Case Of Acute Monocytic Leukemia Research Articles

The Impact of Hypomethylating Agents and BCL-2 Inhibitor on HLA Expression on THP-1 Cells

Note: BP, MV and LG, KG contributed equallyBackgroundRelapsed acute myeloid leukemia (AML) remains the most common reason for allogeneic hematopoietic cell transplant (HCT) failure. Thus, understanding AML immune escape mechanism is important for improving the odds of curing HCT patients with AML. Downregulation of HLA Class I and II expression by AML is one of the potential immune escape mechanisms. Therefore, treatment to restore HLA surface expression is crucial to prevent and treat relapse. Endogenous cytokines, such as IFN-γ, have been shown to stimulate HLA expression but are poorly tolerated by patients. However, two hypomethylating agents (HMA), decitabine (Dec) and azacitadine (Aza), that are routinely used in AML treatment are known to augment HLA expression. For AML, HMAs are often combined with venetoclax (Ven), a drug that blocks the anti-apoptotic B-cell lymphoma-2 (Bcl-2) protein. Thus, while HMAs have been reported to increase HLA expression, what is unknown is whether these agents impact individual HLA loci differently and whether Ven has any impact on HLA expression. To address these questions, we treated the THP-1 cell line with Dec, Aza or Ven and measured changes in cell-surface expression of HLA proteins by flow cytometry using locus-specific HLA mAbs.MethodsTHP-1 cells were incubated with IFN-γ (500 U/mL), Aza (2µM), Dec (5µM), or Ven (30nM) for 48 hours (drug concentrations were determined by earlier titration experiments). THP-1 cells are a monocytic cell line, derived from the peripheral blood of a childhood case of acute monocytic leukemia (M5 subtype), that express HLA Class I and HLA-DR but not HLA-DQ or -DP under basal conditions, although they are inducible by IFN-γ. Thus, the induction of HLA Class II expression by IFN-γ serves as a positive control. Isotype controls were included to measure background. Data is presented as the difference in MFI (delta MFI) between cells treated with a drug and those treated with diluent only.ResultsTreatment of THP-1 cells with either IFN-γ or Dec led to increases in Class I HLA-A, -B & -C (Figure 1) compared to untreated cells (a mean fold increase of 1.4 and 1.2, respectively). Notably, Aza did not stimulate additional HLA-C expression and induced less of an increase in HLA-A & -B expression (an increase of 1.1-fold) than IFN-γ or Dec. Treatment of THP-1 cells by Ven did not induce a change in HLA Class I expression.For Class II, IFN-γ or Dec increased HLA-DR, -DQ and -DP expression in comparison to untreated cells (Figure 1). IFN-γ induced greater HLA-DR expression compared to Dec (an increase of 2.3-fold and 1.5-fold, respectively), and both stimulated similar increases in HLA-DQ (increases of 1.5-fold and 1.4-fold, respectively) & -DP (increases of 1.9-fold and 1.5-fold, respectively). However, treatment of cells with either Aza or Ven did not lead to changes in HLA Class II expression.DiscussionPrevious studies have illustrated the ability of IFN-γ to induce HLA Class II expression in THP-1 cells, however, data for Dec to induce HLA Class II expression was unconfirmed. We report differences in the degree to which IFN-γ and Dec are capable of stimulating HLA-DR with IFN-γ being more potent. The inability of Aza to induce HLA Class II expression in THP-1 cells may be related to the differing drug activating pathways of the two HMAs. Indeed, there are conflicting reports as to whether Aza can stimulate HLA Class II expression. Though Ven treatment of THP-1 cells did not impact HLA expression, because it is given with HMAs, it remains to be seen what effect these drugs may have on HLA expression when administered together. Additional studies to confirm these observations in patient-derived AML blasts are ongoing.ConclusionWe report that HMAs increased expression of HLA-A, -B, & -C loci and Dec but not Aza stimulated HLA-DR, -DQ, and -DP expression in THP-1 cells. Given these data, Dec may be superior in increasing HLA Class II expression post-HCT. [Display omitted] DisclosuresMarcucci: Abbvie: Other: Speaker and advisory scientific board meetings; Agios: Other: Speaker and advisory scientific board meetings; Novartis: Other: Speaker and advisory scientific board meetings. Al Malki: Neximmune: Consultancy; CareDx: Consultancy; Jazz Pharmaceuticals, Inc.: Consultancy; Rigel Pharma: Consultancy; Hansa Biopharma: Consultancy.

