Biomedical subjects
Publications and source records attributed to B G Gordon.
A discussion of the impact of escalating regulatory requirements is provided, from the point of view of the administration of the institutional review board of an academic institution, and from clinical investigators who conduct studies at that same institution. Current and anticipated future issues are discussed.
Bone marrow transplantation (BMT) for severe combined immunodeficiency (SCID) with human leukocyte antigen (HLA)-identical sibling donors but no pretransplantation cytoreduction results in T-lymphocyte engraftment and correction of immune dysfunction but not in full hematopoietic engraftment. A case of a 17-month-old girl with adenosine deaminase (ADA) deficiency SCID in whom full hematopoietic engraftment developed after BMT from her HLA-identical sister is reported. No myeloablative or immunosuppressive therapy or graft-versus-host disease (GVHD) prophylaxis was given. Mild acute and chronic GVHD developed, her B- and T-cell functions became reconstituted, and she is well almost 11 years after BMT. After BMT, repeated studies demonstrated: (1) Loss of a recipient-specific chromosomal marker in peripheral blood leukocytes (PBLs) and bone marrow, (2) conversion of recipient red blood cell antigens to donor type, (3) conversion of recipient T-cell, B-cell, and granulocyte lineages to donor origin by DNA analysis, and (4) increased ADA activity and metabolic correction in red blood cells and PBLs.
PURPOSE: To determine the treatment outcome and clinical factors that are of prognostic significance for children and adolescents with relapsed or refractory Hodgkin's disease (HD) who received treatment with high-dose chemotherapy and autologous hematopoietic stem-cell transplantation (HSCT). PATIENTS AND METHODS: Fifty-three consecutive children and adolescents 21 years of age or younger with relapsed or refractory HD underwent HSCT. RESULTS: At day 100 after transplantation, 29 patients (55%) were in a complete remission or maintained a continuous complete response, six (11%) had a partial response, and 11 (21%) failed to respond or had progressive disease. The failure-free survival (FFS) at 5 years was 31%, and overall survival was 43%. Twenty-one patients died of progressive HD, and nine died secondary to transplantation-related complications, including two secondary leukemias. Prognostic factors important for FFS were normal pretransplantation lactate dehydrogenase levels (5-year FFS = 42%), compared with patients with elevated LDH levels (5-year FFS = 0%) (P < .001), and disease sensitivity at the time of HSCT with FFS in untreated relapse, sensitive disease, and resistant disease 44%, 35%, and 9%, respectively (P = .06). There was no statistically significant difference in FFS or overall survival between age subgroups that were analyzed (< 13, 13 to 18, 19 to 21) or in comparison with an adult cohort. CONCLUSION: HSCT is an effective treatment modality that can result in long-term cures and should be considered for children and adolescents with relapsed HD.
An HPLC assay for etoposide in human serum was developed. Serum, spiked with podophyllotoxin (internal standard), was treated with sodium dodecyl sulphate prior to solid phase extraction. Analysis was performed on a 300x3.9 mm Bondclone 10 C18 column coupled with a fluorometric detector (lambda(ex) 230 nm, lambda(em) 330 nm). The retention times for etoposide and podophyllotoxin were 14 and 28 min respectively. The range of assay was 0.5 to 20 microg/ml with a detection limit of 0.2 microg/ml. This assay is suitable for use in clinical studies with etoposide.
High-dose therapy and allogeneic matched sibling bone marrow transplantation (BMT) is considered to be the treatment of choice for children with relapsed acute lymphoblastic leukemia (ALL), or for children with acute myeloid leukemia (AML) in first remission. However, the rate of bone marrow relapse after transplant for either of these diseases remains high. In this study, we assessed the efficacy and toxicity of high-dose cytosine arabinoside and total body irradiation (TBI) followed by allogeneic BMT, for children with acute leukemia or myelodysplastic syndrome (MDS). Sixty-five pediatric patients underwent allogeneic related (n = 57) or unrelated (n = 8) BMT. Twenty-seven were transplanted for ALL in second remission (CR2), and 16 for AML in first remission (CR1). The other 22 were high risk patients: six were transplanted for ALL in third remission (CR3), two for AML in CR2, two for myelodysplastic syndrome (MDS) and 12 for acute leukemia in relapse. Patients were prepared with cytosine arabinoside 3000 mg/m2 per dose twice daily for 6 days followed by 12000 cGy TBI as 200 cGy fractions twice daily for 3 days. Minimum follow-up is 21 months. Five-year event-free survival (EFS) and the actuarial relapse rate is 59 and 14% for patients with ALL in second remission, and 38 and 14+% for patients with AML in first remission. Twelve patients have relapsed (three are alive in remission after testicular or marrow relapse) and 28 have died of other causes. Acute GVHD with or without infection was the cause of death in 11 patients. Ten of the 11 patients who died of acute GVHD were considered at 'high risk' for GVHD (inadequate GVHD prophylaxis, or mismatched family donor or a matched unrelated donor). Toxicities in the immediate post-BMT period included diarrhea, oropharyngeal mucositis and conjunctivitis. Significant late toxicities included short stature, avascular necrosis of bone, and poor school performance (most often in patients who had received prior cranial irradiation). Our conclusions are that high-dose Ara-C and TBI followed by allogeneic bone marrow transplantation is effective therapy for children in second complete remission of their acute leukemia. However, significant late toxicities occur, and it is clear that more effective, less toxic therapies are necessary for these patients.
