Amplification Failure by the Cepheid Xpert Xpress SARS-CoV-2 Assay due to a Single-Nucleotide Variant of the N Gene in the Omicron Variant.

BACKGROUND: Rapid identification of SARS-CoV-2 infection using molecular testing has played an important role in preventing the spread of COVID-19. However, the failure of SARS-CoV-2 N gene amplification in the Cepheid Xpert SARS-CoV-2 assay could lead to the failed detection of infections, possibly leading to spread. In this study, we examined N gene amplification failure due to a single-nucleotide variant (SNV) in the N2 region of the gene. METHODS: Xpert assay results obtained at our hospital since March 2021 were retrospectively reviewed and samples with strong E gene and failed N gene amplification were selected. Whole-genome sequencing was performed using the Illumina platform. Lineage analyses were conducted and the N2 target region of the US CDC 2019-nCoV real-time PCR primer sequence, used in PCR assays of SARS-CoV-2 infection, was compared with the reference SARS-COV-2 sequence (Wuhan-Hu-1, NC_045512.2). RESULTS: The two samples eligible for this study were classified as BA.5.2 (22B, Omicron) and included two synony-mous SNVs, C29197T and C29200T, respectively. Both variants resulted in synonymous mutation of the N gene encoding alanine. The distribution of variants varied across different countries. CONCLUSIONS: Clinical laboratories performing molecular tests targeting the N gene of SARS-CoV-2 should consider the probability of N gene amplification failure when reporting the test results.

Preanalytical Errors in the Central Laboratory of a University Hospital Based on the Analysis of Year-Round Data.

BACKGROUND: Preanalytical errors cause a decrease in the accuracy of clinical laboratory results. We analyzed preanalytical errors (preAEs) made in the clinical laboratory of a university hospital. METHODS: All samples received in a centralized laboratory from January 1, to December 31, 2018, were analyzed retrospectively. The categories of preAEs were improper request, incorrect labeling, improper collection/transport, inadequate sample volume, inappropriate container, hemolysis, and sample clotting. The rates of preAEs in these categories were calculated according to sample type, laboratory subunit, department, sampling place, sampling time, and patient age. RESULTS: Of 1,082,014 samples received and analyzed by the laboratory, 6,848 (0.63%) were classified as having preAEs. The most frequent categories of preAE were hemolysis (44.6%), sample clotting (30.8%), and inadequate volume (16.7%). The most frequent preAE category for whole-blood and serum/plasma was clotting and hemolysis, respectively. The most frequent preAE category in the blood bank, clinical chemistry, immunology, and test referral service laboratory subunits was hemolysis, in the hematology subunit it was sample clotting, and in the microbiology and urinalysis subunits it was inadequate sample volume. Surgical departments had a higher rate of preAEs than did non-surgical departments (p < 0.0001). Samples drawn in the sampling room showed the lowest frequencies of preAEs (0.01%). Samples drawn on general wards from 5 pm to 5 am, when duty nurses perform sampling, showed a preAE rate of 2.80%. The rate of preAEs increased with patient age. CONCLUSIONS: This analysis of preAEs is the most comprehensive to date. Our findings will promote the provision of high-quality laboratory services to clinicians and their patients.

Real-time display of laboratory testing status improves satisfaction levels in an emergency department: A pilot study.

BACKGROUND: Clinicians need to know timelines of requested laboratory tests to provide effective patient management. We developed a real-time laboratory progress checking system and measured its effectiveness using appropriate indicators in an emergency room setting. METHODS: In our original in-house health information system display, blank spaces, which were generated for test results when tests were ordered, remained empty until the final results reported. We upgraded the laboratory reporting system to show real-time testing information. The stages included requests for test, label printing, sampling, laboratory receipts, performance of tests, verification of results, and interpretation of results and final report by laboratory physician. To assess the usefulness of the function, we measured the emergency department healthcare workers' satisfaction and compared the number of phone calls about test status before and after implementation. RESULTS: After the system upgrade, the healthcare workers' understanding of the testing process increased significantly as follows. More clinicians could estimate the time of final test results through the real-time testing status information (61.9% and 85.7%, P = .002), and respondents reported that the upgraded system was more convenient than the original system (41.3% and 22.2%, respectively, P = .022). The number of phone calls about the test status decreased after implementation of the upgrade; however, the difference was not statistically significant (before, 0.13% [63 calls/48 637 tests] and after, 0.09% [42/46 666]; P = .066). CONCLUSIONS: The real-time display of laboratory testing status increased understanding of testing process among healthcare workers in emergency room, which ultimately may increase the usefulness and efficiency of the laboratory service use.

