Multiplex reverse transcription polymerase chain reaction (mRT-PCR) has recently emerged as an alternative to cytogenetics. We designed and used simplified mRT-PCR system as a molecular screen for acute leukemia. Fifteen fusion transcripts were included: BCR-ABL1, PML-RARA, ZBTB16-RARA, RUNX1-RUNX1T1, CBFB-MYH11, DEK-NUP214, TCF3-PBX1, ETV6-RUNX1, MLL-AFF1, MLL-MLLT4, MLL-MLLT3, MLL-MLLT10, MLL-ELL, MLL-MLLT1, and MLL-MLLT6. A total of 121 diagnostic acute leukemia specimens were studied, comparing the mRT-PCR system with standard cytogenetics. Fifty-six cases (46.3%) had fusion transcripts revealed by our mRT-PCR assay. The concordance rate between mRT-PCR and cytogenetics was 91.7%. However, false negative results were found in three cases who have inv(16), t(4;11) or t(11;19)(q23;p13.1), respectively. Seven cryptic translocations including ETV6-RUNX1, MLL-MLLT3, MLL-MLLT4, and PML-RARA were detected. This mRT-PCR assay is a useful screening tool in acute leukemia because it provides rapid and reliable detection of clinically important chimeric transcripts. In addition, cryptic translocations provide additional genetic information that could be clinically useful.

In up to 40% of systemic mastocytosis (SM) cases, an associated clonal hematological non-mast cell lineage disease such as AML is diagnosed before, simultaneously with, or after the diagnosis of SM. A 40-yr-old man was diagnosed with AML with t(8;21)(q22;q22). Mast cells were not noted at diagnosis, but appeared as immature forms at relapse. After allogeneic hematopoietic stem cell transplantation (HSCT), leukemic myeloblasts were not observed; however, neoplastic metachromatic blasts strikingly proliferated during the state of bone marrow aplasia, and finally, aleukemic mast cell leukemia developed. As the disease progressed, we observed serial morphologic changes from immature mast cells with myeloblasts to only metachromatic blasts and atypical mast cells as mast cell leukemia; FISH analysis showed that the neoplastic mast cells originated from the same clone as the leukemic myeloblasts of AML.

Background

The prognostic impact of the presence of differentiating neuroblasts in bone marrow (BM) remains unclear in BM metastatic neuroblastoma (NB). We aimed to identify the prognostic impact of differentiating neuroblasts in BM at diagnosis and after chemotherapy.

Methods

A total of 51 patients diagnosed with BM metastatic NB at Asan Medical Center between January 1990 and July 2005 were enrolled. BM histology and laboratory data along with overall survival (OS) were compared with regard to the differentiation status of neuroblasts in BM at diagnosis and after chemotherapy.

Results

Among the 51 patients, 13 (25.5%) exhibited differentiating neuroblasts in BM at diagnosis and 17/51 (33.3%) exhibited them after chemotherapy. The only significant difference among patient groups was the improved OS in patients with differentiated neuroblasts in BM at diagnosis (P=0.021). In contrast, the differentiation status of neuroblasts in BM after chemotherapy did not affect OS (P=0.852).

Conclusions

Our study is the first report describing the presence of differentiating neuroblasts in BM. The presence of differentiating neuroblasts in BM at diagnosis may be a favorable prognostic factor for patients with BM metastatic NB; however, the same phenomenon after chemotherapy is irrelevant to prognosis.

Background

Flow cytometric immunophenotyping has been used to identify neoplastic plasma cell populations in patients with multiple myeloma (MM). Previous reports have described the use of several antigens, including CD38, CD138, CD56, CD117, CD52, CD19 and CD45, to distinguish distinct populations of plasma cells. The aim of this study was to evaluate a simplified immunophenotyping panel for MM analysis.

Methods

A total of 70 patients were enrolled in the study, 62 of which were newly diagnosed with MM (untreated), whereas the remaining 8 were undergoing bone marrow assessment as part of follow-up after treatment (treated). Treated cases included 3 patients with relapse and 5 patients with persistence of MM. Multiparametric flow cytometric immunophenotyping was performed using monoclonal antibodies against CD56, CD19, CD138 (CD38), and CD45.

Results

In differential counts, plasma cells in bone marrow (BM) accounted for 3.6-93.2% of the total nucleated cell count. The positive expression rates of CD56, CD19, CD138, and CD45 in neoplastic myeloma cells were 83.9%, 0%, 98.4%, and 37.1%, respectively, among the 62 untreated cases, and 75.0%, 0%, 87.5%, and 37.5%, respectively, among the 8 treated cases. CD19 expression of neoplastic plasma cells was negative in both untreated and treated cases.