The boundary between therapy and research may at times be difficult to distinguish, and it is, therefore, important for health care professionals to recognize when a clinical activity should be properly classified as research. Research may be subject to federal regulations which require advance review and approval by an Institutional Review Board (IRB) in order to protect the rights and welfare of patients who serve as human subjects. This paper will discuss the criteria health care professionals can use to distinguish between therapy, innovative therapy, and therapeutic or clinical research.
Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.
Veno-occlusive disease (VOD) of the liver is a common complication of BMT and is accompanied by reduced levels of natural anticoagulants and by multi-organ dysfunction. We describe two cases of clinical VOD developing after autologous BMT and accompanied by ultrasonographic features of reversed portal venous flow. In both cases the patients had decreased levels of antithrombin (AT). Once the diagnosis of VOD was made, these patients were treated with tissue plasminogen activator (tPA) and continuous infusion AT. Each patient had radiographic and clinical resolution of VOD with the therapy. This novel treatment appears to have reversed the course of VOD without the increased risk of bleeding seen in the use of heparin therapy.
OBJECTIVE: To define the frequency and outcome of organ dysfunction in bone marrow transplantation (BMT) and to determine if patients with organ dysfunction have lower levels of protein C (PC) and/or antithrombin III (ATIII) than those without organ dysfunction. DESIGN: Inception cohort of patients undergoing BMT, followed for 28 days, until hospital dismissal, or until death. SETTING: Bone marrow transplant department of a university hospital. PATIENTS: A total of 199 consecutive patients admitted for BMT. INTERVENTIONS: Standard supportive care was given to all patients. MAIN OUTCOME MEASURES: Definitions of organ dysfunction were arrived at prior to beginning the study. They include pulmonary, central nervous system (CNS), hepatic, and renal dysfunction. Protein C and ATIII levels were measured prior to beginning the preparative regimen and weekly thereafter. RESULTS: Single organ dysfunction, manifesting as pulmonary, CNS, or hepatic dysfunction, occurred in 93 (48.5%) of the 199 patients and was a strong predictor of multiple organ dysfunction syndrome (MODS) and death. Death occurred in 14 (7.0%) of the patients. Cause of death was precisely identified in only four patients. Low levels of either PC or ATIII were associated with death and pulmonary, CNS, and hepatic dysfunction. Multivariate analysis showed ATIII and PC levels were associated with single organ dysfunction independent of the type of transplant, the type of preparative regimen, and the presence of bacteremia. CONCLUSIONS: Single organ dysfunction during BMT is a marker for a systemic abnormality that has a high likelihood of progressing to MODS, similar to that seen in other critically ill patient populations. MODS is the leading cause of death in series of BMT patients. Low levels of ATIII and PC are markers of and may be involved in the pathogenesis of MODS in BMT.
Antithrombin is a naturally-occurring anticoagulant protein. Congenital deficiency of this protein predisposes to thrombotic complications. Acquired deficiency of antithrombin occurs in a variety of clinical circumstances, including hematopoietic stem cell transplantation (HSCT), and is associated with multiorgan failure and death in these situations. Normalization of antithrombin levels by infusion of concentrates of this protein has been found to be beneficial in many of these situations, but has not been routinely used in HSCT. Before antithrombin concentrates can be widely recommended in HSCT, its pharmacokinetics at various phases of the transplant process must be defined to allow estimation of the proper dose and dosing interval. To this end, the recovery and half-life of antithrombin concentrate was determined prior to and 7, 14 and 28 days after beginning the preparative regimen in nine patients with lymphoma undergoing HSCT. The recovery of the infused material was constant during the transplant hospitalization, averaging 2.0% per unit/kg. The half-life, however, dropped significantly during the latter half of the transplant procedure. The half-lives pre-chemotherapy and on day 7 were similar and averaged 20.4 h. On days 14 and 21 the the half-lives were significantly lower at 12.2 and 15.5 h, respectively. The drop in half-life during the transplant process will require antithrombin concentrate to be given more frequently during this time to maintain constant antithrombin levels.
