Prevalence of SARS-CoV-2 Antibody in 2,935 Healthcare Workers at 6 Major Hospitals, Daegu, Korea

Background@#In Korea, the first community outbreak of coronavirus disease 2019 (COVID-19) occurred in Daegu on February 18, 2020. This study was performed to investigate the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies in healthcare workers (HCWs) at 6 major hospitals in Daegu. @*Methods@#Blood specimens of 2,935 HCWs at 6 major hospitals in Daegu from January 2021 to February 2021 were collected. Every specimen was tested for antibody against SARS-CoV-2 using both Elecsys Anti-SARS-CoV-2 electrochemiluminescence immunoassay (Roche Diagnostics, Rotkreuz, Switzerland) and R-FIND COVID-19 IgG/M/A enzyme-linked immunosorbent assay kit (SG medical Inc., Seoul, Korea) as screening tests. If 1 or more of these screening test results was positive, 2 additional antibody tests were performed using Abbott Anti-SARS-CoV-2 IgG assay (Abbott, Abbott Park, IL, USA) and cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript USA Inc., Piscataway, NJ, USA). If 2 or more of the total 4 test results were positive, it was determined as positive for the antibody against SARS-CoV-2. @*Results@#According to the criteria of SARS-CoV-2 antibody positivity determination, 12 subjects were determined as positive. The overall positive rate of the SARS-CoV-2 antibody was 0.41% (12/2,935). Of the 12 subjects determined as positive, 7 were diagnosed with COVID-19, and the remaining 5 were nondiagnosed cases of COVID-19. @*Conclusion@#In early 2021, the overall seroprevalence of SARS-CoV-2 antibody among HCW located in Daegu was 0.41%, and 0.17% excluding COVID-19 confirmed subjects. These results were not particularly high compared with the general public and were much lower than HCWs in other countries.

Two Cases of Bacteremia Due to Roseomonas mucosa

Roseomonas is a genus of pink-pigmented nonfermentative bacilli. These slow-growing, gram-negative cocobacilli form pink-colored colonies on sheep blood agar. They differ from other pink-pigmented nonfermenters, including Methylobacterium, in morphology, biochemical characteristics, and DNA sequence. Roseomonas strains are rarely isolated in clinical laboratories; therefore, we report two cases in order to improve our ability to identify these pathogens. We isolated two strains of Roseomonas mucosa from the venous blood cultures of two patients, an 84-yr-old woman with common bile duct obstruction and a 17-yr-old male with acute myeloid leukemia who had an indwelling central-venous catheter for chemotherapy. The isolated strains were confirmed as R. mucosa by 16S rRNA sequencing.

A Case of Alternaria alternata Keratitis Isolated from Corneal Tissue / 대한의진균학회지

A 71-year-old man presented with pain in the left eye that revealed a 3x3 mm deep corneal stromal infiltrate, with a 2x2 mm epithelial defect. The patient started topical moxifloxacin, voriconazole 2%, and natamycin for 2 weeks. However, the treatment was not effective and the corneal infiltration worsened. Subsequently, the patient underwent therapeutic penetrating keratoplasty. Thick brown/gray mold colonies on Potato Corn Meal Tween 80 agar was isolated from excised corneal tissue and on slide culture many septated, and club-shaped ascospores were revealed. Histological findings also showed numerous hyphae scattered in corneal tissue. A. alternata colonies were confirmed by 18S rRNA sequencing. Intracameral voriconazole was injected every other day for 2 weeks to eliminate remaining fungi on the deep corneal stroma. The remaining corneal infiltration was improved one month after the injection. During 5 months postoperative follow up, the infection did not recurred. In conclusion, deep corneal infection of A. alternata was effectively treated with intracameral voriconazole injection.

A Case of Trichosporon asahii Fungemia with Urinary Tract Infection as a Primary Focus / 대한임상미생물학회지

Since the report of disseminated trichosporonosis in 1970s, several cases of infection by various Trichosporon species in different clinical patients were published. We've isolated a strain of T. asahii from not only blood but also urine. We report 71 year-old male patient with Trichosporon asahii fungemia, who had renal stones. It was identified as T. asahii using conventional method and also confirmed by 18S rRNA gene sequencing. The patient was discharged without any complication, in which case only antibiotic agent was used without any antifungal one.

