J. Uberti

Chronic graft-versus-host disease: clinical manifestation and therapy

Chronic graft-versus-host disease (GVHD) is a major cause of morbidity and mortality in long-term survivors of allogeneic stem cell transplantation. The immunopathogenesis of chronic GVHD is, in part, TH-2 mediated, resulting in a syndrome of immunodeficiency and an autoimmune disorder. The most important risk factor for chronic GVHD is prior history of acute GVHD and strategies that prevent acute GVHD also decrease the risk of chronic GVHD. Other important risk factors are the use of a non-T cell-depleted graft, and older age of donor and recipient. Whether recipients of peripheral blood stem cells are at increased risk of chronic GVHD remains unsettled. There are no known pharmacologic agents which can specifically prevent development of chronic GVHD. Agents which have efficacy in the treatment of autoimmune disorders have been utilized as therapy for established chronic GVHD and are associated with response rates of 20% to 80%. Most responses are confined to skin, soft tissue, oral mucosa and occasionally liver. Bronchiolitis obliterans responds infrequently to therapy and is associated with a dismal prognosis. Newer, promising therapeutic strategies under investigation include thalidomide, photopheresis therapy, anti-tumor necrosis factor and B cell depletion with anti-CD20 monoclonal antibody. Bone Marrow Transplantation (2001) 28, 121–129.

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.

Anti-CD20 Chimeric Monoclonal Antibody Treatment of Refractory Immune-Mediated Thrombocytopenia in a Patient with Chronic Graft-versus-Host Disease

