Diagnosis of Viral Hepatitis

Prevalence of Antihepatitis C Antibodies in Patients Treated with Continuous Ambulatory Peritoneal Dialysis and Hemodialysis

“…Unfortu nately, the high prevalence of hepatitis B infection mark ers, the possibility for coexistence of hepatitis B and C, and the potential for false-positive and false-negative results make it difficult to establish the real prevalence of HCV infection in our patient population. Assuming that the appearance of HBsAb implies healing of hepatitis B (a concept disputed in patients on dialysis [11]) and that an isolated HBcAb may indicate persistent B virus infection [12], we estimate that 66% of chronic non-A, non-B hepa titis are type C hepatitis. Based on the same assumptions, 19% are either non-A, non-B, non-C hepatitis or false negative results, and 15% are unclassifiable using sero logic methods (hepatitis B an d /o r hepatitis C).…”

Immunodiagnosis of viral hepatitides A to E and non-A to -E

“…The illustration was provided by courtesy of Pierre Tiollais, Pasteur Institute, Paris, France. markers used in the differential diagnosis of viral hepatitis and related disorders (45). There are four major serological subtypes of HBV, viz., adw, ayw, adr, and ayr.…”

“…Although the subtypes are useful as epidemiological tracers of infection, they are of no pathogenetic significance. The resolution of any HBV infection culminates in production of anti-HBs, a long-lasting antibody response against the ''a'' determinant(s) of HBsAg, which confers lifelong immunity against all serotypes of HBV (5,44,45). In contrast, a failure of the immune response to the HBsAg ''a'' determinant establishes a persistent infection and leads to a spectrum of conditions with or without disease (82).…”

“…Therefore, HBV is considered noncytopathic, and the pathogenetic significance of high-level viremia in liver disease remains enigmatic. Testing for HBsAg alone may fail to detect as many as 5 to 10% of acute cases because either the host immune response may have already cleared HBsAg before the clinical symptoms are noticed or the level of HBsAg may be below the detection limits of current methods (45).…”

“…Upon entry into the endoplasmic reticulum and proteolytic cleavage at both the C and N termini, the degraded composite protein reveals an HBeAg determinant, which has been used as a marker of virus replication and as a correlate of the patient's infectivity and which is an indicator of the severity of liver disease. Generally, seroconversion from HBeAg positivity to anti-HBe suggests a decline in virus replication and/or a consequent improvement in liver disease (40,45). The simultaneous occurrence of HBeAg and anti-HBe is uncommon and transient during seroconversion.…”