The added values of multiplex reverse transcriptase-PCR followed by mutation screening in the initial evaluation of acute leukemia.

INTRODUCTION: This study investigates the benefits of using multiplex reverse transcriptase-PCR (RT-PCR) in addition to standard karyotyping during the initial evaluation of acute leukemia. METHODS: A total of 1114 consecutive specimens from patients with acute leukemia were tested using a commercial multiplex RT-PCR kit (HemaVision, DNA Diagnostic). NPM1 and CEBPA mutations were selectively tested in acute myeloid leukemia (AML) patients with multiplex RT-PCR negativity. RESULTS: In specimens with optimal cytogenetics, the frequency of recurrent translocations was 31.3%, and cryptic translocations were detected in 2.1% of samples. The concordance rate between karyotyping and multiplex RT-PCR was 97.5%. In addition to the established functions, we demonstrated the additional benefits of multiplex RT-PCR, including successful molecular characterization, even in cytogenetically suboptimal specimens (5.7%); detection of submicroscopic aberrations (1.0%); detection of rare but potentially significant translocations or variants (2.5%); selection of AML candidates for mutation analysis (68.3%); and finally exclusion of recurrent translocations in patients with acute lymphoblastic leukemia or mixed phenotype acute leukemia (22.5%). CONCLUSION: We reconfirmed the accuracy and reliability of multiplex RT-PCR for diagnosing acute leukemia and demonstrated additional advantages of this system for the initial evaluation of acute leukemia. Thus, multiplex RT-PCR is worth considering in diagnostic testing of acute leukemias.

FISH analysis of MLL gene rearrangements: detection of the concurrent loss or gain of the 3' signal and its prognostic significance.

INTRODUCTION: The rearrangement of the mixed-lineage leukemia (MLL) gene occurs through translocations and insertions involving a variety of partner chromosome genes. However, there are few studies on aberrant MLL signal patterns such as concurrent 3' MLL deletion. METHODS: A total of 84 patients with acute leukemia (AL) who had MLL rearrangements detected by florescence in situ hybridization (FISH) were enrolled in the study. The distribution of MLL fusion partner genes was analyzed, and aberrant MLL signals were evaluated. RESULTS: Seventy-seven (91.7%) patients had MLL rearrangements, involving previously described translocation partner genes (TPGs). Among these TPGs, the frequencies of MLLT3, AFF1, MLLT4, and ELL were 29.8%, 17.9%, 15.5%, and 13.1%, respectively. A high frequency of MLLT4 in our study was due to the high proportion of acute myeloid leukemia cases in pediatric and adult patients. Aberrant MLL signals were found in 18 patients: 11 (61.1%) with 3' MLL signal loss and 7 with 3' MLL signal gain. All cases with 3' MLL signal gain were due to an extra derivative partner chromosome. The median overall survival period of patients with 3' MLL gain was shorter than that in patients without aberrant MLL signal patterns. CONCLUSION: Aberrant MLL signals were frequently detected by FISH analysis. The 3' MLL gain was associated with poor prognosis in patients with AL. Therefore, it is important to detect aberrant MLL signal patterns using FISH analysis.

Lack of positive effect of intravitreal bevacizumab in central serous chorioretinopathy: meta-analysis and review.

PURPOSE: To review and evaluate the effects of intravitreal bevacizumab injection (IVB) in centralserous chorioretinopathy (CSC) by meta-analysis. PATIENTS AND METHODS: Clinical controlled studies that evaluated the effect of IVB in CSC were identified through systematic searches of Embase, PubMed, and the Cochrane Central Register of Controlled Trials. Data on the best-corrected visual acuity (BCVA) in logMAR and central macular thickness (CMT) in µm at baseline and 6 months after IVB were extracted and compared with those treated by simple observation. RESULTS: Four clinical controlled studies were included in the meta-analysis. The IVB injection group achieved better BCVA at a follow-up of 6 months. However, the analysis showed that there were no significant differences of BCVA at 6 months after injection between IVB group and the observation group (-0.02 logMAR, 95% CI -0.14 to 0.11, P=0.80). The analysis of the reduction in CMT revealed that the difference between groups was not statistically significant (-8.37 µm, 95% CI -97.26 to 80.52, P=0.85). No report assessed severe complications or side effects of IVB in patients with CSC. CONCLUSIONS: Meta-analysis failed to verify the positive effect of IVB in CSC based on the epidemiological literature published to date.

