Kyechul Kwon

Analysis of monocyte subsets and toll-like receptor 4 expression in peripheral blood monocytes of women in preterm labor

Preterm labor is associated with both localized inflammation of the uterus and elevated proinflammatory cytokines. Recently, specific roles have been suggested for distinct monocyte subsets and toll-like receptor 4 (TLR4) expression in inflammation. The aim of this study was to determine whether specific monocyte subsets and increased TLR4 expression in monocyte subsets contribute to preterm labor. The study included 30 preterm labor, 40 full-term labor and 20 pregnant women (not in labor). Four-color flow cytometry was used to examine the distribution of three monocyte subsets (CD14(+)CD16(-), CD14(high)CD16(+), and CD14(low)CD16(+)) and the TLR4 expression in each monocyte subset in each group of women. A larger percentage of CD14(high)CD16(+) cells was found in the preterm labor group than in the other groups (P=0.08, P=0.06). Women in preterm labor also showed significantly higher TLR4 expression in all monocyte subsets and increased fluorescence intensity in the CD14(+)CD16(-) and CD14(high)CD16(+) cells. Expression of TLR4 and mean fluorescence intensity on each monocyte subset were also significantly correlated. We conclude that women with preterm labor have higher CD16 monocytes, with high concomitant expression of CD14 and enhanced TLR4 expression in monocytes, and that monocyte TLR4 levels could be used as a marker to predict preterm delivery.

Expression of CD154 (CD40L) on stimulated T lymphocytes in patients with idopathic thrombocytopenic purpura

Objectives: The role of CD40–CD154 (CD40L) interaction in T cell-dependent humoral immune response is strongly established. Increased expression of CD154 on stimulated T cells is observed in rheumatic diseases and is associated with disease activity. We investigated the expression of CD154 on T cells from idiopathic thrombocytopenic purpura (ITP) patients and assessed the significance of CD154 expression in disease status. Methods: We enrolled 59 ITP patients, 23 healthy controls, and 19 patients with non-immune thrombocytopenia. Isolated mononuclear cells were stimulated in RPMI medium containing phorbol myristate acetate (PMA) (5 ng/mL) and ionomycin (500 ng/mL) for 2 h at 37°C. The expression of CD154 on CD4+T cells was evaluated using flow cytometry and serum soluble CD40L levels were measured. Results: In ITP patients, the percentage of CD4+ CD154+ cells and mean fluorescence intensity (MFI) of CD154 on activated CD4+T cells was not different from that in the healthy controls and non-immune thrombocytopenia patients. Additionally, the percentage and expression level of CD154 was not different between ITP patients with low platelet counts (<50 000/μL) and those with 50 000/μL or more. Soluble CD40L levels were significantly lower in ITP patients with low platelet counts than in healthy controls, but were not correlated with CD154 expression. Conclusion: Increased CD154 expression on CD4+T cells was not observed in ITP patients and was not related with low platelet counts. Overexpression of CD154 on CD4+T cells is unlikely to be central to the pathogenesis of ITP, and other immune dysfunctions should be targeted for therapy purposes.

The 99th percentile values of six cardiac troponin assays established for a reference population using strict selection criteria

BACKGROUND Since the 99th percentile reference limit for cardiac troponin (Tn) can vary depending on the reference population, Sandoval et al. published systematic selection criteria. In this study, these systematic criteria were applied for the first time to obtain the 99th percentile reference limits for 6 Tn tests. METHODS The reference population was selected in accordance with the systematic criteria, and reference limits were set with respect to the six types of Tn assays. The coefficient of variation (CV) at the reference limit was determined using 3-4 concentrations of frozen serum. RESULTS In total, 641 South Koreans (303 males, 338 females) were selected as the reference population. The 99th percentile reference limit of Tn in the six assays ranged from 13.4 to 34.2pg/ml. The measurable fractions among the reference population ranged from 1.3% to 80.5%. The CVs at the reference limit ranged from 5.3% to 43.0%, and three were <10%. CONCLUSIONS In this study, a reference population was selected for the first time in accordance with the systematic criteria of Sandoval et al., and the reference limit for South Koreans was established. The values obtained in this study are different from those proposed by manufacturers, which confirms the importance of having a reference population. Four out of six assays did not fulfill the criteria for high-sensitivity tests.

The prognostic impact of lymphocyte subsets in newly diagnosed acute myeloid leukemia

Background Tumor-infiltrating lymphocytes, which form a part of the host immune system, affect the development and progression of cancer. This study investigated whether subsets of lymphocytes reflecting host-tumor immunologic interactions are related to the prognosis of patients with acute myeloid leukemia (AML). Methods Lymphocyte subsets in the peripheral blood of 88 patients who were newly diagnosed with AML were analyzed by quantitative flow cytometry. The relationships of lymphocyte subsets with AML subtypes, genetic risk, and clinical courses were analyzed. Results The percentages of T and NK cells differed between patients with acute promyelocytic leukemia (APL) and those with AML with myelodysplasia-related changes. In non-APL, a high proportion of NK cells (>16.6%) was associated with a higher rate of death before remission (P=0.0438), whereas a low proportion of NK cells (≤9.4%) was associated with higher rates of adverse genetic abnormalities (P=0.0244) and relapse (P=0.0567). A multivariate analysis showed that the lymphocyte subsets were not independent predictors of survival. Conclusion Lymphocyte subsets at diagnosis differ between patients with different specific subtypes of AML. A low proportion of NK cells is associated with adverse genetic abnormalities, whereas a high proportion is related to death before remission. However, the proportion of NK cells may not show independent correlations with survival.

