Cotinine has been widely used as an objective marker to identify current smokers. We conducted this study to address the absence of Korean studies investigating the efficacy of immunoassays and liquid chromatography–tandem mass spectrometry (LC-MS/MS) for the detection of serum cotinine and to determine the optimal serum cotinine cut-off level for differentiating current smokers from nonsmokers.
Serum specimens were obtained from 120 subjects. They were randomly chosen to represent a broad distribution of urine cotinine levels based on a retrospective review of questionnaires and results of urine cotinine levels. We determined serum cotinine levels using the IMMULITE 2000 XPi Immunoassay System (Siemens Healthcare Diagnostics Inc., USA) and LC-MS/MS (API-4000, Applied Biosystems, USA). Correlation was analyzed between IMMULITE serum cotinine, urine cotinine, and LC-MS/MS serum cotinine levels. ROC curve was analyzed to identify the optimal IMMULITE serum cotinine cut-off level for differentiating current smokers from nonsmokers.
IMMULITE serum cotinine levels correlated with both urine cotinine and LC-MS/MS serum cotinine levels, with correlation coefficients of 0.958 and 0.986, respectively. The optimal serum cotinine cut-off level for distinguishing current smokers from nonsmokers was 13.2 ng/mL (95.7% sensitivity, 94.1% specificity) using IMMULITE.
This is the first study to investigate the use of LC-MS/MS for the measurement of serum cotinine and to determine the optimal serum cotinine cut-off level for the IMMULITE immunoassay. Our results could provide guidelines for differentiating current smokers from nonsmokers in the Korean population.
Cotinine; Cut-off; Korean; LC-MS/MS; Serum
Microangiopathic hemolytic anemia (MAHA) occurs occasionally as a paraneoplastic syndrome in some solid tumors, but MAHA accompanied by signet ring cell carcinoma of an unknown origin is very rare. In this study, we present the case of an 80-yr-old man who was admitted to the hospital because of a 1-month history of lower back pain and dyspnea. He was diagnosed with MAHA on the basis of the laboratory findings that revealed anemia with schistocytes, decreased haptoglobin levels, and a negative direct Coombs' test. Bone marrow examination, which was performed because of the progression of anemia, revealed bone marrow metastases of signet ring cell carcinoma with extensive bone marrow necrosis. However, the primary origin of this signet ring cell carcinoma was not found. When the cause of progressive MAHA is unknown, the possibility of cancer-associated MAHA must be excluded by performing additional tumor workup, including the detection of tumor markers, gastric and colorectal endoscopic examinations, bone marrow examinations, and positron emission tomography-computed tomography or bone scans.
Bone marrow metastasis; Microangiopathic hemolytic anemia; Signet ring cell carcinoma
The association between serum bilirubin levels and incident chronic kidney disease (CKD) in the general population is unknown. We aimed to examine the association between serum bilirubin concentration (total, direct, and indirect) and the risk of incident CKD.
Methods and Findings
Longitudinal cohort study of 12,823 Korean male workers 30 to 59 years old without CKD or proteinuria at baseline participating in medical health checkup program in a large worksite. Study participants were followed for incident CKD from 2002 through 2011. Estimated glomerular filtration rate (eGFR) was estimated by using the CKD-EPI equation. CKD was defined as eGFR <60 mL/min per 1.73 m2. Parametric Cox models and pooled logistic regression models were used to estimate adjusted hazard ratios for incident CKD. We observed 238 incident cases of CKD during 70,515.8 person-years of follow-up. In age-adjusted models, the hazard ratios for CKD comparing quartiles 2–4 vs. quartile 1 of serum direct bilirubin were 0.93 (95% CI 0.67–1.28), 0.88 (0.60–1.27) and 0.60 (0.42–0.88), respectively. In multivariable models, the adjusted hazard ratio for CKD comparing the highest to the lowest quartile of serum direct bilirubin levels was 0.60 (95% CI 0.41–0.87; P trend = 0.01). Neither serum total nor indirect bilirubin levels were significantly associated with the incidence of CKD.