Differential diagnosis of myelofibrosis based on WHO 2008 criteria: acute panmyelosis with myelofibrosis, acute megakaryoblastic leukemia with myelofibrosis, primary myelofibrosis and myelodysplastic syndrome with myelofibrosis.

INTRODUCTION: The aim of this study was to characterize clinicopathological features of acute panmyelosis with myelofibrosis (APMF), acute megakaryoblastic leukemia with myelofibrosis (AMKL-MF), primary myelofibrosis (PMF) and myelodysplastic syndrome with myelofibrosis (MDS-MF) in order to provide the keys to the differential diagnosis of bone marrow (BM) fibrosis. METHODS: We compared age, gender, splenomegaly, serum lactate dehydrogenase level, blood cell counts, blast counts in peripheral blood (PB) and BM, megakaryocyte counts, BM cellularity, dysplasia, and the karyotypes of patients with APMF (n = 6), AMKL-MF (n = 7), PMF (n = 44), and MDS-MF (n = 44). RESULTS: APMF showed hyperplasia of all three lineages, increase in megakaryocyte count with dysplasia and frequent abnormal karyotypes. AMKL-MF was associated with elevated BM blast counts, decreased BM megakaryocyte count with rare megakaryocytic dysplasia and chromosome 21 abnormality. PMF patients displayed splenomegaly, rare blasts in PB/BM, and JAK2 V617F mutation. MDS-MF patients showed pancytopenia, dysplasia in all three lineages and recurrent chromosomal abnormalities involving chromosome 5,7,12, and 17. CONCLUSIONS: Although differential diagnosis among APMF, AMKL-MF, PMF, and MDS-MF is very challenging due to the overlapping clinical and morphological features, meticulous investigation of the patient with respect to splenomegaly, blood cell count, PB and BM findings, and karyotype will serve as a guide to correct diagnosis.

Detection of ABL1 kinase mutations in Philadelphia-positive patients exhibiting an inadequate molecular response using restriction fragment mass polymorphism and its clinical significance: a single-center experience in Korea.

INTRODUCTION: ABL1 kinase mutations represent a major mechanism of imatinib resistance in Philadelphia-positive (Ph+) patients. There is a paucity of data on ABL1 kinase mutations in Ph+ patients in Korea. METHODS: We used restriction fragment mass polymorphism (RFMP) analysis to detect ABL1 kinase mutations in blood or bone marrow specimens from 80 Ph+ patients. RESULTS: Fifty-seven patients met the criteria for inadequate molecular response (IMR). ABL1 kinase mutations were found in 2.6% of patients with chronic-phase chronic myelogenous leukemia (CML), 25.0% of accelerated-phase CML, 66.7% of blast-phase CML, and in 58.3% with Ph+ acute lymphoblastic leukemia. Twelve mutations were identified: 7 T315I, 2 E255V, 1 E255K, 1 F359V, and 1 Y253H. The majority of mutation-positive patients showed an unfavorable clinical course and often had an extra Ph or additional chromosomal abnormalities. Mutations were detected in two patients who had very low or absent BCR-ABL1 normalized ratios. CONCLUSION: Mutation analysis should be performed in Ph+ patients exhibiting an IMR to imatinib. RFMP analysis is helpful for revising therapeutic strategies because it can sensitively detect clinically relevant ABL1 kinase mutations with high frequencies.

Application of an immune-magnetic cell sorting method for CD138-positive plasma cells in FISH analysis of multiple myeloma.

INTRODUCTION: Interphase fluorescence in situ hybridization (FISH) analysis of multiple myeloma (MM) may indiscriminately count signals of nonplasma cells, thus decreasing specificity and sensitivity. We aimed to evaluate the usefulness of an immune-magnetic sorting method for plasma cells in FISH analysis of MM and define optimal sample preparation conditions. METHODS: Plasma cells were purified using EasySep(®) CD138 Positive Selection Cocktail and Magnetic Nanoparticles (Invitrogen). We compared FISH results with and without plasma cell purification for three sample preparation methods: direct harvest, 24-h culture, and 96-h culture with interleukin-4 in five newly diagnosed MM patients. Archived fixed bone marrow cells of 17 MM patients were also studied. RESULTS: The percentage of abnormal cells identified was significantly higher with plasma cell purification than without purification (median, 88.0%; range, 84.0-100.0%vs. 15.0%, 12.5-29.5%, respectively). The three sample preparation methods showed comparable results. Immune-magnetic sorting also significantly increased the percentage of abnormal cells identified in FISH analysis of archived fixed bone marrow cells (P < 0.001). CONCLUSIONS: Immune-magnetic CD138-positive cell sorting significantly increased the percentage of abnormal cells identified in FISH analysis of MM samples for all sample preparation methods. This method could also be applied for retrospective FISH analysis of archived fixed bone marrow cells.