Conclusion

The simplified immunophenotyping panel, CD56/CD19/CD138(CD38)/CD45, is useful for distinguishing neoplastic myeloma cells from reactive plasma cells in clinical practice. In addition, CD19 represents the most valuable antigen for identifying neoplastic myeloma cells in patients with MM.

The development of a prophylactic vaccine that targets human papillomaviruses (HPV) 6, 11, 16, and 18 to prevent cervical cancer has increased interest in the ethnic and geographical distributions of HPV genotypes. We investigated HPV prevalence and type distribution by restriction fragment mass polymorphism (RFMP) testing a total of 60,775 specimens (aged 18-79 yr, median 44) taken from liquid-based cytology. Overall HPV positive rate of total patients was 34.2%. Among the positive patients, 87.7% was single type infections, and 12.3% was multiple HPV types. HPV-16 was the most prevalent genotype observed in 2,307 (26.0%), followed by type 52 in 2,269 (25.5%), type 58 in 1,090 (12.3%), type 18 in 633 (7.1%), type 56 in 436 (4.9%). The pattern of high risk-HPV positive rate according to age showed U-shape with a peak in HPV prevalence among women less than 30 yr of age, and a second peak among the older females aged 70 to 79 yr. The leading four high-risk HPV genotypes were HPV-16, HPV-52, HPV-58, and HPV-18 in descending order. In conclusion, this study provides the most representative prevalence and type-specific distribution of HPV among Korean women, and demonstrates that the epidemiology of HPV infection is different from that of other regions of the world.

Background

It is critical to differentiate heparin-induced thrombocytopenia (HIT) from disseminated intravascular coagulation (DIC) in heparinized intensive care unit (ICU) patients with thrombocytopenia because the therapeutic approach differs based on the cause. We investigated the usefulness of PF4/heparin antibody tests in these patients.

Methods

A total of 127 heparinized ICU patients whose platelet counts were <150×109/L or reduced by >50% after 5-10 days of heparin therapy were enrolled. PF4/heparin antibodies were measured using 2 immunoassays. We assessed the probability of HIT by using Warkentin's 4T's scoring system for antibody positive patients and compared routinely performed coagulation test results between patients with and without antibodies to evaluate the ability of these tests to discriminate between HIT and DIC.

Results

Positive results were obtained for 14 (11.0%) and 11 (8.7%) patients in the 2 assays. The analysis performed using the 4T's scoring system revealed that 11 of 20 (15.7%) patients with antibodies in at least 1 assay had intermediate or greater probability of HIT. Patients without antibodies had significantly higher levels of D-dimer than those with antibodies. However, there were no intergroup differences in platelet counts, PT, aPTT, fibrinogen, DIC score, and rate of overt DIC.

Conclusion

Seropositivity for PF4/heparin antibody was 8.7-11.0% in the patients with thrombocytopenia, and more than a half of them had an increased probability of HIT. Among the routine coagulation tests, only D-dimer was informative for differentiating HIT from DIC. PF4/heparin antibody test is useful to ensure appropriate treatment for thrombocytopenic heparinized ICU patients.

Background

Primary central nervous system lymphoma (PCNSL) rarely relapses in extracranial sites, and no specialized guidelines for follow-up evaluation have been proposed.

Methods

We analyzed 65 patients with newly diagnosed PNCSL to evaluate the pattern of relapse and prognostic factors.

Results

Of the 65 patients analyzed, 55 had only parenchymal brain disease, and 10 had both intracranial and extracranial lesions. As a first-line treatment, 29 patients received chemotherapy only (CTx), 13 received chemotherapy followed by whole brain radiotherapy (CTx-WBRT), 18 received chemotherapy followed by autologous stem cell transplantation (CTx-ASCT), 2 received palliative WBRT, and 3 received best supportive care. The overall response rate to the initial treatment was 75.8%, with specific response rates of 62.1% to CTx, 84.6% to CTx-WBRT, and 100% to CTx-ASCT. The complete response (CR) rate was higher with CTx-ASCT than in the absence of ASCT (77.8% vs. 43.2%; P=0.025). After a median follow-up of 18.8 months, the median failure-free survival (FFS) and overall survival (OS) were 13.0 and 36.1 months, respectively. No systemic relapse without a CNS lesion was noted. Multivariate analysis showed that ASCT was predictive of better FFS but not of OS. Age and the Memorial-Sloan Kettering Cancer Center prognostic score were predictive of survival.

