A study of disseminated intravascular coagulation in acute leukemia reveals markedly elevated D-dimer levels are a sensitive indicator of acute promyelocytic leukemia.

INTRODUCTION: While the presence of disseminated intravascular coagulation (DIC) has been implicated in worse clinical outcome in acute leukemia, the relationship between different subtypes of acute leukemia and the clinicopathologic features of DIC has not been systematically well studied. METHODS: In this study, we retrospectively reviewed 149 cases of newly diagnosed acute leukemia and assessed the utility of evaluating red blood cell morphologic features, and coagulation parameters in determining the presence of DIC as well as differentiating subtypes of acute leukemia. RESULTS: Review of our cohort demonstrates a novel finding, that elevated D-dimer concentrations ≥19 000 ng/mL fibrinogen equivalent units (FEU) are a sensitive diagnostic indicator of acute promyelocytic leukemia (APL) with moderate specificity, sensitivity 96%, specificity 92% in acute leukemia subtyping. Similar to other studies, APL showed an increased incidence of DIC (P < 0.01) compared to other subtypes of acute leukemia. Surprisingly, the presence of schistocytes on the peripheral blood smear was not a statistically significant indicator of DIC, sensitivity of 36% and specificity of 89%. Finally, the presence of DIC was not a significant indicator of poorer prognosis amongst all patients with AML. CONCLUSION: Overall we identify elevated D-dimer concentrations ≥19 000 ng/mL FEU are a sensitive indicator of acute promyelocytic leukemia (APL), with a sensitivity of 96% and specificity of 92% in the subtyping of acute leukemias, and that the presence of schistocytes in peripheral blood smears is not a diagnostically sensitive screening test for DIC with a sensitivity of 36%.

Isocitrate dehydrogenase mutations in myeloid malignancies.

Alterations to genes involved in cellular metabolism and epigenetic regulation are implicated in the pathogenesis of myeloid malignancies. Recurring mutations in isocitrate dehydrogenase (IDH) genes are detected in approximately 20% of adult patients with acute myeloid leukemia (AML) and 5% of adults with myelodysplastic syndromes (MDS). IDH proteins are homodimeric enzymes involved in diverse cellular processes, including adaptation to hypoxia, histone demethylation and DNA modification. The IDH2 protein is localized in the mitochondria and is a critical component of the tricarboxylic acid (also called the 'citric acid' or Krebs) cycle. Both IDH2 and IDH1 (localized in the cytoplasm) proteins catalyze the oxidative decarboxylation of isocitrate to α-ketoglutarate (α-KG). Mutant IDH enzymes have neomorphic activity and catalyze reduction of α-KG to the (R) enantiomer of 2-hydroxyglutarate, which is associated with DNA and histone hypermethylation, altered gene expression and blocked differentiation of hematopoietic progenitor cells. The prognostic significance of mutant IDH (mIDH) is controversial but appears to be influenced by co-mutational status and the specific location of the mutation (IDH1-R132, IDH2-R140, IDH2-R172). Treatments specifically or indirectly targeted to mIDH are currently under clinical investigation; these therapies have been generally well tolerated and, when used as single agents, have shown promise for inducing responses in some mIDH patients when used as first-line treatment or in relapsed or refractory AML or MDS. Use of mIDH inhibitors in combination with drugs with non-overlapping mechanisms of action is especially promising, as such regimens may address the clonal heterogeneity and the multifactorial pathogenic processes involved in mIDH myeloid malignancies. Advances in mutational analysis have made testing more rapid and convenient, and less expensive; such testing should become part of routine diagnostic workup and repeated at relapse to identify patients who may benefit from treatments that target mIDH.

Pharmacological targeting of miR-155 via the NEDD8-activating enzyme inhibitor MLN4924 (Pevonedistat) in FLT3-ITD acute myeloid leukemia.