Chronic graft-versus-host disease occurs in approximately 50% of long-term survivors of transplantation with marrow from HLA-identical donors (1); the risk for this disease increases with use of peripheral blood stem cells (2). Chronic graft-versus-host disease shares many of the clinical manifestations of autoimmune collagen vascular diseases, including oral ulceration, lichen planus, xerostomia, keratoconjunctivitis sicca, polyserositis, esophagitis and esophageal stricture, vaginal ulceration and stricture, intrahepatic obstructive liver disease, obstructive pulmonary disease, scleroderma, morphea, fasciitis, and myositis (3). Cytopenias, particularly thrombocytopenia, are a common feature of both chronic graft-versus-host disease and collagen vascular disease, and thrombocytopenia in chronic graft-versus-host disease is associated with poorer survival (4, 5). Antiplatelet antibodies are frequently detected in patients with thrombocytopenia associated with chronic graft-versus-host disease (6). Most patients with chronic graft-versus-host disease have evidence of B-cell dysregulation, with a high prevalence of autoantibodies to several cell surface and intracellular antigens (7). The role of these autoantibodies in the pathogenesis of chronic graft-versus-host disease is unclear. Autoimmune thrombocytopenia in chronic graft-versus-host disease may represent an instance of B-cell dysregulation leading to clinical disease. Rituximab is a humanized murine monoclonal antibody commonly used to treat B-cell lymphomas (8). This antibody is highly effective for in vivo depletion of B cells. Circulating B cells become undetectable after a single 375-mg/m2 infusion of rituximab; recovery of B cells begins at 6 to 9 months after treatment, and counts normalize by 9 to 12 months (9). Because of these biological properties of rituximab and the association of antiplatelet autoantibody with thrombocytopenia in patients with chronic graft-versus-host disease (6), we hypothesized that rituximab might have clinically significant activity in the treatment of refractory immune-mediated thrombocytopenia. We describe a patient with chronic graft-versus-host disease who developed severe refractory thrombocytopenia that responded to anti-CD20 chimeric antibody therapy. The rationale for this treatment was to eliminate B cells producing autoantibodies and thereby reverse the thrombocytopenia. Case Report A 32-year-old woman, gravida 3 para 1, presented with blurred vision and was found to have retinal hemorrhages. Complete blood count showed a leukocyte count of 451 109 cells/L with 2% basophils. A diagnosis of chronic myelogenous leukemia was confirmed by the presence of the Philadelphia chromosome in the marrow sample. The patient began receiving hydroxyurea to reduce her leukocyte count and was referred for stem-cell transplantation. She received 16 doses of busulphan (1 mg/kg of body weight every 6 hours) followed by cyclophosphamide (60 mg/kg daily for 2 days) in preparation for transplantation. Filgrastim-mobilized peripheral blood stem cells were harvested from an HLA-matched brother and were infused into the patient 3 months after diagnosis. The patients blood group was A+, and she was seropositive for cytomegalovirus; the donors blood group was O+, and he was seronegative for cytomegalovirus. Prophylaxis against graft-versus-host disease consisted of tacrolimus and methotrexate (10). The patient had prompt hematologic reconstitution, with an absolute neutrophil count of 0.5 109 cells/L on day 12 after transplantation and a platelet count greater than 100 109 cells/L on day 16 after transplantation. Therapy with ganciclovir, 5 mg/kg twice weekly, was started on day 16 as prophylaxis against cytomegalovirus infection. On day 28 after transplantation, the patient developed a maculopapular rash of the upper torso and diarrhea. Skin biopsy confirmed acute graft-versus-host disease, and she began receiving methylprednisolone, 1 mg/kg daily. The ganciclovir dose was increased prophylactically to 5 mg/kg 5 times per week. Bone marrow aspirate on day 100 after transplantation showed a normal male karyotype, and full donor chimerism was confirmed by polymerase chain reaction of microsatellite markers. The patient responded well to steroid therapy for the skin and gastrointestinal symptoms of graft-versus-host disease, but symptoms of xerophthalmia and xerostomia developed and steroid therapy was continued through day 127. On day 142, she underwent punctal occlusion of both eyes for severe xerophthalmia. Other manifestations of chronic graft-versus-host disease were progressive xerostomia with lichenoid changes of the oral mucosa. During the patients course of therapy with steroids and the increased dose of ganciclovir, her platelet count remained greater than 100 109 cells/L. On day 211, a complete blood count showed an absolute neutrophil count of 2.7 109 cells/L, hemoglobin value of 131 g/L, and platelet count of 178 109 cells/L. On day 230, the patients platelet count decreased to 88 109/cells/L. On day 238, it decreased further to 28 109 cells/L. No microangiopathic changes were seen on peripheral smear. Bone marrow aspiration and biopsy showed normal trilineage hematopoietic maturation with an adequate number of megakaryocytes. Flow cytometry showed the presence of platelet-associated IgG on washed, formalin-fixed platelets. Intravenous immunoglobulin, 500 mg/kg, was administered daily for 3 days; the platelet count increased to 159 109 cells/L, but for only 2 weeks. The patient then received 5 doses of intravenous immunoglobulins with methylprednisolone, 64 mg/d. On day 278, therapy with mycophenolate was started to provide additional immunosuppression. The combination of intravenous immunoglobulins, steroids, and mycophenolate resulted in an increase in platelet count to 114 109 cells/L by day 299. On day 308, the patients platelet count decreased to 51 109 cells/L. A dose of anti-D antibody (50 g/kg) was given, and the platelet count increased to 127 109 cells/L. However, the patient experienced significant hemolysis; her hemoglobin value decreased from 131 g/L to 78 g/L, an expected side effect related to the destruction of Rho (D)positive red cells. On day 337, she underwent laparoscopic splenectomy; an accessory spleen was also removed. By day 341, the platelet count increased to 139 109 cells/L but decreased to 2 109 cells/L 1 week later. Intravenous vincristine, 2 mg, was administered in four weekly doses starting on day 356, but it did not produce a response. The patient subsequently received intravenous cyclophosphamide, 1.5 g/m2, on day 384, again without response. On day 404, the patient received the first of four weekly doses of anti-CD20 antibody (rituximab [Rituxan, Genentech/IDEC, South San Francisco, California]). Peripheral blood flow cytometry on day 377 showed a CD19+ cell count (B cells) of 0.116 109 cells/L; by day 474, after rituximab therapy, CD19+ cells were absent. A gradual but sustained increase in the platelet count was noted after 2 doses of rituximab. The dose of mycophenolate mofetil was tapered and therapy was discontinued 3 weeks after initiation of rituximab therapy. At the time of this report, the patient has no clinically significant signs or symptoms of chronic graft-versus-host disease despite continued tapering of the tacrolimus dose and discontinuation of this therapy on day 667. The platelet-associated antibody assay remained weakly positive at day 485 and became negative on day 532. The patient has now been followed for 11 months since initiation of rituximab therapy, and the platelet count has not decreased (Table and Figure). Table. Chronological Clinical Course of the Patient Figure. Clinical course of a patient with chronic graft-versus-host disease in whom severe refractory immune-mediated thrombocytopenia responded to treatment with anti-CD20 monoclonal antibody. Discussion The reversal of our patients immune-mediated thrombocytopenia was especially noteworthy because of the lack of a sustained response to intensive immunosuppression, including treatment with steroids, mycophenolate, tacrolimus, vincristine, cyclophosphamide, intravenous immunoglobulins, anti-D antibody, and splenectomy. The improvement of thrombocytopenia was also associated with decreased levels of platelet-associated antibody and lack of progression of chronic graft-versus-host disease despite the discontinuation of immunosuppression. It is possible that cyclophosphamide therapy contributed in part to the platelet response. Reiner and colleagues (11) reported a series of 20 cases of refractory idiopathic thrombocytopenia purpura treated with pulse cyclophosphamide (1 to 1.5 g/m2), with complete remission in 65% of patients and partial remission in 20%. However, most patients required multiple pulses (mean, 2; maximum, 4), and the mean time to response was 7 weeks. Considering the intensity of the immunosuppressive therapy that our patient received and the lack of platelet response at the time of neutrophil recovery, it is unlikely that cyclophosphamide contributed substantially. Studies of B cells in patients with chronic graft-versus-host disease have not convincingly explained the clinical abnormalities, including reduced B-cell count, decreased Ig production, and increased spontaneous Ig production (12), seen in this condition. Clonal dysregulation of B cells in chronic graft-versus-host disease has been suggested by the presence of monoclonal gammopathy (13, 14) and elevated serum IgG and IgM levels (15). Antibody production is a prominent feature of many animal models of chronic graft-versus-host disease (16, 17). Mechanistic studies showed that secretion of Th2 cytokines, such as interleukin-4 and interleukin-5, by donor CD4+ cells are critical to B-cell activation and autoantibody production. Most of the autoantibodies are of the IgG subclass (16), and abnormal cross-linking of IgG receptors on t

