Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play cr... more Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play crucial roles in a variety of diseases, including autoimmunity, infectious diseases, and cancers. However, little is known about the roles of these invariant T cells in acute cholecystitis. The purposes of this study were to examine the levels of MAIT cells and NKT cells in patients with acute cholecystitis and to investigate potential relationships between clinical parameters and these cell levels. Thirty patients with pathologically proven acute cholecystitis and 47 age- and sex-matched healthy controls were enrolled. Disease grades were classified according to the revised Tokyo guidelines (TG13) for the severity assessment for acute cholecystitis. Levels of MAIT and NKT cells in peripheral blood were measured by flow cytometry. Circulating MAIT and NKT cell numbers were significantly lower in acute cholecystitis patients than in healthy controls, and these deficiencies in MAIT cells and...
Janus kinase 2 (JAK2) and calreticulin (CALR) constitute the two most frequent mutations in essen... more Janus kinase 2 (JAK2) and calreticulin (CALR) constitute the two most frequent mutations in essential thrombocythemia (ET), and both are reported to be mutually exclusive. Hence, we examined a cohort of 123 myeloproliferative neoplasm (MPN) patients without BCR-ABL1 rearrangement and additional ET patients (n=96) for coexistence of JAK2 and CALR mutations. The frequency of CALR mutations was 20.3% in 123 MPN patients; 31.1% in ET (n=74), 25% in primary myelofibrosis (n=4) and 2.2% in polycythemia vera (n=45). JAK2 and CALR mutations coexisted in 7 (4.2%) of 167 ET patients. Clinical characteristics, progression-free survival (PFS), and elapsed time to achieve partial remission across 4 groups (JAK2+/CALR+, JAK2+/CALR-, JAK2-/CALR+, JAK2-/CALR-) were reviewed. The JAK2+/CALR- group had higher leukocyte counts and hemoglobin levels and more frequent thrombotic events than JAK2-/CALR- group. JAK2 mutations have a greater effect on the disease phenotype and the clinical features of MPN ...
Clinica chimica acta; international journal of clinical chemistry, Jan 15, 2015
Chromium (Cr) and cobalt (Co) metal ions released from orthopedic prostheses, such as metal-on-me... more Chromium (Cr) and cobalt (Co) metal ions released from orthopedic prostheses, such as metal-on-metal (MoM) bearings, may be related to wear of the bearing surface. These ions may serve as indicators of the in vivo performance of MoM bearing surfaces. We developed a simple and sensitive assay suitable for the simultaneous measurement of serum Cr and Co using inductively coupled plasma-mass spectrometry (ICP-MS) in clinical routine laboratory practice to evaluate analytical performance and clinical utility. We evaluated the linearity, precision, and lower limit of quantification (LOQ) of an ICP-MS method to determine serum Cr and Co concentration in accordance with U.S. Food and Drug Administration guidance for bioanalytical method validation. This method was used to determine the serum Cr and Co levels of 236 clinical samples from 74 patients with MoM hip prosthesis and 51 healthy controls. The assay showed good linearity (0-20 μg/l, r(2)>0.999) and satisfactory accuracy for all t...
Gastric cancer (GC) is one of the most common cancers with high morbidity and mortality. Familial... more Gastric cancer (GC) is one of the most common cancers with high morbidity and mortality. Familial GC is seen in 10% of cases, and approximately 3% of familial GC cases arise owing to hereditary diffuse gastric cancer (HDGC). CDH1, which encodes the protein E-cadherin, is the only gene whose mutations are associated with HDGC. Screening for the familial GC-predisposing gene has been neglected in high-risk countries such as Korea, China, and Japan, where all the cases have been attributed to Helicobacter pylori or other carcinogens. Screening for the GC-causing CDH1 mutation may provide valuable information for genetic counseling, testing, and risk-reduction management for the as-yet unaffected family members. An asymptomatic 44-yr-old Korean male visited our genetic clinic for consultation owing to his family history of GC. Eventually, c.1018A>G in CDH1, a known disease-causing mutation, was found. As of the publication time, the individual is alive without the evidence of GC, and...
This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and de... more This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and developed optimal profiles of leukemic fusion genes for multiplex RT-PCR. We prospectively analyzed blood and bone marrow specimens of patients with acute leukemia. Twenty types of chromosomal abnormalities were detected in 42% from all patients by commercially available multiplex RT-PCR for detecting 28 fusion genes and in 35% by cytogenetic analysis including FISH analysis. The most common cytogenetic aberrations in acute myeloid leukemia patients was PML/PARA, followed by AML1/MGT8 and MLL1, and in acute lymphoid leukemia patients was BCR/ABL, followed by TEL/AML1 and MLL1 gene rearrangement. Among the negative results for multiplex RT-PCR, clinically significant t(3;3)(q21;q26.2), t(8;14)(q24;q32) and i(17)(q10) were detected by conventional cytogenetics. The spectrum and frequency of chromosomal abnormalities in our leukemia patients are differed from previous studies, and may offer o...
