Jong-Ha Yoo

Oxidative status in iron‐deficiency anemia

Oxidative stress is an imbalance between free radicals and antioxidant molecules that can play an important role in the pathogenesis of iron‐deficiency anemia (IDA). The aim of this study was to investigate oxidative status in patients with IDA and alteration of oxidative status after iron treatment. Thirty‐three female patients with IDA and 25 healthy controls were included in this study. Oxidant and total antioxidant capacity were determined using free oxygen radicals test and free oxygen radicals defence (Form CR 3000, Callegari, Parma, Italy). Catalase activity was measured by spectrophotometer using a commercially available kit (Bioxytech Catalase‐520, OxisResearch, Portland, OR). Oxidant activity in patients with IDA was significantly higher than controls (P<0.05), while total antioxidant and catalase activity were significantly lower (P<0.05). After treatment, oxidant, antioxidant, and catalase activity reached the levels of the control group, and no significant differences were observed among groups (P>0.05). In conclusion, our data indicate that blood reactive oxygen species was lower and total antioxidant and catalase activity were higher after rather than before treatment in patients with IDA. The results of our study support the higher oxidative stress hypothesis in IDA; however, due to the limited number of cases included, more studies may be required to confirm the results. J. Clin. Lab. Anal. 23:319–323, 2009.

JAK2 V617F/C618R mutation in a patient with polycythemia vera: a case study and review of the literature.

The acquired Janus kinase 2 (JAK2) V617F mutation shows a high frequency in diverse BCR/ABL-negative chronic myeloproliferative disorders (CMPD), and it is typically associated with polycythemia vera (PV). The frequency of JAK2 V617F mutation is about 90% in patients with PV, 50-60% in patients with essential thrombocythemia (ET), primary myelofibrosis (PMF), and less in patients with other myeloid neoplasms, while extremely rare in lymphoid malignancies. About 20 kinds of novel mutations of JAK2 other than V617F have been reported recently in the literature. Among these mutations, only one case of JAK2 V617F/C618R has been reported in a 67-year-old patient with PV. Here, we report a rare case of JAK2 V617F/C618R in a 41-year-old Korean male patient with review of the relevant literature on JAK2 mutations other than V617F. Although the frequency of JAK2 mutations other than the V617F is very low, this study emphasizes the need for assiduous analysis of the JAK2 gene to characterize new mutations, to determine their frequency, and to improve understanding of the clinical phenotypes as well as prognostic and biologic features associated with these mutations.

Analysis of fluorescence in situ hybridization, mtDNA quantification, and mtDNA sequence for the detection of early bladder cancer

We designed this study to test the sensitivities of cytology, the nuclear matrix protein 22 (NMP22) assay, and fluorescence in situ hybridization (FISH) in the early detection of urothelial carcinoma, and to identify mtDNA alterations in urinary epithelial cells. We collected 41 urine samples and 26 corresponding peripheral blood samples from patients with clinically suspected urothelial carcinoma. The FISH and NMP22 assays detected 92.1% of the cancers, and cytology detected 60.5%. In the low-grade group, NMP22 and FISH analyses were more sensitive than cytology, but in the high-grade group, all three methods showed approximately 90% sensitivity. Overall, the FISH and NMP22, or FISH and cytology assays combined detected 97.4% of cancers, while cytology with NMP22 detected 92.1%. In the low-grade group, the sensitivity of the three methods combined was above 80%, but in high-grade group, the combined sensitivity was approximately 100%. In the mtDNA control region, we detected characteristic heteroplasmic mtDNA substitution mutations in 1 patient and a mtDNA length heteroplasmic mutation in 303 polyC or 16184 poly C in 20 patients. Overall, urothelial carcinoma-specific mtDNA mutations were observed in 20 of the 26 patients (76.9%). The average mtDNA copy numbers in urine samples and corresponding peripheral blood samples (83.45 +/- 60.36 and 39.0 +/- 24.38, respectively) (mean +/- standard deviation [SD]) differed significantly (P < 0.001). The mtDNA copy numbers in the urine samples from patients with high-grade and low-grade tumors (81.83 +/- 67.78 and 86.49 +/- 46.69, respectively) did not differ significantly (P = 0.589). In conclusion, the FISH assay showed the highest sensitivity for detecting low-grade urothelial carcinoma, and mtDNA copy numbers in urine samples were higher than those in the corresponding peripheral blood samples. The frequency of mtDNA mutations in the D-loop region in patients with cancer was approximately 80% in our study. This report further supports the significance of genetic alteration in urothelial carcinoma and the clinical utility of the FISH, mtDNA quantitation polymerase chain reaction, mtDNA sequencing, and capillary electrophoresis for this purpose.