Risk Factors for Anaerobic Bloodstream Infections in Bone Marrow Transplant Recipients

The incidence of anaerobic bloodstream infections (BSI) in patients who underwent bone marrow transplantation (BMT) recently increased at our institution. A retrospective case-control study of patients undergoing BMT from January 1995 through December 1998 was performed to determine the microbiological characteristics, epidemiology, and outcome of anaerobic BSI and to identify independent risk factors for infection. Anaerobic BSI occurred in 23 patients, for a rate of 4 BSIs per 100 BMT procedures, and it accounted for 17% of all BSIs that occurred during the study period. Infection occurred at a mean (+/- standard deviation) of 7+/-4 days after BMT and 7+/-5 days after the onset of neutropenia. Fusobacterium nucleatum was the most frequently isolated pathogen (in 17 patients), followed by Leptotrichia buccalis (in 4), Clostridium septicum (in 1), and Clostridium tertium (in 1). Two case patients (9%) died. Severity of mucositis was an independent predictor of anaerobic BSI (odds ratio, 4.4; P=.01). Controlling mucositis is critical for the prevention of anaerobic BSI in this patient population.

Tacrolimus: A new agent for the prevention of graft-versus-host disease in hematopoietic stem cell transplantation

Tacrolimus (FK506) is a macrolide lactone with potent immunosuppressive activity 100 times that of cyclosporine by weight. The molecular mechanism of action is mediated via an inhibition of the phosphorylase activity of calcineurin by drug–immunophilin complex, resulting in the inhibition of IL-2 gene expression. There are emerging studies now showing significant efficacy of tacrolimus in GVHD prevention in both related and unrelated donor transplantation. Three multicenter randomized studies comparing tacrolimus to cyclosporine have been completed, one each in related and unrelated donor transplantation; the remaining study involved both related and unrelated donor transplantation. All three studies showed a significantly lower incidence of grade II–IV acute GVHD in patients who received tacrolimus. One study in sibling donor transplantation showed that patients with advanced disease who received tacrolimus had a poorer survival than patients who received cyclosporine, but the survival was similar in patients with non-advanced disease. The remaining two studies, one in unrelated donors and the other combining both related and unrelated donors did not show any survival difference between the tacrolimus and cyclosporine groups. In addition, this review also highlights some of the critical questions regarding the role of this agent in allogeneic stem cell transplantation: (1) the contribution of methotrexate in combination with tacrolimus; (2) the starting i.v. dose of tacrolimus; (3) the suggested whole blood level of tacrolimus and its effect on nephrotoxicity; and (4) whether tacrolimus should be used in patients with advanced malignancy. Future studies using tacrolimus in combination with other immunosuppressants, and its use in patients with advanced malignancy will be warranted.

