بررسي ارزش سطح سرمي AFP (آلفا فيتوپروتيين) در بيماران ناقل HBS Ag براي تشخيص هپاتوسلولار كارسينوما

Evaluation of serum AFP (α-fetoprotein) level in HBsAg carrier patients for diagnosis of hepatocellular carcinoma

مقدمه: عفونت HBV با (يا بدون) سيروز كبدي در اكثر مناطق جهان ا جمله ايران مهمترين ريسك فاكتورهاي HCC به شمار مي روند. HCC در صورتي كه زودتر تشخيص داده شود پيش آگهي بسيار كمتري دارد. از مهمترين روشهاي غربالگري اين تومور در جامعه استفاده از سونوگرافي و اندازه گيري سطح سرمي (AFP) به صورت دوره اي است. در اين مطالعه ارزش و دقت تشخيصي Alfa fetorprotein (AFP) در تشخيص هپاتوسلولار كارسينوم در افراد ناقل سالم مورد بررسي قرار گرفت.نتيجه گيري: AFP به تنهايي يك روش تشخيص مفيد و كارآمد جهت تشخيص سرطان كبد در بيماران ناقل HBSAg نمي باشد و داراي ارزش پيشگويي كننده و حساسيت و اختصاصيت قابل قبولي در اين بيماران نمي باشد . يافته ها: AFP بالاتر از ng/ml 20 در 32 بيمار ديده شد كه در بررسيهاي نهايي 13 مورد ( 40% ) سرطان كبدي HCC به روش بيوپسي و تصويرنگاري ثابت شد. افزايش توليد AFP تنها 35% بود كه ميزان قدرت پيشگويي يك تست جهت تشخيص هپاتوم ناكافي است. مواد و روش ها: در اين مطالعه 2452 فرد ناقل HBSAg بدون شواهد سيروز كبدي يا سرطان كبدي بمدت 3 سال (1380-1378) توسط سونوگرافي و اندازه گيري AFP هر 6ماه يكبار مورد بررسي قرار گرفته اند . مردان و زنان غير حامله اي كه سطح سرمي افزايش يافته داشتند با روشهاي تصوير نگاري مورد بررسي زيادتر قرار گرفته اند .

Background: Hepatocellular carcinoma (HCC) is common all over the world as well as Iran. The incidence of HCC is higher in hepatitis B carriers and it is highly recommended to periodically screen these patients by serum alpha-fetoprotein (AFP) and liver ultrasound (US) every 6 months. We explore the diagnostic accuracy and the performance of (AFP) in cases of hepatitis B carriers as a screening tool by using serum total AFP concentration of 20 ng/ml. Materials and Methods: The study included 2452 HBsAg carriers with no evidence of hepatocellular carcinoma or cirrhosis were followed up in a 6-year prospective surveillance program with testing by ultrasound and alphafetoprotein every 6 months referred to the Ahwaz JundiShapour university hospitals and hepatitis clinic (1999-2004). Men and nonpregnant women with an elevated AFP level were evaluated for the presence of HCC by ultrasound (US) examination. Hepatitis B surface antigen (HBsAg), anti-HBc antibody and alpha-fetoprotein (AFP) were determined in all cases by enzyme-linked immunosorbent assay (ELISA). Findings: One or more AFP elevations (higher than 20 ng/ml) were found in 32 cases, but 13 (45%) hepatocellular carcinomas were detected in these patients during follow up (9 men and 4 women). Of the 32 HBsAg carriers with AFP serum levels of more than 20 ng/ml, HCC was not detected in 19 cases (65%). The positive predictive value for AFP to detect HCC was only 31% for our AFP cut-off value, and the sensitivity and specificity was approximately 56 and 88%, respectively.The positive predictive value for ultrasound examinations to detect HCC was 64%, while the sensitivity and specificity was 90 and 92%, respectively. Conclusion: We conclude that AFP alone is not a useful marker for HCC screening because of its poor predictive value and low sensitivity, particularly in patients with underlying viral hepatitis B without cirrhosis and is not recommended except when ultrasonography is either not available or of poor quality. Ultrasonography seems more efficient and accurate as a screening tool.