A Sensitive and Specific Liquid ChromatographyTandem Mass Spectrometry Assay for Simultaneous Quantification of Salivary Melatonin and Cortisol:Development and Comparison With Immunoassays

Melatonin and cortisol are clinically important for diagnosing sleep and mood disorders.We developed and validated a liquid chromatography-tandem mass spectrometry (LC-MS/ MS) assay for simultaneous measurement of salivary melatonin and cortisol concentrations according to the Clinical and Laboratory Standards Institute guidelines. Additionally, we compared the LC-MS/MS assay with immunoassays, ELISA (Direct Salivary Melatonin Elisa EK-DSM, Bühlmann Laboratories AG, Schönenbuch, Switzerland) and electrochemiluminescence immunoassay (Cortisol II, Roche, Mannheim, Germany), using 121 saliva samples. The LC-MS/MS assay exhibited good performance in terms of linearity, precision, accuracy, limit of detection, lower limit of quantification, extraction recovery, carry-over, and matrix effect. The LC-MS/MS assay and immunoassays showed strong correlation (Pearson’s r = 0.910 for melatonin, r = 0.955 for cortisol), but demonstrated a significant mean bias of 23.2% (range 54.0–143.7%) for melatonin and 48.9% (range 59.7–184.7%) for cortisol. Our LC-MS/MS assay provided more sensitive and reliable salivary melatonin and cortisol quantification results compared with immunoassays.

Comparison of Three Blood Collection Tubes for 35 Biochemical Analytes: The Becton Dickinson Barricor Tube, Serum Separating Tube, and Plasma Separating Tube

The Barricor tube (Becton Dickinson [BD], Sunnyvale, CA, USA) was recently developed to mechanically separate plasma by increasing the centrifugation rate. We compared the Barricor tube with existing serum- and plasma-based tubes based on 35 biochemical analytes and preanalytical turnaround time (TAT). Blood samples were collected from 30 healthy volunteers in a Barricor tube, serum separating tube (SST, Vacutainer SST II Tube 8.5 mL, #368972; BD), or plasma separating tube (PST, Vacutainer PST Tube 8.0 mL, #367964; BD) in random order. Next, 27 chemistry analytes, six immunochemistry analytes, and two cardiac markers were compared using Passing-Bablok regression and the Bland-Altman method. Preanalytical TAT was measured for each tube.The Barricor tube exhibited bias exceeding the desirable limit for nine and four analytes compared with the SST and PST, respectively. The Barricor tube lactate dehydrogenase value showed a bias of -10.29% and -9.86% compared with that of the SST and PST, respectively. The preanalytical TAT of Barricor tube was 8.8 minutes, which was the shortest among the three tubes. The clinical performance of the Barricor tube was equivalent to that of the SST and PST for most analytes, with an apparent advantage in preanalytical TAT. When using the Barricor tube, the reference range needs to be changed for some analytes that exceed the desirable bias limit.

Psychological effects and risk perception after genetic counseling

Purpose@#Demand for genetic counseling on cancer predisposition syndrome is increasing. We evaluated the psychological effect on counselees after genetic counseling at a clinic in a single center. @*Materials and Methods@#We surveyed a total of 72 enrolled participants who visited a genetic counseling clinic at the Samsung Medical Center (SMC). The initial survey was conducted before the first genetic counseling session, and the second survey was conducted after the second genetic counseling session. A total of 43 participants completed both the initial and second surveys. @*Results@#The initial survey of 72 participants indicated higher feelings of guilt in the group with religion, higher depression and anxiety in the group with a diagnosis of self, and higher anxiety in the group on self-referral to the genetic counseling clinic.In the completed survey of 43 participants, overall decreased depression was observed after the second genetic counseling session (P=0.013). Risk perception and anxiety decreased in the group diagnosed with benign variant/variant of uncertain significance (BV/VUS, 25/3) and increased in the group diagnosed with pathogenic variant (PV, 15). Risk perception and anxiety differed between the BV/VUS and PV groups (P<0.001 and P=0.03, respectively). @*Conclusion@#The genetic counseling clinic at the SMC was effective in ameliorating the depression score. Assessment of survey results revealed different depression scores, feelings of guilt and anxiety, and different effects of the genetic counseling clinic, depending on the subgroups. Understanding the needs and psychological characteristics of different groups is necessary for improving genetic counseling services.

Psychological effects and risk perception after genetic counseling

Purpose@#Demand for genetic counseling on cancer predisposition syndrome is increasing. We evaluated the psychological effect on counselees after genetic counseling at a clinic in a single center. @*Materials and Methods@#We surveyed a total of 72 enrolled participants who visited a genetic counseling clinic at the Samsung Medical Center (SMC). The initial survey was conducted before the first genetic counseling session, and the second survey was conducted after the second genetic counseling session. A total of 43 participants completed both the initial and second surveys. @*Results@#The initial survey of 72 participants indicated higher feelings of guilt in the group with religion, higher depression and anxiety in the group with a diagnosis of self, and higher anxiety in the group on self-referral to the genetic counseling clinic.In the completed survey of 43 participants, overall decreased depression was observed after the second genetic counseling session (P=0.013). Risk perception and anxiety decreased in the group diagnosed with benign variant/variant of uncertain significance (BV/VUS, 25/3) and increased in the group diagnosed with pathogenic variant (PV, 15). Risk perception and anxiety differed between the BV/VUS and PV groups (P<0.001 and P=0.03, respectively). @*Conclusion@#The genetic counseling clinic at the SMC was effective in ameliorating the depression score. Assessment of survey results revealed different depression scores, feelings of guilt and anxiety, and different effects of the genetic counseling clinic, depending on the subgroups. Understanding the needs and psychological characteristics of different groups is necessary for improving genetic counseling services.

