Acanthamoeba castellani encephalitis following partially mismatched related donor peripheral stem cell transplantation.

We describe a case of Acanthamoeba encephalitis in a 45-year-old Caucasian male with acute myelogenous leukemia, who was 140 days status post partially mismatched related donor peripheral blood stem cell transplant. The patient had been transplanted with a highly T-cell-depleted graft, and was not taking any immunosuppressive drugs, and had no history of graft-versus-host disease. He complained of nausea, vomiting, and occasional episodes of confusion; he also had a chronic cough since transplantation. Physical examination was unremarkable except for orthostatic hypotension. Neurologic examination was within normal limits. Laboratory values including electrolytes, white blood cells and platelet counts were normal. Computed tomographic scan of the brain showed a pansinusitis and a hyperdense lesion along the corona radiata suggestive of a fungal abscess. Magnetic resonance imaging showed multifocal areas with mass effect in the posterior fossa and parietal and occipital lobes. The patient had worsening respiratory failure and died three days after admission. At autopsy, specific immunofluorescent staining identified Acanthamoeba castellani in the brain and lungs.

Rapid hematopoietic engraftment following fractionated TBI conditioning and transplantation with CD34(+) enriched hematopoietic progenitor cells from partially mismatched related donors.

Nineteen adult patients with poor-risk hematologic malignancy received T cell-depleted (TCD) hematopoietic progenitor cell (HPC) transplant from partially mismatched related donors (PMRD). The preparative regimen (FITFA) included fractionated TBI, thiotepa, fludarabine, and horse (n = 3) or rabbit (n = 16) anti-thymocyte anti-sera (ATG). GVHD prophylaxis consisted of TCD by positive/negative selection using the Isolex 300i system and pre-transplant ATG with no post-transplant immunosuppression. The mean number (+/-s.d.) of transplanted CD34(+) and CD3(+) cells were 8.9 x 10(6)/kg +/-4.3 (range 2.6-19.3) and 1.4 x 10(4)/kg +/-1.2 (range 0.3-4.6) respectively. Seventeen patients evaluable for neutrophil engraftment achieved an ANC >0.5 x 10(9)/l at a median of 12 days (range 9-27), with evidence of full donor chimerism. Thirteen patients died of the following causes: relapse (n = 6), infections (n = 5), interstitial pneumonia (n = 1), and unknown causes (n = 1) None of the recipients of rabbit ATG required therapy for acute or chronic GVHD. Five patients are alive and disease-free at a median time of 303 days post transplant (range 100-660). The FITFA preparative regimen using fractionated TBI is well tolerated and is sufficiently immunosuppressive to allow rapid and stable donor origin hematopoietic engraftment without 'mega' doses of CD34(+) cells. Combination of stringent ex vivo TCD and pre-transplant ATG is effective GVHD prophylaxis.

Larger numbers of CD4(bright) dendritic cells in donor bone marrow are associated with increased relapse after allogeneic bone marrow transplantation.

Relapse is the major cause of death after allogeneic bone marrow transplantation (BMT). This study tested the hypothesis that the numbers of donor mononuclear cells, lymphocytes, and CD34(+) cells influence relapse and event-free survival (EFS) after BMT. The study population consisted of 113 consecutive patients with hematologic malignancies who underwent non-T-cell-depleted BMT from HLA-matched siblings. Sixty-four patients had low-risk diagnoses (ALL/AML CR1, MDS RA/RARS, and CML CP1); 49 patients had high-risk diagnoses (all others). CD34(+) cells, T cells, B cells, natural killer cells, monocytes, and a rare population of CD3(-), CD4(bright) cells in the allografts were measured by flow cytometry. The CD3(-), CD4(bright) cells in bone marrow had the same frequency and phenotype as CD123(bright) type 2 dendritic cell (DC) progenitors, and they differentiated into typical DCs after short-term culture. Cox regression analyses evaluated risk strata, age, gender, and the numbers of nucleated cells, CD3(+) T cells, CD34(+) hematopoietic cells, and CD4(bright) cells as covariates for EFS, relapse, and nonrelapse mortality. Recipients of larger numbers of CD4(bright) cells had significantly lower EFS, a lower incidence of chronic graft-versus-host disease (cGVHD), and an increased incidence of relapse. Recipients of larger numbers of CD34(+) cells had improved EFS; recipients of fewer CD34(+) cells had delayed hematopoietic engraftment and increased death from infections. In conclusion, the content of donor CD4(bright) cells was associated with decreased cGVHD and graft-versus-leukemia effects in recipients of allogeneic bone marrow transplantation, consistent with a role for donor DCs in determining immune responses after allogeneic BMT.