Monocytic leukeima masquerading as a cutaneous lesion

Cutaneous lesions preceding a leukaemia are extremely rare and are referred to as ‘aleukaemic leukaemia cutis’. We present a case of acute monocytic leukaemia where skin infiltration of leukemic cells preceded any blood or bone marrow evidence of leukaemia. A 67-year-old woman presented with multiple cutaneous nodules all over the body of 3 months duration. Cutaneous examination showed multiple erythematous papules and plaques which were present over the face, trunk, extremities and back. Patient was evaluated at a nearby facility and was found to have normal blood parameters (TLC- 7130/cmm, N-57% L-34% M-09%). A skin biopsy done revealed infiltration of the dermis by atypical cells suggestive of a hematolymphoid malignancy. The patient was then shifted to our institution for tertiary care management. The blood counts over a period of one month showed gradually increasing TLC from an initial normal blood count to one showing absolute monocytosis (TLC-25500/cmm, AMC-3825/cmm) and finally abnormally high TLC (TLC-154050/cmm) with 79% monoblasts and promonocytes suggestive of acute leukaemia. A repeat skin biopsy again showed infiltration of atypical cells in the dermis. IHC done showed the atypical cells to be positive for monocytic markers (CD14, CD64). The patient had now started exhibiting systemic findings corroborating with the cutaneous lesions and skin biopsy. Bone marrow aspirate was hypercellular and showed replacement by monoblasts (82%). Cellular morphology was suggestive of AML-M5. Bone marrow biopsy showed a diffuse replacement of marrow by immature cells/blasts. Flow cytometry reports were also positive for monocytic markers. The patient was hence diagnosed as AML M5 with cutaneous metastasis/leukemia cutis and was immediately started on chemotherapy (3+7). Post induction phase, the patient was in remission and her skin lesions subsided. She was subsequently discharged and advised regular OPD follow up for maintenance therapy. This case is reported for its rarity.

A case of acute monocytic leukemia complicated with multiple myeloma

A case of acute monocytic leukemia complicated with multiple myeloma

The ability of VBNC F. tularensis to replicate within THP-1 cells.

CARLY CUNNINGHAM, STUART CANTLAY, AND JOSEPH HORZEMPA, Department of Natural Sciences and Mathematics, West Liberty University, West Liberty, WV USA. The ability of VBNC F. tularensis to replicate within THP-1 cells. Francisella tularensis, a gram-negative coccobacillus is the causative agent of tularemia, a potentially fatal zoonotic disease. Under laboratory conditions, F. tularensis enters a viable but non-culturable (VBNC) state. VBNC is a state of dormancy bacteria enter during stressful conditions and can have implications for persistence and pathogenicity. Our first aim is to use molecular cloning to create recombinant fluorescent proteins for cell wall and division proteins in F. tularensis. Fusions to FtsZ, MreB and RodA will be generated and used to analyse the localization of these proteins during the transition into the VBNC state. Our second aim is to investigate the effects of transition into the VBNC state on pathogenicity. To test this, we will use microscopy to analyze fluorescently labelled F. tularensis during infection of THP-1 cells. THP-1 cells are a spontaneously immortalized monocyte-like cell line, derived from the peripheral blood of a childhood case of acute monocytic leukemia. THP-1 cells are a model for mammalian blood monocytes that provide protection against infection by gram negative bacteria. Our hypothesis is that VBNC F. tularensis will be able to interact with THP-1 cells in an in vitro infection assay. Further, the ability of VBNC F. tularensis to replicate within THP-1 cells will be analyzed. (Supported by NIH Grant P20GM103434 to the West Virginia IDeA Network for Biomedical Research Excellence).

Decitabine plus CLAG chemotherapy as a bridge to haploidentical transplantation in the setting of acute myeloid leukemia relapse after HLA-matched sibling transplantation: a case report

BackgroundPatients with relapsed/refractory acute myeloid leukemia after hematopoietic stem cell transplantation (HSCT) have a poor prognosis, with a 2-year survival rate of 14%. The optimal treatment for these patients remains unclear. To treat these patients, we designed a new salvage regimen consisting of decitabine, cladribine, cytarabine, and granulocyte-stimulating factor (D-CLAG).Case presentationHere, we describe a case of acute monocytic leukemia with a complex karyotype in a 38-year-old female patient who relapsed after her first HSCT, which was performed using a matched sibling donor. The patient did not respond to standard induction chemotherapy and subsequently achieved complete remission with the D-CLAG regimen. No severe hematological or extramedullary toxicity was observed. Subsequently, the patient received a second D-CLAG regimen as a bridge therapy and directly underwent haploidentical related HSCT. Following HSCT, the marrow showed complete hematologic and cytogenetic remission. Currently, 1 year after transplantation, the patient’s general condition remains good.ConclusionsThis case suggests that the D-CLAG regimen can be an option for reinduction in relapsed refractory AML patients as a bridge to transplantation. Nevertheless, further research will be required in the future as this report describes only a single case.

