Ibrutinib in Steroid-Refractory Chronic Graft-versus-Host Disease, a Single-Center Experience

Chronic graft-versus-host disease (cGVHD) is a leading cause of late morbidity and mortality after allogenic hematopoietic stem cell transplantation. Corticosteroid-based therapies are a mainstay of its initial treatment but there is no consensus in how to treat steroid-refractory cGVHD. Ibrutinib is a Bruton tyrosine kinase and IL-2-inducible kinase inhibitor thought to affect pathways driving cGVHD, and it was approved for the treatment of refractory cGVHD by the Food and Drug Administration (FDA) in August 2017 after a landmark phase 1b/2 study. It was the first medication approved for this indication, but how to best treat refractory cGVHD remains an open question, and there has been limited literature on ibrutinib after the FDA approval. This study sought to characterize the utilization and outcomes associated with ibrutinib use in cGVHD via a retrospective single-center study. Fifty-three patients were identified as having been treated with ibrutinib for cGVHD following FDA approval between September 1, 2017, and December 31, 2020, using an institutional data repository. Their records were reviewed for demographics, cGVHD characteristics, and outcomes. For the entire cohort, two-year overall survival was 76% (95% confidence interval [CI], 60% to 86%), with a median follow-up among survivors of 26 months (range, 1.3 to 39.5 months). However, the 2-year failure-free survival (FFS) after initiation of ibrutinib was 9% (95% CI, 2.6% to 20%), and the median FFS was 4.5 months (95% CI, 2.8 to 7.1 months). Events of FFS included treatment change due to lack of response or toxicity, malignant relapse, or non-treatment related mortality. At the time of this report, 11 patients (21%) remained on ibrutinib. At the time of the FFS event or last follow-up, 6 patients (12%) had a complete or partial response, 34 (64%) had stable disease, and 13 (25%) had progressive disease. Ibrutinib use was associated with no reduction in corticosteroid dose between ibrutinib initiation and FFS event or last follow-up (mean difference, 0.00; P = .98). The most frequently used noncorticosteroid cGVHD therapy after ibrutinib was ruxolitinib (n = 14; 33%). The most common adverse events associated with treatment discontinuation were infection (lung, skin, enterocolitis; n = 6), bleeding and bruising (hematoma, epistaxis, gastrointestinal bleed; n = 5), and muscle aches (n = 2). In a real-world setting, ibrutinib is associated with a modest response rate and FFS and its use in a narrower, more targeted patient population may be indicated.

Hematopoietic Stem Cell Transplantation for Shwachman-Diamond Syndrome

We report the outcomes of hematopoietic stem cell transplantation (HSCT) for 52 patients with Shwachman-Diamond syndrome (SDS) who underwent transplantation between 2000 and 2017. The median age at transplantation was 11 years, and the median duration of follow-up was 60 months. The indication for HSCT was bone marrow failure (BMF; cytopenia or aplastic anemia) in 39 patients and myelodysplasia (MDS)/acute myelogenous leukemia (AML) in 13 patients. The donor type was an HLA-matched sibling for 18 patients, an HLA-matched or mismatched relative for 6 patients, and an HLA-matched or mismatched unrelated donor for 28 patients. Preparative regimens for BMF were myeloablative in 13 patients and reduced intensity in 26. At the time of this report, 29 of the 39 patients with BMF were alive, and the 5-year overall survival was 72% (95% confidence interval, 57% to 86%). Graft failure and graft-versus-host disease were the predominant causes of death. Preparative regimens for patients with MDS/AML were myeloablative in 8 and reduced intensity in 5. At the time of this report, only 2 of 13 patients were alive (15%), with relapse the predominant cause of death. Survival after transplantation for SDS-related BMF is better compared with historical reports, but strategies are needed to overcome graft failure and graft-versus-host disease. For SDS- related MDS or AML, transplantation does not extend survival. Rigorous surveillance and novel treatments for leukemia are urgently needed.

