Yazar "Mengeloglu, Zafer" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Impact of Storage Time of Fresh Serum Samples on Rapid Test Results of HBsAg
    (Galenos Yayincilik, 2014) Mengeloglu, Zafer; Bucak, Ozlem; Kocoglu, Esra; Tas, Tekin; Karabork, Seyda
    Objective: Rapid tests, amongst the methods used in the diagnosis of hepatitis B virus infection, detect hepatitis B surface antigen (HBsAg). It is important to know whether the elapsed time between sample collection and the process has negative impact on the test results. It was aimed to evaluate the impact of samples stored either at room temperature (RT) or at +4 degrees C for different durations on rapid test results. Materials and Methods: A total of 51 serum samples were used. HBsAg tests were performed at the time the samples arrived at our laboratory using chemiluminescence method. 21 samples positive for HBsAg were accepted as the study group, and 30 negative samples were the controls. All the samples were tested immediately using rapid assay. Then the samples were divided into two aliquots and divided again into two groups; the first group was stored at RT, and the second was stored at +4 degrees C. Two or three hours after the first tests, all the samples were tested again using rapid assay, and then, they were continued to be stored; and after 24 hours, the tests were repeated for the third time. Test results were scored between negative and +++. Results: In the initial rapid tests, the sensitivity rate was 85.7%, and the specificity was 100%. A statistically significant association was found between the positivity grades and the mean HBsAg levels (p<0.001; r=0.831). The accuracy was found to be 96.1% (49/51) for the second hour tests in terms of positivity grades. It was observed that the accuracy rate was decreased to 84.3% (43/51) in samples stored for 24 hours in both conditions, and positivity grades of eight samples were decreased for one degree for each. Amongst all tests, no false negative and false positive results were obtained according to the initial tests. In addition, it was found that all the results of the samples stored either at RT or +4 degrees C overlapped, and that the difference was caused just by the duration of storage. Conclusion: In conclusion, sera should not be stored for long time in cases they will be tested using HBsAg rapid assays, and storage of the samples for one day decrease the reliability of the results.
  • Küçük Resim Yok
    Öğe
    Performance of Rapid Test in Detection of Anti-HCV in Frozen Sera
    (Galenos Yayincilik, 2014) Mengeloglu, Zafer; Bucak, Ozlem; Kocoglu, Esra; Tas, Tekin; Karabork, Seyda
    Objective: Hepatitis C is a common infectious disease throughout the world. Rapid test of hepatitis C, detecting anti-HCV, is a useful test that is easy to perform as well as it may have lack of sensitivity and specificity. In the present study, it was aimed to investigate whether the rapid test of HCV infection can still reveal accurate results in anti-HCV-positive sera frozen for a few years. Materials and Methods: Sera of a total of 100 patients that were determined to be positive for anti-HCV using chemiluminescence technology system (Architect i2000sr, IL, USA) were stored at -200 degrees C for a maximum period of 3.5 years. The sera were thawed and tested again for anti-HCV using the Nanosign rapid test kit (Bioland, Korea) for HCV infection. Results: The positivity rate of the test was 37%. In addition, the rapid test revealed a very low positivity rate as 5.2% in sera with a level of anti-HCV below 10.0 S/CO. In contrast, the positivity rate was 71.4% in samples with high anti-HCV levels. A significant positive correlation was found between positivity levels and anti-HCV levels (r=0.708, p<0.001). No correlation was found between positivity levels and time passed after freezing the samples (r=-0.91, p=0.367). Besides this, no significant difference was observed amongst the groups in terms of the time intervals of freezing (p>0.05). Conclusion: The findings of this study suggest that the rapid test of HCV infection is not reliable in frozen sera with low anti-HCV levels due to the instability of the molecules in the samples, and the time passed after freezing of the sample doesn't change the results of the tests.