (n=5), cerebrovascular events (n=2) and the central nervous system (CNS) relapse of the underlying disease (n=2). In particular, cerebral aspergillosis and toxoplasmosis after allogeneic unrelated SCT are a major challenge and are associated with a high mortality. In conclusion, our data suggest that patients presenting with progressive neurological symptoms after SCT require prompt diagnostic procedures and initiation in antimicrobial therapy in case of any findings suggestive of CNS infection.

Diagnosis and treatment of transplantation-associated thrombotic microangiopathy: real progress or are we still waiting?

Transplantation-associated thrombotic microangiopathy (TA-TMA) is an infrequent but devastating syndrome that occurs in allogeneic hematopoietic stem cell transplant recipients, and is associated with a variety of transplantation-related factors, including conditioning regimens, immunosuppressive agents, GVHD and opportunistic infections. Progress in managing this condition has been hampered by lack of a consensus definition and poor understanding of the pathophysiology of the disorder. Two different groups recently have proposed consensus definitions, yet they fail to distinguish the primary syndrome from the secondary causes, such as a variety of infections, medication exposure or other conditions. Increasing evidence suggests that TA-TMA is a multifactorial disorder that is distinct from thrombotic thrombocytopenic purpura (TTP), and likely represents the final common pathway of a number of endothelial cell insults. TA-TMA responds poorly to conventional treatment for TTP, including plasma exchange, but newer agents, including daclizumab and defibrotide show promise. In addition, other agents known to modify endothelial responses to injury, including statins, prostacyclin analogues, endothelin-receptor antagonists and free radical scavengers, may lead to improved outcomes for patients affected by this disorder.

Risk assessment in haematopoietic stem cell transplantation: GvHD prevention and treatment

Graft-versus-host disease (GvHD) is the major cause of transplant-related mortality and morbidity. As it is closely related to the major therapeutic principle, graft-versus-leukaemia (GvL) effect, risk assessment has to balance both risks depending on the pre-transplant status. This is clearly demonstrated when comparing the two major strategies for prevention of GvHD. While the majority of approaches aiming at T-cell depletion show efficacy in reducing acute and chronic GvHD and transplant-related mortality, T-cell depletion also affects graft-versus-leukaemia effects and thus results in a higher relapse rate. Thus, standard prophylaxis relying on calcineurin inhibitors frequently results in at least equivalent or even superior long-term disease-free survival, and the risk of relapse has to be considered when selecting regimens for prevention of GvHD. In addition to this general dilemma, drug-specific side-effects and risks have to be considered when selecting regimens for GvHD prevention and treatment.

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.

Pseudotumor cerebri after allogeneic bone marrow transplant associated with cyclosporine a use for graft-versus-host disease prophylaxis

Pseudotumor cerebri (PTC) is a syndrome of increased intracranial pressure for which several risk factors have been described. We report 2 patients who developed PTC after cyclosporine A (CsA) therapy for graft-versus-host disease (GvHD) prevention after bone marrow transplant. Both patients were obese which may have also contributed to the PTC. Cessation of CsA and combinations of mycophenolate mofetil or tacrolimus and systemic steroids and/or acetazoleamide were effective in managing the symptoms, improving the ocular complications and keeping GvHD asymptomatic. These cases suggest that induction of PTC by CsA used for GvHD prophylaxis in patients undergoing bone marrow transplant is not rare. Physicians who are following patients on CsA need to be alert to the possibility of PTC. Prompt diagnosis followed by thorough evaluation and treatment are crucial for preventing visual loss and improving associated symptoms.

Prophylaxis and treatment of acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) remains a major obstacle to successful allogeneic hematopoietic stem cell transplantation (HSCT). The ability to prevent GVHD--the application of successful prophylaxis--is crucial as treatment when prophylaxis fails or remains suboptimal. A calcineurin inhibitor in combination with methotrexate is still the mainstream regimen for prophylaxis of GVHD. Despite a steady increase in the repertoire of available drugs, corticosteroids remain the first-line therapy for patients who fail prevention and develop GVHD. Pan T-cell depletion studies suggest that success in prophylaxis and treatment of GVHD will depend on whether GVHD can be prevented without losing anti-malignancy and anti-infectious effects. Better understanding of the allogeneic response that is responsible for GVHD will facilitate the development of such an approach.

Severe intestinal graft versus host disease after donor lymphocyte infusion; response to extracorporeal photochemotherapy

We present a patient with acute myelogenous leukemia who developed severe acute intestinal graft versus host disease (GVHD) after donor lymphocyte infusion (DLI) following non-myeloablative allogeneic peripheral blood stem cell transplantation (allo-PBCT). One month after DLI, patient developed severe abdominal cramps, watery diarrhea without any signs or symptoms of the skin and liver GVHD. Treatment with steroid, cyclosporine A, tacrolimus and mycophenolat mofetil were not effective in controlling intestinal symptoms. Extracorporeal photochemotherapy (ECP), a recently used procedure in the treatment of GVHD was employed periodically and the symptoms subsided gradually. Acute GVHD after DLI may occur severely and atypically, but being limited to the intestine has rarely been reported.

