Jihyang Lim

The extent of minimal residual disease reduction after the first 4‐week imatinib therapy determines outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosome‐positive acute lymphoblastic leukemia

Previously, the authors demonstrated the positive impact of imatinib on the outcome of allogeneic stem cell transplantation in adults with Philadelphia chromosome‐positive acute lymphoblastic leukemia (Ph‐positive ALL). Here, the authors analyzed for risk factors that affect transplantation outcome, and they focused particularly on the prognostic relevance of minimal residual disease level at each treatment stage.

In vitro effects of ciprofloxacin and roxithromycin on apoptosis of jurkat T lymphocytes.

ABSTRACT Ciprofloxacin (CPFX) and roxithromycin (RXM) induced apoptosis of activated Jurkat T cells in vitro. CPFX showed concentration-dependent acceleration of apoptosis of activated Jurkat T cells by enhancing the expression of FasL and activities of caspase-3 and -8. RXM accelerated cell death, enhanced expression of FasL and caspase-3 but not caspase-8, and did not show the concentration dependency.

Comparison of Quantitative Cytomegalovirus Real-time PCR in Whole Blood and pp65 Antigenemia Assay: Clinical Utility of CMV Real-time PCR in Hematopoietic Stem Cell Transplant Recipients

Successful preemptive therapy for cytomegalovirus (CMV) infection in transplant patients depends on the availability of sensitive, specific, and timely diagnostic tests for CMV infection. Although the pp65 antigenemia assay has been widely used for this purpose, real-time quantification of CMV DNA has recently been recognized as an alternative diagnostic approach. However, the guidelines for antiviral therapy based on real-time quantitative polymerase chain reaction (RQ-PCR) have yet to be established. From November 2004 to March 2005, a total of 555 whole blood samples from 131 hematopoietic stem cell transplant (HSCT) recipients were prospectively collected. RQ-PCR was conducted using an Artus® CMV LC PCR kit (QIAGEN). Both qualitative and quantitative correlations were drawn between the two methods. Exposure to the antiviral agent influenced the results of the two assays. Additionally, the discrepancy was observed at low levels of antigenemia and CMV DNA load. Via ROC curve analysis, the tentative cutoff value for preemptive therapy was determined to be approximately 2×104 copies/mL (sensitivity, 80.0%; specificity, 50.0%) in the high risk patients, and approximately 3×104 copies/mL (sensitivity, 90.0%; specificity, 70.0%) in the patients at low risk for CMV disease. Further study to validate the optimal cutoff value for the initiation of preemptive therapy is currently underway.

Expression of Functional Markers in Acute Nonlymphoblastic Leukemia

Multidrug resistance parameters, tissue infiltration parameters, receptors for colony-stimulating factors (CSFr) and cell cycle parameters were analyzed using flow cytometry in 145, 109 initial and 36 relapsed or refractory, acute nonlymphoblastic leukemia (ANLL) patients to find out clinically more reliable functional parameters. Lung resistance-associated protein (LRP) was most frequently expressed in ANLL (44.1%) followed by P-glycoprotein (PGP) (35.9%) and multidrug resistance-associated protein (MRP) (8.3%). LRP and PGP were expressed more frequently in relapsed or refractory ANLL than initial ANLL cases. Complete remission rate after standard chemotherapy falls in PGP-positive cases (p = 0.001). CD44-positive ANLL cases relapsed more frequently. The organ tropism is different depending on the infiltration parameters, vascular cell adhesion molecule to splenomegaly, matrix metalloprotease-2 to hepatomegaly and to extramedullary infiltration other than spleen, liver or lymph node. The percentage of the granulocyte-macrophage-CSFr expression was high in M4 and M5, and granulocyte-CSFr-positive ANLL showed less extramedullary infiltration (p = 0.007) and more PGP expression. Ki-67 was expressed significantly less in refractory ANLL than initial ANLL and DNA topisomerase IIα was expressed significantly more in the surviving patients group. In conclusion, analysis of these new functional parameters could help to predict and overcome the clinical behavior of each ANLL at the time of diagnosis.

Cytogenetic characteristics and prognosis analysis in 231 myelodysplastic syndrome patients from a single institution

We analyzed the clinical and hematologic data of 231 patients diagnosed with de novo myelodysplastic syndrome (MDS), identified cytogenetic characteristics, and evaluated the significance of prognostic systems. The median age was 51 years and the distribution of MDS subtypes demonstrated a markedly low incidence of MDS with deletion 5q (0.9%). The proportions of World Health Organization (WHO) categories differed according to patient age group. Refractory anemia with excess blasts-2 demonstrated the most significant trend toward increased frequency with advancing age. The incidence of abnormal karyotypes in our study was comparable to a previous study (50.2%), although with different patterns. The most frequent cytogenetic abnormality was +8 (34.5% of patients with abnormality), followed by 1q+ (17.2%), 5q- (15.5%), and 20q- (12.9%). Majority of +8, 1q+, -5/5q- and -7/7q- cases combined with additional cytogenetic abnormalities (60.0%, 75.0%, 88.5% and 100%, respectively). The median survival time was 49.5 months and 13.8% patients developed acute leukemia. WHO Prognostic Scoring System (WPSS) and age group were significant factors associated with overall survival. Otherwise, International Prognostic Scoring System was not included in the model. These results demonstrated the different cytogenetic features in Korean MDS patients compared to those of Western country. In addition, WPSS and age group are applicable to our patients as an effective and reliable prognostic model.