Automated Detection of Malaria-Associated Pseudoeosinophilia and Abnormal WBC Scattergram by the Sysmex XE-2100 Hematology Analyzer: A Clinical Study with 1,801 Patients and Real-Time Quantitative PCR Analysis in Vivax Malaria-Endemic Area

Recently, the XE-2100 hematology analyzer was investigated in a rather small patient group; pseudoeosinophilia or abnormal white blood cell (WBC) scattergrams reported by this instrument were considered as significantly valuable diagnostic parameters in detecting vivax malaria. This study was conducted not only to assess the usefulness of pseudoeosinophilia or abnormal WBC scattergram in vivax malaria-endemic areas with large patient groups (N = 1,801) but also to investigate the correlation of parasitemia and platelet count with pseudoeosinophilia and abnormal WBC scattergrams. Of the 1,801 analyzed patients, 413 (22.9%) were found to have malaria by Wright-Giemsa stained blood smears. Overall, either pseudoeosinophilia or abnormal WBC scattergram was detected in 191 of 413 malaria patients and 4 of 1,388 patients without malaria (sensitivity = 46.2%, specificity = 99.7%). We suggest that clinical hematology laboratories using the XE-2100 analyzer should be aware of such specific parameters, even with the absence of a clinical request.

Clinical characterization and molecular classification of 12 Korean patients with pseudohypoparathyroidism and pseudopseudohypoparathyroidism.

CONTEXT Pseudohypoparathyroidism (PHP) is defined as resistance toward parathyroid hormones. PHP and pseudopseudohypoparathyroidism (PPHP) are rare disorders resulting from genetic and epigenetic aberrations within or upstream of the GNAS locus. This study investigated the clinical characteristics and performed a molecular analysis of PHP and PPHP. METHODS A total of 12 patients with (P)PHP from 11 unrelated families (4 with PHP-Ia, 6 with PHP-Ib, and 2 with PPHP) were characterized using both clinical and molecular methods. Clinical features included the presenting symptoms, Albright hereditary osteodystrophy features, and resistance to hormones. Comprehensive analysis of the GNAS and STX16 loci was undertaken to investigate the molecular defects underlying (P)PHP. RESULTS All PHP-Ib patients displayed hypocalcemic symptoms. All PHP-Ia patients showed resistance toward TSH, in addition to PTH. In most patients with PHP, when the diagnosis of PHP was first established, hypocalcemia and hyperphosphatemia were associated with a significant increase in serum PTH levels. One patient with PHP-Ia was diagnosed with growth hormone deficiency and showed a good response to human recombinant growth hormone therapy. 6 patients with PHP-Ia and PPHP showed 5 different mutations in the GNAS gene. 5 patients with PHP-Ib displayed a loss of differentially methylated region (DMR) imprints of the maternal GNAS. One PHP-Ib patient showed a de novo microdeletion in STX16 and a loss of methylation of exon A/B on the maternal allele. No patients revealed paternal disomy among 4 patients with PHP-Ib. CONCLUSIONS Identification of the molecular causes of PHP and PPHP explains their distinctive clinical features and enables confirmation of the diagnosis and exact genetic counseling.

Hereditary protein S deficiency from a novel large deletion mutation of the PROS1 gene detected by multiplex ligation-dependent probe amplification (MLPA).

a Department of Laboratory Medicine, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea b Department of Laboratory Medicine & Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea c Department of Internal Medicine, National Health Insurance Corporation Ilsan Hospital, Goyang, Korea d Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea

Heterogeneous lengths of copy number mutations in human coagulopathy revealed by genome-wide high-density SNP array

Background The recent advent of genome-wide molecular platforms has facilitated our understanding of the human genome and disease, particularly copy number aberrations. We performed genome-wide single nucleotide polymorphism-array in hereditary coagulopathy to delineate the extent of copy number mutations and to assess its diagnostic utility. Design and Methods The study subjects were 17 patients with hereditary coagulopathy from copy number mutations in coagulation genes detected by multiple ligation-dependent probe amplification. Eleven had hemophilia (7 hemophilia A and 4 hemophilia B) and 6 had thrombophilia (4 protein S deficiency and 2 antithrombin deficiency). Single nucleotide polymorphism-array experiments were performed using Affymetrix Genome-Wide Human SNP arrays 6.0. Results Copy number mutations were identified by single nucleotide polymorphism-array in 9 patients, which ranged in length from 51 Kb to 6,288 Kb harboring 2 to ~160 genes. Single nucleotide polymorphism-array showed a neutral copy number status in 8 patients including 7 with either a single-exon copy number mutation or duplication mutations of PROS1. Conclusions This study revealed unexpectedly heterogeneous lengths of copy number mutations underlying human coagulopathy. Single nucleotide polymorphism-array had limitations in detecting copy number mutations involving a single exon or those of a gene with homologous sequences such as a pseudogene.