We analyzed T cell receptor beta chain (TCRB) gene to investigate the presence of putative T cell... more We analyzed T cell receptor beta chain (TCRB) gene to investigate the presence of putative T cell clones and its clinicopathologic implications in Korean patients with aplastic anemia (AA). Twenty-nine bone marrow specimens were collected from 20 AA patients, 19 specimens from initial diagnosis and 10 from follow-up. T cell clonality assay was performed using IdentiClone TCRB Gene Clonality Assay kit (InVivoScirbe Technology, USA) and automatic genetic analyzer. Patients' clinical information and laboratory parameters were also analyzed. Five patients had definitive underlying factors related with aplastic anemia, such as hepatitis B virus (4 cases) and benzene exposure (1 case). Putative T cell clones were detected in bone marrow specimens of 11 (58%) out of 19 patients at diagnosis. The location of putative T cell clones of TCRB gene (diversity region, Dbeta; joining region, Jbeta; variable region, Vbeta) was distributed in Dbeta2+Jbeta2 (6 cases), Dbeta1+Jbeta1 (3 cases), Vbe...
Hereditary tyrosinemia type I (HT I) is a severe inborn metabolic disorder affecting the tyrosine... more Hereditary tyrosinemia type I (HT I) is a severe inborn metabolic disorder affecting the tyrosine degradation pathway. Most untreated patients die within the first two years of life. HT I results from fumarylacetoacetate hydrolase (FAH) deficiency caused by mutations in the FAH gene. The diagnosis of HT I is confirmed by measuring FAH enzyme activity in cultured fibroblasts or liver tissue and/or detecting disease-causing mutations in the FAH gene. A female neonate was referred to our hospital for further evaluation of an abnormal newborn screening test that showed elevated tyrosine levels. We analyzed amino acids and organic acids in the patient's blood and urine. To identify the genetic abnormality, all the coding exons and flanking introns of the FAH gene were analyzed via PCR. A repeat newborn screening test and plasma amino acid analysis revealed increased tyrosine levels in the patient. Urine organic acid analysis showed increased urinary excretion of 4-hydroxyphenyllactat...
We hypothesized that serum PTH might be associated with various clinicopathological parameters in... more We hypothesized that serum PTH might be associated with various clinicopathological parameters in multiple myeloma (MM). So we investigated the implications of serum PTH in MM patients and the relationship with other risk factors of MM. A total of 115 patients who were newly diagnosed with MM were enrolled. Serum PTH level was 24.7 ± 34.9 (ranged 0.0–284.1) pg/mL. Serum levels of IgG, IgM, FLC-lambda, albumin, and LDH were in positive correlation with serum PTH. Compared to non-high PTH (<68.3 pg/mL) group, the hazard ratio (HR) for overall survival was higher for group with high PTH level (≥68.3 pg/mL) (HR, 1.710). Furthermore, the patient group with high PTH level showed inferior progression-free survival than non-high PTH group (P=0.056). Interestingly, subgroup analysis showed that serum PTH level at diagnosis was associated with risk factors and clinical outcome in MM patients, especially in complete remission group, transplantation cases, ISS stage II cases, and cases witho...
The AdvanSure tuberculosis/non-tuberculous mycobacterium (TB/NTM) PCR (LG Life Science, Korea) an... more The AdvanSure tuberculosis/non-tuberculous mycobacterium (TB/NTM) PCR (LG Life Science, Korea) and COBAS TaqMan Mycobacterium tuberculosis (MTB) PCR (Roche Diagnostics, USA) are commonly used in clinical microbiology laboratories. We aimed to evaluate these two commercial real-time PCR assays for detection of MTB in a large set of clinical samples over a two-year period. AdvanSure TB/NTM PCR and COBAS TaqMan MTB PCR were performed on 9,119 (75.2%) and 3,010 (24.8%) of 12,129 (9,728 respiratory and 2,401 non-respiratory) MTB specimens, with 361 (4.0%) and 102 (3.4%) acid-fast bacilli (AFB)-positive results, respectively. In MTB culture, 788 (6.5%) MTB and 514 (4.2%) NTM were identified. The total sensitivity and specificity of the AdvanSure assay were 67.8% (95% confidence interval [CI], 63.9-71.6) and 98.3% (95% CI, 98.0-98.6), while those of the COBAS TaqMan assay were 67.2% (95% CI, 60.0-73.8) and 98.4% (95% CI, 97.9-98.9), respectively. The sensitivities and specificities of the ...
Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play cr... more Mucosal-associated invariant T (MAIT) cells and natural killer T (NKT) cells are known to play crucial roles in a variety of diseases, including autoimmunity, infectious diseases, and cancers. However, little is known about the roles of these invariant T cells in acute cholecystitis. The purposes of this study were to examine the levels of MAIT cells and NKT cells in patients with acute cholecystitis and to investigate potential relationships between clinical parameters and these cell levels. Thirty patients with pathologically proven acute cholecystitis and 47 age- and sex-matched healthy controls were enrolled. Disease grades were classified according to the revised Tokyo guidelines (TG13) for the severity assessment for acute cholecystitis. Levels of MAIT and NKT cells in peripheral blood were measured by flow cytometry. Circulating MAIT and NKT cell numbers were significantly lower in acute cholecystitis patients than in healthy controls, and these deficiencies in MAIT cells and...
Janus kinase 2 (JAK2) and calreticulin (CALR) constitute the two most frequent mutations in essen... more Janus kinase 2 (JAK2) and calreticulin (CALR) constitute the two most frequent mutations in essential thrombocythemia (ET), and both are reported to be mutually exclusive. Hence, we examined a cohort of 123 myeloproliferative neoplasm (MPN) patients without BCR-ABL1 rearrangement and additional ET patients (n=96) for coexistence of JAK2 and CALR mutations. The frequency of CALR mutations was 20.3% in 123 MPN patients; 31.1% in ET (n=74), 25% in primary myelofibrosis (n=4) and 2.2% in polycythemia vera (n=45). JAK2 and CALR mutations coexisted in 7 (4.2%) of 167 ET patients. Clinical characteristics, progression-free survival (PFS), and elapsed time to achieve partial remission across 4 groups (JAK2+/CALR+, JAK2+/CALR-, JAK2-/CALR+, JAK2-/CALR-) were reviewed. The JAK2+/CALR- group had higher leukocyte counts and hemoglobin levels and more frequent thrombotic events than JAK2-/CALR- group. JAK2 mutations have a greater effect on the disease phenotype and the clinical features of MPN ...
Clinica chimica acta; international journal of clinical chemistry, Jan 15, 2015
Chromium (Cr) and cobalt (Co) metal ions released from orthopedic prostheses, such as metal-on-me... more Chromium (Cr) and cobalt (Co) metal ions released from orthopedic prostheses, such as metal-on-metal (MoM) bearings, may be related to wear of the bearing surface. These ions may serve as indicators of the in vivo performance of MoM bearing surfaces. We developed a simple and sensitive assay suitable for the simultaneous measurement of serum Cr and Co using inductively coupled plasma-mass spectrometry (ICP-MS) in clinical routine laboratory practice to evaluate analytical performance and clinical utility. We evaluated the linearity, precision, and lower limit of quantification (LOQ) of an ICP-MS method to determine serum Cr and Co concentration in accordance with U.S. Food and Drug Administration guidance for bioanalytical method validation. This method was used to determine the serum Cr and Co levels of 236 clinical samples from 74 patients with MoM hip prosthesis and 51 healthy controls. The assay showed good linearity (0-20 μg/l, r(2)>0.999) and satisfactory accuracy for all t...
Gastric cancer (GC) is one of the most common cancers with high morbidity and mortality. Familial... more Gastric cancer (GC) is one of the most common cancers with high morbidity and mortality. Familial GC is seen in 10% of cases, and approximately 3% of familial GC cases arise owing to hereditary diffuse gastric cancer (HDGC). CDH1, which encodes the protein E-cadherin, is the only gene whose mutations are associated with HDGC. Screening for the familial GC-predisposing gene has been neglected in high-risk countries such as Korea, China, and Japan, where all the cases have been attributed to Helicobacter pylori or other carcinogens. Screening for the GC-causing CDH1 mutation may provide valuable information for genetic counseling, testing, and risk-reduction management for the as-yet unaffected family members. An asymptomatic 44-yr-old Korean male visited our genetic clinic for consultation owing to his family history of GC. Eventually, c.1018A>G in CDH1, a known disease-causing mutation, was found. As of the publication time, the individual is alive without the evidence of GC, and...
This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and de... more This study investigated the spectrum of chromosomal abnormalities in 325 leukemia patients and developed optimal profiles of leukemic fusion genes for multiplex RT-PCR. We prospectively analyzed blood and bone marrow specimens of patients with acute leukemia. Twenty types of chromosomal abnormalities were detected in 42% from all patients by commercially available multiplex RT-PCR for detecting 28 fusion genes and in 35% by cytogenetic analysis including FISH analysis. The most common cytogenetic aberrations in acute myeloid leukemia patients was PML/PARA, followed by AML1/MGT8 and MLL1, and in acute lymphoid leukemia patients was BCR/ABL, followed by TEL/AML1 and MLL1 gene rearrangement. Among the negative results for multiplex RT-PCR, clinically significant t(3;3)(q21;q26.2), t(8;14)(q24;q32) and i(17)(q10) were detected by conventional cytogenetics. The spectrum and frequency of chromosomal abnormalities in our leukemia patients are differed from previous studies, and may offer o...