Clinical and Microbiological Characteristics of Chryseobacterium indologenes Bacteremia: A 20-Year Experience in a Single University Hospital.

BACKGROUND: Chryseobacterium indologenes is ubiquitous in nature and rarely causes infections. However, the clinical impact of C. indologenes has increased in recent years, especially in immunocompromised patients, and has resulted in high mortality rates. We aimed to investigate the clinical and microbiological characteristics of C. indologenes bacteremia. MATERIALS AND METHODS: We retrospectively reviewed medical records of a 642-bed university-affiliated hospital in Korea, dating from January 2001 to December 2020, to investigate C. indologenes bacteremia. RESULTS: A total of 22 C. indologenes isolates were identified from blood culture records. All patients were hospitalized at the time of bacteremia, and the most common manifestation was primary bacteremia. A sizable majority of the patients (83.3%) had underlying diseases, and all patients received intensive care unit care during their admission. The 14-day and 28-day mortality rates were 8.3% and 16.7%, respectively. Importantly, all C. indologenes isolates were 100% susceptible to trimethoprim-sulfamethoxazole. CONCLUSION: In our study, most of the infections were hospital-acquired, and the susceptibility pattern of the C. indologenes isolates showed multidrug resistance. However, trimethoprim-sulfamethoxazole is a potentially useful antibiotic for C. indologenes bacteremia treatment. More attention is required to identify C. indologenes as one of the most important nosocomial bacteria with detrimental effects in immunocompromised patients.

A 20-year trend of prevalence and susceptibility to trimethoprim/sulfamethoxazole of Stenotrophomonas maltophilia in a single secondary care hospital in Korea.

Stenotrophomonas maltophilia is a Gram-negative opportunistic pathogen that can cause serious infection. We aimed to analyze the prevalence and susceptibility rates to trimethoprim/sulfamethoxazole of S. maltophilia. We conducted a retrospective study of S. maltophilia isolates from a university hospital from 2001 to 2020. Clinical information, the numbers of isolates and susceptibility rates were analyzed by year. Susceptibility rates and changes in respiratory and non-respiratory samples were compared. 1805 S. maltophilia isolates were identified, of which 81.4% (1469/1805) were from respiratory samples. There was a male predominance and 52% of the isolates were from general wards. The average susceptibility rate was 87.7% and there was no significant annual trend (P = .519). The susceptibility rate was 88.7% in respiratory samples and 84.1% in non-respiratory samples (P = .018). Susceptibility analyses using clinical data over long periods can guide the choice of antimicrobials especially for pathogen whose treatment options are limited.

Prevalence and distribution of human papillomavirus infection in Korean women as determined by restriction fragment mass polymorphism assay.

The development of a prophylactic vaccine that targets human papillomaviruses (HPV) 6, 11, 16, and 18 to prevent cervical cancer has increased interest in the ethnic and geographical distributions of HPV genotypes. We investigated HPV prevalence and type distribution by restriction fragment mass polymorphism (RFMP) testing a total of 60,775 specimens (aged 18-79 yr, median 44) taken from liquid-based cytology. Overall HPV positive rate of total patients was 34.2%. Among the positive patients, 87.7% was single type infections, and 12.3% was multiple HPV types. HPV-16 was the most prevalent genotype observed in 2,307 (26.0%), followed by type 52 in 2,269 (25.5%), type 58 in 1,090 (12.3%), type 18 in 633 (7.1%), type 56 in 436 (4.9%). The pattern of high risk-HPV positive rate according to age showed U-shape with a peak in HPV prevalence among women less than 30 yr of age, and a second peak among the older females aged 70 to 79 yr. The leading four high-risk HPV genotypes were HPV-16, HPV-52, HPV-58, and HPV-18 in descending order. In conclusion, this study provides the most representative prevalence and type-specific distribution of HPV among Korean women, and demonstrates that the epidemiology of HPV infection is different from that of other regions of the world.