Three-way complex translocations in infant acute myeloid leukemia with t(7;12)(q36;p13): The incidence and correlation of a HLXB9 overexpression

The t(7;12)(q36;p13) is one of the recurrent cytogenetic abnormalities that involves the ETV6 gene. It is found in patients suffering with infantile acute myeloid leukemia (AML). We reviewed the cytogenetic and clinical findings of 215 pediatric patients (ages </=17) who were diagnosed with AML to check for abnormalities of 7q and/or 12p. Fluorescence in situ hybridization (FISH) analysis using an ETV6 (12p13) break-apart probe was done to confirm the breakage of the ETV6 gene on 12p. We also performed immunohistochemistry to verify the upregulated expression of the HLXB9 protein, which is coded by the HLXB9 gene at 7q36. Three patients (1.4%) with t(7;12) were detected and they made up 15.8% of the patients who were less than 24 months old. New three-way complex translocations were found in two cases - t(5;7;12)(q31;q36;p13) and t(1;7;12)(q25;q36;p13) - and we detected these by performing FISH. All three patients died early during treatment due to multiple organ failure or relapse. HLXB9 overexpression was proven by immunohistochemistry for the first time in this study. In connection with this, we prudently propose that downregulation of the HLXB9 expression may be a new treatment strategy for AML patients with t(7;12).

Expression of functional markers in acute lymphoblastic leukemia

We analyzed surface antigens, multidrug resistance (MDR) parameters (PGP, MRP, LRP), tissue infiltration parameters (CD18, CD44, VCAM, MMP2), receptors for colony stimulating factors (G-CSFr, GM-CSFr) and cell cycle parameters (Ki-67, topoisomerase IIalpha) in 86 patients with acute lymphoblastic leukemia (ALL). LRP, PGP and CD18 were associated with poor clinical outcome, and LRP expression was related with CD18, CD44 and G-CSFr. Of the cell cycle parameters, Ki-67 (+) fraction was increased in ALL with hepato-splenomegaly and extramedullary involvement. In conclusion, analysis of LRP, PGP, CD18 and Ki-67 could be helpful to predict the clinical behavior of ALL.

Flow cytometric monocyte phagocytic assay for predicting platelet transfusion outcome

BACKGROUND: A new flow cytometric monocyte phagocytic assay (FMPA) was developed with 5‐chloromethyl fluorescein diacetate (CMFDA)‐labeled platelets for predicting the outcome of platelet transfusion.

Reliable, accurate determination of the leukocyte differential of leukopenic samples by using Hematoflow method.

Background Hematology analyzers may ineffectively recognize abnormal cells, and manual differential counts may be imprecise for leukopenic samples. We evaluated the efficacy of the Hematoflow method for determining the leukocyte differential in leukopenic samples and compared this method with the manual differential method. Methods We selected 249 blood samples from 167 patients with leukopenia (WBC counts, 500-2,000/µL) for analysis in this study. The EDTA-anticoagulated blood samples were analyzed using an automatic blood cell counter (DxH800; Beckman Coulter, USA) and flow cytometry (FC 500; Beckman Coulter) by using Cytodiff reagent and analysis software (Beckman Coulter). Hematoflow results were selected or calculated from DxH800 and Cytodiff results. Two trained pathologists performed a manual differential count by counting 50-100 cells. Results The precision of the Hematoflow method was superior to that of the manual method in counting 5 leukocyte subpopulations, immature granulocytes (IGs), and blasts. Blasts were detected in all 45 cases (100%) by Hematoflow. The correlation of the Cytodiff blast count to the reference count was high (r = 0.8325). For all other cell populations, the correlation of the Hematoflow results with the reference count was stronger than that of the other manual counts with the reference count. Conclusions The Hematoflow differential counting method is more reproducible and sensitive than manual counting, and is relatively easy to perform. In particular, this method detected leukemic blasts more sensitively than manual differential counts. The Hematoflow method is a very useful supplement to automated cell counting.

Vitamin B12-Responsive Pancytopenia Mimicking Myelodysplastic Syndrome

This study presents 12 patients (7 women and 5 men) with vitamin B12-responsive pancytopenia who had discordant laboratory findings and were misdiagnosed as having myelodysplastic syndrome (MDS). The median hemoglobin level was 6.5 g/dl, and the leukocyte and platelet counts were 2.85 × 109/l and 55.5 × 109/l, respectively. The median serum lactate dehydrogenase level was high (3,204.5 IU/l). The serum vitamin B12 levels were within normal limits at the initial evaluation, but a serial follow-up of the vitamin B12 levels revealed either fluctuations or a gradual decrease. The patients were initially diagnosed with MDS and responded rapidly to a 7-day parenteral B12 treatment with normal complete blood counts (CBCs). We propose that patients suspected to have MDS may suffer from vitamin B12 deficiency and that this can be revealed by a normalization of CBCs following 7 days of treatment with parental vitamin B12.