Clinical chemistry values in elderly Korean people: single institutional study

Laboratory values change with age and interpreting laboratory results from elderly people using the reference intervals for younger adults may not be appropriate. The authors investigated the distribution patterns of routine chemistry values from elderly people to determine whether current reference intervals are also valid for elderly people. A total of 1,215 persons older than 65 years and 1,827 healthy adults below 65 years of age were evaluated. Blood samples were collected after an overnight fast and analyzed for chemistry tests. Computing the central 95th percentile showed that the total protein, albumin, ALP, LD, creatinine, uric acid, triglyceride, HDL-cholesterol, and electrolytes of elderly people were within the standard reference intervals used in our laboratory. For AST and ALT, the upper range of the central 95th percentile in the elderly population was found to be outside the common reference interval. However, the central 90th percentile values of AST and ALT were compatible with the common reference intervals. GGT, BUN, total cholesterol, LDL-cholesterol, and glucose showed higher values than the upper limits of the reference intervals. For common clinical chemistry tests, the common reference values in general should be applicable to elderly people, even though some parameters showed wider distributions in the elderly.

Immunoglobulin Isotype Switching in a Plasma Cell Myeloma Patient Treated with High-dose Chemotherapy and Hematopoietic Stem Cell Transplantation

A malignant plasma cell clone usually produces a single abnormal monoclonal protein with a constant isotype. However, switching of paraprotein isotype has been reported to be a transient phenomenon associated with the recovery of B-cell function, and, in some cases, the switching might be misinterpreted as relapse. In August 2008, we encountered a case of a 59-year-old man with proteinuria and high IgG level (5.6 g/dL), kappa free light chain level of 2,660 mg/L, reversed A/G ratio (0.51), and multiple osteolytic lesions. Plasma cells, which accounted for 57% of all the nucleated cells, in bone marrow aspirates were positive for kappa immunostaining. Serum protein electrophoresis showed one M-spike, concentration of 4.87 g/dL in the beta region. Immunofixation electrophoresis revealed the peak as an IgG-kappa monoclonal protein; therefore, a diagnosis of plasma cell myeloma was made. Complete remission was achieved after chemotherapy, and autologous peripheral stem cell collection was performed. In March 2009, the patient underwent high-dose chemotherapy and autologous peripheral stem cell transplantation support. After 2 months, serum protein electrophoresis showed 2 M-spikes in the gamma region with positive IgM-lambda, IgG-lambda, and IgG-kappa, and these bands persisted. The electrophoretic mobility of the IgG-kappa protein was different from that of the original disease protein, and bone marrow results were the same as the previous ones. Although immunoglobulin isotype switch is known to have a benign course, it always requires careful monitoring because, in rare cases, true clonal switching may occur.

Individual Variation in Growth Factor Concentrations in Platelet-rich Plasma and Its Influence on Human Mesenchymal Stem Cells / 대한진단검사의학회지

BACKGROUND: The objective of this study was to explore whether individual variations in the concentration of growth factors (GFs) influence the biologic effects of platelet-rich plasma (PRP) on human mesenchymal stem cells (HMSCs). METHODS: The concentrations of 7 representative GFs in activated PRP (aPRP) were measured using ELISA. The effects of PRP on the proliferation and alkaline phosphatase (ALP) activity of HMSCs were examined using several concentrations of aPRP from 3 donors; the relationships between the GF levels and these biologic effects were then evaluated using 10% aPRP from 5 subgroups derived from 39 total donors. HMSCs were cultured in DMEM with the addition of aPRP for 4 or 12 days; then, DNA content and ALP activity were measured. RESULTS: The quantity of DNA increased significantly at a 10% concentration of aPRP, but the ALP activity was suppressed at this concentration of aPRP. The GF concentrations varied among donors, and 5 subgroups of characteristic GF release patterns were identified via cluster analysis. DNA levels differed significantly between groups and tended to be higher in groups with higher concentrations of transforming growth factor-beta1 (TGF-beta1) and platelet-derived growth factors (PDGFs). DNA quantity was positively correlated with TGF-beta1 concentration, and was negatively correlated with donor age. ALP activity was negatively correlated with PDGF-BB concentration. CONCLUSIONS: The varying GF concentrations may result in different biologic effects; thus, individual differences in GF levels should be considered for reliable interpretation of the biologic functions and standardized application of PRP.