A rare case of Lennert's type peripheral T-cell lymphoma with t(14;19)(q11.2;q13.3).

Although most patients with peripheral T-cell lymphoma (PTCL) show clonal rearrangement of T-cell receptor genes, few PTCLs show recurrent chromosomal abnormalities. We describe here a rare chromosomal rearrangement, t(14;19)(q11.2;q13.3), in a Lennert's lymphoma, a variant of PTCL, not otherwise specified. Sequential fluorescence in situ hybridization assays showed that the breakpoint in 19q13.3 was located distal to the BCL3 and PVRL2 genes, both of which may be candidate proto-oncogenes. These findings suggest that another gene is involved in the pathogenic characteristics observed in this patient with Lennert's lymphoma.

Allogeneic hematopoietic cell transplantation for myelodysplastic syndrome: prognostic significance of pre-transplant IPSS score and comorbidity.

We analyzed the clinical significance of pre-transplant International Prognostic Scoring System (IPSS) score and comorbidity in 68 patients who underwent allogeneic hematopoietic cell transplantation (HCT) for myelodysplastic syndrome (MDS) (n=48) or acute myeloid leukemia evolved from MDS (n=20) between December 1995 and January 2008 in a single institute. During a median follow-up period of 41.0 months (range, 3.2-132.0 months), 27 patients died, and 7 relapsed. The 5-year probabilities of overall survival (OS) and event-free survival (EFS) were 60.0 and 57.4%, respectively, and the 5-year cumulative incidences of non-relapse mortality (CINRM) and relapse were 32.7 and 9.9%, respectively. OS, EFS, and CINRM were significantly different according to pre-transplant IPSS score and presence of pre-transplant comorbidity, which were independent risk factors along with Karnofsky performance score in multivariate analyses. In conclusion, pre-transplant IPSS score and comorbidity may stratify the risk of post transplant outcomes in MDS.

Clinical effect of imatinib added to intensive combination chemotherapy for newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia.

Clinical impact of imatinib was evaluated in 20 patients (median age, 37 years; range, 15-67 years) with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), who were administered with induction chemotherapy of daunorubicin, vincristine, prednisolone, and L-asparaginase, along with imatinib 600 mg/day during remission induction and 400 mg/day during consolidation courses. One patient died on day 14 from septic shock, while the remaining 19 achieved complete remission (CR). In total, 15 patients underwent allogeneic hematopoietic cell transplantation (HCT) during first CR. After median follow-up period of 799 days, six patients experienced recurrence; two with early recurrence within 100 days, one with leptomeningeal recurrence at 11 month, and three with post-HCT recurrence. Eight patients died. Median CR duration (821 days) and median patient survival (894 days) in the study were significantly longer by 2.9- and 2.3-fold, respectively, when compared to those of 18 historical patients treated with same regimen of combination chemotherapy without imatinib. Toxicities of the combined treatment were manageable and included grade 4 myelosuppression (n = 20) and reversible > or = grade 3 hyperbilirubinemia (n = 4). Beneficial clinical effects were observed when imatinib was added to combination chemotherapy in patients with newly diagnosed Ph+ ALL. Further studies with larger number of patients are necessary.

Bone marrow vs extramedullary relapse of acute leukemia after allogeneic hematopoietic cell transplantation: risk factors and clinical course.