High levels of microRNA-155 (miR-155) are associated with poor outcome in acute myeloid leukemia (AML). In AML, miR-155 is regulated by NF-κB, the activity of which is, in part, controlled by the NEDD8-dependent ubiquitin ligases. We demonstrate that MLN4924, an inhibitor of NEDD8-activating enzyme presently being evaluated in clinical trials, decreases binding of NF-κB to the miR-155 promoter and downregulates miR-155 in AML cells. This results in the upregulation of the miR-155 targets SHIP1, an inhibitor of the PI3K/Akt pathway, and PU.1, a transcription factor important for myeloid differentiation, leading to monocytic differentiation and apoptosis. Consistent with these results, overexpression of miR-155 diminishes MLN4924-induced antileukemic effects. In vivo, MLN4924 reduces miR-155 expression and prolongs the survival of mice engrafted with leukemic cells. Our study demonstrates the potential of miR-155 as a novel therapeutic target in AML via pharmacologic interference with NF-κB-dependent regulatory mechanisms. We show the targeting of this oncogenic microRNA with MLN4924, a compound presently being evaluated in clinical trials in AML. As high miR-155 levels have been consistently associated with aggressive clinical phenotypes, our work opens new avenues for microRNA-targeting therapeutic approaches to leukemia and cancer patients.

Assessment of extended-spectrum ß-lactamase, KPC carbapenemase and porin resistance mechanisms in clinical samples of Klebsiella pneumoniae and Enterobacter spp.

The emergence and spread of resistance mechanisms in Gram-negative bacilli has complicated the treatment of serious nosocomial infections. Current automated systems for detection of Klebsiella pneumoniae carbapenemase (KPC)-producing isolates are unreliable. One possible straightforward alternative method is evaluation of ertapenem resistance. However, the accuracy of this method is affected by other resistance mechanisms such as AmpC gene expression or extended-spectrum ß-lactamase production associated with porin loss. This study included 128 samples of K. pneumoniae and Enterobacter spp. that were non-susceptible to ertapenem. The disk diffusion and Etest method were applied to determine susceptibility to imipenem, meropenem and ertapenem. Isolates exhibiting intermediate or complete resistance to ertapenem were evaluated for resistance mechanisms. bla(TEM), bla(SHV), bla(CTX-M), bla(CTX-M-2) and bla(KPC) genes were tested for by PCR, and the presence of outer membrane protein was investigated by dot-blot assay. bla(TEM) was detected in 52.9% and 10.3%, bla(SHV) in 29.4% and 0.94%, bla(CTX-M) in 41.4% and 1.9% and bla(CTX-M-2) in 23.5% and 1.9% of K. pneumoniae and Enterobacter cloacae isolates, respectively. The bla(KPC) gene was present in 12.6% of Enterobacter spp. isolates. OmpC and OmpF were present in 6.6% of E. cloacae isolates. These results indicate that several resistance mechanisms contribute to potential therapeutic failure of carbapenem therapy and point to the need for better detection methods and surveillance strategies.

CD19-CD45 low/- CD38 high/CD138+ plasma cells enrich for human tumorigenic myeloma cells.

Multiple myeloma is a hematological neoplasm characterized by the accumulation of clonal plasma cells in the bone marrow. Its frequent relapse following achievement of clinical remissions implicates the existence of therapy-resistant myeloma-initiating cells. To date, results on the identity of myeloma-initiating cells have differed. Here, we prospectively identified a myeloma-initiating population by fractionating and transplanting patient bone marrow cells into human bone-bearing immunocompromised mice. Xenotransplantation of fractionated CD138(+)/CD38(high) cells from 40% of patients (8/20) led to a repopulation of CD19(+)CD38(low) or CD138(+)CD38(+) B-lineage cells in human bone grafts; and these grafts were clonally derived from patient myeloma cells. Meanwhile, CD19(+)CD38(low) xenografts were detected in human bone-bearing mice transplanted with CD19(+)CD38(low/-) B cells from 8 of 22 samples but were not clonally related to patient myeloma cells. Further fractionation and xenotransplantation of CD138(+)CD38(high) cells demonstrated that (CD45(low/-) or CD19(-)) CD38(high)/CD138(+) plasma cells, but not (CD45(high) or CD19(+)) CD38(high)/CD138(+) plasmablasts enrich for myeloma-initiating cells. Quantitative reverse transcription-PCR of two serially transplantable xenografts, which were CD19(-)CD138(+), revealed that they were Pax5 (a B-cell-specific transactivator)-negative. These results suggest that CD19(-)CD45(low/-) fully differentiated plasma cells enrich for long-lived and tumor-initiating cells whereas B cells or plasmablasts do not.

Safety, efficacy and biological predictors of response to sequential azacitidine and lenalidomide for elderly patients with acute myeloid leukemia.