Diagnostic Performance of the GENEDIA MTB/NTM Detection Kit for Detecting Mycobacterium tuberculosis and Nontuberculous Mycobacteria With Sputum Specimens

The GENEDIA MTB/NTM Detection Kit (GENEDIA MTB/NTM; Green Cross Medical Science Corp., Chungbuk, Korea) is a multiplex real-time PCR assay used for differential identification of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM). While the importance of differential identification of MTB/NTM is recognized, there is limited data on the performance of GENEDIA MTB/NTM assay to date. A total of 687 consecutive sputum specimens were cultured and analyzed with the GENEDIA MTB/NTM and GENEDIA MTB assays. Nineteen specimens (2.8%) were MTBC-positive, and 69 (10.0%) were NTM-positive based on mycobacterial culture. All specimens showed concordant results for MTBC using both assays, with a kappa value of 1.00, overall sensitivity of 63.2% (12/19), and specificity of 100% (668/668). The overall NTM sensitivity and specificity were 23.2% (16/69) and 99.7% (616/618) for GENEDIA MTB/NTM. The association between NTM-positivity using GENEDIA MTB/NTM and the diagnosis of NTM pulmonary disease was not statistically significant. In conclusion, the two real-time PCR assays showed similar diagnostic performance for MTBC detection. However, the sensitivity for NTM detection was lower than that for MTBC detection.

Mycobacterium shimoidei Pulmonary Disease: The First Case in Korea

Mycobacterium shimoidei is a nontuberculous mycobacterium (NTM), and is rarely reported as a pathogen causing the NTM pulmonary disease. We describe here the case of a 52-year-old male with symptoms such as chronic cough and a history of pulmonary tuberculosis. Radiologic studies revealed a cavitary lesion in the left upper lobe of his lung. Sputum culture was positive for NTM, which was later identified as M. shimoidei using 16S rRNA and hsp65 sequencing. The patient's symptoms, radiologic evidence, and positive culture results together substantiate that this is the first case of M. shimoidei pulmonary disease from Korea.

An Experience of Various Pretransfusion Test Protocols in a Tertiary Referral Hospital / 대한수혈학회지

BACKGROUND: Pretransfusion tests are essential for safe transfusions, but occasionally, part or all can be omitted when a transfusion is needed urgently in an emergency. The purpose of this study was to share the authors' experience of various pretransfusion test protocols in a tertiary referral hospital in Korea. METHODS: From July 2016 to June 2017, all transfusion cases at Samsung Medical Center were analyzed retrospectively. For each pretransfusion test protocol, the parameters regarding issue, return and disposal rate of blood products, occurrence of hemolytic transfusion adverse effect, and prescription frequency of each respective department and ordering site were analyzed. RESULTS: A total of 90,539 units of red blood cells, 24,814 units of fresh frozen plasmas, 24,758 units of single donor platelets, and 23,303 units of platelet concentrates were issued during the study period. Among them, 3.6%, 1.8%, 0.3%, and 0.4% of red blood cells, fresh frozen plasmas, single donor platelets, and platelet concentrates were issued according to the emergency transfusion protocols. When various pretransfusion test protocols were applied to issue blood products, there was no case in which an adverse hemolytic transfusion reaction was suspected. When compared with usual pretransfusion test protocol, all emergency transfusion protocols showed significantly higher return and wastage rates in red blood cells and fresh frozen plasmas. Platelets also had a higher return and wastage rate, but the difference was not significant. CONCLUSION: These results suggests that there is no different risk of adverse hemolytic transfusion reaction regardless the pre-transfusion protocols, but management about of the increased rate of return and wastage of blood products in emergency transfusions should be considered.

Anti-LW Showing Anti-D Mimicking Specificity: A Case Report / 대한수혈학회지

LW antigens are expressed in higher intensities in D-positive blood cells than D-negative cells, which can result in false identification of anti-D in pretransfusion testing. Although several cases of anti-LW have been reported abroad, to the best of our knowledge, none have been reported in Korea. Herein, we report a case of anti-LW in a 58 year-old RhD positive patient with non-Hodgkin's lymphoma with a positive direct Coombs test and a suspicion of the presence of passive anti-D antibodies because of a history of intravenous immunoglobulin administration. However, during a 5-month follow up, the antibody was confirmed as anti-LW on grounds that it showed weakened reaction in dithiothreitol treated cells and enforced reaction in cord O+ cells when compared to the results from antibody identification panel cells.

Interference of Unexpected Antibody Detection Test in Patients Administering Daratumumab / 대한수혈학회지

No abstract available.