Serological evaluation of patients with coronavirus disease-2019 in Daegu, South Korea.

BACKGROUND: Early and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is critical to prevent spread of the infection. Understanding of the antibody response to SARS-CoV-2 in patients with coronavirus disease 2019 (COVID-19) is insufficient, particularly in relation to those whose responses persist for more than 1 month after the onset of symptoms. We conducted a SARS-CoV-2 antibody test to identify factors affecting the serological response and to evaluate its diagnostic utility in patients with COVID-19. METHODS AND FINDING: We collected 1,048 residual serum samples from 396 patients with COVID-19 confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR) for SARS-CoV-2. The samples had been used for routine admission tests in six healthcare institutions in Daegu. Antibody to SARS-CoV-2 was analyzed and the cutoff index (COI) was calculated for quantitative analysis. The patients' information was reviewed to evaluate the relationship between antibody positivity and clinical characteristics. The anti-SARS-CoV-2 antibody positivity rate was 85% and the average COI was 24·3. The positivity rate and COI increased with time elapsed since symptom onset. Anti-SARS-CoV-2 antibody persisted for at least 13 weeks after symptom onset at a high COI. There was a significant difference in anti-SARS-CoV-2 antibody positivity rate between patients with and without symptoms, but not according to sex or disease course. The descending COI pattern at weeks 1 to 5 after symptom onset was significantly more frequent in patients who died than in those who recovered. CONCLUSIONS: Anti-SARS-CoV-2 antibody persisted for at least 13 weeks at a high COI in patients with COVID-19. A decreasing COI pattern up to fifth week may be associated with a poor prognosis of COVID-19. As new treatments and vaccines are introduced, it is important to monitor continuously the usefulness of anti-SARS-CoV-2 antibody assays.

Clinical features and outcomes of JAK2 V617F-positive polycythemia vera and essential thrombocythemia according to the JAK2 V617F allele burden.

BACKGROUND: JAK2 mutation status is a well-known risk factor for thrombosis in patients with myeloproliferative neoplasms. However, the clinical usefulness of JAK2 V617F allele burden is under investigation. METHODS: We retrospectively evaluated the impact of the JAK2 V617F allele burden on clinical characteristics and outcomes of JAK2 V617F-positive polycythemia vera (PV) and essential thrombocythemia (ET). The JAK2 V617F allele burden was measured using sequencing. RESULTS: Altogether, 127 patients with JAK2 V617F mutation (PV, N=61; ET, N=66) were included in this study. JAK2 V617F allele burdens were positively correlated with white blood cell counts, hemoglobin values, lactate dehydrogenase levels, and platelet counts. The median values of JAK2 V617F allele burden in patients with PV and ET were 58% and 30%, respectively. A JAK2 V617F allele burden of ≥30%, older age, and a higher hemoglobin level were risk factors for thrombotic events in ET. In patients with PV, older age was the only thrombotic risk factor. The 8-year probabilities of overall survival (OS) were 82.9% in all patients. A high JAK2 V617F allele burden (≥58%) was associated with poor OS in patients with PV. For the patients with ET, the difference in 8-year OS based on the JAK2 V617F allele burden was not significant. CONCLUSION: The JAK2 V617F allele burden was correlated with hematologic parameters and clinical outcomes. Assessing the JAK2 V617F allele burden can be helpful in predicting the thrombotic risk and disease course in patients with JAK2 V617F-positive PV and ET.

Severe Acute Respiratory Syndrome Coronavirus-2 Antibody Responses in Hospitalized Patients with Coronavirus Disease 2019 in Daegu, Korea.

BACKGROUND: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) started to spread in Daegu beginning at the end of February 2020. IgG and IgM antibodies against SARS-CoV-2 were measured in hospitalized patients with COVID-19 with moderate to severe symptoms to improve the understanding of antibody responses. METHODS: We enrolled 312 patients with COVID-19 admitted to seven hospitals located in Daegu. Using serum (or plasma) samples from patients with polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infections, both IgG and IgM antibodies were measured using commercial enzyme-linked immunosorbent assay (R-FIND CO¬VID-19 ELISA, SG medical, Seoul, Korea). RESULTS: The median value from the initial diagnosis, confirmed by SARS-CoV-2 PCR, to the sampling date was 24 days (day 1 to 88). The total positive rate of IgG was 93.9% and the positive IgM rate was 39.4%, without considering the elapsed period after diagnosis. Positive IgG and IgM rates were highest at 100.0% and 59.0%, respectively, at 3 weeks (15 - 21 days). IgG showed a high positive rate of 79.3% even within 7 days after the initial diag-nosis of the disease and maintained a positive rate of 97.8% until after 8 weeks. CONCLUSIONS: Among hospitalized patients with COVID-19, IgG was detected from the beginning of the diagnosis and persisted for an extended time period.