Acute myeloid leukemia (AML) is a disease of the elderly. Poor outcomes with standard therapies necessitate novel approaches. Outpatient regimens sufficiently potent and well tolerated to induce remissions and enable continuation therapy may be beneficial. In this phase-1 study, we determined the maximum tolerated dose (MTD) and the efficacy for sequential azacitidine and lenalidomide as remission induction and continuation therapy in elderly, previously untreated patients. We investigated the impact on global DNA methylation and bone marrow cytokines, and sought biological predictors of response. Eighteen patients were enrolled. The MTD was not reached. Median follow-up was 8.2 months (10.3 months for survivors). Common adverse events included fatigue, injection site reactions, constipation, nausea, pruritus and febrile neutropenia. Ten patients responded (56%), and the rate of complete remissions (CRs) or CRs with incomplete recovery of blood counts for evaluable patients was 44% (7/16). The median response duration was 6.2 months. DNA demethylation and changes in bone marrow cytokines were observed; responders had a unique cytokine profile and a trend towards lower methylation levels. Sequential azacitidine and lenalidomide was well tolerated with encouraging clinical and biological activity in previously untreated elderly AML patients. This trial is registered at ClinicalTrials.gov (NCT00890929).

The farnesyl transferase inhibitor, tipifarnib, is a potent inhibitor of the MDR1 gene product, P-glycoprotein, and demonstrates significant cytotoxic synergism against human leukemia cell lines.

Farnesyl transferase inhibitors (FTIs) target signal-transduction pathways responsible for the proliferation and survival of hematologic malignancies, including acute myelogenous leukemias (AML). Lonafarnib has been shown to be a potent inhibitor of Pgp-mediated drug efflux. On the basis of these findings, we examined the Pgp-inhibitory properties of tipifarnib and assessed its activity when combined with anthracyclines. The effects of tipifarnib on cell proliferation, induction of apoptosis and inhibition of Pgp-mediated anthracycline efflux were analyzed in two human leukemia cell lines overexpressing Pgp (CCRF-CEM and KG1a). Measurement of residual daunorubicin (DNR)-mediated fluorescence after incubation with DNR and tipifarnib demonstrated that tipifarnib significantly inhibited DNR efflux in CCRF-CEM with an IC(50) value less than 0.5 microM. Proliferation and apoptosis assays after exposure to DNR in the presence or absence of tipifarnib demonstrated synergistic inhibition of cellular proliferation, and induction of apoptosis with the combination of tipifarnib and DNR. Similar data was obtained with an enantiomer of tipifarnib that possesses no FTI activity. Incubation with tipifarnib and DNR did not interfere with inhibition of the post-translational processing of HDJ-2. These data suggest that tipifarnib possesses Pgp-inhibitory activity in addition to its FTI activity. In high risk and refractory patients these properties may be exploited as a dual targeting mechanism in the therapy of AML.

Nonmyeloablative allogeneic hematopoietic stem cell transplantation for congenital sideroblastic anemia.

Congenital sideroblastic anemia (CSA) is a dyserythropoietic disorder that leads to transfusion dependency and subsequent iron overload. Nonmyeloablative allogeneic hematopoietic stem cell transplantation (NST) was performed for a patient with CSA, who had contraindications to conventional allografting. Conditioning was fludarabine, low-dose total body irradiation and antithymocyte globulin, followed by peripheral blood stem cell transplant. Cyclosporine and mycophenolate mofetil were used for graft-versus-host disease prophylaxis. Complete donor chimerism was observed day +131. Early after transplant, the patient became transfusion independent, allowing a regular phlebotomy program. On day +190, refractory lactic acidosis followed by fatal cardiovascular collapse developed, without evidence of infection. Data from this case demonstrates that NST may correct the erythropoietic defect of CSA.

Intracranial hemorrhage following bone marrow transplantation: an autopsy study of 58 patients.