Annual Report on External Quality Assessment in Therapeutic Drug Monitoring and Drug of Abuse in Korea (2009) / 임상검사와정도관리

We performed two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) in 2009. The number of participating laboratories were 110, which is similar with that of previous 3 years. Average response rates were 97.8% in both trials, similar to those of previous years. Two kinds of control materials were requested to be tested in each trial so that each institution could find the possible systematic errors. The average drug item responded was 6.2 per institution, which was decreased slightly from 6.5 in recent 5 years. The most common test items were valproic acid, digoxin, carbamazepine, phenytoin, and theophylline which were peformed in more than 63.8% of participating laboratories, followed by phenobarbital, cyclosporine, tacrolimus, vancomycin, lithium, methotrexate, amikacin, gentamicin, acetaminophen, tobramycin, salicylate, free phenytoin, amitryptyline, ethosuximide, and primidone. The widely used TDM analyzers were Abbott AxSym (26.9%), followed by Abbott TDx/TDxFLx (24.8%), Roche Cobas Integra (15.1%), Siemens Diagnostics Viva-E (5.5%), Roche cobas c501 (5.1%), Siemens Diagnostics Dimension (3.4%), and many other analyzers. The inter-laboratory coefficients of variations showed similar tendency comparing with those of the previous years. The number of participating laboratories for drug of abuse (DOA) tests were 19, which was slightly increased compared to that of the previous year. Average DOA items were 3.8~4.2. We found the good performance of participating laboratories for DOA. In conclusion, the TDM and DOA external quality assessment of 2009 showed similar performance comparing with that of the recent 3 years.

Novel Influenza A (H1N1) Infection in Immunocompromised Patients / 대한진단검사의학회지

BACKGROUND: Since April 2009, novel influenza A (H1N1) infection is spreading throughout the world. This infection might be fatal for immunocompromised patients who are at a potentially high risk of developing infectious complications. We investigated the detection rate and features of H1N1 infection in immunocompromised patients. METHODS: Between August 2009 and February 2010, we examined 8,112 subjects, including 390 immunocompromised patients, for H1N1. Swab samples were taken from the nose and throat of the participants. Real-time PCR was performed to identify H1N1 viral genes. RESULTS: Positive results were obtained in 2,953/8,112 (36.4%) subjects and 46/390 (11.8%) immunocompromised patients. H1N1 was identified in 8.7% patients with solid cancer, 12.9% patients with hematologic malignancy, 16.7% patients with chronic renal disease, and 14.5% patients with kidney transplantation. The mean cycle threshold (Ct) value of PCR was significantly lower (P<0.05) in patients with hematologic malignancy as compared to that in patients with chronic renal disease and control subjects. Four patients died due to respiratory complications. CONCLUSIONS: The detection rate of H1N1 was significantly lower in immunocompromised patients than in other patients. The Ct value of patients with hematologic malignancy was significantly lower than that of other immunocompromised patients and control subjects.

Proposal of Laboratory Test Panel Based on Patients' Chief Complaints in Emergency Department / 대한진단검사의학회지

BACKGROUND: A test panel is a group of tests that are simultaneously performed for diagnosis and follow-up of patients. Organ-specific or disease-specific test panels are currently available. Since the patient's chief complaint plays a key role in obtaining the personal and medical history and performing physical examinations, we proposed a test panel based on the chief complaints of the patients. METHODS: We collected data from 3,127 adults with apparent symptoms who visited the emergency department from April 2009 to May 2009. Subsequently, we classified the patients' chief complaints, ordered the laboratory tests on the basis of these complaints, considered the patients' disease entities, and reviewed the relevant literature. RESULTS: The patients were categorized into 14 groups on the basis of the most common chief complaints presented in the emergency department. We first selected the basic test panels and then organized the test panel for each chief complaint to enable differential diagnosis. CONCLUSIONS: We proposed test panels based on the chief complaints of the patients; these test panels could allow rapid diagnosis and be more useful than the organ-specific or disease-specific tests in critical pathway development. The next step will be evaluating the efficiency and cost effectiveness of the test panel that we suggested.