Morphologic and immunophenotypic features of a case of acute monoblastic leukemia with unusual positivity for Glycophorin-A.

Acute monoblastic leukemia (AMoL) is characterized by cells with highly undifferentiated morphology. Cytochemistry with non-specific esterases is negative in up to 20% of cases. Immunophenotyping by flow cytometry has an essential role in diagnosing such a subtype of leukemia and a multiparametric approach with a wide monoclonal antibody panel is necessary. We describe a case of AMoL with morphology resembling either plasma blasts or very immature erythroblasts. Diagnosis was made by alpha-naphtyl-acetate esterase staining and with immunophenotyping, which was made with a wide monoclonal antibody panel. Blasts were positive for monocytic markers. Most of leukemic cells, however, were positive for Glycophorin-A. The presence of Glycophorin-A, which is considered as a specific marker of the erythroid lineage, has never been reported previously in cases of AMoL. This peculiar immunophenotype might be interpreted as deriving from a common myelo-erythroid precursor undergone leukemic transformation.

Characterization of an acquired jumping translocation involving 3q13.31-qter in a patient with de novo acute monocytic leukemia

We studied an adult with de novo acute monocytic leukemia and a dismal outcome where her leukemic cells harbored an acquired rare jumping translocation (JT). We used oligo-based array CGH (oaCGH) analysis, fluorescence in situ hybridization (FISH), and 24-color karyotyping to enhance the characterization of the JT.G-banding detected a JT involving the 3q13.3-qter chromosomal segment and the recipient chromosomal regions 17p, 8q, and 15q. Each clone with JT was associated with trisomy 8. oaCGH analysis revealed an additional submicroscopic deletion in 3q13.31 as well as small subtelomeric duplications on several chromosomes. Locus-specific FISH with BAC-based probes from the 3q13.31-q13.32 region showed great heterogeneity. Telomere FISH revealed significantly reduced telomeric content in the aberrant cells with JT compared with cytogenetically normal cells at diagnosis and in normal cells at complete remission. A literature search revealed two previous de novo AML-M5 cases of JT involving the 3q13.3-qter chromosomal segment and concomitant trisomy 8. In addition, a case with an unbalanced der(Y)t(Y;3)(q12;q13.31) and additional trisomy 8 was previously reported in a patient with de novo AML-M5. All of these cases had a dismal outcome. In the present case, and in the der(Y)t(Y;3) case, a concurrent submicroscopic deletion at 3q13.31 was observed affecting the TUSC7 gene.Duplication of 3q13.31-qter might be a non-random chromosomal abnormality with concomitant submicroscopic deletion at 3q13.31 occurring in rare cases of acute monocytic leukemia, being associated with adverse prognosis. The impact of shortened telomeres in forming the JT is reviewed.

Acute Monoblastic Leukemia and Myeloproliferative Neoplasm Observed in an Elderly Man Had the Same Clonal Origin