Burden of illness among patients with severe aplastic anemia who have had insufficient response to immunosuppressive therapy: a multicenter retrospective chart review study

This study assessed treatment patterns and healthcare resource utilization (HRU) of patients with severe aplastic anemia (SAA) with insufficient response to immunosuppressive therapy (IST). A retrospective chart review was conducted at Dana-Farber Cancer Institute (DFCI), United States, and Hôpital Saint-Louis (HSL), France. Eligible patients were ≥ 18 years old, diagnosed with acquired SAA between January 1, 2006, and July 31, 2016, had insufficient response to IST, and had ≥ 12 months of follow-up post-diagnosis. Overall survival (OS) was estimated using the Kaplan-Meier method. Among the 40 patients, mean age at diagnosis was 44 years and 53% were women. Median follow-up time after SAA diagnosis was 48.3 months. Ninety-five percent of patients received antithymocyte globulin (ATG) as primary therapy prior to hematopoietic stem cell transplant (HSCT). Most common secondary SAA therapies prior to HSCT were eltrombopag (28%) and androgens (15%). Seventy-five percent of patients received HSCT. Prior to HSCT, patients received an average of 2.7 red blood cell (RBC) and 3.3 platelet transfusions per month; patients had 0.9 hospitalizations, 0.4 emergency room visits, and 12.8 office visits per year. Five-year OS was 75%, with infection as the primary cause of death. Additionally, this study provides information on the subgroup of patients receiving eltrombopag which was the most common secondary therapy. This study quantified transfusion and HRU burden associated with SAA and demonstrated high 5-year survival in a recently treated cohort.

Factors Associated With Successful Discontinuation of Immune Suppression After Allogeneic Hematopoietic Cell Transplantation

Importance

Immune suppression discontinuation is routinely attempted after allogeneic hematopoietic cell transplantation (HCT) and under current practices may lead to graft-vs-host disease (GVHD)-associated morbidity and death. However, the likelihood and predictive factors associated with successful immune suppression discontinuation after HCT are poorly understood.

Objectives

To examine factors associated with successful immune suppression discontinuation and risk for immune suppression discontinuation failure under conventional HCT approaches and develop a practical tool to estimate successful immune suppression discontinuation likelihood at the clinical point of care.

Design, Setting, and Participants

Using long-term follow-up data from 2 national Blood and Marrow Transplant Clinical Trial Network studies (N = 827), a multistate model was developed to investigate the probability and variables associated with immune suppression discontinuation success. The study began in July 2015, and analyses were completed in August 2019.

Main Outcomes and Measures

Immune suppression discontinuation and immune suppression discontinuation failure.

Results

Of the 827 patients included in the analysis, 456 were men (55.1%). Median age at transplant was 44 (range, <1-67) years. With median follow-up of 72 (range, 11-124) months, 20.0% of the patients were alive and not receiving immune suppression at 5 years. Older recipient age (adjusted odds ratio [aOR] of >50 vs <30 years, 0.27, 99% CI, 0.14-0.50; P < .001), mismatched unrelated donor (aOR, mismatched unrelated vs matched related, 0.37; 99% CI, 0.14-0.97; P = .008), peripheral blood graft (aOR of peripheral blood graft vs bone marrow, 0.46; 99% CI, 0.26-0.82; P < .001), and advanced stage disease (aOR of advanced vs early disease, 0.45; 99% CI, 0.23-0.86, P = 0.002), were significantly associated with decreased odds of immune suppression discontinuation. Failed attempts at immune suppression discontinuation (127 patients [37.1% of total immune suppression discontinuation events]) resulting in GVHD were significantly associated with use of peripheral blood stem cells (HR, 2.62; 99% CI, 1.30-5.29; P < .001), prior GVHD, and earlier immune suppression discontinuation attempts. Earlier immune suppression discontinuation was not associated with protection from cancer relapse after HCT (adjusted hazard ratio for discontinuation vs not, 1.95; 99% CI, 0.88-4.31; P = .03).Dynamic prediction models were developed to provide future immune suppression discontinuation probability according to individual patient characteristics.

Conclusions and Relevance

Successful immune suppression discontinuation is uncommon in the setting of peripheral blood stem cell grafts. The data suggest earlier attempts at ISD conferred no long-term benefit, given frequent ISD failure, limited subsequent success after initial failed ISD attempt, and no evidence of relapse reduction. Using a risk model-based clinical application, physicians may be able to identify individual patients' probability of successful immune suppression discontinuation.