IgG Seroprevalence of COVID-19 among Individuals without a History of the Coronavirus Disease Infection in Daegu, Korea.

BACKGROUND: Seroprevalence studies of coronavirus disease 2019 (COVID-19) from many countries have shown that the number of undiagnosed missing cases is much larger than that of confirmed cases, irrespective of seroprevalence levels. Considering the strategy of Korea entailing massive testing and contact tracing from the beginning of epidemic, the number of undiagnosed missing cases in Korea may be negligible. This study was conducted to estimate the seroprevalence of COVID-19 among individuals who were never diagnosed with COVID-19 in Daegu, the epicenter of COVID-19 epidemic in Korea. METHODS: Serologic testing for immunoglobulin G antibody based on immunochromatographic assay was conducted in 103 patients and 95 guardians aged 18 to 82 years without any history of COVID-19 diagnosis, who visited outpatient clinics of a single university-affiliated hospital from May 25 to June 5, 2020. RESULTS: The estimated seroprevalence was 7.6% (95% confidence interval, 4.3%-12.2%) with 15 positive cases. Among them, only one had a polymerase chain reaction (PCR)-confirmed case among their close contacts and 13 did not experience COVID-19-related symptoms. Seroprevalence was similar between patients and guardians. Based on this figure, the number of undiagnosed missing cases in Daegu was estimated to be a dozen times more than the number of confirmed cases based on PCR testing. CONCLUSION: Despite the limitation of a small and unrepresentative sample, this is the first study on seroprevalence of COVID-19 in Korea. Our study suggested that the number of undiagnosed missing cases was substantial even with the stringent strategy adopted in Korea, similar to that of other countries.

Selective purging of human multiple myeloma cells from peripheral blood mononuclear cells: a preliminary study.

BACKGROUND: High-dose chemotherapy followed by autologous peripheral blood stem-cell transplantation are standards of therapy for patients diagnosed with multiple myeloma. The purging process to remove contaminating residual myeloma cells could improve patient outcomes. In this study, a purging method of human multiple myeloma cells from peripheral blood mononuclear cells was evaluated. MATERIALS AND METHODS: The human myeloma cell line RPMI-8226 (Seoul, Korea) was treated with bortezomib (Selleck Chemicals, Houston, TX, USA) or lenalidomide (Sigma Aldrich, St. Louis, MO, USA). The mixture of the human peripheral blood mononuclear cell line PCS-800-011 (ATCC, USA) and RPMI-8226 was treated with bortezomib or lenalidomide for 24 hours. The efficacy of purging myeloma cells was evaluated by 8-color flow cytometric analysis. RESULTS: The cytotoxicity of bortezomib (10-160 nmol/L) and lenalidomide (200-3,200 nmol/L) was investigated on RPMI-8226 myeloma cell line. A 24-hour incubation with bortezomib at 10, 20, 40, 80, 160 nmol/L induced 5.45%±0.07%, 47.15%±1.20%, 57.15%±0.21%, 72.35%±0.07%, and 84.75%±0.49% growth inhibition in RPMI-8226 cells, respectively. A 24-hour incubation with lenalidomide at 200, 400, 800, 1,600, and 3,200 nmol/L induced 5.45%±0.07%, 7.55%±0.07%, 9.75%±0.35%, 18.25%±0.21%, and 39.75%±0.78% growth inhibition in RPMI-8226 cells, respectively. Bortezomib (40 nmol/L, 24 hours) and lenalidomide (3,200 nmol/L, 24 hours) effectively removed CD38+CD138+ cells from peripheral mononuclear cells. RPMI-8226 cells showed abberant phenotype CD56+/CD45-. CONCLUSION: The results of the present study demonstrated that the bortezomib and lenalidomide treatment in RPMI-8226 multiple myeloma cells effectively removed the contaminated plasma cells.