It is reported that fonder mutations affects the development these disorders closely. However, it is unclear whether hematopoiesis carrying these mutations could contribute to the development of the different diseases, directly. We here report a case of acute monoblastic leukemia (AMoL) followed by myeloproliferative neoplasm, unclassifiable (MPN-U), 2 years later, both derived from the same clonal hematopoiesis. [Case report and Methods] A 75-year-old male was admitted to our hospital duo to fever and fatigue. WBC count was 114.7 x 109/L with 9% blasts and 82% monocytes. Bone marrow aspiration revealed 93% of blasts and promonocytes, which resulted in the diagnosis of AMoL with normal karyotype. He received three courses of chemotherapy, which brought CR, but minor monocytosis (>1 x 109/L) persisted without proliferation of immature blasts. After 2 years from the diagnosis of AMoL, platelet count started to increase. WBC count was between 10 and 20 x 109/L without blast, and platelet count reached 500 x 109/L. Bone marrow examination (2 years from the diagnosis of AMoL) revealed normal cellularity, and less than 5% of blast with normal karyotype. Considering the leukocytosis and thrombocytosis, we evaluated his status as similar to MPN, since dysplasia was not apparent on his hematopoietic cells. Although he had previously received chemotherapy for AMoL, it was diagnosed as MPN-U. Two years after the diagnosis of MPN-U, the disease transformed into AML, not AMoL. He died of AML, four years after AMoL developed. To study clonal status of AMoL and MPN-U in this case, bone marrow mononuclear cells of AMoL (at diagnosis) and MPN-U phases, and buccal swab collected during MPN-U phase were subjected to whole exome sequencing (WES). Validation of mutations was performed by amplicon-base deep sequencing. DNA obtained from bone marrow smear during CR was tested whether mutations existed or not by deep sequencing. Mean depth of WES was 89.15, 140.18, and 98.02 for AMoL, MPN-U, and buccal mucosa samples, respectively. Clonal evolution analysis was performed using clonality inference in tumors using phylogeny. [Results] We found total 22 mutations in samples of AMoL and MPN-U phase with different variant allele frequency (VAF) by WES. When AMoL was diagnosed, 16 genes were mutated with more than 10% of VAF, including genes such as ASXL1, CBL, GATA2, NPM1 (4 bp insertion), SRSF2, and TET2. On the other hand, when MPN-U was diagnosed, there were 16 genes mutated with more than 10% of VAF, and 10 mutations out of 16 were the same mutation as found in the sample of AMoL phase including mutations in SRSF2, GATA2, and TET2. Six mutated genes found only in the sample of MPN-U phase included GNAS and JAK2 (V617F mutation). Since 10 out of 22 genes were commonly mutated in both the AMoL and MPN-U samples, we next analyzed the mutational status of these 22 genes in the CR sample using deep sequencing. It was found that the commonly mutated 10 genes in both AMoL and MPN-U were also mutated in the CR sample with high VAF (> 25%). Some gene mutations found only in AMoL, and some only in MPN-U were also present during CR phase but with low VAF (< 10%). Clonal evolution pathway generated by using deep sequence data suggested that before AMoL, there was a founder clone with mutations of TET2, SRSF2, and GATA2, although we could not analyze the sample before AMoL. Mutations in NPM1, ASXL1, CBL, and ASH1L seemed to contribute to the development of AMoL from the founder clone, and those of JAK2 and GNAS for MPN-U. It is also suggested that small amount of hematopoietic stem / progenitor cells containing the JAK2 mutation already existed in CR sample, and these developed into MPN-U probably with gaining other gene mutations. Our data prospectively showed that clonal hematological disorder would arise from a pre-malignant, clonal hematopoiesis that produced normal levels of mature hematopoietic cells. Our analysis clearly demonstrated that two different clonal hematological disorders developed from the same clonal hematopoiesis that had TET2, SRSF2, and GATA2 mutation, which were previously reported as driver mutations. To our knowledge, this is the first report to analyze the progression of AML and MPN from the identical hematopoietic stem cells by WES and deep sequencing validation to model clonal evolution and a case to give a new suggestion about the development of the myeloid malignancies. DisclosuresMiyazaki:Celgene Japan: Honoraria; Chugai: Honoraria, Research Funding; Sumitomo Dainippon: Honoraria; Shin-bio: Honoraria; Kyowa-Kirin: Honoraria, Research Funding. Moriuchi:Celgene: Other: Research Funding to my institution; travel, accommodations, expenses, Speakers Bureau.

Decitabine in Haploidentical Hematopoietic Stem Cell Transplantation for Treatment Refractory Acute Monocytic Leukemia and Literature Review