Inhibiting EZH2 function prevents and treats chronic graft vs host disease (cGVHD) by disrupting germinal center formation and plasma cell maturation

To determine whether targeting EZH2, a histone methyltransferase necessary for germinal center (GC) formation, could reduce murine cGVHD (cGVHD), we first used a clinically relevant murine model of cGVHD, which recapitulates multi-organ cGVHD with bronchiolitis obliterans (BOS). Bone marrow (BM) from EZH2 fl/fl CD19 Cre B6 mice and WT T cells, or WT B6 BM and EZH2 fl/fl CD4 Cre B6 T cells were given to conditioned B10.BR mice. EZH2 expression in BM and T cells was obligatory for cGVHD. To determine whether EZH2 function could be targeted to treat cGVHD, we tested a novel EZH2 small molecule inhibitor, JQ5 with a favorable toxicity and efficacy profile to other inhibitors. Mice with established cGVHD given JQ5 had dramatically improved cGVHD. Similar results were seen in a sclerodermatous cGVHD model. To assess possible causes of this improvement we performed RNA-seq and ATAC-seq data of MACS purified CD19+ B cells obtained from control and JQ5 treated BOS cGVHD mice. Unsupervised gene set enrichment analysis and weighted gene correlation network analysis showed that among gene clusters associated with JQ5 treatment there was an enrichment for genes expressed in naïve B cells compared to plasma cells (GSEA4142) and an impairment of genes associated with late stage GC B cells compared to early follicular B cells (GSEA11961). This suggested that JQ5 impaired GC B cell and plasma cell maturation. Consistent with these data, splenic follicular cells, GC size and number, and lung resident PCs were reduced compared to cGVHD controls. Taken together these results show that EZH2 is necessary for the initiation of cGVHD and show for the first time that EZH2 inhibition using a novel inhibitor JQ5 can reverse established cGVHD in mice with BOS or scleroderma.

Abstract 17: In situ immune expression signatures before and after ipilimumab therapy for relapsed acute myeloid leukemia after allogeneic stem cell transplantation

Immune evasion may facilitate hematologic relapse after allogeneic hematopoietic stem cell transplantation (allo-SCT). We recently demonstrated that CTLA4 blockade with ipilimumab reinvigorates a graft-versus-leukemia effect to induce complete remissions of acute myeloid leukemia (AML) relapsing after allo-SCT. Here, we hypothesized that immune subpopulation dynamics and activation states inferred from in situ gene expression changes within the leukemic microenvironment are informative of clinical outcome. We undertook an in situ transcriptomic characterization of paired, pre/post ipilimumab leukemic biopsies from five samples with relapsed, extramedullary AML. We performed a response-to-treatment expression analysis for each patient and found three immune patterns corresponding to three clinical response patterns following ipilimumab (durable response, relapse, and primary resistance). Durable responses were characterized by a diverse infiltration of activated cytotoxic T lymphocytes, B cells, and macrophages. In contrast, primary resistance was associated with both marked infiltration of CD8 T cells deficient in T-cell receptor signaling, activation, or cytolytic activity and absent infiltration of other immune effectors. Interestingly, the sample with transient response and eventual relapse demonstrated pre- and post-treatment immunologically “inflamed” states that were strongly downregulated during clinical relapse. In situ gene expression analyses of leukemic biopsies before and after ipilimumab therapy suggest that specific patterns of immune population dynamics and activation states underlie diverse clinical outcomes.

Citation Format: Pavan Bachireddy, Matthew S. Davids, Michael S. Rooney, Michaela Bowden, Chensheng W. Zhou, Scott J. Rodig, Vincent Ho, Joseph Antin, John Koreth, Edwin Alyea, Robert J. Soiffer, Catherine J. Wu. In situ immune expression signatures before and after ipilimumab therapy for relapsed acute myeloid leukemia after allogeneic stem cell transplantation [abstract]. In: Proceedings of the Second AACR Conference on Hematologic Malignancies: Translating Discoveries to Novel Therapies; May 6-9, 2017; Boston, MA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(24_Suppl):Abstract nr 17.