Allogeneic bone marrow transplantation with matched unrelated donors for patients with hematologic malignancies using a preparative regimen of high-dose cyclophosphamide and fractionated total body irradiation.

Allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling donor is effective therapy for patients with bone marrow failure states and those with hematologic malignancies. However, only a minority of them will have an HLA-identical sibling donor; unrelated donors, matched or partially mismatched, have been used successfully for patients lacking a related donor. Even though results with allogeneic transplants using unrelated donors are encouraging, the incidence of complications including graft-versus-host disease (GVHD) and graft rejection or late graft failure is increased compared to identical sibling transplants. The combination of cyclophosphamide and total body irradiation (TBI) has been used as an effective preparative regimen for allogeneic transplants, however, the total dosage and dosing schedule of both the cyclophosphamide and TBI has varied significantly among studies. To decrease the rate of graft rejection and late graft failure with volunteer donors, we evaluated a preparative regimen of high-dose cyclophosphamide (200 mg/kg over 4 consecutive days, days -8, -7, -6, -5) followed by fractionated TBI (1400 cGy administered in eight fractions over 4 days, days -4, -3, -2, -1). GVHD prophylaxis included FK506 and methotrexate. From July 1993 to January 1996, 43 adult patients, median age 38 years (range 18-58 years), were treated with this preparative regimen. Seventeen patients had low-risk disease and 26 had high-risk disease. Thirty-one donor/recipient pairs were matched for HLA-A, -B, and -DR by serology and molecular typing. Seven additional pairs were minor mismatched at the HLA-A or HLA-B loci. Four other donor/recipient pairs were HLA-A,-B, and -DR identical by serology but allele mismatched at either DRB1 or DQB. Forty patients were evaluable for myeloid engraftment. Engraftment occurred in all 40 patients at a median of 19 days. There were no cases of graft rejection or late graft failure. Nephrotoxicity was the primary adverse event with 26 patients (60%) experiencing a doubling of their creatinine. Hepatic veno-occlusive disease occurred in seven patients, six of whom had high-risk disease. All patients who had relapsed or refractory disease prior to BMT achieved a complete remission following BMT. Six patients transplanted for high-risk disease relapsed a median of 377 days post-BMT. None of the patients with low-risk disease have relapsed following transplant; the Kaplan-Meier survival for those patients with low-risk disease is 62% and 37% for those patients transplanted with high-risk disease (P = 0.0129). The median Karnofsky performance status is 100% (range 70-100%). Therefore, a preparative regimen of high-dose cyclophosphamide and fractionated TBI is an acceptable regimen for patients receiving an allograft from unrelated donors.

Detection of a dormant 20q- leukemia clone in bone marrow cultures with hematopoietic growth factors: implications for secondary leukemia post-transplant.

A patient developed secondary acute myelogenous leukemia with a 20q- marker chromosome abnormality six years following chemotherapy and radiation for Hodgkins disease (HD). Routine cytogenetics on the bone marrow which had been harvested and cryopreserved immediately following completion of initial therapy for HD showed no cytogenetic abnormality. However, a 20q- clonal marker was detected after culturing bone marrow with hematopoietic growth factors (HGF). The marrow was used successfully for an autotransplant. Post-transplant, the 20q- marker was again detected in HGF cultured samples. The patient relapsed at 165 days post-transplant with the 20q- marker and trisomy 21. These data suggest that standard cytogenetic assays may not detect abnormal clones which can cause leukemia post-transplant.

Successful engraftment after primary graft failure in aplastic anemia using G-CSF mobilized peripheral stem cell transfusions.

A 19-year-old male underwent allogeneic BMT for severe aplastic anaemia (SAA) from his HLA- and blood group-identical sister. He was conditioned with cyclophosphamide (CY) and single fraction total lymphoid irradiation (TLI). GVHD prophylaxis consisted of FK506 and a short course of methotrexate. The patient failed to achieve durable trilineage hematopoietic engraftment. There was no significant myeloid response to GM-CSF or G-CSF. Evaluation of FACS-sorted peripheral T cells from the patient by fluorescence in situ hybridization (FISH) revealed mixed chimerism (44% host origin). Fifty-three days after the first BMT, he was treated with G-CSF primed, unmanipulated PBSC transfusions (5.28 x 10(8)/kg mononuclear, 4.28 x 10(6)/kg CD34+, 292.51 x 10(6)/kg CD3+ cells) from his original donor without reconditioning. FK506 was continued at the same dose. Neutrophil recovery to 0.5 x 10(9)/l and platelet engraftment to 20 x 10(9)/l was achieved 11 and 27 days following the first dose of allogeneic PBSC transfusion, respectively. On day 23 a repeat FISH on the patient's sorted peripheral T lymphocytes revealed 91% donor origin T cells. The patient is currently well with a stable engraftment 6 months following allogeneic PBSC transfusion, with no signs of acute of chronic GVHD.

