Background: National reference standards for anti-HIV-1 antibody are needed to evaluate the performance and maintain the quality control of anti-HIV-1 antibody assays. The aim of this study was to prepare a mixed-titer performance panel and assess its suitability as a national reference standard for anti-HIV-1 antibody according to stability, collaboration, and other studies. Methods: Nineteen serum samples from different HIV patients were obtained, along with 15 units of fresh frozen plasma samples with negative anti-HIV-1 antibody results. Ten anti-HIV-1 antibody-positive candidate standards and two negative candidate standards were prepared based on the reactivity in the Alinity i HIV Ag/Ab combo assay (Abbott Laboratories, Wiesbaden, Germany). A collaborative study was conducted across eight laboratories using five anti-HIV-1 antibody assays. Real-time and accelerated stability were evaluated to assess the long-term stability. Results: In the collaborative study, results of all five anti-HIV-1 antibody assays were positive for all 10 candidate standards prepared using HIV patient samples. The CV of each assay for every candidate standard was within 10%, except for one assay result. No real-time and accelerated stability change trend was observed at −70°C or −20°C, supporting that the reference standards were maintained in a stable state at −70°C for long-term storage. Conclusions The overall results suggest that the 12 candidate standards could serve as national reference standards for anti-HIV-1 antibody.

Synovial chondromatosis is an uncommon disorder characterized by cartilaginous proliferation within the synovial membrane of the articular joint. Smaller joints are rarely affected and it may be progressed to osteochondromatosis after ossification or calcification of metaplastic cartilage. It is commonly presented in the third to fourth decade of life, but rarely presented in adolescence. We report a unique case of synovial osteochondromatosis of the subtalar joint in 14-year-old baseball player. Arthroscopic removal of loose body and complete excision of the osteochondral mass with concomitant synovectomy resulted in satisfactory outcome without recurrence at final follow-up.
Adolescent* ; Arthroscopy ; Baseball* ; Cartilage ; Chondromatosis, Synovial* ; Follow-Up Studies ; Humans ; Joints ; Osteochondromatosis ; Recurrence ; Subtalar Joint* ; Synovial Membrane

BACKGROUND/AIMS: Procalcitonin (PCT) may prove to be a useful marker to exclude or predict bloodstream infection (BSI). However, the ability of PCT levels to differentiate BSI from non-BSI episodes has not been evaluated in nosocomial BSI. METHODS: We retrospectively reviewed the medical records of patients ≥ 18 years of age with suspected BSI that developed more than 48 hours after admission. RESULTS: Of the 785 included patients, 105 (13.4%) had BSI episodes and 680 (86.6%) had non-BSI episodes. The median serum PCT level was elevated in patients with BSI as compared with those without BSI (0.65 ng/mL vs. 0.22 ng/mL, p = 0.001). The optimal PCT cut-off value of BSI was 0.27 ng/mL, with a corresponding sensitivity of 74.6% (95% confidence interval [CI], 66.4% to 81.7%) and a specificity of 56.5% (95% CI, 52.7% to 60.2%). The area under curve of PCT (0.692) was significantly larger than that of C-reactive protein (CRP; 0.526) or white blood cell (WBC) count (0.518). However, at the optimal cut-off value, PCT failed to predict BSI in 28 of 105 cases (26.7%). The PCT level was significantly higher in patients with an eGFR < 60 mL/min/1.73 m² than in those with an eGFR ≥ 60 mL/min/1.73 m² (0.68 vs. 0.17, p = 0.01). CONCLUSIONS PCT was more useful for predicting nosocomial BSI than CRP or WBC count. However, the diagnostic accuracy of predicting BSI remains inadequate. Thus, PCT is not recommended as a single diagnostic tool to avoid taking blood cultures in the nosocomial setting.