A case of bacterial keratitis caused by multi-drug-resistant Shewanella algae without marine exposure.

Shewanella are Gram-negative rods and marine pathogens. Here, we report a case of bacterial keratitis caused by Shewanella algae without marine exposure. A 66-year-old man with suspected pneumonia was sent to the emergency department from a nursing hospital. He had been in there for 2 years in a vegetative state and could not close his eyes voluntarily. Neither the patient nor his family had experienced any marine exposure. Keratitis was suspected in his right eye. Gram-negative rods grew from swab culture and identified as S. algae by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA sequencing. The patient was treated with topical tobramycin, moxifloxacin and ofloxacin as well as steroids for 14 days, and the keratitis improved. S. algae is a rare human pathogen, and most human infections involve marine exposure. This is the second report of bacterial keratitis caused by S. algae worldwide and the first in Asia.

Eradication of Helicobacter pylori increases ghrelin mRNA expression in the gastric mucosa.

It has been suggested that Helicobacter pylori eradication may influence production of some peptides in the stomach, which can affect appetite. This hypothesis is controversial. To verify the hypothesis, we conducted this randomized controlled trial using H. pylori infected subjects without any gastrointestinal symptoms. The treatment group received triple H. pylori eradication therapy for 7 days and the control group received no medication. We measured ghrelin, obestatin and the tumor necrosis factor-alpha (TNF-alpha) mRNA levels in endoscopic biopsy specimens and the changes from baseline to follow-up. The plasma active n-octanoyl ghrelin and obestatin levels were measured in both groups. The ghrelin/obestatin ratios in plasma and gastric mRNA expression were calculated at baseline and follow-up. Ghrelin mRNA expression in the fundic mucosa after H. pylori eradication increased significantly compared to the control group (4.47+/-2.14 vs. 1.79+/-0.96, P=0.009), independent of inflammatory changes. However, obestatin mRNA expression decreased in the antral mucosa (-0.57+/-1.06 vs. 0.41+/-0.72, P=0.028). The treatment group showed a marginal increase (P=0.060) in plasma ghrelin/obestatin ratio. The TNF-alpha mRNA expression also decreased significantly with treatment. This randomized controlled trial demonstrates that H. pylori eradication increases ghrelin mRNA expression, independent of inflammatory cell changes.

First Case of Intracranial Mycotic Aneurysm Caused by Prevotella intermedia Associated with Chronic Sinusitis in a Korean Adult.

Intracranial infection caused by anaerobic bacteria is rare, and it is difficult to identify absolute anaerobes in the clinical laboratory, especially when the bacterial load is low. Here, we report the first case of intracranial mycotic aneurysm caused by Prevotella intermedia associated with chronic sinusitis and successful identification of the bacteria by 16S rRNA sequencing from bacterial growth in broth only.

The New Diagnosis-Related Group Reimbursement System and Laboratory Test Quality in Korea: Analysis of External Quality Assessment Results.