Treatment of hepatic veno-occlusive disease with low-dose tissue plasminogen activator: impact on coagulation profile.

An 18-year-old white male developed severe hepatic veno-occlusive disease (VOD) during an autologous bone marrow transplant for primary refractory nodular sclerosing Hodgkin's disease. As a result of VOD-induced hepatic dysfunction, coagulation studies revealed depression of vitamin K dependent procoagulant factor VII. Intravenous recombinant tissue plasminogen activator 20 mg over h on 4 consecutive days and continuous heparin infusion (1000 unit bolus followed by 150 units/kg/day) resulted in rapid reversal of the VOD syndrome. During treatment, procoagulant factors II, VII, IX and X levels increased indicating the return of hepatic synthesizing capacity. Factor V levels, which were elevated pre-therapy, also rose dramatically. Plasma antigen levels of protein C, a natural anticoagulant, remained severely depressed. No clinical evidence of bleeding and only minimal systemic fibrinolysis was noted. Despite concerns regarding the use of lytic therapy in a thrombocytopenic post-BMT patient, serial measurements of coagulation parameters during severe VOD suggested that low dose rt-PA improved portions of the systemic hemostatic profile.

Phase II trial of topotecan in advanced or metastatic adenocarcinoma of the pancreas.

PURPOSE: A phase II trial of topotecan, an inhibitor of topoisomerase I, was conducted in patients with advanced or metastatic adenocarcinoma of the pancreas to determine the activity and toxicity of topotecan. PATIENTS AND MATERIALS: 35 patients, previously untreated with chemotherapy, received topotecan 1.5 mg/m2/d for five days intravenously and repeated every 21 days. Patients were assessed for response after 3 cycles. Those with either clinical response or stable disease received additional cycles of the drug until toxicity developed or disease progression occurred. RESULTS: Among 30 patients evaluable for response there were no complete responses and 3 partial responses (10%) for a total response rate of 10% (95% confidence interval = 0-20.6%). Stable disease for at least eight weeks was seen in 11 patients (36%). Median survival was 19 weeks (95% confidence interval 11 to 26 weeks). Therapy was generally well tolerated, with reversible granulocytopenia being the most common toxicity. CONCLUSION: Topotecan given on a 5 day, short infusion schedule, demonstrated limited activity in pancreatic carcinoma with minimal toxicity. Further exploration of topotecan in pancreatic carcinoma using different dosing schedules is warranted.

Techniques for evaluating the cause of bleeding in the ICU. Diagnostic clues and keys to interpreting hemostatic tests.

Begin by obtaining both a bleeding and a family history to help ascertain whether the disorder is acquired or inherited. On physical examination, look for multiple bleeding sites or profuse bleeding; these can indicate a systemic bleeding diathesis. Order hemostatic tests. Prolonged aPTT points to a defect in the intrinsic or common coagulation pathway; prolonged PT, to a defect in the extrinsic or common pathway. Thrombin time is abnormal when hypofibrinogenemia, afibrinogenemia, or thrombin inhibitors are present. Bleeding time is prolonged in thrombocytopenia, platelet dysfunction, severe hypofibrinogenemia, and von Willebrand's disease. Factor assays also may be needed to further define the defect.

Phase II trial of PALA and 6-methylmercaptopurine riboside (MMPR) in combination with 5-fluorouracil in advanced pancreatic cancer.

The biochemical modulators PALA, an inhibitor of aspartate transcarbamylase which depletes uridine nucleotide pools, and 6-methylmercaptopurine riboside (MMPR) which inhibits purine metabolism, selectively potentiate the antitumor activity of 5-fluorouracil (5-FU) in preclinical models. Based on a phase I trial of this combination, we performed a phase II trial in patients with advanced pancreatic cancer. PALA 250 mg/m2 was administered i.v. on day 1, followed 24h later by MMPR 150 mg/m2 as a bolus i.v. injection, and 5-FU 2300 mg/m2 by 24h infusion. Treatments were repeated weekly. Seventeen patients, all previously untreated with chemotherapy, were entered, of whom 14 are evaluable for response. Toxicity > or = grade 2 included nausea (6/17), vomiting (4/17), diarrhea (3/17), stomatitis (5/17), and neurotoxicity (2/17). Among 14 evaluable patients there were no partial responses, and two patients with stable disease. Pretreatment with PALA and MMPR is insufficient to enhance the activity of 5-FU in pancreatic cancer.