Autopsy files of 180 patients were reviewed, who died after BMT between July 1987 and June 1998 and 58 (32.2%) cases, who had experienced intracranial hemorrhage (ICH) were selected. Age, sex, underlying disease, preparatory regimens, immunoprophylaxis, chronic and acute GVHD, survival of the patients and localization and size of hemorrhages were evaluated. There were 33 males and 25 females, with a mean age of 23.4 years. The main underlying disorders for which BMT was performed included SAA (n = 21), CML (n = 13) and AML (n = 10). Forty patients were found to have intraparenchymal hemorrhage, 35 had subarachnoid hemorrhage and eight patients had subdural hemorrhage. In 16 cases the CNS hemorrhage was so extensive that it was considered to be the main cause of death. There was no significant statistical difference concerning sex (P = 0.217), age (P = 0.296), underlying disease (P= 0.352), preparatory regimens (P = 0.07), immunoprophylaxis (P = 0.914), chronic and acute graft-versus-host disease (P = 0.107 and P = 0.631, respectively) and survival (P = 0.701) when comparing patients with or without ICH. However, the number of cases in which the CNS was defined as the main cause of death was higher among patients with ICH than in patients without ICH (n = 16 vs 15) (P = 0.011). We conclude that ICH is common and has a significant mortality rate following BMT.

Second bone marrow transplantation for severe aplastic anemia: analysis of 34 cases.

Severe aplastic anemia (sAA) is a bone marrow failure disorder which is mostly a consequence of immunologically mediated stem cell destruction. Allogeneic bone marrow transplantation (BMT) from a compatible donor provides long-term survival in 60 to 80% of sAA patients. However, graft rejection still remains a major problem, and a second allograft is an alternative for these patients. We retrospectively analyzed 34 patients who received a second BMT (BMT2), nine with primary graft failure (PGF) and 25 with transient engraftment (TE). The probability of survival at 13 years among PGF patients was 22% vs 60% for the TE group (P = 0.0068). Age (<17 vs>17 years), number of mononuclear cells (<3 vs >3 x 10(8)/kg) and year of transplant (1986-1991 vs 1992-1998) at BMT2 had no statistical influence on survival. A significant survival advantage was noted among TE patients (P = 0.0068), which was probably because of a longer intertransplant interval (>90 days). Furthermore, 90% of patients with positive blood cultures at BMT2 did not survive the procedure. We conclude that early detection of primary graft failure (PGF), followed by measures attempting to promote hematopoietic recovery (eg use of growth factors, further infusion of stem cells) may decrease mortality.

Disseminated toxoplasmosis after bone marrow transplantation: report of 9 cases.

Toxoplasma infection following bone marrow transplantation (BMT) is infrequently reported. We report 9 cases of disseminated Toxoplasma gondii infection in BMT recipients documented during an 11-year period at our institution. The incidence of T. gondii infection in our institution (1.14 per 100 allogeneic BMT) is higher than previously reported. The most frequently affected sites were the brain, lungs, and heart. Findings common to most patients who developed toxoplasmosis were positive pre-transplant serology, allogeneic transplant and graft-versus-host disease and its treatment, as well as BMT from matched unrelated donors. All 9 patients died and 8 were diagnosed only after autopsy. Heightened awareness of the occurrence of toxoplasmosis in marrow recipients, especially in highly endemic areas, and early diagnosis and therapy are needed for a better outcome.

Cavernous sinus thrombosis caused by zygomycosis after unrelated bone marrow transplantation.

Invasive zygomycosis is a devastating fungal infection occurring as an opportunistic infection after bone marrow transplantation (BMT). Sinusitis can lead to fungal infection in immunosuppressed patients, and cavernous sinus thrombosis, an uncommon condition in immunocompetent patients, typically follows an infection involving the medial third of the face, nose, or paranasal sinuses. Patients undergoing unrelated-donor BMT (UD-BMT) are prone to develop life-threatening infections because of poor recovery of cellular immunity. Despite adequate clinical evaluation and treatment, the prognosis of patients with invasive fungal infections is dismal, especially when intracerebral structures are affected. We describe a case of a patient who underwent an UD-BMT and developed cavernous sinus thrombosis after sinusitis due to zygomycosis. Moreover, he also had disseminated fungal (Zygomycetes and Aspergillus) and viral (cytomegalovirus and adenovirus) infections.

Unusual presentation of "extracavitary" primary effusion lymphoma in previously unknown HIV disease.