OBJECTIVES: To assess the current state of anemia evaluation in the elderly over 80 years of age. METHODS: Patients who were more than 80 years old and visited Dongguk University Ilsan Hospital from April 2005 to February 2014 were included. Statistical analysis were assessed using the logistic regression model. RESULTS: Total 548 patients, who had anemia according to WHO criteria, were identified. The median age was 85 years old (range, 82 to 99 years) and median hemoglobin level was 11.0 g/dL (range, 2.7 to 12.9 g/dL). Twenty-eight, 468, and 52 patients were classified as microcytic anemia, normocytic anemia, and macrocytic anemia, respectively. Among them, 397 patients (72.4%) did not undergo proper evaluation for the cause anemia i.e., 8 cases (28.5%) of microcytic anemia, 361 cases (77.1%) of normocytic anemia, and the 28 cases (53.84%) of 52 macrocytic anemia patients. The remaining 151 patients (27.6%) had completed the evaluation, and 24 patients (15.9%) were diagnosed as solid malignancies. In the assessment of iron deficiency anemia, hemoglobin levels, and age had no effect on whether or not to perform esophagogastroduodenoscopy. CONCLUSION: This finding showed that physicians often neglected anemia in individuals over 80 years of age. Though these patients have limited life expectancy, physicians should carefully discriminate the sub-population who will be benefit from adequate evaluation and treatment.
Aged ; Anemia* ; Anemia, Iron-Deficiency ; Anemia, Macrocytic ; Endoscopy, Digestive System ; Humans ; Life Expectancy ; Logistic Models

As the Immunoserology Subcommittee of the Korean Association of External Quality Assessment, we organized two trials on the external quality assessment of viral markers and serological tests for syphilis (STS) in 2015. For this purpose, we delivered three kinds of pooled sera specimens for external proficiency testing to 1,071 and 1,074 institutions for the first and second trials, respectively. Pooled sera were checked for their homogeneity and stability using multiple methods between the day of their manufacture and three days after dispatching. The number of participating laboratories was 1,055 (98.5%) and 1,055 (98.2%) in the first and second trial, respectively. The most commonly tested items were hepatitis B surface antigen, followed by the antibodies to hepatitis B surface antigen, antihuman immunodeficiency virus, anti-hepatitis C virus, STS, and anti-hepatitis B core. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay (CLIA) and the electrochemiluminescence immunoassay, which were found to generate few false positive results. In contrast, false negative results were frequently found when the immunochromatographic assay (ICA) was used; the use of ICA for detecting viral markers has been steadily increasing in recent years. Furthermore, the use of turbidoimmunoassay and CLIA, tests recently introduced for the measurement of nontreponemal and treponemal antibodies, is also increasing.
Antibodies ; Biomarkers* ; Hepatitis B ; Hepatitis B Surface Antigens ; Hepatitis C ; HIV ; Immunoassay ; Immunochromatography ; Korea* ; Laboratory Proficiency Testing ; Luminescence ; Serologic Tests* ; Syphilis*

BACKGROUND: Automated Mediace Treponema pallidum latex agglutination (TPLA) and Mediace rapid plasma reagin (RPR) assays are used by many laboratories for syphilis diagnosis. This study compared the results of the traditional syphilis screening algorithm and a reverse algorithm using automated Mediace RPR or Mediace TPLA as first-line screening assays in subjects undergoing a health checkup. METHODS: Samples from 24,681 persons were included in this study. We routinely performed Mediace RPR and Mediace TPLA simultaneously. Results were analyzed according to both the traditional algorithm and reverse algorithm. Samples with discordant results on the reverse algorithm (e.g., positive Mediace TPLA, negative Mediace RPR) were tested with Treponema pallidum particle agglutination (TPPA). RESULTS: Among the 24,681 samples, 30 (0.1%) were found positive by traditional screening, and 190 (0.8%) by reverse screening. The identified syphilis rate and overall false-positive rate according to the traditional algorithm were lower than those according to the reverse algorithm (0.07% and 0.05% vs. 0.64% and 0.13%, respectively). A total of 173 discordant samples were tested with TPPA by using the reverse algorithm, of which 140 (80.9%) were TPPA positive. CONCLUSIONS: Despite the increased false-positive results in populations with a low prevalence of syphilis, the reverse algorithm detected 140 samples with treponemal antibody that went undetected by the traditional algorithm. The reverse algorithm using Mediace TPLA as a screening test is more sensitive for the detection of syphilis.
Algorithms ; Anti-Bacterial Agents/therapeutic use ; Humans ; Latex Fixation Tests ; Reagins/blood ; Syphilis/*diagnosis/drug therapy/microbiology ; Treponema pallidum/isolation & purification