Korea introduced a new diagnosis-related group (NDRG), which is a mixed-bundle reimbursement system. We evaluated the effects of NDRGs on laboratory test quality by analyzing data over three years (2016-2018) from the Korean Association of External Quality Assessment Service (KEQAS). A total of 42 NDRG-participating hospitals (CASE), 84 non-participating similar size-hospitals (CON-1), and 42 tertiary hospitals (CON-2) were included. We assumed the proportion of KEQAS results with a larger than 2 standard deviation index (SDI) to be a bad laboratory quality marker (BLQM). CASE BLQMs were lower than CON-1 BLQMs for more than 2 years in alkaline phosphatase (ALP), alanine aminotransferase (ALT), chloride, glucose, sodium, and total protein, and higher in creatinine. CASE BLQMs were higher than CON-2 BLQMs for more than 2 years in ALP, chloride, creatinine, glucose, lactate dehydrogenase (LDH), phosphorus, potassium, sodium, total calcium, total cholesterol, triglyceride, and uric acid. Mean SDIs for general chemistry tests were not significantly different depending on NDRG participation. However, the NDRG is currently a pilot program that compensates the amount of each institution's reimbursement based on the fee-for-service system, and most participants were public hospitals. Thus, the effects of NDRGs on laboratory test quality should be re-evaluated after the NDRG program has stabilized and more private hospitals are participating.

Status of Quality Control for Laboratory Tests of Medical Institutions in Korea: Analysis of 10 Years of Data on External Quality Assessment Participation.

External quality assessment (EQA) is a commonly used tool to track the performance of laboratory tests. In Korea, EQA participation is not mandatory, and even basic data about EQA participation are not available. We used data of a 10-year period extracted from two databases (2009-2018): (1) the database of the National Health Insurance Service to calculate the number of medical institutions that claimed health insurance benefits, and (2) the database of the Korean Association of External Quality Assessment Service to calculate the number of medical institutions participating in EQA. The proportion of institutions that made claims for the performance of laboratory testing throughout the 10 years were 73.6%-76.0% for clinics, 91.9%-97.5% for long-term care hospitals, 97.9%-99.5% for small to medium hospitals, 99.6%-100% for general hospitals, and 100% for tertiary hospitals. The mean EQA participation rate of institutions that performed laboratory testing for the 10 years was 1.9% for clinics, 3.1% for long-term care hospitals, 27.7% for small to medium hospitals, 96.6% for general hospitals, and 100% for tertiary hospitals. The mean EQA participation of clinics, long-term care hospitals, and small to medium hospitals are increasing but is still not sufficient. Regulatory approaches are needed to increase participation rates. This result would be used for health policymaking on the quality improvement of laboratory tests.

Getting patient blood management Pillar 1 right in the Asia-Pacific: a call for action.

Preoperative anaemia is common in the Asia-Pacific. Iron deficiency anaemia (IDA) is a risk factor that can be addressed under patient blood management (PBM) Pillar 1, leading to reduced morbidity and mortality. We examined PBM implementation under four different healthcare systems, identified challenges and proposed several measures: (a) Test for anaemia once patients are scheduled for surgery. (b) Inform patients about risks of preoperative anaemia and benefits of treatment. (c) Treat IDA and replenish iron stores before surgery, using intravenous iron when oral treatment is ineffective, not tolerated or when rapid iron replenishment is needed; transfusion should not be the default management. (d) Harness support from multiple medical disciplines and relevant bodies to promote PBM implementation. (e) Demonstrate better outcomes and cost savings from reduced mortality and morbidity. Although PBM implementation may seem complex and daunting, it is feasible to start small. Implementing PBM Pillar 1, particularly in preoperative patients, is a sensible first step regardless of the healthcare setting.

Detection and characterization of an emerging type of Babesia sp. similar to Babesia motasi for the first case of human babesiosis and ticks in Korea.