Objective To investigate the feasibility and efficacy of decitabine (DAC) bridge therapy followed by allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with refractory acute monocytic leukemia (AML).Methods In November 2011,a case of refractory acute AML who admitted by the First Affiliated Hospital of Chinese PLA General Hospital was included in this study.This patient recived 7 kinds of chemotherapy regimens,and then underwent with DAC bridge therapy and busulfan combined cyclophosphamide (BUCY) regimen before haploidentical HSCT (haplo-HSCT).The clinical data of this patient were analyzed retrospectively,and its related literatures were reviewed.The clinical protocol and consent forms were approved by the institutional review board for human investigation at the First Affiliated Hospital of Chinese PLA General Hospital.Patient provided written informed consent for inclusion in the study.Results With DAC bridge therapy,this patient achieved successful engraftment and experienced only grade Ⅰ actue graft-versus-host disease (aGVHD) and limited chronic GVHD (cGVHD).This patient achieved full donor chimerism (FDC) and didn't monitor minimal residual disease (MRD) in 1,6,12 and 24 months after HSCT.Until now,he was in 25 months progression-free survival (PFS) and no relapse.Conclusions DAC bridge therapy followed by haplo-HSCT is safe and feasibility for the patient with multidrug resistance (MDR) and refractory AML,which could reduce the relapse efficiently and prolong life-span of the patients. Key words: Decitabine; Hematopoietic stem cell transplantation; Bridge therapy; Leukemia, monocytic, acute

Radiation and chemotherapy induced secondary leukemia in a case treated for carcinoma cervix: A case report

Secondary leukemias are usually forms of leukemias which are developed due to therapy administered for a previous malignancy. Radiotherapy or chemotherapy induced leukemia is a complication which follows treatment of a different primary malignancy. A case of acute monoblastic leukemia following treatment of the invasive carcinoma cervix (treated by radiotherapy and chemotherapy) is reported. This secondary leukemia developed one year after treatment. This case is being presented due to its rarity.

Clinical and laboratory features of acute monocytic leukemia with B lymphoproliferative disorders

To identify the clinical and pathological features of acute myeloid leukemia with B lymphoproliferative disorders. The characteristics of 3 cases of acute monocytic leukemia with untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis were reported with literatures review. The patients presented with a history of anemia, bleeding and/or fever. Acute monocytic leukemia was diagnosed by bone marrow morphology, cytochemistry and pathology studies. Immunophenotyping by flow cytometry analysis showed a significant population of absolute B-lymphocyte count of > 5×10(9)/L in a patients, similar to that of chronic lymphocytic leukemia. The association of acute monocytic leukemia and untreated chronic lymphocytic leukemia/monoclonal B-cell lymphocytosis was a rare event. The abnormal B lymphocytes was likely to be misdiagnosis. Thus, it was important to combine several kinds of laboratory studies, especially flow cytometry to identify this rare disorder.

Segmental amplification of MLL gene associated with high expression of AURKA and AURKB genes in a case of acute monoblastic leukemia with complex karyotype

We report a case of acute monoblastic leukemia showing a jumping translocation with the MLL gene in a 17-year-old male. Classic cytogenetic and spectral karyotyping revealed a complex karyotype, and fluorescence in situ hybridization (FISH) demonstrated amplification of the MLL gene followed by translocation to chromosomes 15q, 17q, and 19q. In addition, molecular analyses showed a high expression of AURKA and AURKB genes. It is already known that overexpression of Aurora kinases is associated with chromosomal instability and poor prognosis. The formation of jumping translocations is a rare cytogenetic event and there is evidence pointing toward preferential involvement of the heterochromatin region of donor chromosomes and the telomere ends of recipient chromosomes. Jumping translocation with the MLL gene rearrangement is an uncommon phenomenon reported in leukemia cytogenetics.

Analysis of Clinical Features and Survival in 42 Cases of Acute Monocytic Leukemia

Background: Acute monocytic leukemia (M5) is a distinct subtype of acute myeloid leukemia (AML) with characteristic biologic and clinical features. This study was designed to analyze the clinical and laboratory features, and management and survival of newly diagnosed patients at with M5.Methods: The white blood counts, immunophenotype and karyotypes were retrospectively analyzed in 42 patients (pts) with M5. The overall survival(OS)was estimated by Kaplan-Meier analysis, and the different groups were compared using log-rank test.Results: Of the 42 pts, 7 had M5a and 35 had M5b. The incidence rates of M5 in newly diagnosed patients with acute leukemia and acute myelocytic leukemia were 13.7% and 22%, respectively. 28(66.7%) pts with M5 had a higher white blood counts more than 25×109/L. 36 pts obtained the outcomes of karyotype, 14(39%) pts with an abnormal cytogenetic clone, seven (19.4%) of these patients had trisomy 8 as the sole or accompanied complex cytogenetic aberration, 5(13.8%) had a translocation involving 11q23. An immunophenotype consistent with acute monocytic leukemia (CD14) was seen in 24(57.1%) of 42 pts. 16 pts (38.1%) gave up the chemotherapy at diagnosis and the complete remission rate was 73.1% for 26 pts who received induction chemotherapy. The OS for all M5 pts was 90 days (95%CI, 51.3~128.7) and the median survival for all M5 pts was 137.5 days. The median OS for the 19 CR pts was 273 days (95% CI, 226~320.1) and 85 days (95% CI, 72.2~97.8) for the 16 NR pts (95% CI, 72.2~97.8). For 16 pts who didn't receive chemotherapy, the median OS was 35 days (95% CI, 33~37)(P<0.0001). M5 presents hyperleukocytosis, 86.1% pts of M5 has a normal clone or trisomy 8 or a translocation involving 11q23. The overall survival of M5 pts with currently available therapy is poor.