As Immunoserology Subcommittee of the Korean Association of External Quality Assessment Service, we organized two trials on the external quality assessment of viral markers and serological tests for syphilis (STS) in 2014. For this purpose, we delivered three kinds of pooled sera specimens for external proficiency testing to 1,060 and 1,064 institutions for the first and second trials, respectively. Pooled sera were checked for their homogeneity and stability by using more than three other methods between the day of their manufacture and 3 days after despatching. The numbers of participating laboratories were 1,053 (99.3%) and 1,046 (99.3%) in the first and second trials, respectively. The most commonly tested items were hepatitis B surface antigen, followed by antibody to hepatitis B surface antigen, anti-human immunodeficiency virus, anti-hepatitis C virus, STS, and anti-hepatitis B core. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay (CLIA) and the electrochemiluminescence immunoassay, which generated few false positive results. In contrast, false negative results were frequently found through the immunochromatography assay, the use of which for detecting viral markers has been steadily increasing in recent years. Furthermore, the use of turbidoimmunoassay and CLIA, which are new tests recently introduced for the measurement of non-treponemal and treponemal antibodies, is also increasing.
Antibodies ; Biomarkers* ; Hepatitis B ; Hepatitis B Surface Antigens ; Hepatitis C ; HIV ; Immunoassay ; Immunochromatography ; Korea* ; Laboratory Proficiency Testing ; Luminescence ; Serologic Tests* ; Syphilis*

No abstract available.
Lymphocytosis* ; T-Lymphocytes* ; Thymoma*

We performed two trials on the external quality assessment of viral markers and serological tests for syphilis (STS) organised by the Immunoserology Subcommittee of the Korean Association of Quality Assurance for Clinical Laboratories in 2013. In each trial, we delivered 3 kinds of pooled sera specimens to 1,021 institutions for external proficiency testing. Pooled sera were checked for their homogeneity and stability by using more than 3 other methods between the day of their manufacture and 3 days after despatching. The numbers of participating laboratories were 1,019 (99.8%) and 1,020 (99.8%) for the first and second trials, respectively. The most commonly tested items were hepatitis B surface antigen followed by antibody to hepatitis B surface antigen, anti-human immunodeficiency virus, anti-hepatitis C virus, STS, and anti-hepatitis B core. The most frequently used methods for detecting viral markers were the chemiluminescence immunoassay (CLIA) and the electrochemiluminescence immunoassay, which generated a few false positive results. In contrast, false negative results were frequently found through the immunochromatography assay, the use of which for detecting viral markers has been steadily increasing in recent years. The new tests, turbidoimmunoassay and CLIA, have recently been introduced for the measurement of non-treponemal and treponemal antibodies, and their use is also increasing.
Antibodies ; Biomarkers* ; Hepatitis B ; Hepatitis B Surface Antigens ; Hepatitis C ; HIV ; Immunoassay ; Immunochromatography ; Korea ; Laboratory Proficiency Testing ; Luminescence ; Serologic Tests* ; Syphilis*

BACKGROUND: Establishment of a national reference panel for syphilis antibodies is necessary to evaluate the performance of in-vitro diagnostic tests for syphilis and to verify test quality. This study aimed to establish a national reference panel for syphilis antibodies, to assess the suitability of a panel for non-treponemal and treponemal testing, and to assess the reactivity of the various tests currently in use. METHODS: Treponemal pallidum particle agglutination (TPPA)-positive and -negative fresh frozen plasma samples were obtained. After the fresh frozen plasma was converted to serum by defibrination, the samples were pooled. Two candidate reference standards containing no syphilis antibodies and 10 candidate reference standards containing syphilis antibodies were prepared on the basis of reactivity in the TPPA assay. Candidate reference standards were tested by three laboratories using five non-treponemal tests and four treponemal tests. RESULTS: All three laboratories reported positive non-treponemal test results for the mixed-titer performance panel (MP)/6-MP/12. MP/1, MP/2, and MP/3 were negative for non-treponemal tests. MP/4 and MP/5 were reported either as positive or negative according to the laboratories. All laboratories reported positive TPPA results for MP/3-MP/12 and negative results for MP/1 and MP/2. No significant difference was detected among the treponemal testing results in three laboratories. CONCLUSIONS: We established 12 candidate national reference standards containing various concentrations of syphilis antibodies. A collaborative study using nine tests demonstrated that 12 candidate national reference standards presented consistent results, except a few assays with low sensitivity, and thus could be used as a national reference panel for syphilis antibody testing.
Agglutination ; Antibodies* ; Diagnostic Tests, Routine ; Korea* ; Plasma ; Syphilis*