Babesiosis is a tick-transmitted intraerythrocytic zoonosis. In Korea, the first mortalities were reported in 2005 due to Babesia sp. detection in sheep; herein we report epidemiological and genetic characteristics of a second case of babesiosis. Microscopic analysis of patient blood revealed polymorphic merozoites. To detect Babesia spp., PCR was performed using Babesia specific primers for ß-tubulin, 18S rDNA, COB, and COX3 gene fragments. 18S rDNA analysis for Babesia sp., showed 98% homology with ovine Babesia sp. and with Babesia infections in Korea in 2005. Moreover, phylogenetic analysis of 18S rDNA, COB, and COX3 revealed close associations with B. motasi. For identifying the infectious agent, Haemaphysalis longicornis (296) and Haemaphysalis flava (301) were collected around the previous residence of the babesiosis patient. Babesia genes were identified in three H. longicornis: one sample was identified as B. microti and two samples were 98% homologous to B. motasi. Our study is the first direct confirmation of the infectious agent for human babesiosis. This case most likely resulted from tick bites from ticks near the patient house of the babesiosis patient. H. longicornis has been implicated as a vector of B. microti and other Babesia sp. infections.

Neonatal hair nicotine levels and fetal exposure to paternal smoking at home.

Exposure to environmental tobacco smoke (ETS) is a major risk to human health, and the home is the greatest single source of ETS for children. The authors investigated fetal exposure to paternal smoking at home during pregnancy. Korean families were included as trios of fathers, mothers, and neonates identified in 2005-2007. Sixty-three trios were finally enrolled in this study after exclusion of those in which the mother was a smoker or was regularly exposed to ETS at places other than the home. Nicotine and cotinine concentrations in hair were measured by using liquid chromatography-tandem mass spectrometry to determine long-term exposure to ETS. The difference between neonatal nicotine concentrations in the smoker and nonsmoker groups was not statistically significant. However, in the indoor-smoker group, neonatal nicotine concentrations were significantly higher than in the outdoor and nonsmoker groups (P < 0.05). Furthermore, neonatal nicotine concentrations in the outdoor-smoker group were not different from those in the nonsmoker group. These findings indicate that paternal smoking inside the home leads to significant fetal and maternal exposure to ETS and may subsequently affect fetal health. Conversely, findings show that paternal smoking outside the home prevents the mother and her fetus from being exposed to ETS.

[Microbiologic study of the bile culture and antimicrobial susceptibility in patients with biliary tract infection].

BACKGROUND/AIMS: Bacterial infection of biliary tract may cause severe inflammatory response or sepsis. An immediate bile culture and appropriate antibiotic administration are important to control the biliary tract infection. The objective of the study was to identify organisms in bile and the features of antibiotic susceptibility in patients with biliary tract infection. METHODS: We retrospectively reviewed the clinical records of 212 patients whose bile had been cultured for variable biliary tract diseases at Inje University Ilsan Paik Hospital from Jan. 2000 to Feb. 2007. Bile samples were obtained from percutaneous transhepatic biliary drainage (PTBD, n=89), percutaneous transhepatic gallbladder drainage (PTGBD, n=14) or endoscopic naso-biliary drainage (ENBD, n=49). RESULTS: The overall positive rate of bile culture was 71.7% (152 cases). The organisms cultured were Escherichia coli (25.0%), Enterococcus spp. (13.4%), Klebsiella spp. (11.1%), Pseudomonas spp. (11.1%), and coagulase-negative Staphylococcus (9.7%) in decreasing order. Effective antibiotics for Gram-negative organisms were amoxicillin/clavulanic acid, amikacin, imipenem, and piperacillin/tazobactam in order of effectiveness. Of the cultured blood samples from 160 patients, fifty (31.2%) showed positive bacterial growth. The organisms isolated from blood were similar to those found in the bile. CONCLUSIONS: A broad spectrum penicillin/beta-lactamase inhibitor is a recommendable antimicrobial for empirical treatment for biliary tract infection. However, Gram-positive bacteria such as Enterococcus spp. or methicillin-resistant Staphylococcus aureus are emerging as causative microorganisms. If these organisms are isolated, antimicrobial drugs should be replaced by narrower-spectrum antimicrobials.

Renoprotective effects of febuxostat compared with allopurinol in patients with hyperuricemia: A systematic review and meta-analysis.