Higher serum direct bilirubin levels were significantly associated with a lower risk of developing CKD, even adjusting for a variety of cardiometabolic parameters. Further research is needed to elucidate the mechanisms underlying this association and to establish the role of serum direct bilirubin as a marker for CKD risk.
Pure red cell aplasia is characterized as a normocytic anemia associated with reticulocytopenia and the absence of erythroblasts in the bone marrow. Pure red cell aplasia can be induced by various causes such as thymoma, connective tissue disease, viral infection, lymphoma, and adverse drug reactions. There have been only a few reports of pure red cell aplasia associated with acute viral hepatitis A. In Korea, no case of pure red cell aplasia caused by acute hepatitis A has yet been reported. We recently experienced a case of acute viral hepatitis A complicated by pure red cell aplasia. The patient was successfully treated with corticosteroids. Here we report this case and review the literature.
Red-cell aplasia; Hepatitis A; Acute Kidney injury
The aim of this study was to investigate the relationship between the -1438A/G polymorphism of serotonin receptor 2A (5HTR2A) and anxiety-related traits in Korean adolescent females.
A total of 174 Korean adolescent females were tested for the -1438A/G polymorphism of 5HTR2A using polymerase chain reaction (PCR)-based methods. Anxiety-related traits were evaluated using the Anxiety Sensitivity Index (ASI) and the trait form of the Spielberg State-Trait Anxiety Inventory (T-STAI).
There was no difference between the genotypes with respect to scores pertaining to anxiety-related traits. Although the G allele carriers (GG or AG genotype) scored lower on the psychological subscale of the ASI (4.76±3.00 vs 5.98±4.00, p=0.038), this difference was not significant after Bonferroni correction.
These findings suggest that the -1438A/G polymorphism of 5HTR2A might not be associated with anxiety sensitivity or trait anxiety.
Anxiety; Anxiety sensitivity; Polymorphism; Serotonin 2A receptor
Background and Purpose
Elevation of serum cardiac troponin T (cTnT) is regarded as a specific marker of acute coronary syndrome. Serum cTnT can be increased in patients with acute ischemic stroke, but its clinical implications remain unclear. The aim of this study was to identify the relationships between elevated cTnT and stroke severity, location, and prognosis.
From January 2005 to December 2006, this study recruited 455 consecutive patients who were admitted to Kangbuk Samsung Hospital due to acute ischemic stroke within 3 days of onset, which was confirmed by diffusion magnetic resonance imaging. A total of 416 patients was finally included and divided into 2 groups: an elevated cTnT group (n=45) and a normal cTnT group (n=371). The short-term prognosis was assessed by 30-day modified Rankin Scale responder analysis was compared between the two groups.
Serum cTnT was elevated in 10.8% of cases, with elevated cTnT associated with greater stroke severity, as assessed by the National Institutes of Health Stroke Scale score, Insular-lobe involvement was more common in patients with elevated cTnT than in the normal cTnT group. Short-term prognosis was more unfavorable in the elevated cTnT group than in the normal cTnT group. Multivariate regression analysis indicated that elevated cTnT was independently related to insular involvement, cardioembolism, and unfavorable outcome.
Elevated cTnT in acute ischemic stroke was associated with severe neurological deficits at stroke onset and damages to the insular lobe. The outcome of acute ischemic stroke was worse for patients with elevated cTnT than for those with normal cTnT. The pathomechanism underlying acute ischemic stroke and subclinical myocardial damage warrants further study.