Allogeneic stem cell transplantation reduces disease progression compared to autologous transplantation in patients with multiple myeloma.

This study compares the probability of disease progression, progression-free survival, and overall survival between patients undergoing an allogeneic or autologous transplant for multiple myeloma using an identical preparative regimen. Patients received a preparative regimen of TBI, busulfan, and cyclophosphamide followed by an allogeneic or autologous transplant. In the allogeneic group (n = 21), six patients received bone marrow and 15 received G-CSF mobilized PBSC; all autologous patients (n = 35) received PBSC mobilized with cyclophosphamide and G-CSF. Allogeneic donors were HLA-identical (n = 20) or one-antigen mismatched (n = 1) siblings. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus (n = 10), tacrolimus/methotrexate (n = 6), cyclosporine/methotrexate (n = 4), or cyclosporine (n = 1). The groups were evenly matched for gender, pretransplant therapy, disease status at time of transplant, myeloma subtype, and time from diagnosis to transplant. The median age was significantly lower in the allogeneic group (48 vs 55 years, P < 0.01). In the allogeneic group the probabilities of developing acute GVHD grade II-IV and chronic GVHD were 55% and 82%, respectively. The Kaplan–Meier probability of disease progression was significantly lower in the allogeneic group (11% vs 64%, P < 0.001) compared to the autologous group. Although progression-free (60% vs 30%, P = 0.19) and overall survival at 2 years (60% vs 42%, P = 0.39) favored the allogeneic group, this did not reach statistical significance. Within the allogeneic transplant group, patients age 50 years or under had a 3-year overall survival significantly higher when compared to older patients (79% vs 29%, P = 0.03). Using identical preparative regimens, allogeneic transplantation reduced disease progression compared to autologous transplantation for myeloma. This suggests that allogeneic transplantation induces a graft-versus-myeloma (GVM) effect. Bone Marrow Transplantation (2001) 27, 801–807.

Factors affecting the pharmacokinetics of tacrolimus (FK506) in hematopoietic cell transplant (HCT) patients

Tacrolimus is an immunosuppressant commonly used in the prevention of graft-versus-host disease (GVHD) following allogeneic HCT. Unfortunately, the use of tacrolimus is associated with variable immunosuppression and toxicity. The purpose of this study was to describe tacrolimus population pharmacokinetic parameters, to identify relationships between clinical covariates and pharmacokinetic estimates, and to develop a model to predict tacrolimus clearance in HCT patients. Steady-state whole blood tacrolimus concentrations (n = 1625) obtained during intravenous and oral therapy were analyzed in 122 patients. Population clearance (CL) was 5.22 l/h and bioavailability (F) was 0.28. The influence of clinical covariates on population estimates of CL and F of tacrolimus were tested with nonlinear mixed effects models (NONMEM). CL was significantly reduced by elevations in total bilirubin 2.0–9.9 mg/dl (CL * 0.797), bilirubin ⩾10 mg/dl (CL * 0.581), serum creatinine ⩾2 mg/dl (CL * 0.587), grade III/IV graft-versus-host disease (CL * 0.814) and veno-occlusive disease (CL 0.814). No covariates were predictive of oral F. The interindividual variabilities in CL and F were 33% and 44%, respectively. Residual variability was 27.5% and 16.8% at tacrolimus concentrations of 10 μg/l and 20 μg/l, respectively. These models may be used to predict tacrolimus clearance and doses in adult patients following HCT. Bone Marrow Transplantation (2001) 28, 753–758.