Conclusion

We observed no systemic relapse without a CNS lesion, suggesting that regular systematic evaluation of extracranial sites may not always be necessary. Age was prognostic of survival irrespective of treatment scheme. ASCT may improve CR rate and FFS.

Background

Myelomatous pleural effusion (MPE) is rare in myeloma patients. We present a consecutive series of patients with MPE in a single institution.

Methods

We retrospectively reviewed the medical records of 19 patients diagnosed with MPE between 1989 and 2008 at the Asan Medical Center. Diagnoses were confirmed by cytologic identification of malignant plasma cells in the pleural fluid.

Results

Our patients showed dominance of IgA (36.8%) and IgD (31.6%) subtypes. Of 734 myeloma patients, the incidence of MPE was remarkably high for the IgD myeloma subtype (16.7%), compared to the other subtypes (1.4% for IgG and 4.6% for IgA). At the time of diagnosis of MPE, elevated serum β2-microglobulin, anemia, elevated serum lactate dehydrogenase, and elevated creatinine levels were found in 100%, 89.5%, 83.3%, and 57.9% of the patients, respectively. Approximately one-third (31.3%) of the patients had adenosine deaminase (ADA) activities in their pleural fluid exceeding the upper limit of the reported cutoff values for tuberculous pleural effusion (55.8 U/L). Chromosome 13 abnormality was seen in 77.8% of the tested patients. The median survival period from the development of MPE was 2.8 months.

Conclusions

Patients with MPE have aggressive clinical and laboratory characteristics. The preponderance of IgD myeloma in MPE patients is a noteworthy finding because IgD myeloma is a rare subtype. Elevated ADA activity in the pleural fluid is also noteworthy, and may be helpful for detecting MPE. Physicians treating myeloma patients should monitor the development of MPE and consider the possibility of a worse clinical course.

Lineage switch in acute leukemia is an uncommon event at relapse, and therefore rarely reported in the literature. Here, we have described the clinical laboratory features of four cases in which the cell lineage switched from acute lymphoblastic leukemia (ALL) to acute myeloid leukemia (AML). One patient was initially diagnosed with B-ALL, switched to T-ALL at the first relapse, and eventually, AML at the second relapse. A lineage switch represented either relapse of the original clone with heterogeneity at the morphologic level or emergence of a new leukemic clone. Further sequential phenotypic and cytogenetic studies may yield valuable insights into the mechanisms of leukemic recurrence, with possible implications for treatment selection.

Background

Fms-like tyrosine kinase 3 internal tandem duplication (FLT3 ITD) mutation is related to poor prognosis in normal-karyotype acute myeloid leukemia (AML). However, the prognostic significance of the mutation at relapse has not been adequately investigated. We investigated the prognostic significance of the FLT3 ITD mutation at relapse in normal-karyotype AML patients.

Methods

We analyzed 69 normal-karyotype AML patients, in whom paired bone marrow samples taken at initial diagnosis and subsequent relapse were analyzed for the FLT3 ITD mutation at the Asan Medical Center between 1995 and 2009.

Results

Forty patients showed a persistent wild-type genotype, 11 showed the FLT3 ITD mutation at diagnosis and relapse, and 9 lost and another 9 acquired the mutation at relapse. The mutation status at relapse affected the overall survival (OS), with the mutation group showing shorter OS and survival after relapse than the wild-type group did (P<0.001 and P<0.001, respectively), despite having received more frequent stem cell transplantation after relapse than the wild-type group did. However, no difference was detected in the OS and survival after relapse with regard to the mutation status at diagnosis.

Conclusion

The patients with FLT3 ITD mutation at relapse showed poorer prognoses than those without the mutation. However, mutation status at diagnosis did not affect the outcome. These results suggest that, in normal-karyotype AML patients with relapse, the prognostic significance of FLT3 ITD mutation at relapse is greater than that of the mutation status at diagnosis.

AML relapsing as ALL has rarely been reported. We describe the case of a 62-yr-old man who was diagnosed with erythroleukemia with a complex karyotype and achieved complete hematologic and cytogenetic remission after induction chemotherapy. However, 4 months after the initial diagnosis, he showed relapse with blasts showing a different morphology and immunophenotype and was diagnosed with precursor B-cell ALL. The relapsing precursor B-cell ALL presented with the same leukemic clones as the primary erythroleukemia. Cytogenetic analysis of his bone marrow (BM) at the time of the primary erythroleukemia showed complex karyotypic abnormalities, including monosomy 5 and monosomy 7. At relapse, his BM showed reemergence of these leukemic clones of complex karyotypic abnormalities with clonal switch. To our knowledge, this is the first case of a lineage switch from erythroleukemia to ALL.