Serum cardiac troponin T (cTnT); Diffusion magnetic resonance imaging; Acute myocardial infarction (AMI); Stroke; Prognosis
The aims of this study were to estimate the incidences of BCR/ABL, MLL, TEL/AML1 rearrangements, and p16 deletions in childhood acute lymphoblastic leukemia (ALL), to identify new abnormalities, and to demonstrate the usefulness of interphase fluorescence in situ hybridization (FISH). We performed G-banding analysis and FISH using probes for BCR/ABL, MLL, TEL/AML1 rearrangements, and p16 deletions on 65 childhood ALL patients diagnosed and uniformly treated at a single hospital. Gene rearrangements were identified in 73.8% of the patients using the combination of G-banding and FISH, while the chromosomal abnormalities were identified in 49.2% using G-banding alone. Gene rearrangements were disclosed by FISH in 24 (72.7%) of 33 patients with normal karyotype or no mitotic cell in G-banding. Among the gene rearrangements detected by FISH, the most common gene rearrangement was p16 deletion (20.3%) and the incidences of others were 14.1% for TEL/AML1, 11.3% for MLL, and 1.8% for BCR/ABL translocations. Infrequent or new aberrations such as AML1 amplification, MLL deletion, ABL deletion, and TEL/AML1 fusion with AML1 deletion were also observed. We established the rough incidences of gene rearrangements in childhood ALL, found new abnormalities and demonstrated the diagnostic capability of interphase FISH to identify cryptic chromosome aberrations.
In Situ Hybridization, Fluorescence; Leukemia, Lymphocytic, Acute; Childhood; Gene Rearrangements
In CD5 positive (CD5+) mature B-cell lymphomas, newly recognized CD5+ diffuse large B-cell lymphoma (DLBCL) has been characterized by aggressive features. We studied twenty-five cases with CD5+ lymphomas involving bone marrow. Eleven cases were diagnosed as chronic lymphocytic leukemia, six cases were diagnosed as mantle cell lymphoma (MCL), and three cases with morphologic characteristics of MCL and without both the cyclin D1 expression and IGH/CCND1 rearrangement were unclassifiable. The remaining five cases, showing large to medium-sized lym-phoid cells with prominent nucleoli and a moderate amount of cytoplasm, were diagnosed as DLBCL. Five DLBCL cases were positive for CD5, CD20, surface immuno-globulin, but negative for CD23. Patients with CD5+ DLBCL showed a high age of onset (median, 68 yr) and two patients expired one month after the diagnosis. Since CD5+ DLBCL forms a distinct subgroup of DLBCL, a study of CD5 expression in DLBCL would be helpful to predict prognosis and to determine future therapeutic strategy. To the best of our knowledge, this is the first report on de novo CD5+ DLBCL in Koreans.
Antigens, CD5; Leukemia, Lymphocytic, Chronic; Lymphoma, Mantle-Cell; Lymphoma, Large-Cell, Diffuse
The identification of marker chromosomes is important for genetic counseling. However, the origin or composition can rarely be defined with conventional cytogenetic technique alone. In this study, we investigated the incidences and types of marker chromosomes in Korean patients and attempted to establish a cost-effective diagnostic approach for marker chromosomes. We reviewed the karyotypes of 2,984 patients that were requested for the cytogenetic analysis between 1997 and 2003 at the Samsung Medical Center. Ten marker chromosomes were found and identified using fluorescent in situ hybridization (FISH). Among the ten marker chromosomes, six were supernumerary marker chromosomes (SMCs) and the rest were marker chromosomes in Turner syndrome (TS). The incidence of SMCs was 2.01/1,000, slightly higher than that previously reported. Five of six SMCs were satellited marker chromosomes. Three bisatellited marker chromosomes originated from chromosome 15 and two from chromosome 22. The origin of one SMC could not be identified. All marker chromosomes in TS originated from X- or Y chromosome. The application of FISH is indispensable to identify marker chromosomes, and the appropriate selection of probes is necessary for cost-effective analysis. For analyzing satellited marker chromosomes, application of probes for chromosome 15 followed by those for chromosome 22 is recommended and in cases of TS, probes for sex chromosomes should take precedence.