Ribosome–Lamella Complex Precursors in Acute Monocytic Leukemia: A Study of 6 Cases

The ribosome–lamella complex (RLC) is a cylindrical structure composed of annular lamella associated particles, regarded as ribosomes, around a central core, which is best known in hairy cell leukemia. RLC has been presumed to originate from aggregating rER and ribosomes. Incomplete and maturing RLC structures have been called RLC precursors (pre-RLC). The present paper investigates the various architectural aspects of pre-RLC and the ultrastructural characteristics of the blasts in 6 cases of acute monocytic leukemia (M5) in which these structures occur. Blasts bearing pre-RLC contained irregular nuclei with less heterochromatin and a prominent nucleolus, and many cytoplasmic organelles in an abundant cytoplasm. The findings indicate that pre-RLC might result from an asymmetrical differentiation of organelles in blasts associated with expression of CD117 and CD56 but default of CD14 in M5.

Inversion (11)(p15q22) with NUP98–DDX10 fusion gene in pediatric acute myeloid leukemia

The inv(11)(p15q22), a rare but recurrent chromosome abnormality that creates a NUP98–DDX10 fusion gene, is associated with de novo or secondary myeloid malignancies. We report a case of acute monocytic leukemia presenting this rearrangement, studied using fluorescence in situ hybridization (FISH) and reverse transcriptase-PCR (RT-PCR). We also review the cases of inv(11) associated with NUP98–DDX10 reported in the literature.

Acute Monocytic Leukemia with t(11;17)(q23;q21) Involving a Rearrangement of Mixed Lineage Leukemia Gene

A case of acute monocytic leukemia (AMoL) by French-American-British (FAB) classification in a 63-year-old male showed the abnormal karyotype 46,XY,t(11;17)(q23;q21), previously reported as a variant translocation in acute promyelocytic leukemia (APL). Fluorescence in situ hybridization (FISH) analysis identified a mixed lineage leukemia (MLL) gene rearrangement, but not visible disruptions of promyelocytic leukemia (PML) or retinoic acid receptor alpha (RARA) genes. We suggest that a certain gene proximal to RARA was rearranged in this case onto a gene close to MLL on chromosome 11q. Now, a few cases of AMoL with a similar translocation have been reported in the literature, and these cases emphasize the importance of cytogenetic and FISH studies in addition to morphology, cytochemistry, and immunophenotype in classifying acute myeloid leukemia (AML).

Acute monocytic leukemia after orthotopic liver transplantation: clinical features, molecular genetics, and significance thereof

To study the clinical features and molecular genetics of acute monocytic leukemia (AML) after orthotopic liver transplantation and significance thereof. The clinical manifestations, laboratory findings, development, diagnosis, treatment, and prognosis of the first case of AML after orthotopic liver transplantation in the world, a Chinese, male, aged 46, were observed. RT-PCR was used to analyze the mRNA expression of FLT3, Pim-1, and Hsp-70 in the bone marrow mononuclear cells (BMMCs) of the patient. Nucleotide sequence analysis was used to detect the mutation of FLT3-ITD. Flow cytometry was used to examine the protein expression of C-kit, a stem cell factor receptor, and platelet derived growth factor receptor-alpha (PDGFRalpha). (1) Three months after the orthotopic liver transplantation the patient manifested symptoms and signs of anemia and thrombocytopenia. Laboratory tests found increase of white blood cells and myeloblasts with Auer's rods. Cytogenetic analysis showed a genotype of 46XY/47XY with an extra chromosome 8. Bone marrow examination revealed increased promonocytes. The diagnosis of chronic myelomonocytic leukemia was made. Five months after the liver transplantation the disease developed to AML. The patient underwent combined chemotherapy (HA or DA regimens) for 5 courses and showed a partial remission both hematologically and in bone marrow examination at first, however, became resistant to all chemotherapeutic agents. RT-PCR showed absence of wild type FLT3 allele. At last the patient died of infection. (2) A FLT3-ITD mutation of "insertion" type was identified in the BMMCs. The Pim-1 mRNA was weakly expressed and the expression of Hsp-70 mRNA was upregulated in the BMMCs. (3) The protein expression of C-kit and that of PDGFRalpha were both upregulated in the BMMCs as showed by flow cytometry. Orthotopic liver transplantation may be complicated with acute leukemia heterogeneous in clinical features and hematology. Certain defects in cytogenetics/molecular genetics may attribute to unfavorable prognosis.