Infection Rates among Acute Leukemia Patients Receiving Alternative Donor Hematopoietic Cell Transplantation

Alternative graft sources (umbilical cord blood [UCB], matched unrelated donors [MUD], or mismatched unrelated donors [MMUD]) enable patients without a matched sibling donor to receive potentially curative hematopoietic cell transplantation (HCT). Retrospective studies demonstrate comparable outcomes among different graft sources. However, the risk and types of infections have not been compared among graft sources. Such information may influence the choice of a particular graft source. We compared the incidence of bacterial, viral, and fungal infections in 1781 adults with acute leukemia who received alternative donor HCT (UCB, n= 568; MUD, n = 930; MMUD, n = 283) between 2008 and 2011. The incidences of bacterial infection at 1 year were 72%, 59%, and 65% (P < .0001) for UCB, MUD, and MMUD, respectively. Incidences of viral infection at 1 year were 68%, 45%, and 53% (P < .0001) for UCB, MUD, and MMUD, respectively. In multivariable analysis, bacterial, fungal, and viral infections were more common after either UCB or MMUD than after MUD (P < .0001). Bacterial and viral but not fungal infections were more common after UCB than MMUD (P = .0009 and <.0001, respectively). The presence of viral infection was not associated with an increased mortality. Overall survival (OS) was comparable among UCB and MMUD patients with Karnofsky performance status (KPS) ≥ 90% but was inferior for UCB for patients with KPS < 90%. Bacterial and fungal infections were associated with poorer OS. Future strategies focusing on infection prevention and treatment are indicated to improve HCT outcomes.

Therapeutic treatment of multi-organ system, obstructive pulmonary and scleradermatous chronic graft-versus-host disease with the BTK and ITK inhibitor Ibrutinib (TRAN3P.873)

Chronic GVHD (cGVHD) is dependent on the ability of donor bone marrow (BM) B cells to produce pathogenic antibody (Ab) deposited in target organs, which is associated with increased germinal centers (GCs). BTK is necessary for B cells to enter GCs and ITK is necessary for T cell activation. We hypothesized that alloreactive GC B cells and T follicular helper cells require BTK or ITK and inhibition by ibrutinib (Ib) would prevent cGVHD. We evaluated the therapeutic effect of Ib in two models of cGVHD: a MHC-disparate (B6→B10.BR) multi-organ model complicated by bronchiolitis obliterans (BO) and a sclerodermatous (SCL) minor-mismatch (LP/J→B6) model. Mice treated with Ib had a decrease in pathogenic Ab, collagen deposition and GC B cells in target organs similar to healthy control mice. In contrast to cGVHD mice, pulmonary function in Ib treated mice was similar to control mice. To confirm that BTK and ITK are required for cGVHD we used donor mice with an ablation of BTK or ITK. Absence of BTK in B cells impeded GCs, Ab deposition and BO. Mice transplanted with T cells lacking ITK and WT BM did not develop BO. In the SCL model, mice treated with Ib did not develop clinical signs of cGVHD including less alopecia and SCL lesions. Furthermore, there was a decrease in lymphocyte infiltration surrounding the bronchioles and nephrons in treated mice. The inhibition of TEC-family kinases with Ib is a novel therapeutic for multi-organ system cGVHD with BO or SCL manifestations.

Allogeneic hematopoietic cell transplantation for advanced polycythemia vera and essential thrombocythemia

Allogeneic hematopoietic cell transplantation (HCT) is curative for selected patients with advanced essential thrombocythemia (ET) or polycythemia vera (PV). From 1990 to 2007, 75 patients with ET (median age 49 years) and 42 patients with PV (median age 53 years) underwent transplantations at the Fred Hutchinson Cancer Research Center (FHCRC; n = 43) or at other Center for International Blood and Marrow Transplant Research (CIBMTR) centers (n = 74). Thirty-eight percent of the patients had splenomegaly and 28% had a prior splenectomy. Most patients (69% for ET and 67% for PV) received a myeloablative (MA) conditioning regimen. Cumulative incidence of neutrophil engraftment at 28 days was 88% for ET patients and 90% for PV patients. Acute graft-versus-host disease (aGVHD) grades II to IV occurred in 57% and 50% of ET and PV patients, respectively. The 1-year treatment-related mortality (TRM) was 27% for ET and 22% for PV. The 5-year cumulative incidence of relapse was 13% for ET and 30% for PV. Five-year survival/progression-free survival (PFS) was 55%/47% and 71%/48% for ET and PV, respectively. Patients without splenomegaly had faster neutrophil and platelet engraftment, but there were no differences in TRM, survival, or PFS. Presence of myelofibrosis (MF) did not affect engraftment or TRM. Over 45% of the patients who undergo transplantations for ET and PV experience long-term PFS.