Effects of one directional pneumatic tube system on routine hematology and chemistry parameters; A validation study at a tertiary care hospital.

BACKGROUND: The validation of sample stability through pneumatic tube system (PTS) is essential. The objective of this study was to evaluate the effects of PTS transportation on laboratory results. METHODS: Paired EDTA and SST blood samples were collected from 56 randomly selected patients. Laboratory parameters were compared between PTS group and hand-delivered group. RESULTS: No statistical differences were observed for complete blood counts, white blood cell differential parameters, erythrocyte sedimentation rate and most chemistry parameters between PTS and hand-delivered transport procedures. Mean platelet volume results obtained from samples transported through PTS were lower than that obtained from samples transported through hand-delivered method (P = 0.001). The results of aspartate aminotransferase (P = 0.000), lactate dehydrogenase (P = 0.000), and hemolysis index (P = 0.000) from PTS group were higher than that from hand-delivered group. CONCLUSIONS: All laboratories should validate the stability of the results from samples according to transportation method.

Analysis of Turnaround Time for Intraoperative Red Blood Cell Issues: A Single-Center Study.

BACKGROUND: When unpredicted surgical blood loss occurs, it is essential that blood arrive from the blood bank in a timely manner. OBJECTIVE: To evaluate the turnaround time (TAT) for red blood cells (RBCs) from the blood bank to the operating suite. Cases with delayed TATs were further analyzed to determine potential causes for the delays. METHODS: During a 6-month period, intraoperative RBC requests were included among the blood component request lists at a single tertiary care hospital. RESULTS: A total of 387 RBC-product requests were received from the operating room, of which 220 (56.8%) cases were intraoperative requests. The overall mean (SD) TAT was 19.4 (9.8) minutes. Mean (SD) preparation-to-issuance time (14.9 [7.8] minutes) contributed more to the overall TAT than did mean (SD) request-to-preparation time (4.5 [7.4] minutes). The 31 cases (14.1%) exceeded the internally mandated TAT threshold (> 30 minutes). Prolonged compatibility testing and delayed courier arrival contributed to TAT delay. CONCLUSIONS: TAT standards for issuing RBCs from the blood bank to the operating suite should be established and carefully monitored for quality improvement of transfusion services.

Utility of preoperative in vitro platelet function tests for predicting bleeding risk in patients undergoing functional endoscopic sinus surgery.

BACKGROUND: It is necessary to predict the bleeding risk in patients undergoing functional endoscopic sinus surgery (FESS). To evaluate the adequacy of primary hemostasis, preoperative hemostatic screening tests are used. In the present study, we determined whether there is a positive correlation between prolonged closure time (CT) with collagen/epinephrine (CT-epi), prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT) and bleeding during FESS. PATIENTS AND METHODS: We reviewed the medical records of 90 patients without bleeding histories who had undergone FESS from March 2013 to June 2014. More than 200 mL of blood loss was defined as moderate bleeding during surgery. With respect to bleeding during surgery, we determined the sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of CT-epi, PT, INR and aPTT. RESULTS: Of the 90 patients, 17 (18.9%) patients had preoperative prolonged CT values and three (17.6%) patients had bleeding. In comparison, five (6.8%) of the 73 (81.1%) patients who had undergone FESS with preoperative normal PFA values experienced bleeding (P=0.171). On the other hand, patients with prolonged PT values (2, 2.2%), prolonged INR values (3, 3.3%) or prolonged PTT values (1, 1.1%) had no bleeding episode. Preoperative CT had low sensitivity (44.4%) and PPV (23.5%). CONCLUSION: During preoperative period, the hemostatic screening may not be helpful to detect the bleeding tendency in adult patients undergoing FESS. Routine measurement of CT-epi, PT, INR and aPTT for preoperative screening may not be recommended for FESS patients.

Total extract of Korean red ginseng facilitates human bone marrow hematopoietic colony formation in vitro.

