412 PREVALENCE, VIROLOGICAL AND CLINICAL CHARACTERISTICS OF CHRONIC HEPATITIS DELTA VIRUS INFECTION (CHD) IN ROMANIA

receiving anti-viral therapy could be used as a response marker at baseline (BL), or early during treatment to predict treatment outcome. Methods: A prototype array-based assay served (IMPACT – Immunological Multi-Parameter Chip Technology, Roche Diagnostics) to determine HBsAg, anti-HBs and complex levels. We tested a panel of serum samples of 40 HBeAg-positive and 44 HBeAg negative patients who received pegylated interferon and adefovir for 48 weeks and were followed subsequently for 2 years. Results: HBsAg loss occurred in 4 of 40 HBeAg positive and 7 of 44 HBeAg negative patients. Sixteen of 40 HBeAg positive patients lost HBeAg and 13 of them formed anti-HBe. At BL complexes were present in 83 (99%) patients, whereas free anti-HBs levels were only detectable in 5 patients. Complex levels at BL and WK 12 were higher in HBeAg positive patients with HBeAg loss, compared to patients who retained HBeAg (p =0.0046 and p=0.026 respectively). ROC analysis for HBeAg loss in HBeAg positive patients at BL and WK 12 showed AUC 0.77 (p =0.004) and AUC 0.73 (p =0.026) for complex levels and AUC 0.57 (non significant) and AUC 0.61 (non significant) for HBsAg levels. We saw no correlation in either HBeAg-positive or -negative patients between complex levels and HBsAg loss. Nor did we find any correlation between complex and HBsAg or anti-HBs levels. Discussion: We demonstrated for the first time that before and during treatment HBsAg/anti-HBs immune complex levels can predict HBeAg loss in HBeAg positive CHB patients treated with peg-interferon and adefovir. Complexes were present in almost all patients at BL and were higher in patients that lost HBeAg. In conclusion, determining HBsAg/anti-HBs immune complex levels before and early during treatment could select CHB patients with an optimal chance to achieve HBeAg loss.