Tacrolimus and methotrexate for the prophylaxis of acute graft-versus-host disease in allogeneic bone marrow transplantation in patients with hematologic malignancies

We conducted a study to evaluate the efficacy of the combination of tacrolimus and short-course methotrexate for the prevention of acute GVHD in patients with hematologic malignancies. Patients received preparative regimens specific for their disease category. Twenty-six out of 28 received HLA-identical sibling transplants and the two remaining patients received one-antigen mismatched transplants from a family member. With a median follow-up of 14 months, the Kaplan–Meier estimate of event-free survival was 50 ± 9%. The probability of grade II–IV GVHD was 15 ± 7%. Four patients developed GVHD: two had grade II and one each developed grade III and IV GVHD. Administration of methotrexate was associated with severe mucositis and there was no correlation between the distribution of the GVHD grade and the cumulative dose of methotrexate given. Thirteen patients have died; nine from transplant-related complications and four from relapse. The major toxicity of tacrolimus was renal. Nine out of 28 patients (32%) developed renal dysfunction attributed to tacrolimus. The combination of tacrolimus and methotrexate is an effective regimen for GVHD prophylaxis but associated with significant renal and mucosal toxicity. Further studies of tacrolimus as a single agent or in combination with either steroids or with a lower dose of methotrexate or with other antiproliferative drugs to modify the adverse events may improve the therapeutic index of this useful and promising agent.

Double dose-intensive chemotherapy with autologous stem cell support for relapsed and refractory testicular cancer: The University of Michigan experience and literature review

Testicular cancer patients refractory or in relapse after primary chemotherapy have ⩽25% 5-year progression-free survival with salvage. To improve prognosis, patients entered a phase I/II tandem dose-escalation trial of carboplatin (1500–2100 mg/m2) and etoposide (1200–2250 mg/m2) with ABMT. Patients were eligible for a second cycle if disease progression was absent and performance status allowed. From August 1990 to June 1998, 29 males (25 NSGCT) were treated. At the time of ABMT, 10 were chemosensitive, four were chemoresistant, and 10 were absolutely refractory to platinum. Disease status (no. patients) at transplant: primary refractory disease (six), first relapse (10), second relapse (eight), third relapse (five). Fifteen (52%) received both transplants. Treatment-related mortality was 10%. Best response after ABMT included: two CR, one CR surgically NED, five PR, three PR surgically NED, seven SD, and eight PD. Eight (28%) patients are continuously progression-free a median 60 months (range, 31–93) from first ABMT. Three seminoma patients remain progression-free. Of five long-term NSGCT survivors, four were treated in first relapse with platinum-sensitive disease. Eighteen relapses occurred a median of 4 months after ABMT I (two late relapses at 28 and 44 months). The median PFS and OS for the whole group are 4 and 14 months, respectively. Patients with relapsed/ refractory testicular cancer benefit most from ABMT if they have platinum-sensitive disease in first relapse. Patients who do poorly despite ABMT have a mediastinal primary site, true cisplatin-refractory disease, disease progression prior to ABMT, and/or markedly elevated βHCG at ABMT. New treatment modalities are needed for the latter group. Bone Marrow Transplantation (2001) 27, 939–947.

Tacrolimus as monotherapy or combined with minidose methotrexate for graft-versus-host disease prophylaxis after allogeneic peripheral blood stem cell transplantation: long-term outcomes

Summary:We report long-term outcomes for allogeneic peripheral blood stem cell (PBSC) recipients, evaluating cumulative incidence (CI) of acute and chronic graft-versus-host disease (GVHD), after use of tacrolimus with or without minidose methotrexate for GVHD prophylaxis. From April 1996 to April 1998, 97 adults underwent allogeneic PBSC transplantation. The first 49 received tacrolimus monotherapy as GVHD prophylaxis and the subsequent 48 received combination therapy. The median follow-up for survivors was 67 months. Compared to combination therapy, tacrolimus monotherapy resulted in enhanced neutrophil engraftment, shortened hospitalization, comparable rates of GVHD, and equivalent 100-day survival. The CI of grades II–IV acute GVHD was 35% with tacrolimus and 23% with the combination (P=0.19). The CI of III–IV GVHD was 22% for tacrolimus and 19% for the combination. CI of chronic GVHD was similar between the two groups (P=0.5). Patients with good-risk disease had superior overall survival (OS) when compared to those with poor-risk features (P<0.001). Within the good-risk disease category, patients receiving methotrexate had a trend towards improved OS (P=0.07). Multivariate analysis indicated good-risk disease status and methotrexate were independently associated with improved OS, progression-free survival (PFS), and relapse. In addition, patients developing chronic GVHD had a significantly reduced risk of relapse and improved PFS.