BACKGROUND: The number of CD34+ cells in a peripheral blood stem cell collection is the key factor in predicting successful treatment of hematologic malignancies. Korean Red Ginseng (KRG) (Panax ginseng C.A. Meyer) is the most popular medicinal herb in Korea. The objective of this study was to determine the effect of KRG on hematopoietic colony formation. METHODS: Bone marrow (BM) samples were obtained from 8 human donors after acquiring informed consent. BM mononuclear cells (MNCs) were isolated, and CD34+ cells were sorted using magnetic beads. The sorted CD34+ cells were incubated with or without total extract of KRG (50 µg/mL, 100 µg/mL) or Ginsenoside Rg1 (100 µg/mL), and the hematopoietic colony assay was performed using methylcellulose semisolid medium. The CD34+ cell counts were measured by a single platform assay using flow cytometry. RESULTS: The numbers of human BM-MNCs and CD34+ cells obtained after purification were variable among donors (5.6×10(7) and 1.3-48×10(7) and 8.9×10(4) and 1.8-80×10(4), respectively). The cells expanded 1,944 times after incubation for 12 d. Total extract of KRG added to the hematopoietic stem cell (HSC)-specific medium increased CD34+ cell counts 3.6 times compared to 2.6 times when using HSC medium alone. Total numbers of hematopoietic colonies in KRG medium were more than those observed in conventional medium, especially that of erythroid colonies such as burst forming unit-erythroid. CONCLUSION: Total extract of KRG facilitated CD34+ cell expansion and hematopoietic colony formation, especially of the erythroid lineage.

Changes of peripheral blood lymphocyte subtypes in patients with end stage cancer administered localized radiotherapy and bojungikki-tang.

Localized radiotherapy (RT) can cause immune dysfunction. Bojungikki-tang is known to restore immune function. We investigated the absolute counts and percentages of peripheral blood (PB) lymphocyte subtypes in end stage cancer patients before and after RT and after oral administration of Bojungikki-tang water extract (BJITE) and to evaluate the changes mediated by RT and BJITE. Absolute counts and percentages of lymphocyte and lymphocyte subsets were determined in whole blood using the TetraONE System (Beckman Coulter, USA). Flow cytometry results were compared before and after RT and after administration of BJITE. Absolute numbers of CD3+, CD4+, and CD8+ T cells and CD19+ B cells decreased significantly after RT (P < 0.05). Absolute numbers of CD3-CD56+ cells did not change in both groups. No significant differences were observed in the absolute counts of lymphocyte subtypes before and after administration of BJITE or vitamin group. When BJITE group was compared with vitamin group, absolute numbers of CD19+ B cells increased. RT-induced decrease in T cells and B cells in PB suggests that immune deterioration occurs after RT. Administration of BJITE might be effective in the restoration of number of B cells.

Mean cell volumes of neutrophils and monocytes are promising markers of sepsis in elderly patients.

BACKGROUND: Sepsis in elderly patients is a major cause of morbidity and mortality in the clinical setting. The aim of this study was to assess the diagnostic significance of volume conductivity scatter (VCS) parameters and to compare their reliability with that of inflammatory markers. METHODS: Patients (N=85) were divided into 3 groups according to their clinical history and culture results: control (N=29), localized infection (N=38), and sepsis (N=18). VCS parameters were obtained using a UniCel DxH 800 Coulter system. Cut-off values were established based on receiver operator characteristic (ROC) curves. RESULTS: The mean volumes of neutrophils (MNV) and monocytes (MMV) were higher in the sepsis group than in the localized infection and control groups (P=0.000 for both). The mean cell conductivity and low median angle light scatter of neutrophils were lower in the sepsis group than in the localized infection and control groups (P=0.029 and P=0.022, respectively). With a cut-off of 156.5, MNV had a sensitivity of 83.3% and a specificity of 78% in predicting sepsis. CONCLUSION: MNV and MMV, which can be obtained easily using an automated blood analyzer, may be promising hematologic parameters for distinguishing elderly individuals with and without sepsis and may help clinicians in the diagnosis of sepsis.

A case of myelodysplastic syndrome with marked eosinophilia showing favorable prognosis.

Myelodysplastic syndrome (MDS) with eosinophilia is a rare condition and has yet to be classified under the 2008 World Health Organization classification. However, reports have described the prognostic significance of chronic persistent eosinophilia in MDS. Here, we report a case of a 67-year-old woman who was admitted to the hospital in July 2007 with generalized weakness, dizziness, and dyspnea on exertion persisting for 5 years. In the initial investigation, eosinophilia (22.1%) in peripheral blood and an increased proportion of eosinophils (5.6%) in normocellular bone marrow with dysplastic megakaryocytes and erythroid cells were noted. Eosinophilia was continuously detected during follow-up over 3 years. In a second bone marrow examination in August 2010, hypercellular bone marrow with similar features was observed. These findings led to the diagnosis of MDS with chronic persistent eosinophilia. To increase awareness of the prognostic significance of MDS with chronic eosinophilia, here we report a slow-progressing case of MDS with chronic persistent eosinophilia lasting over 6 years.