Transient myeloproliferative disorder (TMD) and subsequent acute myeloid leukemia (AML) occur with increased frequency in infants and children with Down syndrome. TMD can also occur in phenotypically normal newborns. We describe the second case of a non-Down syndrome child with TMD who subsequently developed AML. Trisomy 21 karyotypic was restricted to hematopoietic cells in the blood and bone marrow. No other karyotypic abnormalities were found. Leukemic blasts showed megakaryoblastic features with immunophenotyping. This case shows that TMD in a child without Down syndrome may not be entirely benign. Close follow-up is warranted.
Although PTCL in children, as in adults, has a spectrum of clinical, morphologic, cytogenetic and immunologic features, there are several significant differences in these features between children and adults. Our data show that CD30 expression is much more common in pediatric PTCL than is reported in adult PTCL. Furthermore, the majority of children with CD30-positive PTCL do not have tumors with anaplastic large cell histology. Our data also suggest that the t(2;5) is not a specific marker of anaplastic large cell lymphoma in childhood. The likelihood of cure for children with PTCL is unclear, predominantly because of the lack of large numbers of pediatric patients with this less common entity. As with other NHL, we expect that treatment with conventional dose chemotherapy following relapse will be unsuccessful in most cases. Although the data are preliminary, it appears that high dose chemoradiotherapy followed by hematopoietic stem cell transplantation is an effective therapy in these patients. We have been particularly successful with a regimen based on thioTEPA, VP-16 and total body irradiation, but other regimens may also be efficacious. Further studies of this interesting group of tumors are clearly needed.
BACKGROUND: Peripheral T-cell lymphoma (PTCL), although the most common T-cell lymphoma in adults, is relatively rare in childhood, and only small series have been reported. METHODS/RESULTS: Twenty-two cases of PTCL were studied that occurred in patients 18 months to 20 years of age. Nine were seen when the condition was diagnosed, and the other 13 were referred after they had relapses. The stage at diagnosis was I or II (45%), III (41%), and IV (14%). Patients with Stage IV disease were younger than those with Stage I or II disease (2.5 versus 14.8 years, P = 0.04). Twelve patients had extranodal disease when the diagnosis was made; the skin was the most common site. Ten tumors were classified as diffuse large cell type; five, as diffuse anaplastic large cell type; and seven, as diffuse mixed cell type. Twenty of the 21 tumors tested were CD30 (Ki-1 or Ber-H2) antigen positive. Of the nine patients seen when the diagnosis was made and treated by the authors, three had a relapse (median, 12 months), a 2-year relapse-free survival (RFS) rate of 61%. For the total group, the RFS was longer for patients older than 12 years of age compared with those who were younger (20 versus 12 months, P = 0.05). Overall, six patients remained in their first complete remission. Sixteen patients had a relapse, and 13 of these underwent bone marrow transplantation (BMT). Six of these remained in complete remission (median, 18 months after BMT). Overall, only 6 of 22 patients died (median survival, > 60 months). CONCLUSION: It was concluded that aggressive therapy, including BMT for relapses, can provide prolonged disease control in most children with PTCL.
Patients undergoing hematopoietic stem cell transplantation (HSCT) are dependent on i.v. vitamin K supplementation to prevent deficiency. Vitamin K deficiency may contribute to the development of a hypercoagulable state by limiting hepatic synthesis of fully functional carboxylated anticoagulant protein C (PC). The ratio of PC antigen (CAg) to PC measured in a clot-based functional assay (CFx) reflects the degree to which PC is carboxylated. The 133 patients undergoing HSCT received vitamin K 10 mg per week (low dose, 101 patients) or 5 mg per day (high dose, 32 patients) i.v. as their sole exogenous source of vitamin K. CAg and CFx were assayed before HSCT preparative regimen and again 14 days later. CAg and CFx fell significantly in both groups from day 0 to day 14 but there were no differences between the low-dose and high-dose vitamin K groups. For both groups, CAg correlated strongly with CFx at day 14 (p = 0.0001). At day 14, the CAg/CFx ratio for the low-dose group was significantly greater than for the high-dose group (1.26 +/- 0.4 vs 1.09 +/- 0.1, p < 0.0002), suggesting that low-dose patients had a higher proportion of incompletely carboxylated PC. The CAg/CFx ratio at day 14 correlated with serum albumin for the high-dose group (p = 0.05), but not the low-dose group (p = 0.09), suggesting that the change in ratio in the low-dose group was not simply due to a lack of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
A decrease in levels of circulating anticoagulant protein C has been shown to occur following autologous BMT, and this deficiency may contribute to a hypercoagulable state placing patients at risk for thromboembolic events. We report four patients who suffered a variety of thrombotic complications following BMT (non-bacterial thrombotic endocarditis, superior vena cava thrombosis, thrombotic stroke, purpura fulminans, small bowel infarction secondary to diffuse microvascular thrombosis), which were preceded by or temporally related to decreased levels of protein C. Treatment with fresh frozen plasma (FFP) led to slight, temporary increases in protein C levels but infusions of FFP did not prevent either death or extension of the thrombus in these four cases, suggesting the need for higher protein C doses and/or concomitant anticoagulation. Though no direct causal relationship between these thrombotic complications and the protein C deficiency can be proved, a generalized hypercoagulable state caused by protein C deficiency may have contributed to the development, severity or progression of these complications.