A novel de novo mutation in the serine-threonine kinase STK11 gene in a Korean patient with Peutz-Jeghers syndrome

BackgroundPeutz-Jeghers syndrome (PJS) is an unusual autosomal dominant disorder characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartomatous polyps. Patients with PJS are at an increased risk of developing multi-organ cancer, most frequently those involving the gastrointestinal tract. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS.MethodsUsing DNA samples obtained from the patient and his family members, we sequenced nine exons and flanking intron regions of the STK11 gene using polymerase chain reaction (PCR) and direct sequencing.ResultsSequencing of the STK11 gene in the proband of the family revealed a novel 1-base pair deletion of guanine (G) in exon 6 (c.826delG; Gly276AlafsX11). This mutation resulted in a premature termination at codon 286, predicting a partial loss of the kinase domain and complete loss of the C-terminal domain. We did not observe this mutation in both parents of the PJS patient. Therefore, it is considered a novel de novo mutation.ConclusionThe results presented herein enlarge the spectrum of mutations of the STK11 gene by identifying a novel de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS with or without a positive family history.

Detection of SET-NUP214 rearrangement using multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) in acute leukemias: a case report and literature review on a Korean case series

Dear Editor, We read an interesting article in a recent issue of the Annals of Hematology by Chae et al. entitled “Phenotypic and genetic characterization of adult T-cell acute lymphoblastic leukemia with del (9) (q34); SET-NUP214 rearrangement” [1]. Here, we would like to point out why the number of recent reports on the above gene rearrangement in Korea is increasing and suggest the most appropriate molecular diagnostic method for the detection of the SET-NUP214 rearrangement, by reporting a new case of SET-NUP214 from a T-cell acute lymphoblastic leukemia (T-ALL) patient and through literature review of the ten reported cases, including our new case, that reports on acute leukemias with SET-NUP214 in Korea between the 2-year period of 2010–2011 from the literature [1–4]. A 43-year-old Korean woman was examined in the outpatient clinic with fever and skin rash lasting from 50 days ago. She received uterine leiomyomectomy a year ago and had her breast mass monitored periodically. A chest X-ray revealed bilateral mediastinal widening, suggesting huge mediastinal mass or lymphadenopathy and abdominal ultrasonography showed splenomegaly. An initial complete blood count showed a hemoglobin level of 8.8 g/dL, a platelet count of 114×10/L, and a white blood cell count of 60.6×10/L with 85% blasts, 2% neutrophils, and 13% lymphocytes (Fig. 1a). Bone marrow study showed a hypercellularity with markedly increased leukemic blasts (91%, Fig. 1a). The karyotype of the bone marrow cells was 46,XX,dup(1)(p22p36.1) in 16 out of 20 metaphase cells analyzed (Fig. 1b). According to immunophenotyping, blasts were positive for CD3 (84%), CD5 (78%), CD7 (99%), CD13 (43%), CD33 (48%), and CD34 (80%). However, these cells did not express CD10, CD19, CD20, cCD22, CD14, HLA-DR, and myeloperoxidase. Multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) analysis using bone marrow specimen was performed with HemaVision kit (HemaVision; DNA technology, Aarhus, Denmark) and revealed the presence of SET-NUP214 fusion transcript measuring 393 bp (Fig. 1c). Eun Young Lee and Tae Sung Park equally contributed to this study as first authors. E. Y. Lee : S.-J. Park : J. R. Choi : J.-H. Yoo (*) Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea e-mail: jhyoo92@nhimc.or.kr

Clinical Implications of Quantitative JAK2 V617F Analysis using Droplet Digital PCR in Myeloproliferative Neoplasms

Background JAK2 V617F is the most common mutation in myeloproliferative neoplasms (MPNs) and is a major diagnostic criterion. Mutation quantification is useful for classifying patients with MPN into subgroups and for prognostic prediction. Droplet digital PCR (ddPCR) can provide accurate and reproducible quantitative analysis of DNA. This study was designed to verify the correlation of ddPCR with pyrosequencing results in the diagnosis of MPN and to investigate clinical implications of the mutational burden. Methods Peripheral blood or bone marrow samples were obtained from 56 patients newly diagnosed with MPN or previously diagnosed with MPN but not yet indicated for JAK2 inhibitor treatment between 2012 and 2016. The JAK2 V617F mutation was detected by pyrosequencing as a diagnostic work-up. The same samples were used for ddPCR to determine the correlation between assays and establish a detection sensitivity cut-off. Clinical and hematologic aspects were reviewed. Results Forty-two (75%) and 46 (82.1%) patients were positive for JAK2 V617F by pyrosequencing and ddPCR, respectively. The mean mutated allele frequency at diagnosis was 37.5±30.1% and was 40.7±31.2% with ddPCR, representing a strong correlation (r=0.9712, P<0.001). Follow-up samples were available for 12 patients, including eight that were JAK2 V617F-positive. Of these, mutational burden reduction after treatment was observed in six patients (75%), consistent with trends of hematologic improvement. Conclusions Quantitative analysis of the JAK2 V617F mutation using ddPCR was highly correlated with pyrosequencing data and may reflect the clinical response to treatment.