The distinct expressions of interleukin-15 and interleukin-15 receptor α in Behçet's disease.

Interleukin-15 (IL-15) is a pleotrophic cytokine that is involved in the pathogenesis of diverse inflammatory rheumatic diseases. The aims of this study were to compare serum IL-15 levels and expression of its receptor (IL-15Rα) in Behçet's disease (BD) with those in other rheumatic diseases and to identify the relationship between serum IL-15 levels and various clinical parameters in BD. One hundred fifty-eight subjects consisting of 40 BD, 38 systemic lupus erythematosus (SLE), 40 rheumatoid arthritis (RA), and 40 healthy controls were enrolled. Serum IL-15 levels were measured using an enzyme-linked immunosorbent assay. The proportion of IL-15Rα expression on each leukocyte subset was measured by flow cytometry. Erythrocyte sediment rate (ESR) and C-reactive protein (CRP) were measured for each enrolled subject. The clinical activity index of BD was assessed for BD patients. Serum IL-15 levels in BD patients are significantly higher than those of healthy controls, SLE, and RA patients (p < 0.001, p < 0.001, and p < 0.001, respectively). Serum IL-15 levels in BD were closely related to ESR (r = 0.405, p = 0.027), but not to CRP or the clinical activity index of BD (p > 0.05 for both). Additionally, there was no difference in serum IL-15 levels between active and inactive disease states in BD (p > 0.05). The proportion of IL-15Rα expression on total leukocytes was much lower for all rheumatic diseases, including BD, than in healthy controls (p < 0.01 for SLE, p < 0.01 for RA, and p < 0.05 for BD). IL-15 and IL-15Rα system may be involved in the inflammatory process and pathogenesis of BD.

γδ T cells are increased in the peripheral blood of patients with gastric cancer.

BACKGROUND: γδ T cells are implicated in immunoregulation. However, little is known about the characteristics of γδ T cells in gastric cancer. In this study, we assessed the incidence of γδ T cells and lymphocyte subsets in the peripheral blood of gastric cancer patients. METHODS: We enrolled 48 patients and 49 healthy controls. The γδ T cells, lymphocyte subsets were analyzed with flow cytometry. RESULTS: The mean percentage of γδ T cells in patients with gastric cancer was 5.0±3.4% and for controls 2.3±1.6%. Twenty (41.7%) of the 48 patients with gastric cancer had a high percentage (more than 5%) of peripheral blood γδ T cells, while 4 (8.2%) of the 49 controls did. The percentage of CD3⁺ T cells were elevated in gastric cancer compared to controls (P=0.007). The CD4/CD8 ratio increased in gastric cancer (P=0.311). The percentage of CD3⁺CD4⁻CD8⁻ T cells increased in gastric cancer compared to controls (P=0.004). CONCLUSION: The proportion of γδ T cells in the peripheral blood of gastric cancer patients was significantly higher in comparison to that in the healthy controls. Our findings suggest that increased proportion of peripheral γδ T cells may explain anti-tumor immunity against gastric cancer partly.

Inhibition of P-glycoprotein facilitated glycosaminoglycan accumulation during chondrogenesis of human bone marrow mesenchymal stem cells.

AIM: P-glycoprotein (P-gp) is an adenosine-5-triphosphate Binding Cassettes B 1 (ABCB1) transporter that exports various substrates on cellular membrane. Surface expression of P-gp was decreased during chondrogenesis of human bone marrow mesenchymal stem cells (BM-MSCs). We examined the role of P-gp in extracellular matrix deposition during chondrogenesis of human BM-MSCs. METHOD: BM-MSCs were isolated from 16 volunteers after informed consent and incubated for 28 days using three-dimensional culture methods in chondrogenic medium with and without P-gp inhibitor (verapamil, 10 µmol/L). RESULTS: Hematoxylin and eosin staining revealed a cartilaginous structure with chondrogenic cells in the lacunae after 2 weeks of culture. Total glycosaminoglycan (GAG) content was increased and rose during pellet culture. Hyaluronan (HA) content of the culture medium decreased with P-gp inhibitor. Type II collagen deposition decreased with P-gp inhibitor. CONCLUSION: Inhibition of P-gp facilitated GAG accumulation via HA export inhibition during chondrogenic differentiation of human BM-MSCs. Modulation of P-gp expression during chondrogenesis would be a possible therapeutic approach for articular cartilage regeneration.