We report nine children with relapsed (n = 8) or high-risk (n = 1) peripheral T-cell lymphoma (PTCL) who underwent autologous (n = 6) or allogeneic (n = 3) bone marrow transplantation (BMT). These children received transplants as part of a prospective phase I/II study of thioTEPA (TT) and total body irradiation (TBI) with escalating doses of VP-16. The median age of these patients at time of BMT was 6.5 years (range 2.5 years to 14 years). Three were transplanted with active disease after failing salvage chemotherapy. Of the other six, one was transplanted in first complete remission (CR) and five in second or subsequent CR. Of these nine patients, eight are free of disease a median of 25 months after BMT (range, 6 to 48 months), with an estimated 2-year relapse-free survival (RFS) of 89%. Six of these eight patients have been followed for 12 or more months after BMT, and in each their current remission exceeds their longest previous remission duration. The toxicity of the TT/TBI +/- VP-16 regimens was significant but manageable, predominantly consisting of severe mucositis. For a comparison, we reviewed retrospective data on the six additional children and adolescents with PTCL who underwent BMT during the 3-year period preceding this phase I/II study. The median age at BMT of these six patients was 19 years (range 15.5 years to 20 years). These patients were prepared for BMT with a variety of other regimens. One had no response to BMT and the other five relapsed at 1.5 to 5 months after BMT (median, 3 months) with an RFS of 0%. Our data suggest that thioTEPA plus TBI, with or without VP-16, is an effective preparative regimen for BMT for young patients with relapsed or high-stage PTCL and leads to prolonged RFS.
We examined the effect of catecholaminergic neurotoxin 6-hydroxydopamine (6-OHDA) on murine committed megakaryocyte progenitor cells, the megakaryocyte-colony forming unit (CFU-Meg). More mature cells of the megakaryocyte series have the capacity for active uptake of catecholamines, and we speculated that the CFU-Meg would also take up 6-OHDA and be selectively killed. CFU-Meg were much more sensitive to the effects of this agent than were granulocyte-macrophage colony forming units (CFU-GM) or spleen-colony forming units. Co-incubation with catalase, which would destroy hydrogen peroxide generated extracellularly by the autoxidation of 6-OHDA, ablated 6-OHDA toxicity towards CFU-GM, but also significantly reduced the effect on CFU-Meg. Mazindol, a selective dopamine uptake inhibitor did not alter 6-OHDA effect on either CFU-Meg or CFU-GM. Finally, CFU-Meg were no more sensitive to incubation with hydrogen peroxide than were CFU-GM. These data suggest that CFU-Meg, unlike their more mature progeny, do not actively concentrate 6-OHDA, and the excess toxicity of this agent towards CFU-Meg is probably due to increased sensitivity to autoxidation products of 6-OHDA, other than hydrogen peroxide, generated extracellularly.
We have performed bone marrow transplants on four children with severe aplastic anemia who lacked an human leukocyte antigen (HLA)-identical sibling donor. Patients were prepared with cyclophosphamide and 600 cGy fractionated total body irradiation, and then received marrow from a parent donor mismatched for one (two patients), two (one patient), or three (one patient) HLA antigens. All four patients engrafted. One died early of acute graft-versus-host disease. The three others showed sustained complete hematopoietic reconstitution. Two are alive and hematologically normal 43-87 months after transplant. Both have had acute and chronic graft-versus-host disease (CGVHD), and one of the two remains on immunosuppressive drugs. The fourth died at 48 months after transplant of CGVHD. The previous experience with HLA-incompatible marrow transplants is reviewed, and the rationale for this preparative regimen is discussed. Cyclophosphamide and 600 cGy fractionated total body irradiation is an effective preparative regimen for children with severe aplastic anemia receiving transplants from HLA-nonidentical parental donors, allowing engraftment and full hematologic reconstitution.