BACKGROUND: Hyperuricemia is reported to be related to rapid progression of renal function in patients with chronic kidney disease (CKD). Allopurinol, a uric acid lowering agent, protects renal progression. However, it is not widely used in patients with CKD because of its serious adverse event. Febuxostat can be alternatively used for patients who are intolerable to allopurinol. We aimed to determine renoprotective effect and urate-lowering effect between the two drugs. METHODS: We performed a systematic review and meta-analysis of randomized controlled trials to assess the effects of febuxostat compared to allopurinol in patients with hyperuricemia. MEDLINE, Embase, and Cochrane Library databases were searched to identify research publications. RESULTS: Four relevant publications were selected from among 3,815 studies. No significant differences were found in the changes in serum creatinine from baseline between the febuxostat and allopurinol groups. Changes in estimated glomerular filtration rate (eGFR) were observed between the two groups at 1 month (mean difference 1.65 mL/min/1.73 m2, 95% confidence interval [CI] 0.38, 2.91 mL/min/1.73 m2; heterogeneity χ2 = 1.25, I2 = 0%, P = 0.01); however, the changes in eGFR were not significantly different at 3 months. A significant difference did exist in the changes in albuminuria levels from baseline between the febuxostat and allopurinol groups (mean difference -80.47 mg/gCr, 95% CI -149.29, -11.64 mg/gCr; heterogeneity χ2 = 0.81, I2 = 0%, P = 0.02). A significant difference was also observed in the changes in serum uric acid from baseline between the febuxostat and allopurinol groups (mean difference -0.92 mg/dL, 95% CI -1.29, -0.56 mg/dL; heterogeneity χ2 = 6.24, I2 = 52%, P < 0.001). CONCLUSION: Febuxostat might be more renoprotective than allopurinol.

CKAP2 (cytoskeleton-associated protein2) is a new prognostic marker in HER2-negative luminal type breast cancer.

BACKGROUND: Recently, we reported cytoskeleton-associated protein2 (CKAP2) as a possible new prognostic breast cancer marker. However, it has not yet been applied in clinic. Therefore, clinical significance of CKAP2 was evaluated in comparison with that of Ki-67 in a cohort of breast cancer patients, and the expression difference was analyzed in cell cycle-arrested cancer and fibroblast cells. METHODS: A total of 579 early breast cancer patients who underwent surgery at the National Cancer Center Hospital in Korea between 2001 and 2005 were accrued. CKAP2-positive cell count (CPCC) and Ki-67 labeling index (Ki-67LI) were evaluated by immunohistochemcal staining. The immunocytochemical staining patterns of CKAP2 and Ki-67 were analyzed in HeLa and human fibroblast cells after synchronization by double thymidine block. RESULTS: Although there was a significant correlation (R = 0.754, P < 0.001) between CPCC and Ki-67LI, only CPCC was correlated with DFS in overall population (HR, 2.029; 95% CI, 1.012-4.068; P = 0.046) and HER2-negative luminal subgroup (HR, 3.984; 95% CI, 1.350-11.762; P = 0.012) by multivariate analysis. In immunocytochemical staining, more than 50% of serum-starved or non-mitotic cell phase HeLa cells were positive for Ki-67, in comparison to the low CKAP2-positivity, which might explain the prognostic difference between CPCC and Ki-67LI. CONCLUSIONS: The current study showed that CPCC but not Ki-67LI is an independent prognostic indicator in early breast cancer, more specifically in HER2-negative luminal breast cancer. The difference between two markers may be related to the lower background expression of CKAP2 in cancer cells.

Is plasma neutrophil gelatinase-associated lipocalin a predictive biomarker for acute kidney injury in sepsis patients? A systematic review and meta-analysis.

