Eun Youn Roh

Comparison of Explant-Derived and Enzymatic Digestion-Derived MSCs and the Growth Factors from Wharton’s Jelly

Whartons jelly is not only one of the most promising tissue sources for mesenchymal stem cells (MSCs) but also a source of natural growth factors. To prove that we can get both natural growth factors and MSCs from Whartons jelly, we compared cellular characteristics and the level of basic fibroblast growth factor (bFGF) from samples using the explant culture method to those derived from the traditional enzymatic culture method. The levels of bFGF were 27.0 ± 11.7 ng/g on day 3, 15.6 ± 11.1 ng/g on day 6, and decreased to 2.6 ± 1.2 ng/g on day 14. The total amount of bFGF released was 55.0 ± 25.6 ng/g on explant culture. Compared with the traditional enzymatic digestion method, the explant culture method showed a tendency to release higher levels of bFGF in supernatant media for the first week of culture, and the higher cellular yield at passage 0 (4.89 ± 3.2 × 105/g versus 1.75 ± 2.2 × 105/g, P = 0.01). In addition, the genes related to mitosis were upregulated in the explant-derived MSCs.

Performances of Four Fourth-Generation Human Immunodeficiency Virus-1 Screening Assays

Fourth‐generation human immunodeficiency virus‐1 (HIV‐1) screening assays have improved sensitivity, but vary in performance characteristics. The purpose of this study was to evaluate four different fourth‐generation HIV‐1 assays. These assays included the AxSYM HIV Ag/Ab Combo (Abbott diagnostics, Delkenheim, Germany), ARCHITECT HIV Ag/Ab Combo (Abbott), Elecsys 2010 HIV Combi (Roche Diagnostics GmbH, Mannheim, Germany), and Elecsys HIV Combi PT (Roche). A total of 1,306 samples that included 1,225 clinical samples and 81 samples consisting of seroconversion panels, an HIV‐1 p24 antigen sensitivity panel, and dilution series of HIV‐1 lysates and HIV‐1 antibodies were tested. All of the assays had sensitivities of 100% on clinical samples. The specificities of the AxSYM, ARCHITECT, Elecsys 2010 HIV Combi, and Elecsys HIV Combi PT were 99.6, 99.6, 99.0, and 99.5%, respectively. Of the 81 samples with different levels of HIV antigen or antibody and/or subtypes, Elecsys HIV Combi PT and ARCHITECT HIV Ag/Ab Combo showed better analytical sensitivities than the other two assays. In summary, the performance characteristics of AxSYM, ARCHITECT, and Elecsys HIV Combi PT were comparable and satisfactory for clinical samples. ARCHITECT HIV Ag/Ab Combo and Elecsys HIV Combi PT have the higher analytical sensitivities, and would be preferable for reducing the window period. J. Med. Virol. 84:1884–1888, 2012.

Differences in Circulating Dendritic Cell Subtypes in Pregnant Women, Cord Blood and Healthy Adult Women

Different subtypes of dendritic cells (DC) influence the differentiation of naíve T lymphocytes into T helper type 1 (Th1) and Th2 effector cells. We evaluated the percentages of DC subtypes in peripheral blood from pregnant women (maternal blood) and their cord blood compared to the peripheral blood of healthy non pregnant women (control). Circulating DC were identified by flow cytometry as lineage (CD3, CD14, CD16, CD19, CD20, and CD56)-negative and HLA-DR-positive cells. Subtypes of DC were further characterized as myeloid DC (CD11c+/CD123±), lymphoid DC (CD11c-/CD123+++) and less differentiated DC (CD11c-/CD123±). The frequency of DC out of all nucleated cells was significantly lower in maternal blood than in control (P<0.001). The ratio of myeloid DC/lymphoid DC was significantly higher in maternal blood than in control (P<0.01). HLA-DR expressions of myeloid DC as mean fluorescence intensity (MFI) were significantly less in maternal blood and in cord blood than in control (P<0.001, respectively). The DC differentiation factors, TNF-α and GM-CSF, released from mononuclear cells after lipopolysaccharide stimulation were significantly lower in maternal blood than in control (P<0.01). The distribution of DC subtypes was different in maternal and cord blood from those of non-pregnant women. Their role during pregnancy remains to be determined.

Increased numbers of total nucleated and CD34+ cells in blood group O cord blood: an analysis of neonatal innate factors in the Korean population

BACKGROUND: We analyzed neonatal factors that could affect hematopoietic variables of cord blood (CB) donated from Korean neonates.