Recovery of thymic epithelial cells and immune reconstitution after cord blood transplantation depends on angiogenesis and neovascularization (126.12)

Umbilical cord blood (UCB) is increasingly used as an alternative source for allogeneic hematopoietic stem cell transplantation (HSCT). HSCT compromises thymopoiesis due to injury of thymic epithelial cells (TEC). Human UCB is enriched in endothelial precursors, which promote neovascularization and thymopoiesis in SCID mice transplanted with human thymus. We examined whether markers of angiogenesis, ANG1 and VEGF, might correlate with recovery of TEC, which support T cell development and expansion by producing IL-7 and SCF (a kit ligand). We analyzed 27 patients pre and 1, 2, 3, 6 and 12 months after UCBT. Early after UCBT, IL-7 and SCF levels inversely correlated with TREC, CD4, CD8 and Treg numbers suggesting that uptake of these cytokines by IL-7R and Kit on T cell progenitors induced their expansion. IL-7 and SCF were also inversely correlated with T cell differentiation into pathogen-specific effectors as determined by CMV-specific, IFN-γ ELISpot. Conversely, VEGF and ANG1 positively correlated with CD4, CD4CD25 and CD4CD45RA numbers. Interestingly, VEGF and ANG1 displayed inverse correlation with SCF and more so with IL-7 at early time points after UCBT, which converted to strong positive correlation (r=0.78, p=0.0004) at 12 months, when T cell recovery had occurred. Our results are consistent with a model of TEC recovery supported by VEGF and ANG1, leading to production and uptake of SCF and IL-7 by T cell progenitors, resulting in their differentiation and expansion.

Prior rituximab correlates with less acute graft-versus-host disease and better survival in B-cell lymphoma patients who received allogeneic peripheral blood stem cell transplantation

Prior therapy with rituximab might attenuate disparate histocompatibility antigen presentation by B cells, thus decreased the risk of acute graft-versus-host disease (GVHD) and improved survival. We tested this hypothesis by comparing the outcomes of 435 B-cell lymphoma patients who received allogeneic transplantation from 1999 to 2004 in the Center for International Blood and Marrow Transplant Research database: 179 subjects who received rituximab within 6 months prior to transplantation (RTX cohort) and 256 subjects who did not receive RTX within 6 months prior to transplantation (No-RTX cohort). The RTX cohort had a significantly lower incidence of treatment-related mortality (TRM) [relative risk (RR) = 0.68; 95% confidence interval (CI), 0.47-1.0; P = 0.05], lower acute grade II-IV (RR = 0.72; 95% CI, 0.53-0.97; P = 0.03) and III-IV GVHD (RR = 0.55; 95% CI, 0.34-0.91; P = 0.02). There was no difference in the risk of chronic GVHD, disease progression or relapse. Progression-free survival (PFS) (RR = 0.68; 95% CI 0.50-0.92; P = 0.01) and overall survival (OS) (RR = 0.63; 95% CI, 0.46-0.86; P = 0.004) were significantly better in the RTX cohort. Prior RTX therapy correlated with less acute GVHD, similar chronic GVHD, less TRM, better PFS and OS.

Blood and Marrow Transplant Clinical Trials Network State of the Science Symposium 2007

Outcomes of hematopoietic cell transplantation are steadily improving. New techniques have reduced transplant toxicities, and there are new sources of hematopoietic stem cells from unrelated donors. In June 2007 the Blood and Marrow Transplant Clinical Trials Network convened a State of the Science Symposium of more than 200 participants in Ann Arbor to identify the most compelling clinical research opportunities in the field. This report summarizes the symposium's discussions and identifies eleven high priority clinical trials that the network plans to pursue over the course of the next several years.

Randomized trial of CD8+ T-cell depletion in the prevention of graft-versus-host disease associated with donor lymphocyte infusion