Dermatologic treatment of cutaneous graft versus host disease

Cutaneous involvement in graft versus host disease (GVHD) after allogeneic hematopoietic cell transplant can be separated into acute GVHD (aGVHD), lichenoid chronic GVHD (cGVHD) and sclerodermatous cGVHD. It seems clear that these syndromes result from different mechanisms and entail different treatment approaches. Standard treatment of cutaneous aGVHD involves the intensification of immunosuppressive therapy with adequate topical supportive management. In skin-limited disease, phototherapy has shown promising results. In cutaneous cGVHD, the combination of corticosteroids and cyclosporine (ciclosporin) is the recommended therapy, and other immunosuppressants may be added depending on whether lichenoid or sclerodermatous lesions are present. High response rates to phototherapy have been found in lichenoid disease, while sclerodermatous disease responds better to etretinate or extracorporeal photochemotherapy. Localized cutaneous cGVHD may be treated with topical corticosteroids alone. Few reports on the effect of treatments in GVHD clearly describe the cutaneous involvement and the influence of the treatment on the skin. Therefore, dermatologists should be deeply involved in the diagnosis and treatment of GVHD, and good dermatologic grading systems should be developed. Theses changes will increase our knowledge of cutaneous GVHD, and relevant data in the evaluation of the effect of therapy in the disease will be obtained.

Life-threatening graft-vs-host disease

Hematopoietic stem cell transplant (SCT) is considered standard therapy for a variety of malignant and nonmalignant diseases. Graft-versus-host disease (GVHD) still represents today a major complication of hematopoietic SCT. Two types of GVHD have traditionally been recognized on the basis of the time of onset following transplantation, distinct pathobiological pathways, and different clinical presentations. The acute form commonly breaks out 2 to 6 weeks after transplantation, affecting up to 60% of patients receiving allogeneic transplants from HLA identical donors. Transfer of immunocompetent donor T cells contained in the graft may undergo alloreactivity against recipient cells because of major or minor histocompatibility antigens disparities between the donor and the immunosuppressed host. Target specificity in acute GVHD involves preferential injury to epithelial surfaces of the skin and mucous membranes, biliary ducts of the liver, and crypts of the intestinal tract. Chronic GVHD affects approximately 30% to 80% of patients surviving 6 months or longer after stem cell transplantation and is the leading cause of nonrelapse deaths occurring more than 2 years after transplantation. Chronic GVHD is a multiorgan syndrome with clinical features suggesting some autoimmune diseases, and possibly both alloreactive and autoreactive T cell clones are involved in its pathophysiology. Although GVHD may convey beneficial graft-versus-leukemia/lymphoma effects, it also entails a significant risk of morbidity and mortality. Patients with mild GVHD need only minimal, if any, immunosuppressive treatment, whereas prognosis of patients with extensive disease or resistant to standard immunosuppressive treatment may be dismal. Early recognition of GVHD followed by prompt therapeutic intervention may prevent the progression to higher-grade disease and improve the outcome for patients receiving hematopoietic SCT.

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.

Long-term outcomes of allogeneic stem cell transplant recipients after calcineurin inhibitor-induced neurotoxicity

Calcineurin inhibitor-induced central nervous system toxicities are uncommon and often resolve after discontinuation of the offending drug. The long-term outcome of these patients is, however, unknown. Resolution of symptoms occurred in 70% of 30 allografted recipients who developed calcineurin inhibitor-induced neurotoxicity. When patients were rechallenged with the same or a different calcineurin inhibitor, symptoms recurred in 41%, leading to permanent discontinuation of the drug. De novo or progressive acute graft-versus-host disease (GVHD) was observed in 54% of patients at a median of 7 d (range 1-70 d) after initial onset of neurotoxicity. The prognosis was grim, with 24 (80%) of these patients dying a median 33 d after the onset of neurotoxicity (range 2-594 d). GVHD and/or infection occurred in 54% and were the most common primary causes of death. We conclude that calcineurin inhibitor-induced neurotoxicity is frequently reversible but associated with a poor prognosis.

Tacrolimus: a further update of its use in the management of organ transplantation

Extensive clinical use has confirmed that tacrolimus (Prograf) is a key option for immunosuppression after transplantation. In large, prospective, randomised, multicentre trials in adults and children receiving solid organ transplants, tacrolimus was at least as effective or provided better efficacy than cyclosporin microemulsion in terms of patient and graft survival, treatment failure rates and the incidence of biopsy-proven acute and corticosteroid-resistant rejection episodes. Notably, the lower incidence of rejection episodes after renal transplantation in tacrolimus recipients was reflected in improved cost effectiveness. In bone marrow transplant (BMT) recipients, the incidence of tacrolimus grade II-IV graft-versus-host disease was significantly lower with tacrolimus than cyclosporin treatment. Efficacy was maintained in renal and liver transplant recipients after total withdrawal of corticosteroid therapy from tacrolimus-based immunosuppression, with the incidence of acute rejection episodes at up to 2 years' follow-up being similar with or without corticosteroids. Tacrolimus provided effective rescue therapy in transplant recipients with persistent acute or chronic allograft rejection or drug-related toxicity associated with cyclosporin treatment. Typically, conversion to tacrolimus reversed rejection episodes and/or improved the tolerability profile, particularly in terms of reduced hyperlipidaemia. In lung transplant recipients with obliterative bronchiolitis, conversion to tacrolimus reduced the decline in and/or improved lung function in terms of forced expiratory volume in 1 second. Tolerability issues may be a factor when choosing a calcineurin inhibitor. Cyclosporin tends to be associated with a higher incidence of significant hypertension, hyperlipidaemia, hirsutism, gingivitis and gum hyperplasia, whereas the incidence of some types of neurotoxicity, disturbances in glucose metabolism, diarrhoea, pruritus and alopecia may be higher with tacrolimus treatment. Renal function, as assessed by serum creatinine levels and glomerular filtration rates, was better in tacrolimus than cyclosporin recipients at up to 5 years' follow-up.