PURPOSE: Neutrophil gelatinase-associated lipocalin (NGAL) is a useful biomarker for early diagnosis of acute kidney injury (AKI). However, the diagnostic value of NGAL for predicting AKI in sepsis patients is unclear. METHODS: MEDLINE, EMBASE, and Cochrane Library databases were searched to identify research publications. RESULTS: Twelve studies from 9 countries including a total of 1582 patients, of whom 315 (19.9%) developed AKI, were included in the study; plasma NGAL levels were significantly higher in adult sepsis patients with AKI than in those without AKI (mean difference, 274.65; 95% confidence interval [CI], 106.16-443.15; I(2) = 94%). Urine NGAL levels were not significantly different. The diagnostic odds ratio of plasma NGAL for predicting AKI in sepsis patients was 6.64 (95% CI, 3.80-11.58). The diagnostic accuracy of plasma NGAL was 0.881 (95% CI, 0.819-0.923) for sensitivity, 0.474 (95% CI, 0.367-0.582) for specificity, 0.216 (95% CI, 0.177-0.261) for positive predictive value and 0.965 (95% CI, 0.945-0.977) for negative predictive value. CONCLUSION: Plasma NGAL has a high sensitivity and a high negative predictive value for detection of AKI in adult sepsis patients. However, its low specificity and low positive predictive value could limit its clinical utility. The usefulness of urine NGAL was not revealed in this study.

Comparison of commercial genetic-testing services in Korea with 23andMe service.

INTRODUCTION: Genetic testing services for disease prediction, drug responses, and traits are commercially available by several companies in Korea. However, there has been no evaluation study for the accuracy and usefulness of these services. We aimed to compare two genetic testing services popular in Korea with 23andMe service in the United States. MATERIALS AND METHODS: We compared the results of two persons (one man and one woman) serviced by Hellogene Platinum (Theragen Bio Institute), DNAGPS Optimus (DNAlink), and 23andMe service. RESULTS: Among 3 services, there were differences in the estimation of relative risks for the same disease. For lung cancer, the range of relative risk was from 0.9 to 2.09. These differences were thought to be due to the differences of applied single nucleotide polymorphisms (SNPs) in each service for the calculation of risk. Also, the algorithm and population database would have influence on the estimation of relative disease risks. The concordance rate of SNP calls between DNAGPS Optimus and 23andMe services was 100% (30/30). conclusions: Our study showed differences in disease risk estimations among three services, although they gave good concordance rate for SNP calls. We realized that the genetic services need further evaluation and standardization, especially in disease risk estimation algorithm.

Serum BDNF levels in relation to illness severity, suicide attempts, and central serotonin activity in patients with major depressive disorder: a pilot study.

The aim of this study was to test the hypothesis that serum levels of brain-derived neurotrophic factor (BDNF) are correlated with the loudness dependence of auditory evoked potentials (LDAEP). The question of whether there is a difference in BDNF levels between depressive patients according to their illness severity, history of suicide attempts, and central serotonin activity was also addressed. A sample of 51 patients who met the criteria for major depressive disorder following diagnosis using axis I of the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders - text revision comprised the study subjects. The patients were stratified into two subgroups based on their illness severity, history of suicide attempts, and their LDAEP values. The LDAEP was evaluated by measuring the auditory event-related potentials, and serum BDNF was measured using blood sampling before beginning medication with serotonergic agents. There was no difference in serum BDNF levels between the two patient subgroups. The subgroup with moderate-to-severe depression (n = 16) was reanalyzed after stratifying it into two subgroups according to LDAEP and BDNF values (dichotomized at the medians into low and high). The high-LDAEP subgroup had higher serum BDNF levels and total Barratt Impulsiveness Scale score than the low-LDAEP subgroup (p = 0.03 and 0.036, respectively). Serum BDNF levels were positively correlated with LDAEP and total Beck Hopelessness Scale (BHS) score (r = 0.56, p = 0.025, and r = 0.59, p = 0.016, respectively). The high-BDNF subgroup had a higher LDAEP and total BHS score than the low-BDNF subgroup (p = 0.046 and p = 0.011, respectively). This is the first study to demonstrate a relationship between the BDNF level and LDAEP in Asian depressive patients. Intriguingly, the high-BDNF subgroup (divided according to illness severity) exhibited a more severe psychopathology on some psychometric rating scales, a finding that conflicts with previous results.