The application of DLI is limited by the potential development of GVHD. Results of single-arm trials suggest that CD8+ depletion of DLI may reduce the incidence of GVHD while still inducing pathologic and cytogenetic remissions. To test the impact of CD8 depletion on GVHD, we initiated a randomized trial comparing outcome among patients receiving unselected donor lymphocytes or CD8+-depleted cells. DLI was administered to patients with disease in remission to prevent relapse 6 months after T-cell-depleted allogeneic BMT. CD8 depletion was performed with monoclonal antibody and rabbit complement. Donor lymphocytes obtained from the original donor were infused fresh without cryopreservation. Infusions were adjusted so that all patients received 1.0 x 10(7) CD4+ cells/kg. Patients randomized to CD8 depletion received a median of 0.7 x 10(5) versus 32.0 x 10(5) CD8+ cells/kg in the unmanipulated cohort. Six (67%) of 9 patients receiving unselected DLI developed acute GVHD compared with 0 (0%) of 9 recipients of CD8-depleted DLI (P = .009). In the unselected group, 2 patients died while the disease was in remission, and 3 patients had relapses. In the CD8-depleted cohort, there were no toxic deaths and only 1 relapse. Measures of immunologic reconstitution by T-cell receptor excision circle analysis and T-cell receptor spectratyping demonstrated similar patterns of T-cell recovery in both the CD8-depleted and the unselected cohorts. Both groups converted from mixed to full donor hematopoietic chimerism after DLI. Our results indicate that CD8 depletion reduces the incidence of GVHD associated with DLI without adversely affecting conversion to donor hematopoiesis or immunologic recovery.

Incidence of post transplant myelodysplasia/acute leukemia in non-Hodgkin's lymphoma patients compared with Hodgkin's disease patients undergoing autologous transplantation following cyclophosphamide, carmustine, and etoposide (CBV)

Secondary malignancies, particularly myelodysplasia (MDS), are serious events following high dose therapy with autologous stem cell support. We observed a higher frequency of secondary malignancies in patients with Hodgkin's disease (HD) than in patients with non-Hodgkin's lymphoma (NHL) undergoing high dose therapy with the same non-TBI conditioning regimen. Three hundred patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) were treated with cyclophosphamide, carmustine and etoposide and autologous stem cell support from 1986 through 1994. Median follow up of survivors is 3.9 years. Five-year survival is 51% for HD and 48% for NHL. Eleven patients developed second malignancies (9/150 treated for HD vs. 2/150 treated for NHL) a median of 2.4 years from transplantation and 5.2 years from initial diagnosis. Six patients had myelodysplasia or acute leukemia (MDS/AML) and 5 had lymphomas or solid tumors. Actuarial risk of MDS/AML at five years for patients transplanted for non-Hodgkin's lymphoma is 3% (95% CI 0.6-9.6%). HD patients had significantly different pretreatment characteristics than patients with NHL. A Cox model showed that greater number of prior relapses and prior radiation therapy were significant risk factors for the development of MDS/AML. These data suggest that CBV is associated with a lower risk of secondary MDS/AML than TBI containing regimens and that much of the risk is associated with the pre-transplantation therapy. The use of autotransplantation early in the course of therapy for relapsed lymphoma might prevent some cases of MDS/AML.

Relationship of Bcl-2 expression with apoptosis and proliferation in colonic graft versus host disease

Graft versus host disease (GVHD) occurs in up to 75% of patients who have had an allogeneic bone marrow transplant (BMT). However, the pathophysiology of this disorder, including the mechanisms responsible for enhanced apoptosis, are poorly understood. Bcl-2 is a cellular protein known to inhibit apoptosis in a variety of human tissues. Therefore, the aim of this study was to evaluate the expression of Bcl-2 in colonic GVHD and to determine its relationship to cell proliferation and apoptosis in this disease. Routinely processed colonic mucosal biopsy specimens from 47 allogeneic BMT patients with diarrhea were evaluated histologically for the grade of GVHD (0-4) and for the degree of apoptosis (apoptosis index). Immunohistochemical staining for Bcl-2 and MIB-1, a cell proliferation marker, was performed, and the results were correlated with the histological findings and with each other. Normal-appearing colonic mucosal biopsy specimens from 10 age-matched patients with noncolonic diarrhea served as controls. Also evaluated were 13 colonic biopsy specimens from 13 patients with chronic ulcerative colitis (three inactive, four mild chronic-active, six moderately severe chronic active) to test the specificity of our findings. When compared with controls, a slight trend toward increased Bcl-2 expression was noted in patients with high-grade GVHD (grade 3 or 4) (P=.09). However, Bcl-2 expression did not correlate with the degree of apoptosis in these patients. In contrast, the degree of Bcl-2 staining correlated positively with the crypt proliferative rate (P=.04). Furthermore, crypt proliferation was significantly higher in the GVHD patients in comparison with controls (MIB-1 index, 27.7+/-17.1 v 15.6+/-11.4, =.02), and increased progressively with each successively higher grade of GVHD, and with the degree of apoptosis. Similar to GVHD, Bcl-2 expression was increased in biopsy specimens of CUC patients with higher grades of active injury and epithelial regeneration. This immunohistochemical study does not provide support for Bcl-2 in the pathogenesis of GVHD-induced apoptosis in the colon, but instead, indicates that this protein may play a nonspecific role in the generalized response to cellular injury in GVHD.