We analyzed T cell receptor beta chain (TCRB) gene to investigate the presence of putative T cell... more We analyzed T cell receptor beta chain (TCRB) gene to investigate the presence of putative T cell clones and its clinicopathologic implications in Korean patients with aplastic anemia (AA). Twenty-nine bone marrow specimens were collected from 20 AA patients, 19 specimens from initial diagnosis and 10 from follow-up. T cell clonality assay was performed using IdentiClone TCRB Gene Clonality Assay kit (InVivoScirbe Technology, USA) and automatic genetic analyzer. Patients' clinical information and laboratory parameters were also analyzed. Five patients had definitive underlying factors related with aplastic anemia, such as hepatitis B virus (4 cases) and benzene exposure (1 case). Putative T cell clones were detected in bone marrow specimens of 11 (58%) out of 19 patients at diagnosis. The location of putative T cell clones of TCRB gene (diversity region, Dbeta; joining region, Jbeta; variable region, Vbeta) was distributed in Dbeta2+Jbeta2 (6 cases), Dbeta1+Jbeta1 (3 cases), Vbe...
Hereditary tyrosinemia type I (HT I) is a severe inborn metabolic disorder affecting the tyrosine... more Hereditary tyrosinemia type I (HT I) is a severe inborn metabolic disorder affecting the tyrosine degradation pathway. Most untreated patients die within the first two years of life. HT I results from fumarylacetoacetate hydrolase (FAH) deficiency caused by mutations in the FAH gene. The diagnosis of HT I is confirmed by measuring FAH enzyme activity in cultured fibroblasts or liver tissue and/or detecting disease-causing mutations in the FAH gene. A female neonate was referred to our hospital for further evaluation of an abnormal newborn screening test that showed elevated tyrosine levels. We analyzed amino acids and organic acids in the patient's blood and urine. To identify the genetic abnormality, all the coding exons and flanking introns of the FAH gene were analyzed via PCR. A repeat newborn screening test and plasma amino acid analysis revealed increased tyrosine levels in the patient. Urine organic acid analysis showed increased urinary excretion of 4-hydroxyphenyllactat...
We hypothesized that serum PTH might be associated with various clinicopathological parameters in... more We hypothesized that serum PTH might be associated with various clinicopathological parameters in multiple myeloma (MM). So we investigated the implications of serum PTH in MM patients and the relationship with other risk factors of MM. A total of 115 patients who were newly diagnosed with MM were enrolled. Serum PTH level was 24.7 ± 34.9 (ranged 0.0–284.1) pg/mL. Serum levels of IgG, IgM, FLC-lambda, albumin, and LDH were in positive correlation with serum PTH. Compared to non-high PTH (<68.3 pg/mL) group, the hazard ratio (HR) for overall survival was higher for group with high PTH level (≥68.3 pg/mL) (HR, 1.710). Furthermore, the patient group with high PTH level showed inferior progression-free survival than non-high PTH group (P=0.056). Interestingly, subgroup analysis showed that serum PTH level at diagnosis was associated with risk factors and clinical outcome in MM patients, especially in complete remission group, transplantation cases, ISS stage II cases, and cases witho...
The AdvanSure tuberculosis/non-tuberculous mycobacterium (TB/NTM) PCR (LG Life Science, Korea) an... more The AdvanSure tuberculosis/non-tuberculous mycobacterium (TB/NTM) PCR (LG Life Science, Korea) and COBAS TaqMan Mycobacterium tuberculosis (MTB) PCR (Roche Diagnostics, USA) are commonly used in clinical microbiology laboratories. We aimed to evaluate these two commercial real-time PCR assays for detection of MTB in a large set of clinical samples over a two-year period. AdvanSure TB/NTM PCR and COBAS TaqMan MTB PCR were performed on 9,119 (75.2%) and 3,010 (24.8%) of 12,129 (9,728 respiratory and 2,401 non-respiratory) MTB specimens, with 361 (4.0%) and 102 (3.4%) acid-fast bacilli (AFB)-positive results, respectively. In MTB culture, 788 (6.5%) MTB and 514 (4.2%) NTM were identified. The total sensitivity and specificity of the AdvanSure assay were 67.8% (95% confidence interval [CI], 63.9-71.6) and 98.3% (95% CI, 98.0-98.6), while those of the COBAS TaqMan assay were 67.2% (95% CI, 60.0-73.8) and 98.4% (95% CI, 97.9-98.9), respectively. The sensitivities and specificities of the ...
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Papers by Hyun-jung Choi