The serological diagnosis of hepatitis A, B, C, D, and E is a comprehensive exploration of the immunological methods employed in identifying and differentiating these distinct hepatitis viruses. This presentation delves into the intricacies of serological assays, such as enzyme-linked immunosorbent assays (ELISAs), Western blotting, and nucleic acid testing, elucidating their application in detecting specific antibodies and antigens associated with each hepatitis type. The content encompasses the nuances of serological markers, including hepatitis A virus (HAV) IgM and IgG antibodies, hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV) antibodies, anti-hepatitis D virus (HDV) antibodies, and markers indicative of hepatitis E virus (HEV) infection. Through a systematic examination of serological diagnostics, this presentation contributes to a deeper understanding of the immunological aspects crucial for accurate and timely diagnosis.
2. Hepatitis
Hepatitis is a general term that
means inflammation of the liver.
It can be caused by several
viruses and by noninfectious
agents, including ionizing
radiation, chemicals, and
autoimmune processes.
6. Interpretations and Limitations
Limitations
False Positive Conditions for HAV:
Cross-reactivity
Vaccination
Non-specific binding
False Negative Conditions for HAV:
Early Infection
Immunocompromised Individuals
Testing during the Window Period
9. Serological Diagnosis of Hepatitis B
HBsAg - general marker of infection.
HBsAb - Recover or immunity
anti-HBc IgM
anti-HBcIgG
HBeAg - indicates active replication of
virus and therefore infectiveness.
Anti-Hbe - virus no longer replicating.
anti-HBc Appears at the onset of symptoms in acute hepatitis
B, is a measure of both IgM and IgG, and persists for life
IgM anti-HBc Positivity indicates recent infection
with hepatitis B virus (<6 mos)
12. Limitations
False-Positive HBV Test Results
Can occur due to cross-reactivity with
other viral infections (e.g., hepatitis A
or C) or autoimmune diseases.
Confirmatory tests, such as HBV DNA
testing or additional serologic markers,
may be needed to rule out false
positives.
13. Limitations
False-Negative HBV Test Results
Early or acute stage of infection
Immunosuppression (e.g., in HIV-
infected individuals)
False non-reactivity due to
technical errors or test limitations
15. Hepatitis C
Virus
Flavivirus family.
Six genotypes and
multiple sub-
genotypes
Enveloped virion
The hepatitis C virus is a bloodborne virus and most infection occur through
exposure to blood from unsafe injection practices
Acute and chronic hepatitis, ranging in severity from a mild illness to a
serious, lifelong illness including liver cirrhosis and cancer.
16. Serological Diagnosis of Hepatitis C
Serological Testing
HCV Antibody Test: Detects the presence of
antibodies against HCV in the blood.
HCV Core Antigen Test Detects HCV core
antigen, a viral protein, in the blood.
CLIA
17. Limitations
False-Positive Anti-HCV Test
Results
Anti-HCV is present, but HCV RNA is
undetectable
Cross reactivity
Non-specific reactive antibodies
Occurs in 1 % population
Recovery from acute infection
Occurs in 60-80 % of cases of new
infection
25. Hepatitis E Virus
Transmission
food borne transmission from ingestion of
products derived from infected animals;
zoonotic transmission from animals to
humans;
transfusion of infected blood products;
vertical transmission from a pregnant woman
to her fetus.
27. Limitations
Variability in Seroprevalence
Seroprevalence of HEV varies geographically, with higher rates in endemic regions.
Serological tests may yield false-positive results in regions with low HEV prevalence,
leading to overdiagnosis.
Immune Response Duration
Antibodies against HEV can persist for an extended period, even after clearance of
the virus.
Serological tests cannot distinguish between active and resolved infections.