Central nervous system (CNS) involvement in acute promyelocytic leukemia (APL) is rare, and the presence of CNS symptoms at the time of diagnosis of APL is even rarer. We report 2 cases of APL presenting with CNS involvement. A 43-yr-old woman presented with easy bruising and stuporous mentality. Her complete blood count (CBC) revealed leukocytosis with increased blasts. Bone marrow (BM) analysis was carried out, and the diagnosis of APL was confirmed. This was done by cytogenetic analysis and demonstration of PML-RARα rearrangement by reverse transcriptase PCR in the BM cells. A lumbar puncture was performed to investigate the cause of her stuporous mentality, and her cerebrospinal fluid (CSF) analysis revealed 97% leukemic promyelocytes. Despite systemic and CNS therapy, she died due to septic shock by infection and rapid disease progression only 3 days after her admission. Another patient, a 3-yr-old girl, presented with easy bruising and epistaxis, and her CBC showed pancytopenia with increased blasts. BM studies confirmed APL. Quantitative PCR for PML-RARα in the BM cells revealed a PML-RARα/ABL ratio of 0.33 and CSF analysis revealed 9.5% leukemic promyelocytes (2 of 21 cells). She received induction chemotherapy and intrathecal therapy and achieved complete remission (CR) in the BM and CNS. She has been maintained in the CR status for the past 31 months. Thus, patients with APL must be evaluated for CNS involvement if any neurological symptoms are present at the time of diagnosis.

This observational study aimed at evaluating recent superwarfarin intoxication of Korean patients. Ten patients were diagnosed as or highly suspicious for superwarfarin intoxication. Case report forms described by attending hematologists of the patients were collected and analyzed. Bleeding symptoms were varied among the patients. Patients uniformly showed prolonged prothrombin time (PT) and activated thromboplastin time (aPTT) with decreased activity of vitamin K dependent coagulation factors. Positive serum brodifacoum test results in 4 of 5 requested patients contributed to confirmatory diagnosis. Psychiatric interview revealed an attempted ingestion in one patient. High dose vitamin K1 therapy promptly corrected prolonged PT and aPTT, but hasty discontinuation caused repeated bleeding diathesis in 6 patients. Route of intoxication was unknown or not definite among 8 of 10 patients. Three patients had a possibility of environmental exposure considering their occupations: there might be intoxication by transdermal absorption or inhalation. Therefore, high dose and prolonged use of vitamin K1 therapy is necessary for effective detoxification. Further detailed investigation on environmental exposure and efforts to improve availability of the blood level test in clinic are requested.

Purpose

Our study attempted to determine the prognostic significance of minimal residual disease (MRD) detected by a simplified flow cytometric assay during induction chemotherapy in children with B-cell acute lymphoblastic leukemia (B-ALL).

Methods

A total of 98 patients were newly diagnosed with precursor B-ALL from June 2004 to December 2008 at the Asan Medical Center (Seoul, Korea). Of those, 37 were eligible for flow cytometric MRD study analysis on day 14 of their induction treatment. The flow cytometric MRD assay was based on the expression intensity of CD19/CD10/CD34 or aberrant expression of myeloid antigens by bone marrow nucleated cells.

Results

Thirty-five patients (94.6%) had CD19-positive leukemic cells that also expressed CD10 and/or CD34, and 18 (48.6%) had leukemic cells with aberrant expression of myeloid antigens. Seven patients with ≥1% leukemic cells on day 14 had a significantly lower relapse-free survival (RFS) compared to the 30 patients with lower levels (42.9% [18.7%] vs. 92.0% [5.4%], P=0.004). Stratification into 3 MRD groups (≥1%, 0.1-1%, and <0.1%) also showed a statistically significant difference in RFS (42.9% [18.7%] vs. 86.9% [8.7%] vs. 100%, P=0.013). However, the MRD status had no significant influence on overall survival. Multivariate analysis demonstrated that the MRD level on day 14 was an independent prognostic factor with borderline significance.

Conclusion

An MRD assay using simplified flow cytometry during induction chemotherapy may help to identify patients with B-ALL who have an excellent outcome and patients who are at higher risk for relapse.

Background

Therapy-related myeloid neoplasm (t-MN) is a distinct class of acute myeloid leukemia (AML) in the World Health Organization (WHO) classification. Both AML and acute lymphoblastic leukemia (ALL) may develop after treatment for primary cancer. Topoisomerase inhibitors are commonly used to treat breast cancer patients and are well-known for their effect on leukemogenesis of therapy-related acute leukemias (t-AL).