Decreased interleukin-18 response in asthmatic children with severe Mycoplasma pneumoniae pneumonia.

PURPOSE: Mycoplasma pneumoniae (M. pneumoniae) is a common causative agent of pneumonia in children. The aim of this study is to determine whether there is any difference in selected cytokine or chemokines response in asthmatic children compared to non-asthmatic children during acute M. pneumoniae pneumonia. METHODS: Seventy-five children, 6-12 years of age, admitted with M. pneumoniae pneumonia were enrolled. Two patient groups were defined: the children with known asthma (N=40) and non-asthmatic children (N=35). Interleukin (IL)-18 and selected chemokines, IL-8, CXCL9, CXCL10, and regulation upon activation normal T-cell expressed and secreted (RANTES) were measured by means of ELISA in the plasma samples of the patients collected on admission. We investigated the values of these mediators in relation to the asthma status and symptom severity of the patients. Twenty age-matched, non-infected controls were also studied. RESULTS: Plasma levels of IL-18 and the chemokines increased significantly in the patients with M. pneumoniae pneumonia compared to non-infected, age-matched controls (P<0.01). However, the asthmatic patients showed significantly reduced IL-18 and CXCL10 responses (P<0.01, <0.05, respectively) and had more severe pneumonia symptoms (P<0.01) compared to non-asthmatic patients. IL-18 was significantly lower in severe pneumonia group than in non-severe group (P<0.05). CONCLUSIONS: Our study suggests that IL-18 and the chemokines are importantly involved in the pathogenesis of M. pneumoniae pneumonia. It also indicates that some asthmatic children have deficient IL-18 response when affected by M. pneumoniae pneumonia, which might be associated with more severe pneumonia observed in this group of patients.

[Anti-inflammatory effect of near-infrared irradiated cell culture media].

BACKGROUND: Near-infrared light (NIR, 0.8-1.5 microm light) has been used in therapeutic devices for various injuries such as infected, ischemic and hypoxic wound. NIR-emitting technology has been developed recently in Korea. We hypothesized that NIR may have an anti-inflammatory effect and investigated the effect of NIR-irradiated media on cell culture. METHODS: Three kinds of cell lines, CAPE (vascular endothelial cell), NIH3T3 (fibroblast), and RD (smooth muscle cell) cells were cultured for 4 days in 10% FBS-containing media (1 x 10(4) cells/well), which were irradiated or not irradiated (control) by Eco-NFIR Drive (Model #0210, Ecowavetech, Korea). The cells were stimulated by 10 mcg/mL of bacterial lipopolysaccharide (LPS) or sodium nitroprusside (SNP). Cellular proliferation was measured by methylthiazol tetrazolium assay. Expression of interleukin (IL)-1 beta and nitric oxide was measured by ELISA. Expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was measured by immunofluorescence staining. RESULTS: NIR-irradiated medium was favorable for CAPE cell proliferation (N=8, P=0.000). IL-1 beta secretion from LPS-stimulated NIH3T3 cells incubated in the NIR medium was below that of control medium (N=4, P=0.026). Nitrate production seemed to be low in NIR-irradiated medium although statistically insignificant (N=4, P=0.076). Expression of iNOS of the LPS-stimulated cells was decreased in NIR medium, however, Cox-2 expression was not different between the two media. CONCLUSIONS: NIR-irradiated medium supported vascular endothelial cell proliferation and showed an anti-inflammatory effect on fibroblast culture. These results can be used as basic data for future research on the clinical application of NIR.

A case of natural killer cell leukemia misdiagnosed as tuberculous lymphadenopathy.

