Comparative Evaluation of the STANDARD F Influenza A/B FIA Test with the Sofia Influenza A+B FIA and SD BIOLINE Influenza Ag A/B/A(H1N1) tests for Influenza A Virus Detection / 대한임상미생물학회지

Background@#This study aimed to evaluate the diagnostic performance of the STANDARD F Influenza A/B FIA test (SD Biosensor Inc., Korea) for the rapid detection of influenza A virus in comparison with the Sofia Influenza A+B FIA (Quidel Corp., USA) and SD BIOLINE Influenza Ag A/B/A(H1N1) (Standard Diagnostic, Inc., Korea) tests. @*Methods@#A total of 227 non-duplicated nasopharyngeal aspirates submitted for real-time RT-PCR analysis were included in the study. We used the three commercial tests in remnant samples from routine assays, according to the manufacturer’s instructions. We analyzed the diagnostic performance, including sensitivity and specificity, of the three tests. @*Results@#Real-time RT-PCR analysis showed that 67 (29.5%) samples were positive and 160 (70.5%) were negative for influenza A virus, and that all the specimens were negative for influenza B. The overall sensitivity and specificity for influenza A virus detection were 50.7% and 100% for the STANDARD F, 50.7% and 100% for the Sofia, and 29.9% and 100% for the SD BIOLINE tests, respectively. The STANDARD F and SD BIOLINE tests showed negative results for influenza B virus in all specimens, whereas the Sofia test showed two false-positive results. @*Conclusion@#The STANDARD F Influenza A/B test showed a good diagnostic performance and may be useful for the rapid diagnosis of influenza A.

Comparison of COBAS AmpliPrep/COBAS TaqMan HCV Qualitative Test v2.0 with COBAS AMPLICOR Hepatitis C Virus Test v2.0 for the Qualitative Detection of Hepatitis C Virus RNA in Korean Clinical Samples / 임상검사와정도관리

BACKGROUND: We comparatively evaluated the performance of the conventional COBAS Amplicor HCV test v2.0 (CAM; Roche Molecular Systems, USA) and the newly developed COBAS AmpliPrep/COBAS TaqMan HCV test v2.0 (CAP/CTM; Roche Molecular Systems) for qualitative detection of hepatitis C virus (HCV) RNA in clinical samples. METHODS: Six hundred serum samples (100 HCV-positive, 500 HCV-negative, as determined by CAM) were selected and analysed using the new qualitative HCV RNA test, CAP/CTM qualitative test. Results were compared by confirmatory CAP/CTM quantitative test, which is a quantitative HCV RNA real-time polymerase chain reaction by Roche Molecular Systems, and anti-HCV test (Roche Diagnostics GmbH, Germany). Twenty-two additional serum samples, which gave a gray zone result by CAM, were selected for comparison. RESULTS: The two qualitative HCV RNA assays yielded concordant results for 586 of 600 tested samples (concordance rate, 97.7%; kappa coefficient, 0.92; 95% confidence interval [CI], 0.87 to 0.96; P<0.001). Upon re-testing by CAM, we found that the concordance rate increased to 98.2% (kappa coefficient, 0.93; 95% CI, 0.89 to 0.97; P<0.001). The additional 22 samples showing gray zone results for CAM were retested and were also tested by CAP/CTM. The results for 13 of these samples changed to negative and were now concordant with the CAP/CTM and confirmatory CAP/CTM quantitative results. For the remaining samples, the results were variable. For all the 22 samples, the results of the new CAP/CTM were in agreement with those obtained by confirmatory CAP/CTM quantitative test. CONCLUSIONS: The results of the two assays were in good agreement, with 97.7% concordance rate. However, CAP/CTM is more sensitive than CAM and showed no gray zone results. Therefore, it can be a more efficient and useful test for the qualitative detection of HCV RNA in clinical samples.

Role of Plasma Exchange in ABO-incompatible Kidney Transplantation

BACKGROUND: In the past, ABO incompatibility was an absolute contraindication for solid organ transplantation. However, multiple recent trials have suggested strategies for overcoming the reactions between graft antigens and recipient antibodies that cause graft rejection. In this study, we determined the usefulness of plasma exchange (PE) for removing anti-A/B antibodies that cause hyperacute/acute humoral graft rejection in patients undergoing ABO-incompatible kidney transplantation. METHODS: In our study, 12 patients underwent ABO-incompatible kidney transplantation. All recipients received pre-transplantation conditioning by PE or intravenous immunoglobulin (IVIG) administration. After pre-transplantation conditioning, anti-A/B antibody titers were evaluated, and transplantation was performed when the titer was below 1:8. To assess the transplantation outcome, anti-A/B antibody titers, creatinine level, estimated glomerular filtration rate (eGFR), and proteinuria levels were measured. RESULTS: Anti-A/B antibody titers were below 1:8 in all patients at the time of transplantation. eGFR measured on post-transplant day 14 showed that 10 patients had immediate recovery of graft function, while 2 patients had slow recovery of graft function. Short-term outcomes of ABO-incompatible kidney transplantation (measured as creatinine levels) after reducing anti-A/B antibody titers were similar to those of ABO-compatible kidney transplantation. After transplantation, the anti-A/B antibody titers were below 1:8 in 7 patients, but the remaining 5 patients required post-transplantation PE and IVIG treatment to prevent antigen-antibody reactions. CONCLUSIONS: With the increasing demand for kidney donations, interest in overcoming the ABO incompatibility barrier has increased. PE may be an important breakthrough in increasing the availability of kidneys for transplantation.

Recognition of a Pseudo-Outbreak of Cladosporium Species by Continuous Monitoring of Culture Results / 병원감염관리

BACKGROUND: Cladosporium spp. are dematiaceous fungi that are commonly isolated from indoor and outdoor environments, including hospital air. This fungus is rarely pathogenic to humans, but has been reported to cause infections of the skin and toenails, as well as sinusitis and pulmonary infections. The monitoring of culture results was conducted to identify the outbreak of an unknown black fungal infection between January and March 2006 in a University hospital, and infection control activity was performed to identify the cause of the outbreak. METHODS: An epidemiological investigation of 22 patients with infections caused by an unknown black fungus was conducted. Microscopic examination and molecular analysis on the internal transcript spacer (ITS) region was performed to identify the black fungus. To detect the source of contamination, a culture of environmental specimens was performed, and then, disinfection of the laboratory was implemented. RESULTS: The patients with black fungi belonged to various departments and wards. No symptoms of fungal infection were recognized on the basis of the survey. The black fungus was identified as Cladosporium spp. on the basis of morphological features and ITS region sequencing. Culturing of environmental specimens was performed in the laboratory. Black fungi were isolated from a specimen from a rack and had the same morphological features with Cladosporium spp. from clinical specimens. After the rack was autoclaved, Cladosporium spp. from clinical specimens was no longer isolated. CONCLUSION: Epidemiological investigation, microscopic examination, and molecular analysis revealed that the sudden increase in the isolation rate of Cladosporium spp. from clinical specimens was the result of a pseudo-outbreak caused by the contamination of a rack. To our knowledge, this is the first report of a pseudo-outbreak of Cladosporium spp. Continuous monitoring of culture results is important to avoid unnecessary labor for nosocomial infection control.