Biomedical subjects

Hee Du Jung

Publications and source records attributed to Hee Du Jung.

4 recordsLinked to original sources

PubMed2007

Flow cytometry PRA using lymphocyte pools from random donors.

BACKGROUND: Pools of lymphocytes from carefully chosen donors have been used for flow cytometry (FC) panel reactive antibody (PRA) assays. We intended to devise an FC PRA assay using mixed lymphocyte pools from a large number of randomly selected donors (RD FC PRA) to accurately predict the likelihood of a positive HLA crossmatch. METHODS: Lymphocyte pools were prepared from randomly selected donors (N = 120). %PRA was calculated based on the anti-IgG FITC histogram of the T cells. The proposed RD FC PRA assay was assessed in comparison with the bead FC PRA, antiglobulin-augmented CDC (AHG-CDC) PRA assay, and the expected %PRA calculated by summing up the antigen frequencies of the known specificities. RESULTS: In 29 FC crossmatch positive sera, the positivity rate for the bead FC, RD FC, and AHG-CDC PRA was 100, 100, and 79%, and the mean %PRA was 77% +/- 0.205). In 19 sensitized patients with a negative FC crossmatch, the positivity rate was 21% using the RD FC PRA and 16% using the bead FC PRA, which suggested that both assays had similar abilities to detect low levels of HLA antibodies. CONCLUSIONS: The RD FC PRA assay allows easy panel preparation, reduces cost, and naturally reflects the probabilities of a positive crossmatch in the population to which the cadaveric donor belongs. Therefore, this new assay is expected to be useful as another approach to determine the % PRA.

Antigens, Surface↗

PubMed2006

FCGR3A gene polymorphisms may correlate with response to frontline R-CHOP therapy for diffuse large B-cell lymphoma.

The precise mechanism of rituximab plus cyclophosphamide/doxorubicin/vincristine/prednisone (R-CHOP) therapy in diffuse large B-cell lymphoma (DLBCL) is not fully elucidated. Besides overcoming bcl-2-mediated chemoresistance, antibody-dependent cellular cytotoxicity (ADCC), which is activated by effector cells via immunoglobulin G (IgG) fragment C receptors (FcRs), was also proposed as a mechanism of rituximab. The current study evaluated the impact of FcR polymorphism on the response to R-CHOP therapy for DLBCL with the basis that FcR polymorphism can affect rituximab's affinity for ADCC effector cells. The FCGR3A and FCGR2A gene polymorphisms were determined in DLBCL patients receiving R-CHOP (n = 113) compared with CHOP therapy (n = 85). The FCGR3A valine (V) allele was significantly correlated with a higher complete response rate to R-CHOP compared with the phenylalanine (F) allele (88% in V/V vs 79% in V/F vs 50% in F/F; P = .002), while no difference was found between FCGR2A polymorphisms. In addition, V/V allele was associated with faster achievement of response than other alleles. The impact of the FCGR3A gene polymorphism on response rate was not noted in the CHOP group. In terms of overall or event-free survival, no difference was found according to FCGR3A or FCGR2A alleles. The FCGR3A single nucleotide polymorphism (SNP) is predictive of response to R-CHOP, but does not correlate with survival in patients with DLBCL.

Adolescent↗

PubMed2006

Predicting outcomes of HLA-identical allogeneic stem cell transplants from variable number of tandem repeat disparity between donors and recipients.

BACKGROUND AND OBJECTIVES: Detecting differences in the variable number of tandem repeats (VNTR) between a recipient and a donor has already been used to monitor the degree of chimerism after allogeneic stem cell transplantation (SCT). Alongside major histocompatibility complex disparity, the disparity of various polymorphous proteins encoded by several genes may play a critical role in the pathogenesis of graft-versus-host disease (GVHD) in allogenic SCT. However, the biological effect of VNTR disparity has scarcely been studied. BACKGROUND AND OBJECTIVES: Eighty-four patients receiving an SCT from an HLA-identical sibling (n=68) or an unrelated donor (n=16) were analyzed. The patients were transplanted because of acute myeloid leukemia (ns=48), acute lymphoblastic leukemia (n=8), chronic myeloid leukemia (n=15), non-Hodgkin's lymphoma (n=18) and myelodysplastic syndrome (n=3). Polymerase chain reaction analysis was performed to amplify three VNTR regions (D1S80, D1S111, and D17S5). These regions were classified as fully matched, partially matched, or mismatched between donors recipients. RESULTS: A strong correlation was observed between D1S80 matching status and transplant outcomes in terms of overall survival (p=0.0179) and non-relapse mortality (p=0.0305), but not for the D1S111 or D17S5 disparity. The fully matched D1S80 pairs showed a better overall survival (72% vs 38%) and lower non-relapse mortality (17% vs 50%) compared to the partially matched or mismatched pairs. In multivariate analyses, a fully matched D1S80 pair was found to be an independent favorable prognostic factor for overall survival (p=0.03) and non-relapse mortality (p=0.05). In addition, D1S80 disparity was significantly associated with the occurrence of gut chronic GVHD (p=0.05). INTERPRETATION AND CONCLUSIONS: The present data suggest that disparities in D1S80--located in chromosome 1--are associated with an increased incidence of gut chronic GVHD and non-relapse mortality.

Adolescent↗

PubMed2004

Molecular analysis of HLA class II-associated susceptibility to neuroinflammatory diseases in Korean children.

The work was done to study immunogenetic peculiarities of neuroinflammatory diseases among Korean children. A total of 13 children with neuroinflammatory diseases (8 males and 5 females; mean age 4.6 +/-2.6 yr) were consecutively recruited. Geno-mic typing was performed on their HLA DRB/HLA DQB genes using PCR-SSOP/SSP techniques with gel immunoelectrophoresis. The frequencies of HLA-DR1 *15 in children with acute disseminated encephalomyelitis (ADEM) (31%) and DQB1 *06 in other neuroinflammatory diseases (38%) were significantly increased compared with control subjects. The frequencies of HLA-DRB3 * 0202 (100%), HLA-DRB1 * 1302 (67%), HLA-DRB3 * 0301 (67%), and HLA-DQB1 * 0301 (67%) were significantly increased in children with multiple sclerosis and the frequencies of HLA-DRB1 * 1501 (40%) and HLA-DRB5 * 0101 (40%) were significantly increased in children with ADEM. HLA-DRB1 * 1401, HLA- DRB3 * 0202, and HLA-DQB1 * 0502 were found in children with acute necrotizing encephalopathy. In conclusion, HLA-DR1 * 15 and DQB1 * 06 may be involved in susceptibility to inflammation in Korean children. The frequencies of HLA-DRB1 * 1501, HLA-DRB5 * 0101, HLA-DRB3 * 0301, and HLA-DQB1* 0602 were not as high in Korean children with multiple sclerosis as in western children. However, HLA-DRB3 * 0202 was seen in all children with multiple sclerosis. Our data may provide further evidence that the immunogenetic background of neuroinflammatory diseases in Korean is distinctly different from the ones in western countries. Further studies are necessary to confirm this finding.

Alleles↗