A total of 118 consecutive adult patients with acute leukemia (78 AML, 36 ALL, and four acute mixed lineage leukemia) underwent allogeneic hematopoietic cell transplantation (HCT) after conditioning with BuCy (n=113) or a nonmyeloablative regimen of busulfan-fludarabine (n=5). After a median follow-up of 35.8 months (range, 6.4-91.0), 34 patients experienced at least one episode of leukemia relapse. Of 34 initial episodes, 14 (41%) occurred in extramedullary sites, with (n=8) or without (n=6) concomitant bone marrow involvement. The median time to relapse in the extramedullary sites was longer than that of relapse in bone marrow only (13.5 vs 6.1 months, P=0.046). Acute leukemia subtype and disease status at HCT showed an independent predictive value for overall relapse, as well as for extramedullary relapse with or without bone marrow involvement (Philadelphia chromosome positive acute leukemia vs low-risk AML, relative risk 22.68 (95% CI, 2.18-235.64); other than first CR vs first CR, relative risk 5.61 (95% CI, 1.80-17.51)), but not for bone marrow relapse. Our study suggests that there may be different pathogenetic mechanisms for bone marrow vs extramedullary relapse of acute leukemia after allogeneic HCT. The mode of relapse needs to be investigated in future reports of acute leukemia treated with allogeneic HCT.

Application of different prognostic scoring systems and comparison of the FAB and WHO classifications in Korean patients with myelodysplastic syndrome.

We retrospectively studied 227 patients with MDS (1) to identify the prognostic factors of survival and acute leukemia evolution in Korean patients with MDS, (2) to apply different prognostic scoring systems to the same group of patients, and (3) to compare the FAB with the WHO classification. Six scoring systems were applied to the patients, and the FAB and WHO classifications were compared. The patients' median age was 57 years. The median survival time was 21 months, and age, dysgranulopoiesis and the IPSS cytogenetic groups were independent prognostic factors for survival. Acute leukemia occurred in 34 patients, and the cumulative incidence was 27.1% at 3 years. Marrow blast percentage was the only independent prognostic factor for acute leukemia evolution. Most scoring systems successfully discriminated risk groups for survival and acute leukemia evolution, but patient distribution into risk groups varied according to the scoring systems. Refractory cytopenia with multilineage dysplasia and RAEB II seemed to have different prognoses from RA or RARS and RAEB I, respectively. In summary, our MDS patients had different disease natures from those of Western countries regarding clinical features, prognostic factors and cytogenetic profiles. Although the WHO classification seems to improve the FAB classification, further studies are warranted to validate the utility of the WHO classification before it is accepted for routine clinical use. Our study has the limitations of retrospective analysis, and our results should be verified in future prospective studies.

A case of biphenotypic blast crisis of unclassified myeloproliferative disorder.

We report a first case of biphenotypic blast crisis of unclassified myeloproliferative disorder (MPD). A 20-year-old patient presented with fever, splenomegaly, marked leukocytosis (603 x 10(3)/ micro l), and blasts in the peripheral blood. Since Ph chromosome and bcr-abl gene rearrangement were absent, the diagnosis of an unclassified MPD in the blast crisis phase was established. Immunophenotyping confirmed a biphenotypic crisis of myeloid and T-lymphoid antigens. The patient went into a complete remission after chemotherapy, but marked granulocytic hyperplasia (M:E ratio of 5.7) and 90% cellularity remained. Blast crisis recurred during subsequent intensification chemotherapy and the patient did not go into a complete remission regardless of the intense chemotherapy. The blast crisis transformed from unclassified MPD had a grave prognosis as it responded poorly to chemotherapy. This unique blast crisis is distinguishable from the blast crisis of chronic myelogenous leukemia.

Role of the connectivity of secondary structure segments in the folding of alpha(1)-antitrypsin.

The native form of serpins (serine protease inhibitors) is metastable, which is critical to their biological functions. Spontaneous conversion from the native form of serpins into a more stable conformation, called the "latent" form, is restricted. To examine whether the connectivity of strand 1 of beta-sheet C to the hydrophobic core is critical to the serpin's preferential folding to the metastable native conformation, we designed a circularly-permuted mutant of alpha(1)-antitrypsin, the prototype serpin, in which strand 1C is disconnected from the hydrophobic core. Conformation of the circular permutant was similar to that of the latent form, as revealed by equilibrium unfolding, limited proteolysis, and spectroscopic properties. Our results support the notion that rapid folding of the hydrophobic core with concomitant incorporation of strand 1C into beta-sheet C traps the serpin molecule into its native metastable conformation.

Juxtaglomerular cell tumor of the kidney: a case report.

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3 x 3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.

A 2.1 A resolution structure of an uncleaved alpha(1)-antitrypsin shows variability of the reactive center and other loops.