Cytomegalovirus infection in the colon of bone marrow transplantation patients

The histologic distinction between cytomegalovirus (CMV) infection and graft-versus-host disease (GVHD) in the colon in bone marrow transplantation (BMT) patients relies heavily on the identification of viral inclusions, because the morphologic features of these two diseases are otherwise similar. The aim of this study was to assess (1) the prevalence of colonic CMV infection in BMT patients with the use of DNA in situ hybridization (ISH); and (2) the sensitivity and specificity of light microscopy in establishing a diagnosis of CMV infection in the colon of these patients. Fifty-five colonic mucosal biopsy samples from 50 consecutive allogeneic BMT patients with diarrhea were evaluated histologically for the presence of typical or atypical (suspicious, but not diagnostic) CMV inclusions and, if negative, for the grade of GVHD. CMV DNA ISH analysis was performed on all of the biopsy specimens and was correlated with the histologic and clinical findings. Histologic analysis revealed only one patient with morphologically typical CMV inclusions. Four other cases contained an isolated atypical mesenchymal cell with features considered suspicious, but not diagnostic, for CMV inclusions. All of these five cases exhibited histologic features that were otherwise indistinguishable from GVHD grades 1 to 2. The single case that was histologically positive for CMV was confirmed by DNA ISH. Of the four histologically atypical cases, only one was confirmed to be CMV positive by DNA ISH. Of the remaining 45 patients, 35 had GVHD, 1 had pseudomembranous colitis, 1 had ischemic colitis, and 8 had no abnormalities found. Light microscopic examination is a sensitive method of screening for CMV infection in the colon of BMT patients but is less specific than DNA ISH. CMV infection is an infrequent cause of colitis in our BMT population.

Tacrolimus pharmacokinetics in BMT patients

The pharmacokinetics of tacrolimus following its administration as monotherapy or in combination with corticosteroids or methotrexate to 31 BMT patients are presented. All patients received i.v. tacrolimus initially and were subsequently switched to p.o. dosing. Patients received methotrexate by i.v. bolus on post-transplantation days 1, 3, 6 and 11. Patients were started on i.v. corticosteroids beginning on post-transplantation day 7. The noncompartmental pharmacokinetics of tacrolimus based on whole blood concentrations were determined following the i.v. and p.o. doses and were not different at steady-state compared to a single dose. The mean terminal elimination half-life of tacrolimus was 18.2 h following i.v. administration; the total body clearance was 71 ml/h/kg, the volume of distribution was 1.67 1/kg. Co-administration of methylprednisolone or methotrexate did not significantly alter tacrolimus pharmacokinetics. The p.o. bioavailability was 31-49%. Trough blood concentrations (Cmin) at 0 h (pre-dose) and 12 h (post-dose) correlated well to AUC(0-12)indicating that, as in solid organ transplantation, Cmin was a good index of drug exposure. Correlation at 0 h (r = 0.92) and at 12 h (r = 0.93) indicate that either time point can be used for therapeutic drug monitoring in patient management.

High-dose cyclophosphamide, carmustine, and etoposide with autologous transplantation in Hodgkin's disease: a prognostic model for treatment outcomes

PURPOSE

To identify clinical factors predictive of treatment outcome after high-dose chemotherapy (HDC) for Hodgkin's disease and to develop a prognostic model for progression-free and overall survival.

PATIENTS AND METHODS

102 patients with relapsed or refractory Hodgkin's disease were treated with high-dose cyclophosphamide, carmustine, and etoposide and autologous marrow and/or peripheral blood progenitor cell support. Median follow-up of survivors is 4.1 years (1.8-7.5 years). Factors potentially important for treatment outcome were examined in univariate analysis, and Cox regression with forward selection was performed. A prognostic model was developed.