Human herpes virus, type 8, also called Kaposi's sarcoma-associated virus, is associated with primary effusion lymphoma, an uncommon and unusual subset of acquired immunodeficiency syndrome-related lymphomas mostly confined to body cavities, which primarily affects human immunodeficiency virus-positive men. We report the case of a 40-year-old male with primary effusion lymphoma that presented initially with generalized lymphadenopathy and hepatosplenomegaly, followed by pericardial effusion and cardiac tamponade, in a previously undiagnosed human immunodeficiency virus patient. Cytomorphological studies disclosed a large-cell lymphoma with a population of cells demonstrating intermediate CD45 expression and partial coexpression of CD20 and CD23 markers, as well as universal expression of HLA-DR, CD71, CD38, and CD-30. Molecular studies showed clonal B-cell gene rearrangements and molecular evidence of human herpes virus, type 8. This case stresses the necessity, even in the absence of the 'classical clinical features,' of molecular testing for human herpes virus, type 8 in a subset of patients with high risk for human herpes virus, type 8-associated lymphomas.

Central nervous system infections following bone marrow transplantation: an autopsy report of 27 cases.

The authors retrospectively assess the autopsy findings of central nervous system (CNS) infections in marrow transplant recipients. From July 1987 to June 1998, 845 patients at our institution were submitted to bone marrow transplantation (BMT). The CNS of 180 patients was studied through autopsy and these patients had their medical records reviewed. Twenty-seven (15%) patients presented brain parenchyma infection. Fungi were isolated in approximately 60% of the cases. Mean survival time was 153 days (0-1,264 days) and the majority of the patients died during the first 3 months after BMT (18 cases; 67%). Aspergillus sp. were the most prevalent fungi (approximately 30%), followed by Candida sp. infection (approximately 18%). There was one case of Fusarium sp. infection and two cases of unidentified fungus. All patients with fungal infections had documented involvement at widespread sites. Toxoplasma gondii encephalitis was demonstrated in 8 patents (approximately 30%). Bacterial abscesses were responsible for approximately 11% of the findings. Eleven (41%) of the 27 patients died secondary to cerebral causes. These results show that infectious compromise of the CNS following BMT is a highly fatal event, caused mainly by fungi and T. gondii. Furthermore, they provide a likely guide to the possible causes of brain abscesses following BMT.

Neuropathological findings after bone marrow transplantation: an autopsy study of 180 cases.

We prospectively evaluated the neuropathological complications of 180 patients who underwent autopsy studies following bone marrow transplantation (BMT) (177 allogeneic, three autologous). The most frequent underlying disorders included severe aplastic anemia (n = 55), chronic myelogenous leukemia (n = 53), acute myelogenous leukemia (n = 24) and Fanconi anemia (n = 16). There were 114 males and 66 females. Neuropathological findings were detected in 90.55% of the patients. The most frequent findings were subarachnoid hemorrhages (SAH) (n = 57), intraparenchymal hemorrhages (IHP) (n = 49), fungal infections (n = 16), Wernicke's encephalopathy (n = 10), microglial nodular encephalopathy (n = 10) and neurotoxoplasmosis (n = 8). In only 17 patients was the brain within normal limits. Survival time after BMT averaged 5.4 months and the majority of patients died in the first 3 months post BMT (n = 105). Central nervous system (CNS) pathology was the main cause of death in 17% of the patients (n = 31), with a predominance of IHP in this particular group. Furthermore, the survival time of these patients who died of CNS causes (96.3 days) was almost half of the survival time of those who died of extra-cerebral causes (177.8 days) (P = 0.0162). IHP (70. 96 vs27.22%) (P < 0.001), fungal infections (25.8 vs 8.88%) (P < 0. 001) and toxoplasmosis (9.67 vs 4.44%) (P < 0.001) were significantly more frequent in the group of patients who died due to CNS causes than in the control group. The findings of this work provide a possible guide to the possible causes of neurological syndromes following BMT. Bone Marrow Transplantation (2000) 25, 301-307.

Cholestasis secondary to Hodgkin's disease: report of 2 cases of vanishing bile duct syndrome.

Only a small percentage of patients with Hodgkin's disease become clinically Jaundiced during their disease. This Jaundice may be secondary to biliary obstruction, hemolysis, direct hepatic infiltration by the disease, drug toxicity or viral hepatitis. Vanishing bile duct syndrome secondary to Hodgkin's disease is a rare cause of cholestasis in these patients, only 13 cases having been reported so far. The authors describe 2 patients who developed severe Jaundice secondary to Hodgkin's disease due to vanishing bile duct syndrome affecting small intrahepatic bile ducts.