Reducing Patient Waiting Time for the Outpatient Phlebotomy Service Using Six Sigma / 대한진단검사의학회지

BACKGROUND: One of the challenging issues of the outpatient phlebotomy services at most hospitals is that patients have a long wait. The outpatient phlebotomy team of Kyungpook National University Hospital applied six sigma breakthrough methodologies to reduce the patient waiting time. METHODS: The DMAIC (Define, Measure, Analyze, Improve, and Control) model was employed to approach the project. Two hundred patients visiting the outpatient phlebotomy section were asked to answer the questionnaires at inception of the study to ascertain root causes. After correction, we surveyed 285 patients for same questionnaires again to follow-up the effects. RESULTS: A defect was defined as extending patient waiting time so long and at the beginning of the project, the performance level was 2.61 sigma. Using fishbone diagram, all the possible reasons for extending patient waiting time were captured, and among them, 16 causes were proven to be statistically significant. Improvement plans including a new receptionist, automatic specimen transport system, and adding one phlebotomist were put into practice. As a result, the number of patients waited more than 5 min significantly decreased, and the performance level reached 3.0 sigma in December 2007 and finally 3.35 sigma in July 2008. CONCLUSIONS: Applying the six sigma, the performance level of waiting times for blood drawing exceeding five minutes were improved from 2.61 sigma to 3.35 sigma.

Annual Report on 2008 External Quality Assessment in Therapeutic Drug Monitoring and Drug of Abuse in Korea (2008) / 임상검사와정도관리

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2008. The number of participating laboratories were 114, which is similar with that of the previous year. Average response rates were 97.8% in both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each laboratory could know the possible systematic error. The average drug item was 6.3 per laboratory, which was decreased slightly from 6.8 in recent 5 years, and the maximum was 18 items. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 52.1% of participating laboratories, followed by cyclosporine, vancomycin, tacrolimus, lithium, methotrexate, amikacin, tobramycin, gentamycin, acetaminophen, salicylate, free phenytoin, primidone, and amitryptyline. The widely used TDM analyzers were Abbott TDx/TDxFLx (35.3%), followed by Abbott AxSym (26.5%) and Roche Cobas Integra (17.3%), Abbott IMx (3.3%), and Siemens Viva E (3.0%). The inter-laboratory coefficients of variations showed similar tendency comparing with those of the previous years. The number of participating laboratories for drug of abuse tests were 17, which is similar to that of the previous year. Average drug item were 3.7 for the 1st trial. We found the relatively good performance as we got the correct answers for all laboratories except 2 laboratories. In conclusion, the TDM external quality assessment of 2008 showed grossly similar pattern comparing with that of previous year.

The Characteristics of Salivary alpha-Amylase Reactivity to Negative Affective Stimuli / 신경정신의학

OBJECTIVES: The aim of this study is to understand the characteristics of salivary ALPHA-amylase reactivity (sAA), as a biological maker of stress, by viewing negative affective pictures. METHODS: Forty six normal healthy subjects participated in this study. Prior to the experiment, the participants completed baseline psychological assessment including trait-dependent anxiety scales. On experiment, saliva samples were collected one time before and three times after exposure to 5-min stressor consisting 20 negative affective pictures. The state-related scales were measured before and just after exposure to stressor to assess the subjects' state anxiety. RESULTS: Overall, sAA was significantly decreased over time with the increase of negative affect score and state-anxiety. The Anxiety Scale Inventory scores were negatively correlated with the baseline as well as the other following sAA levels (all ps or =2, N=19) than in the lower counterpart (<2, N=27) in comparison between them (mean:46.6 vs. 76.5 U/mL, p=.024). After the exposure, the means of sAA levels significantly decreased over time in the lower susceptible group, whereas did not in the higher one (mean:-1.7 vs. -23.0 U/mL, p=.031). CONCLUSION: These findings suggest that the baseline level of sAA and its reactivity depend on individual trait of anxiety as well as state of reactivity to affective stress.