CD163

Paraffin-section immunohistochemical analysis was performed using a monoclonal antibody against CD163 to evaluate the antibody’s usefulness in identifying cells of monocyte/macrophage lineage in normal and neoplastic conditions. Normal human tissue samples and samples from 211 hematopoietic disorders and 115 nonhematopoietic neoplasms were examined. The distribution of KP1 and PG-M1, monoclonal antibodies to the macrophage-associated CD68 antigen, also were evaluated for comparison. CD163 immunoreactivity was observed in resident macrophages of all normal tissue samples except splenic white pulp macrophages and germinal center tingible body macrophages. Among hematopoietic disorders and nonhematopoietic neoplasms, CD163 expression was restricted largely to cases of chronic myelomonocytic leukemia, histiocytic sarcoma, sinus histiocytosis with massive lymphadenopathy, and littoral cell angioma. Acute myeloid leukemias (AMLs) with monocytic differentiation were CD163– with the exception of 1 case of acute monoblastic leukemia. Most myeloid sarcomas also were CD163–. Compared with the CD68 antibodies, CD163 demonstrated greater specificity as a marker of disorders of monocyte/macrophage origin. However, immunohistochemical evaluation of CD163 expression does not seem to be a sensitive means of determining monocytic differentiation in AMLs in paraffin sections or establishing a diagnosis of myeloid sarcoma.

CD163: A Specific Marker of Macrophages in Paraffin-Embedded Tissue Samples

Paraffin-section immunohistochemical analysis was performed using a monoclonal antibody against CD163 to evaluate the antibody's usefulness in identifying cells of monocyte/macrophage lineage in normal and neoplastic conditions. Normal human tissue samples and samples from 211 hematopoietic disorders and 115 nonhematopoietic neoplasms were examined. The distribution of KP1 and PG-M1, monoclonal antibodies to the macrophage-associated CD68 antigen, also were evaluated for comparison. CD163 immunoreactivity was observed in resident macrophages of all normal tissue samples except splenic white pulp macrophages and germinal center tingible body macrophages. Among hematopoietic disorders and nonhematopoietic neoplasms, CD163 expression was restricted largely to cases of chronic myelomonocytic leukemia, histiocytic sarcoma, sinus histiocytosis with massive lymphadenopathy, and littoral cell angioma. Acute myeloid leukemias (AMLs) with monocytic differentiation were CD163- with the exception of 1 case of acute monoblastic leukemia. Most myeloid sarcomas also were CD163-. Compared with the CD68 antibodies, CD163 demonstrated greater specificity as a marker of disorders of monocyte/macrophage origin. However, immunohistochemical evaluation of CD163 expression does not seem to be a sensitive means of determining monocytic differentiation in AMLs in paraffin sections or establishing a diagnosis of myeloid sarcoma.

A further case of acute myelomonocytic leukemia with inv(8) chromosomal rearrangement and MOZ-NCOA2 gene fusion

We report here the sixth case of acute monoblastic leukemia associated with the inv(8)(p11q13) pericentric inversion. As seen in the previous cases, the inv(8)(p11q13) molecular characterization showed that the alteration results in a MOZ-NCOA2 gene fusion. The presence of erythrophagocytosis is a distinctive morphologic feature that is observed in all patients with MOZ alteration. However, the relative young age of the 6 patients (median: 23.5 years) and same sex (female) are the common characteristics that are only observed in the inv(8)-positive leukemia subgroup. In addition, we tested whether the presence of FLT3 internal duplications (ITD) are frequently found in malignant hemopathies with 8p11-12 rearrangements. We did not find any FLT3 ITD in any of the studied cases.