DETERMINATION OF GRAY ZONE RANGE IN HBsAg TEST AND ITS IMPLICATION FOR HBsAg CONFIRMATION TEST
DOI:
https://doi.org/10.24293/ijcpml.v24i2.1310Keywords:
HBsAg, HBsAg confirmation test, gray zone, hepatitis BAbstract
Hepatitis is an inflammation of liver cells caused by infection (virus, bacteria, paracytes), medication, alcohol consumption, excessive lipid and autoimmune disease. Increasing method (sensitivity) of HBsAg test is often followed by a lot of false positive test results, which need a confirmation test which takes a longer time and higher cost so that it is needed to determine an optimal gray zone range for a confirmation test. This analytical cross-sectional study was held at the Clinical Pathology Laboratory of the Dr.Wahidin Sudirohusodo Hospital Makassar. The subjects were specimens which HBsAg value was within 0.06-1 COI. Specimens were examined using HBsAg confirmation test. Over 49 samples collected there were 32 reactive and 17 non-reactive. 14 out of 32 reactive samples (43.8%) were confirmed as negative (false positive) by HBsAg confirmation test and 3 out of 17 non-reactive samples (17.6%) were confirmed as positive (false negative). Chi-square test showed a significant correlation between HBsAg value and HBsAg confirmation test value (p=0.009). Chi-square test with some intervals with α=1% showed that the interval of HBsAg value 0.13-0.17 COI was the interval with the lowest significant value (p=0.004). This subsequent interval was recommended as the gray zone range. The range 0.13-0.17 was most optimal as HBsAg gray zone to determine the need for a confirmation test. A further study with larger samples is suggested.
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References
Kementrian Kesehatan Republik Indonesia. Situasi dan analisis hepatitis, Jakarta, Pusat data dan informasi kementrian kesehatan RI. 2014; 1-8.
Santiyoso A. Hepatitis virus akut, Dalam: Buku ajar Ilmu penyakit dalam, Ed Kelima., Jakarta, Interna Publishing, 2010; 644-652.
Lyn F. Hepatitis B. Center of disease control and prevention. VPD surveillance manual. 5th Ed., 2011; 1-15. Available at: http://www.cdc.gov. Access on May 21, 2015
Shao H, Yan Li, Wan Zhou. Increased need for testing to confirm initial weakly reactive results for hepatitis B virus surface antigen. Labmedicine. American Society for Clinical Pathology. 2012; 43(4): 15-17. Available at: www.medscape.com. Accessed on May 21, 2015
Dufour R. Hepatitis B Surface Antigen (HBsAg) Assay-are they good enough for their current uses?. Veterans Affairs Medical Center and George Washington, Washington DC, University Medical Center, 2006; 5(28): 1457-59.
Rysgard CD, Moris CS, Drees D, Bebber T, Davis SR, et al. Positive hepatitis B surface antigen test due to recent vaccination: a persistent problem. BMC Clinical Pathology. Department of Pathology, University of Lowa Hospital and Clinics, Lowa City. 2012; 12(15): 1-6
Vidas® HBsAg Ultra Confirmation insert kit. France. 2012. Available at: www. Biomerieux.com. Access on May 21, 2015
Vidas® HBsAg insert kit. France. 2011. Available at: www. Biomerieux.com. Accessed on May 21, 2015
Hepatitis Bs Antigen (HBsAg) Neutralization (Confirmation). Laboratory Service Manual. 2004. Available at: http://www. Childrensmn.org. Accessed on May 21, 2015
Fletcher GJ, Manu Gnanamony, Joel D, Ismail AM, Subramani T, Abraham P. Do we need an in-house neutralization assay for confirmation