Methods

We retrospectively evaluated bone marrow test results, chromosomal findings, and clinical characteristics of 12 patients who received topoisomerase inhibitors for breast cancer treatment and later developed acute leukemia.

Results

Fourteen patients (0.2%) developed t-AL after treatment for breast cancer. Topoisomerase inhibitors were administered to 12 patients. Among them, 9 patients (75%, 9/12) were diagnosed with therapy-related AML (t-AML) and 3 patients (25%, 3/12) with therapy-related ALL (t-ALL). Eight patients (67%, 8/12) showed translocation involving 11q23 and 3 different partner genes, 19p13.1 (37.5%, 3/8), 9p22 (37.5%, 3/8), and 4q21 (25%, 2/8). The median interval between completion of chemotherapy for breast cancer and occurrence of t-AL was 25 months. Patients with 11q23 translocation showed markedly poorer event-free survival than the group without involvement of 11q23.

Conclusion

The incidence rate of t-AL after treatment for breast cancer was 0.2% in a tertiary hospital in Korea. Translocation involving the MLL gene was frequently found in t-AL caused by a topoisomerase inhibitor and was related to poor prognosis.

Although acquired mutations in the GATA1 gene have been reported for Down syndrome-related acute megakaryoblastic leukemia (DS-AMKL) in Caucasians, this is the first report of a Korean Down syndrome patient with AMKL carrying a novel mutation of the GATA1 gene. A 3-yr-old Korean girl with Down syndrome was admitted to our hospital complaining of pallor and fever. The findings of a peripheral blood smear and bone marrow study were compatible with the presence of AMKL. A chromosome study showed 48,XX,-7,+21c,+21,+r[3]/47,XX,+21c[17]. Following GATA1 gene mutation analysis, a novel mutation, c.145dupG (p.Ala49GlyfsX18), was identified in the N-terminal activation domain of the GATA1 gene. This mutation caused a premature termination at codon 67 and expression of an abnormal GATA-1 protein with a defective N-terminal activation domain, and the absence of full-length GATA-1 protein. This case demonstrates that a leukemogenic mechanism for DS-AMKL is contributed by a unique collaboration between overexpressed genes from trisomy 21 and an acquired GATA1 mutation previously seen in Caucasians and now in a Korean patient.

Pleural effusion in chronic myeloid leukemia (CML) is poorly understood and rarely reported in the literature. When the pleural effusion is caused by leukemic pleural infiltration, the differential white blood cell count of the effusion is identical to that of the peripheral blood, and the fluid cytology reveals leukemic blasts. We report here a case of bilateral pleural involvement of atypical CML in an 83-yr old male diagnosed with pancreatic cancer with abdominal wall metastasis and incidental peripheral leukocytosis. Based on bone marrow examination, chromosome analysis and polymerase chain reaction he was diagnosed with Philadelphia chromosome negative, BCR/ABL gene rearrangement negative CML. Following 3 months of treatment with gemcitabine for pancreatic cancer, he developed bilateral pleural effusions. All stages of granulocytes and a few blasts were present in both the pleural fluid and a peripheral blood smear. After treatment with hydroxyurea and pleurodesis, the pleural effusion resolved.

The prognostic significance of multidrug resistance (MDR) gene expression is controversial. We investigated whether multidrug resistance gene 1 (MDR1), multidrug resistance-related protein (MRP) and lung resistance protein (LRP) mRNA expression are associated with outcomes in acute leukemia patients. At diagnosis we examined MDR1, MRP and LRP mRNA expression in bone marrow samples from 71 acute leukemia patients (39 myeloid, 32 lymphoblastic) using nested RT-PCR. The expression of each of these genes was then expressed as a ratio in relation to β-actin gene expression, and the three genes were categorized as being either 0, 1+, 2+ or 3+. MDR1, MRP and LRP mRNA expression was detected in 23.9%, 83.1% and 45.1%, respectively. LRP mRNA expression was significantly associated with resistance to induction chemotherapy in acute leukemia patients, and in the AML proportion (p=0.02 and p=0.03, respectively). MRP and high MDR1 mRNA expression was associated with poorer 2-yr survival (p=0.049 and p=0.04, respectively). Patients expressing both MRP and LRP mRNA had poorer outcomes and had worse 2-yr survival. The present data suggest that MDR expression affects complete remission and survival rates in acute leukemia patients. Thus, determination of MDR gene expression at diagnosis appears likely to provide useful prognostic information for acute leukemia patients.