The role of PFA‐100 measurement in preoperative screening in total knee arthroplasty patients with perioperative replacement of cyclooxygenase‐2 inhibitor

Sir, With the introduction of the platelet function analyzer-100 (PFA-100; Dade Behring, Dudingen, Switzerland) as a screening tool to detect impaired hemostasis in the mid-1990s, its clinical use to predict surgical hemostasis has been increasing in major orthopedic surgery including total knee arthroplasty (TKA) [1]. Although preoperative PFA-100 testing has been adopted as routine screening, its predictive value in TKA is questionable because non-steroidal anti-inflammatory drugs (NSAIDs) can act as an acquired variable. The use of NSAIDs can affect closure time (CT), but few studies have evaluated the abnormalities on the PFA-100 in TKA patients. In previous studies, preoperative NSAIDs exerted a heterogenous antiplatelet effect among patients in whom platelet dysfunction was identified using the PFA-100 [2], and CT prolongation measured upon arrival in the operation room was correlated with the first 24-h drain output but not to intra-operative blood loss or a need for transfusion [3]. Recently, in Korea, a cyclooxygenase (COX)-2 inhibitor with no effects on platelet function is alternatively administered as preoperative workup [4], but the effect of alternative administration of selective COX-2 inhibitors on CT of PFA-100 analysis has not been explored. It remains unclear that preoperative measurements using the PFA-100 system are needed for predicting blood loss after TKA. The purpose of this study was to investigate the degree of platelet dysfunction in patients with arthritis who were using NSAIDs and the change of CT after COX-2 replacement. Moreover, we intended to assess whether abnormal CT on the PFA-100 at preoperative workup can be associated with perioperative blood loss and transfusion requirements in TKA patients with COX-2 replacement. This retrospective study assessed patients who underwent elective TKA between January 2012 and September 2013. The exclusion criteria included known hemostatic disorders, the administration of other antiplatelet drugs or anticoagulants, revision surgery, a hemoglobin (Hb) level < 10 mg/dL, and a platelet count < 150 000/lL. In total, 132 patients (108 women, 24 men; mean age, 70.1 7.4 years) were included. At 7 days before surgery, all patients presented to the outpatient clinic for a preoperative workup. The use of any NSAIDs was discontinued since presentation. Instead, patients received celecoxib (only available selective COX-2 inhibitor in Korea) for pain control. The CT was measured on the PFA-100 analyzer with collagen/epinephrine (CEPI) or collagen/adenosine diphosphate (CADP) cartridges by a single technician, and the maximum CT was 300 s. The reference intervals for CEPI-CT and CADP-CT were defined as 80–162 and 64–121 s, respectively [5]. In the case of prolonged CT, the PFA-100 analysis was repeated the day before surgery. In addition, complete blood counts, prothrombin time (PT), and activated partial thromboplastin time were assessed. Each patient’s Hb concentration was measured at 1 h, second day, 1 week, and 2 weeks after surgery. The surgery was performed by the same surgeon in all patients. A tourniquet was applied to the proximal part of the limb after skin protection padding and released prior to wound closure. Because intraoperative blood loss was negligible due to the application of the tourniquet, blood loss was assessed by the postoperative Hb reduction, the volume in the drains, and the unit of transfused RBC. The total loss of Hb was calculated by subtracting the second day from preoperative Hb level and adding the number of transfused RBC units, assuming 1 unit of RBC as 1 g/dL [6]. The volume collected from the drains was recorded at 12, 24, and 48 h. All statistical analyses were performed using MEDCALC version 12.3.0.0 (MedCalc Software, Mariakerke, Belgium). P < 0.05 was considered statistically significant. At the time of presentation, patients had been prescribed various NSAIDs at local clinics and exhibited a wide range of CTs on the PFA-100 assay. The mean CT was 156 60 s (95% confidence interval [CI] 146–167) with the CEPI cartridge and 84 17 s (95% CI 81–87) with the CADP cartridge. Among the 132 patients, 32 (24.2%) displayed CT prolongation for the CEPI cartridge, vs. 2 (1.5%) for the CADP cartridge. All patients

Detection of a dup(17q) and inv(16) by fluorescence in situ hybridization in acute myelomonocytic leukemia

Two cases of acute myelomonocytic leukemia (AMMoL) of FAB type M4Eo are described in which a primary subclone containing a dup(17)(q21q25) and a subclone containing dup(17)(q21q25), inv(16)(p13q22) were seen in one patient, and -7, dup(17)(q21q25) in another. Fluorescence in situ hybridization (FISH) was carried out for the confirmation of the duplicated segment and breakpoint of inv(16). Inv(16) is a well known anomaly in AMMoL, whereas dup(17q) is rare though as not yet confirmed, this anomaly could be a nonrandom or novel change in AMMoL.