CONCLUSION

Recent well designed trials have consolidated the place of tacrolimus as an important choice for primary immunosuppression in solid organ transplantation and in BMT. Notably, in adults and children receiving transplants, tacrolimus-based primary immunosuppression was at least as effective or provided better efficacy than cyclosporin microemulsion treatment in terms of patient and graft survival, treatment failure and the incidence of acute and corticosteroid-resistant rejection episodes. The reduced incidence of rejection episodes in renal transplant recipients receiving tacrolimus translated into a better cost effectiveness relative to cyclosporin microemulsion treatment. The optimal immunosuppression regimen is ultimately dependent on balancing such factors as the efficacy of the individual drugs, their tolerability, potential for drug interactions and pharmacoeconomic issues.

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

Despite current standard preventive strategies that include optimizing donor selection and the combination of methorexate and a calcineurine inhibitor, acute and chronic GVHD remains a major barrier to successful hematopoietic cell transplantation for a sizeable proportion of patients. When acute and chronic GVHD become manifest a standard primary therapy approach has been the addition of glucocorticoid therapy to a background of calcineurine inhibition. When this approach fails patients with GVHD require secondary therapy. Ideally, second-line agents should promote transplantation tolerance so that the morbidity associated with prolonged use of glucocorticoids and other immunosuppressive agents can be minimized. Promising new agents or strategies which warrant further controlled clinical trials include: mycophenolate mofetil, sirolimus, humanized or chimeric monoclonal antibodies such as visilizumab, daclizumab and infliximab, and extracorporeal photopheresis. Co-operative studies are necessary to hasten the process of evaluating novel treatment strategies for acute and chronic GVHD.

Neurologic complications of bone marrow transplantation

The various forms of HSCT are or will soon be accepted treatments for an ever-increasing number of hematologic and solid cancers. Attempts to reduce the mortality and morbidity of HSCT and at the same time preserve or increase its efficacy in tumor control include development of nonmyeloablative allogeneic stem-cell transplant strategies [208] and allogeneic laboratory research-enhancing graft acceptance [209,210]. Eventually, these efforts will reduce complication rates of HSCT, including neurologic complications. In the interim, the consultant neuro-oncologist or neurologist with a specific inteest in this field is faced with complex clinical syndromes, neuroradiologic imaging studies and neurophysiologic tests, and generally poorly understood pathophysiologic mechanisms. Prospective studies of HSCT patients in large transplantation centers using clinical registries are needed.

Thrombotic microangiopathy in blood and marrow transplant patients receiving tacrolimus or cyclosporine A

BACKGROUND

Cyclosporine A (CSA) and tacrolimus (FK-506) are both associated with thrombotic microangiopathy (TMA) in allogeneic BMT recipients, although it is not known which drug is more likely to cause the syndrome. The optimal treatment of BMT-associated TMA is also not known.

STUDY DESIGN AND METHODS

To estimate the risks, predisposing factors, and outcomes of TMA, data were analyzed from two cohorts of BMT patients who had received CSA or FK-506 in our institution with the same clinical definition for TMA. TMA was diagnosed in 11 of 55 patients (CSA, 3 of 24; FK-506, 8 of 31).

RESULTS

The daily risk of developing TMA was 0.12 percent for patients receiving CSA and 0.26 percent for those receiving FK-506 (p = 0.16, chi-square). Among patients receiving FK-506, sibling donor BMT recipients were as likely to develop TMA as matched unrelated donor recipients. Serum CSA and FK-506 concentrations were not elevated above the therapeutic range in most patients with TMA. The blood urea nitrogen to serum creatinine ratio was elevated in patients with TMA. Despite daily plasmapheresis, 9 of 11 patients died without resolution of TMA; however, the causes of death were multifactorial, including GVHD. Histologic evidence for TMA was absent in 1 patient who died with persistent clinical signs attributed to microangiopathy.

CONCLUSIONS

In this study, a high incidence of TMA was found in patients receiving either CSA or FK-506 following BMT, with uniform diagnostic criteria and strict monitoring. Neither drug showed elevated levels in most patients with TMA. Plasmapheresis was unsuccessful in reversing most cases of TMA.