Perspectives of potential donors on cord blood and cord blood cryopreservation: a survey of highly educated, pregnant Korean women receiving active prenatal care

BACKGROUND: The aim of the study was to investigate the knowledge of cord blood (CB) and attitudes toward CB banking among high‐potential donors (i.e., well‐educated pregnant Koreans) because their voluntary donation is indispensable to the success of unrelated CB transplantation.

MBP-positive and CD11c-positive cells are associated with different phenotypes of Korean patients with non-asthmatic chronic rhinosinusitis.

Background Asthmatic nasal polyps primarily exhibit eosinophilic infiltration. However, the identities of the immune cells that infiltrate non-asthmatic nasal polyps remain unclear. Thus, we thought to investigate the distribution of innate immune cells and its clinical relevance in non-asthmatic chronic rhinosinusitis (CRS) in Korea. Methods Tissues from uncinate process (UP) were obtained from controls (n = 18) and CRS without nasal polyps (CRSsNP, n = 45). Nasal polyps (NP) and UP were obtained from CRS with nasal polyps (CRSwNP, n = 56). The innate immune cells was evaluated by immunohistochemistry such as, eosinophil major basic protein (MBP), tryptase, CD68, CD163, CD11c, 2D7, human neutrophil elastase (HNE) and its distribution was analyzed according to clinical parameters. Results In comparisons between UP from each group, CRSwNP had a higher number of MPB+, CD68+, and CD11c+ cells relative to CRSsNP. Comparisons between UP and NP from CRSwNP indicated that NP have a higher infiltrate of MBP+, CD163+, CD11c+, 2D7+ and HNE+ cells, whereas fewer CD68+ cells were found in NP. In addition, MBP+ and CD11c+ cells were increased from UP of CRSsNP, to UP of CRSwNP, and to NP of CRSwNP. Moreover, in UP from CRSwNP, the number of MBP+ and CD11c+ cells positively correlated with CT scores. In the analysis of CRSwNP phenotype, allergic eosinophilic polyps had a higher number of MBP+, tryptase+, CD11c+, 2D7+ cells than others, whereas allergic non-eosinophilic polyps showed mainly infiltration of HNE+ and 2D7+ cells. Conclusions The infiltration of MBP+ and CD11c+ innate immune cells show a significant association with phenotype and disease extent of CRS and allergic status also may influences cellular phenotype in non-asthmatic CRSwNP in Korea.

Characterization of Sera with Discordant Results from Reverse Sequence Screening for Syphilis

Reverse sequence screening for syphilis (RSSS) (screening with treponemal tests, followed by confirmation with nontreponemal tests) has been increasingly adopted. CDC recommends confirmation of discordant results (reactive EIA/CIA and nonreactive nontreponemal test) with Treponema pallidum particle agglutination assay (TP-PA). We characterized sera with discordant results from RSSS with Architect Syphilis TP CIA. Among 15,713 screening tests using Architect Syphilis TP at Seoul National University Gangnam Center between October 2010 and May 2011, 260 (1.7%) showed reactive results. Rapid plasma reagin (RPR) and TP-PA were performed on 153 available sera among them. On sera with discordant results between Architect Syphilis TP and TP-PA, INNO-LIA Syphilis Score and FTA-ABS were performed. Among 153 sera, RPR was nonreactive in 126 (82.4%). Among them, TP-PA was positive in 103 (81.7%), indeterminate (±) in 7 (5.6%), and negative in 16 (12.7%). Out of 16 CIA(+)/RPR(−)/TP-PA(−) sera, INNO-LIA Syphilis Score and/or FTA-ABS were negative on 14 sera. Out of 7 CIA(+)/RPR(−)/TP-PA(±) sera, INNO-LIA Syphilis Score and FTA-ABS were positive/reactive in 6 sera. RSSS with confirmation by TP-PA on sera with discordant results between Architect Syphilis TP and RPR effectively delineated those discordant results and could be successfully adopted for routine checkup for syphilis.

Serum HBsAg levels during peginterferon α-2a treatment with or without thymosin α-1 in HBeAg-positive chronic hepatitis B patients.