Annual Report on External Quality Assessment in Therapeutic Drug Monitoring and Drug of Abuse in Korea (2007) / 임상검사와정도관리

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2007. Number of participating laboratories were increased to 109, by 5.63% increase comparing with the previous year. Response rates reached 98.7% for both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.3 per institution, which was decreased slightly from 6.8 in recent 5 years. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 55% of the participating laboratories, followed by cyclosporine, vancomycin, lithium, tacrolimus, methotrexate, amikacin, gentamicin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The inter-laboratory coefficients of variations showed simliar tendency comparing with those of the previous years. We started the proficiency test for drug of abuse from 2007 and got the response from 13 and 17 laboratories in the 1st and 2nd trial, respectively. Average drug items were 3.4 for the 2nd trial. We found the relatively good performances as we got the correct answers from all laboratories except 4 for each one mistake. In conclusion, the TDM external quality assessment of 2007 showed grossly similar pattern comparing with those of previous year and drug of abuse proficiency testing showed a relatively good performance.

Annual Report on External Quality Assessment in Therapeutic Drug Monitoring and Drug of Abuse in Korea (2007) / 임상검사와정도관리

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Laboratory (KAQACL) were performed in 2007. Number of participating laboratories were increased to 109, by 5.63% increase comparing with the previous year. Response rates reached 98.7% for both trials slightly lower than that of the previous year. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.3 per institution, which was decreased slightly from 6.8 in recent 5 years. The most common test items were valproic acid, digoxin, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 55% of the participating laboratories, followed by cyclosporine, vancomycin, lithium, tacrolimus, methotrexate, amikacin, gentamicin, salicylate, tobramycin, acetaminophen, primidone, free phenytoin, and amitryptyline. The inter-laboratory coefficients of variations showed simliar tendency comparing with those of the previous years. We started the proficiency test for drug of abuse from 2007 and got the response from 13 and 17 laboratories in the 1st and 2nd trial, respectively. Average drug items were 3.4 for the 2nd trial. We found the relatively good performances as we got the correct answers from all laboratories except 4 for each one mistake. In conclusion, the TDM external quality assessment of 2007 showed grossly similar pattern comparing with those of previous year and drug of abuse proficiency testing showed a relatively good performance.

Measurement of Amylase in Saliva Collected by Salivette / 대한진단검사의학회지

BACKGROUND: Saliva is increasingly being used as a specimen for systemic disease as well as for oral health status. Especially, salivary amylase has been studied as an excellent index for psychological stress. Authors evaluated the measurement of salivary amylase activities collected by Salivettes (Sarstedt, Germany). METHODS: Saliva specimens were collected from 13 healthy adults between 10:00 and 11:00 a.m. Participants were asked to gently chew tampons of Salivettes for 1 min. Immediately after collection, all specimens were stored frozen. On the day of testing, they were centrifuged after thawing and diluted with distilled water. Amylase was measured by Dimension RxL Max (Dade Behring Inc., USA). We evaluated precision, linearity, and recovery rate of Salivette. Amylase activities between collection of saliva by Salivette and passive drool were compared, and also the changes of amylase by the storage temperature were evaluated. RESULTS: Intra-run CVs for three levels of amylase were excellent. Between-day CVs and total CVs were good only for mid and high levels. A good linear relationship was found at all diluted levels. Dosing Salivettes with 2 mL, 1.5 mL, and 1 mL yielded sample recovery 85.5+/-2.4%, 82.4+/-1.5%, and 72.2+/-3.1%, respectively and amylase recovery 78.9+/-10.9%, 74.1+/-13.7%, and 37.3+/-26.9%, respectively. Amylase by Salivette and passive drool were correlated well (r=0.757), although they showed a significant difference. Amylase activity was not affected by the storage temperature. CONCLUSIONS: Measurement of salivary amylase using Salivette could be a useful test having good intra-run CVs and linearity. More than 1.5 mL of saliva would be needed to have more than 70% recovery of Salivette.

A Case Report of Familial Benign Hypocalciuric Hypercalcemia: A Mutation in the Calcium-Sensing Receptor Gene

Familial benign hypocalciuric hypercalcemia (FBHH) is an autosomal dominant trait with high penetrance, clinically manifestating a relatively benign, lifelong, persistent hypercalcemia and hypocalciuria without hypercalcemic related complications. The calcium-sensing receptor (CaSR) plays an important role in the regulation of PTH secretion and calcium metabolism. Here we present a family with FBHH of an autosomal dominant inheritance. A heterozygous mutation of E297K (GAG -> AAG, exon 4) of CaSR gene was found in 3 family members. To our knowledge, it is the first confirmed case of FBHH with CaSR gene mutation in Korea.