RESULTS

Poorer progression-free and overall survival were associated with nodular sclerosis histology, abnormal performance status, progressive disease at HDC, more than one extranodal site of disease, and shorter time from initial diagnosis to HDC. These factors and the presence of B symptoms at relapse also predicted for decreased overall survival. Progressive disease immediately prior to HDC, more than one extranodal disease site, and abnormal performance status retained significance for both progression-free and overall survival in multivariate analysis. Progression-free and overall survival are 42% (95% confidence interval, CI, 34 to 53) and 65% (95% CI 54 to 73) at three years. A model based on number of risk factors present divides patients into low, intermediate, and high risk groups with three-year actuarial survival of 82%, 56%, and 19% respectively. Treatment outcome for patients treated with HDC at first chemotherapy relapse was not significantly different from that of the group overall (p > 0.3).

CONCLUSIONS

Asymptomatic patients with Hodgkin's disease involving at most one extranodal site whose disease is controlled by conventional dose chemotherapy or radiation therapy at the time of HDC have good outcomes after this therapy. Presence of increasing numbers of risk factors are associated with poorer outcomes. Results of HDC compare favorably to those of standard dose salvage therapy. These data can be used to estimate likely outcomes in patients undergoing HDC for Hodgkin's disease, to identify potential candidates for innovative therapies, and to evaluate strategies for the optimal use of HDC in Hodgkin's disease.

Flow cytometric surface light chain analysis of lymphocyte-rich effusions. A useful adjunct to cytologic diagnosis

The cytologic diagnoses in 49 body cavity fluids from 46 patients, of whom 30 had a clinical diagnosis of lymphoma or lymphatic leukemia, and 16 patients with benign inflammatory or reactive conditions, were compared to flow cytometric surface immunoglobulin light chain analysis (kappa-lambda analysis [KLA]). The results of both tests were correlated with clinical outcome and all available information from biopsy, autopsy, and additional cell marker studies. When the diagnoses by both cytologic analysis and KLA were in agreement (57.1% of cases), there were no false-negative or false-positive results. Overall, false-positive and false-negative rates were, respectively, 6.1% and 12.2% with cytologic study, and 4.1% and 4.1% with KLA. Sixteen samples were from patients with small lymphocytic lymphoma (CLL) and small cleaved lymphoma, which had a false-negative rate of 37.5% by cytologic study, and only 6.2% by KLA. There was one false-positive result by KLA among the benign effusions. These findings indicate that KLA is a powerful adjunct to the cytologic evaluation of lymphocyte-rich effusions, especially in cases of lymphoproliferative disorders characterized by small lymphocytes, in which the cytologic diagnosis is frequently difficult.

Regulation of cytotoxic T lymphocyte-mediated graft rejection following bone marrow transplantation

Cytotoxic T lymphocytes have been implicated as the effector cell mediating graft rejection following human allogeneic bone marrow transplantation. We have studied a BMT patient who rejected haploidentical T cell-depleted marrow. In vitro studies demonstrated that the circulating lymphocytes were CD3+ and CD8+, of recipient origin, and exhibited selective cytotoxicity against donor-specific class I major histocompatibility complex antigens. Cytotoxicity was inhibited by monoclonal antibodies directed against CD3, CD8, CD2, and lymphocyte function-associated antigen-1 on the T cell, and against MHC class I proteins on the target cell. Furthermore, these circulating cells inhibited the in vitro growth and differentiation of enriched donor bone marrow progenitor cells, an inhibition that was partially reversed by anti-CD3 MAb. Donor-specific recipient-derived CTL may mediate resistance to engraftment, and CTL activity may be inhibited by a number of MAb. The implications of these findings for host preparation and treatment are discussed.

Cholecystokinin elicits the complete behavioral sequence of satiety in rats

The behavior of intact rats and rats with chronic gastric fistulas was observed and scored during a 60-min test period when they were offered liquid diet after 17 hr of food deprivation. Intact rats and rats with closed fistulas displayed a specific behavioral sequence at the end of each meal: They stopped eating, engaged in grooming and exploration for a short time, and then rested or slept. Thus, a fixed behavioral sequence characterizes satiety in the rat. Although the behavioral sequence of satiety was fixed, the cessation of feeding was not a sufficient condition for the appearance of the rest of the sequence: Quinine adulteration of the liquid diet stopped sham feeding but did not elicit the complete sequence. Intraperitoneal injection of the intestinal hormone cholecystokinin during sham feeding, however, elicited the complete sequence of satiety. The observation that cholecystokinin not only stops feeding but elicits the complete sequence of satiety supports our hypothesis that endogenous cholecystokinin is a satiety signal for the rat.