Background: Hepatitis B viral infection is an oncogenic lethal infection, which is represented by different features. Those features are interpreted according to the coordination of different serological HBV markers. One of the most controversial features is the isolated HBc-Ab serologic profile pattern. In HBV/HCV co-infection, HCV can suppress HBV replication, thus HBV infection may decline. Isolated HBc-Ab serologic profile pattern represents a challenge in patients with chronic HCV, because it may represent a reservoir of latent HBV infection, which may be reactivated later. Objective: This study aims to investigate the incidence of the isolated HBc-Ab serologic profile pattern in samples of Egyptian patients chronically infected with HCV, and to demonstrate its clinical implications. Methods: The current study proceeded on blood samples of a total of 154 subjects (124 patients with chronic HCV infection and 30 controls). They were evaluated for liver function parameters and AFP as a tumour marker. The serum samples were tested serologically by ELISA for HBs-Ag, HBs-Ab, and HBc-Ab total. Real-time PCR was applied to measure HCV-RNA and HBV-DNA in samples of those patients. Upon interpretations of  HBV infection, HCV- patients were divided into 5 groups from G1 to G5. Results: A significant increase (p = <0.001) in the incidence of HBc-Ab was detected in samples of HCV- patients (68/124, 54%) compared to controls (2/30, 6.66%). Likewise, a significant increase (p = 0.009) in the incidence of isolated HBc-Ab serologic profile pattern was detected in samples of HCV- patients (28/124, 22.58 %) compared to controls (0/30, 0%). Based on the comparison study, samples of HCV- patients with isolated HBc-Ab serologic profile pattern (G5) showed a significant decrease (p = 0.017) in albumin, and a significant increase (p = 0.032) in total bilirubin compared to samples of HCV-patients who resolved HBV infection (G2). Also, the former group of patients (G5) showed a non-significant change in any of the clinical biochemical parameters or AFP compared to the group of HCV- patients who were susceptible to HBV infection (G1)  Conclusion: Isolated HBc-Ab serologic profile is a pattern of HBV infection, which increases significantly in chronic HCV- patients. The increase in hypoalbuminemia and hyperbilirubinemia are the clinical implications associated with the presence of the isolated HBc-Ab serologic profile pattern in HCV-patients who cannot develop HBs-Ab compared to other HCV-patients who can develop HBs-Ab in the presence of HBc-Ab and resolve HBV infection.