Relationships among Oxidative Stress Markers, Life Style Factors and Biochemical Findings / 대한진단검사의학회지

BACKGROUND: In many studies, oxidative stress markers have been employed to serve as a measure of a disease process or to reflect oxidative status. These oxidative stress markers must have some degree of predictive validity, but full substantiation of this relation is still lacking. This paper presents data on levels of three biomarkers, oxidized low-density lipoproteins (LDL), carbonyl, and 8-hydroxy-2'-deoxyguanosine (8-OHdG), and a number of life style factors associated with oxidative stress in healthy adults. METHODS: For 237 healthy adults aged 40-60 years, a number of life style factors, biochemical characteristics and oxidative status were evaluated. Markers of oxidative stress were measured by an ELISA method. RESULTS: Waist-hip ratio and use of vitamin supplement were associated with serum oxidized LDL (P<0.05). Body mass index and stress had a relationship (P<0.05) with protein carbonyl. Creactive protein was related to serum oxidized LDL (P<0.01). There was no correlation among three oxidative stress markers, oxidized LDL, carbonyl, and 8-OHdG. CONCLUSIONS: The oxidative stress markers used in this study could not be regarded as a general estimate of the healthy individual oxidative status. Further studies focusing on the development of biomarkers to reflect changes in the oxidative status under normal, non-pathological conditions in humans will be required.

Annual Report on External Quality Assessment in Therapeutic Drug Monitoring in Korea (2005) / 임상검사와정도관리

Two trials of external quality assessment for Therapeutic Drug Monitoring (TDM) subcommittee of Korean Association of Quality Assurance for Clinical Pathology (KAQACP) were performed in 2005. The number of participating laboratories were increased to 95, by 6.7% comparing with the previous year. Response rates were 100.0% for both trials just like the two previous years. Two kinds of control materials were requested to be tested in each trial so that each institution could know the possible systematic error. In both trials, 20 test items were responded at least from one laboratory. The average drug item was 6.7 per institution, which was elevated slightly from 6.5 in recent 5 years. The most common test items were digoxin, valproic acid, carbamazepine, theophylline, phenytoin, and phenobarbital which were peformed in more than 65% of participating laboratories, followed by cyclosporine, lithium, vancomycin, tacrolimus, methotrexate, amikacin, gentamycin, tobramycin, salicylate, primidone, acetaminophen, free phenytoin, amitryptyline, and ethosuximide. The most widely used TDM analyzer was Abbott TDx/TDxFLx (41.7%), followed by Abbott AxSym (23.3%), and Roche Cobas Integra (19.2%). The inter-laboratory coefficients of variations were not much improved comparing with previous years. We also determined cyclosporine with reference method using liquid chromatography-tandem mass spectrometry. In conclusion, the TDM external quality assessment of 2005 showed grossly similar pattern comparing with those of previous year with increasing participating laboratories.

The Usefulness of Measuring Urinary Proteins by SDS-PAGE in Children with Type I DM without Overt Proteinuria / 대한신장학회잡지

BACKGROUND: The present study was done to evaluate the usefulness of SDS-PAGE in measuring glomerular proteins and tubular proteins in patients with type I DM without overt proteinuria. METHODS: The study population consisted of 76 children with type I DM who have been participated in the Taegu Diabetic Camp from 1997 to 2000. We measured urine albumin, NAG, beta2-microglobulin, creatinine level in urine samples collected for 12 hours in 22 children and simultaneously we analyzed urinary proteins by SDS-PAGE. In remainder 54 children, we measured urine albumin, NAG, creatinine level in random morning urines and urinary proteins by SDS-PAGE. RESULTS: In 22 of 76 children, urinary albumin-to-creatinine ratio (mg/mg), NAG (U/g) and beta2-microglobulin (microgram/g) were 0.021, 2.99 and 170.2, respectively. Positive correlation between urine albumin and NAG was statistically significant (r=0.51, p< 0.05). No significant relations between urinary proteins, such as albumin, NAG, beta2-microglobulin, and clinical characteristics, such as age, duration of illness, HbA1c, were observed. In diagnosing `microalbuminuria', sensitivity of SDS-PAGE was 63% and band of tubular proteins was not detected in any children. CONCLUSION: We thought that SDS-PAGE could be one of useful methods in diagnosing early stage of diabetic nephropathy. The more large scale study is necessary.