Serpin (serine protease inhibitor) proteins are involved in diverse physiological processes including inflammation, coagulation, matrix remodeling, and cell differentiation. Deficiency of normal serpin functions leads to various hereditary diseases. Besides their clinical importance, serpin proteins draw much attention due to the large conformational changes that occur upon interaction with proteases. We present here the crystal structure of an uncleaved alpha(1)-antitrypsin determined by the multiple isomorphous replacement method and refined to 2.1 A resolution. The structure, which is the first active serpin structure based on experimental phases, reveals novel conformations in the flexible loops, including the proximal hinge region of the reactive center loop and the surface cavity region in the central beta-sheet, sheet A. The determined loop conformation explains the results of recent mutagenesis studies and provides detailed insights into the protease inhibition mechanism. The high-resolution structure of active alpha(1)-antitrypsin also provides evidence for the existence of localized van-der-Waals strain in the central hydrophobic core.

Interaction of blood components with heparin-immobilized polyurethanes prepared by plasma glow discharge.

The blood compatibility of poly(ethylene oxide) (PEO)-grafted and heparin (Hep) immobilized polyurethanes was investigated using in vitro plasma recalcification time (PRT), activated partial thromboplastin time (APTT), platelet adhesion and activation, and peripheral blood mononuclear cell (PBMC) adhesion and activation. In the experiment with plasma proteins, the PRT of the polyurethane (PU) surface was prolonged by PEO grafting and further prolonged by heparin immobilization. The APTT was prolonged on PU-Hep, suggesting the binding of immobilized heparin to antithrombin III. The percentage of platelet adhesion on PU was not much different from that on acrylic acid- and PEO-grafted PUs (PU-C, PU-6, PU-33), yet was substantially decreased by heparin immobilization (PU-6-Hep, PU-33-Hep). The release of serotonin from adhering platelets was slightly suppressed on PEO-grafted PUs yet significantly suppressed on heparin-immobilized PUs. In the PBMC experiments, the adhesion and activation of the cells were significantly suppressed on heparin-immobilized PUs, and the amount of interleukin-6 (IL-6) released from PBMCs stimulated with surface-modified PUs decreased with a decrease in PBMC adhesion.

Ontogeny of natural killer cells and T cells by analysis of BCR-ABL rearrangement from patients with chronic myelogenous leukaemia.

Chronic myelogenous leukaemia (CML) is a haematological malignant disorder characterized by the Philadelphia chromosome (Ph) and BCR-ABL gene rearrangement. This abnormal fusion gene can be considered to serve as a marker for the transformed cell clone in CML and is found in all cells arising from the same malignant precursor cell. It has been detected in CML cells of the myeloid, monocytic, erythroid and B-lymphocytic lineages. However, it is still arguable as to whether T lymphocytes or natural killer (NK) cells carry this marker. Answering this question would clarify the ontogenic relationship between NK cells and T cells. We examined 12 CML patients and studied the expression of BCR-ABL rearrangement by fluorescence in situ hybridization (FISH) in both NK cells and T cells sorted by flow cytometry. The purity of T cells was 95.6-99.8% and that of NK cells was 95.3-99.3% after sorting. Neither NK cells nor T cells showed any positive BCR-ABL signal with the exception of one patient who recovered from a lymphoid blastic crisis. We speculate that T cells and NK cells originate from BCR-ABL-negative stem cells.

p53 gene mutations in Bowen's disease in Koreans: clustering in exon 5 and multiple mutations.

We analyzed the p53 protein expression and gene mutations to evaluate the role of ultraviolet radiation or other carcinogens, and possible racial differences in 17 samples from 12 Korean patients with Bowen's disease. A simple microdissection technique was used to collect the tumor cells selectively. p53 protein expression was found in eight of 17 (47%) samples. Abnormalities in polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis were observed in 16 (94%) samples. A total of 14 missense mutations were detected in eight (47%) samples; 11 were clustered in exon 5 and the remaining three were located in exon 8. UV-like mutations were seen in five of 14 (36%) mutations, but no CC to TT transitions, UV-fingerprint mutations were observed. Multiple mutations were present in two cases and double mutation in a single case. Each lesion in multiple Bowen's disease showed different mutations and was suggested to be of different clonal origins. TP53-loss of heterozygosity (LOH) was detected in four out of 15 (27%) informative samples. Clustering of mutations in exon 5 suggests the role of another carcinogen in Koreans or Asians other than the UVR. Microdissection would increase the detection rate of the p53 gene mutations and LOH not only in skin cancer but also in precancerous lesions.