Natural killer (NK) cell neoplasms are a group of rare but highly malignant tumors. We report here one case of NK cell leukemia. A 54-yr-old woman presented with a 2-month history of progressive left neck mass. Based on the positive result of tissue PCR for Mycobacterium tuberculosis, she was at first diagnosed with tuberculous lymphadenopathy. After two weeks, she developed generalized lymphadenopathy, hepatosplenomegaly, fever and anemia. Subsequent evaluation was performed including bone marrow aspiration and biopsy. Peripheral blood smear showed leukoerythroblastic features with 31% blasts. Bone marrow was packed with agranular blastoid cells, which were periodic acid-Schiff (PAS) positive and myeloperoxidase (MPO) negative. Immunophenotyping showed that these cells were positive for CD45 and HLA-DR, whereas negative for CD3, CD5, CD7, CD10, CD13, CD14, CD19, CD20, CD22, CD33, CD34, and CD61. Because of the absence of the markers of T-cell, B-cell, and myeloid lineage-specific antigens, we added CD16/56 for the immunophenotyping and the blasts were positive (94%). The tumor cells of biopsied lymph node were only positive for CD56, consistent with NK cell lymphoma. Epstein-Barr virus (EBV) was not detected by RNA in situ hybridization. Culture for M. tuberculosis was negative. Thus this patient was diagnosed with blastic NK cell lymphoma/leukemia involving bone marrow and lymph node.

Human leucocyte antigen-B27 subtypes in Korean patients with ankylosing spondylitis: higher B*2705 in the patient group.

AIM: To investigate the distribution of human leucocyte antigen (HLA) class I antigens and B27 subtypings in a group of B27(+) ankylosing spondylitis (AS) patients and a group of B27(+) control individuals, and to compare differences in their clinical features using subtyping. METHODS: A total of 143 B27(+) AS samples and 32 B27(+) control samples were collected consecutively from two rheumatology centres in South Korea. All patients were diagnosed according to the modified New York criteria for AS. Medical records of the patients were retrospectively reviewed for demographic information, Bath disease activity index (BASDAI) scores, laboratory parameters at diagnosis and extra-articular manifestations. Polymerase chain reaction-sequence-specific primer typing for the B27 subtypes was performed using the Dynal HLA-B27 high resolution kit. RESULTS: Whereas subtypes in Korean AS patients include B*2704 (n = 11, 7.7%) B*2705 (n = 130, 90.9%), and B*2710 (n = 2, 1.4%), those of the control groups include B*2704 (n = 11, 34.4%), B*2705 (n = 19, 59.4%), B*2710 (n = 1, 3.1%), and B*2715 (n = 1, 3.1%). The proportion of B*2705 subtypes were significantly higher in the AS group than the control group (P < 0.01). There were no differences in clinical features (peripheral arthritis, uveitis, BASDAI scores) or laboratory parameters between the two groups. CONCLUSION: In Korean AS patients, not in the control group, the HLA-B*2705 subtype was higher than other subtypes, in contrast to AS patients from Japan and China. B27 subtypes in AS patients were not associated with clinical features or laboratory parameters.

P-glycoprotein expression in extracellular matrix formation of chondrogenic differentiation of human adult stem cells.

Mesenchymal stem cell (MSC) has been known as a good source of progenitor for multiple connective tissue including cartilage, muscle, adipocyte, and bone. P-glycoproteins (P-gps) also known as ABCB1 that exports diverse substrates are the product of the multidrug resistance-1 (MDR-1) gene. P-gp expression has been reported in chondrosarcoma and hypertrophic chondrocyte in the human growth plate. This study was designed to investigate the expression of P-gp during chondrogenic differentiation of adult human stem cells. Bone marrow samples were obtained from nine human donors after informed consent. The isolated mononuclear cells (MNCs) were incubated as one pellet/tube and 0.5ml chondrogenic medium in the presence of 10ng/ml of TGF-beta 1 and TGF-beta 3 for 28 days. The expression of surface P-gps was analyzed by flow cytometry and quantitative RT-PCR was performed for the detection of mRNA expression of MDR-1 and type II collagen gene. Total collagen and glycosaminoglycan (GAG) contents of the pellets were measured. Surface P-gp expression of the MSCs was decreased during chondrogenic differentiation. MDR-1 gene was decreased 10-fold after the 2-week incubation whereas type II collagen gene was increased 491-fold after the 4-week incubation in chondrogenic medium. The total amount of collagen and GAG were increased during pellet culture. This study has demonstrated a decrease in expression of P-gp and down regulation of MDR-1 gene consistently by flow cytometry and quantitative RT-PCR, but an increased expression of type II collagen on MSC during chondrogenesis.