The importance of serum hepatitis B surface antigen (HBsAg) level as a surrogate marker for viral load and a predictor of treatment response remains unclear. The aim of this study was to investigate whether serum HBsAg correlates with serum hepatitis B virus (HBV) DNA during peginterferon (PEG‐IFN) α‐2a treatment (with or without thymosin α‐1) in hepatitis B e antigen (HBeAg)‐positive chronic hepatitis B patients and whether it can predict treatment response. Sera from 37 HBeAg‐positive chronic hepatitis B patients receiving 48‐weeks PEG‐IFN α‐2a with (n = 20) or without (n = 17) an initial 12‐weeks thymosin α‐1 were obtained at baseline and at weeks 12, 24, 36, 48 (end of treatment), 56, 72, 84, and 96 (end of follow‐up). Taqman HBV DNA tests (Roche) and Architect HBsAg QT (Abbott) were performed. There was a moderate correlation between the HBsAg and HBV DNA levels (r = 0.452, P < 0.001). Median HBsAg levels at baseline and at week 96 were 6,218 IU/ml and 4,038 IU/ml, respectively. The mean HBV DNA and alanine aminotransferase (ALT) levels were 7.48 log10 IU/ml and 173 IU/L at baseline and 5.37 log10 IU/ml and 102 IU/L at week 96, respectively. A decrease to <60% of baseline levels of HBsAg at week 12 was identified as an independent predictive factor for HBeAg seroconversion (OR = 45.7, P < 0.05) at week 96. Serum HBsAg levels may be helpful for predicting the response to PEG‐IFN therapy in HBeAg‐positive chronic hepatitis B patients. J. Med. Virol. 83:88–94, 2011.

Allele and haplotype frequencies of human leukocyte antigen-A, -B, -C, -DRB1, and -DQB1 from sequence-based DNA typing data in Koreans.

Background Data on allele frequencies (AFs) and haplotype frequencies (HFs) of HLA-C and -DQB1 are limited in Koreans. We investigated AFs and HFs of HLA-A, -B, -C, -DRB1, and -DQB1 in Koreans by high-resolution sequence-based typing (SBT). Methods Hematopoietic stem cells were obtained from 613 healthy, unrelated donors to analyze HLA-A, -B, -C, -DRB1, and -DQB1 genotypes by using AlleleSEQR HLA-A, -B, -C, -DRB1, and -DQB1 SBT kits (Abbott Molecular, USA), respectively. Alleles belonging to HLA-C*07:01/07:06 group were further discriminated by using PCR-sequence specific primer analysis. AFs and HFs were calculated by direct counting and maximum likelihood method, respectively. Results In all, 24 HLA-A, 46 HLA-B, 24 HLA-C, 29 HLA-DRB1, and 15 HLA-DQB1 alleles were identified. AFs and HFs of HLA-A, -B, and -DRB1 were similar to those reported previously. For the HLA-C locus, C*01:02 was the most common allele, followed by C*03:03, C*03:04, C*14:02, C*03:02, and C*07:02 (AF ≥7%). AFs of C*07:01 and C*07:06 were 0.16% and 3.18%, respectively. For the HLA-DQB1 locus, DQB1*03:01 was the most common allele, followed by DQB1*03:03, *03:02, *06:01, *05:01, *04:01, and *06:02 (AF ≥7%). AFs of DQB1*02:01 and DQB1*02:02 were 2.12% and 6.69%, respectively. HFs of A*33:03-C*07:06 and C*07:06-B*44:03 were 3.09% and 3.10%, respectively, while those of DRB1*07:01-DQB1*02:02 and DRB1*03:01-DQB1*02:01 were 6.61% and 2.04%, respectively. Conclusions This study reported AFs and HFs of HLA, including HLA-C and -DQB1, in Koreans by using high-resolution SBT. These data can be used to resolve ambiguous results of HLA typing for organ and hematopoietic stem cell transplantations.

Association of TAP1 and TAP2 genes with susceptibility to pulmonary tuberculosis in Koreans

Tuberculosis remains an important public health problem in Koreans. However, very few studies have reported on the genetic factors associated with TB susceptibility in Koreans. The aim of this study was to elucidate the genetic factors associated with susceptibility to pulmonary tuberculosis (PTB). We investigated the transporter associated with antigen processing –1 (TAP1) and TAP2 gene polymorphisms in 160 Korean PTB patients (categorized according to extent of lesion and TB medication history) and 210 controls. TAP2*C/E frequency was significantly increased in the PTB (pc = 0.004, OR = 2.28). TAP2*Bky2/C/E were enriched in the retreated, far‐advanced and total PTB compared with the controls (pc = 0.015, OR = 3.27; pc = 0.019, OR = 2.56; pc = 2.8 × 10−4, OR = 2.42, respectively). In the comparison of TAP2 gene with the DRB1*08:03, which is associated with TAP2*Bky2 and PTB in Koreans, we demonstrated the hierarchy of these association factors. TAP2*C/E is independent factors as strong as DRB1*08:03, and TAP2*C/E interacts with DRB1*08:03, resulting in a striking combined association. Our results suggest that TAP2 gene has an association with PTB susceptibility, the extent of the lesion or recurrence. These associations are independent from and additive with DRB1*08:03.