Slide 1 — Title Hepatitis Serology as a Diagnostic Puzzle: Working with Marker Patterns Eswatini Medical Christian University Department of Medical Laboratory Sciences ML 302 Medical Microbiology II, Level 3 Group 6: 1. Mashaya Nduduzo — 202450453 2. Mkhweli Nkosikhona Simphiwe — 202450459 3. Dlamini Siphosethu Gift — 202450441 4. Simelane Sanele Lerato — 202450478 Primary evidence paper: Chang JJ, Mohtashemi N, Bhattacharya D. Curr HIV/AIDS Rep. 2018;15(2):172–181. --- Slide 2 — What this presentation answers · How to analyse combinations of hepatitis serological markers and explain what different patterns indicate · How to identify potentially confusing profiles that can mislead interpretation · When an additional molecular test such as viral nucleic acid testing provides useful information --- Slide 3 — First principle: each marker answers a different question · Antigen: a viral component is present — often indicates current infection · Antibody: the host has responded — from exposure or from vaccination · Nucleic acid: the virus is replicating now · Rule: interpret the pattern, the timeline, and the patient — never one marker in isolation --- Slide 4 — HBV: start with the triple panel · HBsAg: current infection — acute or chronic · Total anti-HBc: exposure to natural HBV — past or current; not produced by vaccination · Anti-HBs: immunity — from vaccination or resolved infection · Anti-HBc positive with HBsAg negative and anti-HBs negative = isolated anti-HBc --- Slide 5 — Confusing profile: isolated anti-HBc Pattern: HBsAg negative, anti-HBs negative, total anti-HBc positive · Resolved infection with waned anti-HBs — most common · False-positive anti-HBc — repeat with a second assay · Occult HBV — HBsAg negative but HBV DNA detectable · Window period — IgM anti-HBc may be positive · HBsAg escape mutant not detected by standard assay · Passive maternal anti-HBc in infants — do not test before 24 months --- Slide 6 — Confusing profiles: window period and occult HBV · Window period: HBsAg negative, IgM anti-HBc positive, anti-HBs negative — HBV DNA confirms acute infection · Occult HBV: HBsAg negative but HBV DNA detectable — anti-HBc raises suspicion but cannot diagnose alone · HBsAg positive with anti-HBc negative: consider very early acute infection, false result, or mutant — repeat serology and consider HBV DNA · These are the profiles where serology alone is insufficient --- Slide 7 — HCV: antibody is exposure, RNA is current infection · Anti-HCV positive: exposure — does not prove current infection · HCV RNA positive: current infection · Anti-HCV positive with HCV RNA negative: past cleared or treated infection, or false-reactive antibody · After cure, anti-HCV usually stays positive — use RNA to detect reinfection --- Slide 8 — HDV and a note on HAV and HEV · HDV requires HBsAg to assemble and propagate · Anti-HDV indicates exposure — but can persist after clearance · HDV RNA confirms active viraemia — reflex te
Slide 1 — Title
Hepatitis Serology as a Diagnostic Puzzle: Working with Marker Patterns
Eswatini Medical Christian University
Department of Medical Laboratory Sciences
ML 302 Medical Microbiology II, Level 3
Group 6:
1. Mashaya Nduduzo — 202450453
2. Mkhweli Nkosikhona Simphiwe — 202450459
3. Dlamini Siphosethu Gift — 202450441
4. Simelane Sanele Lerato — 202450478
Primary evidence paper: Chang JJ, Mohtashemi N, Bhattacharya D. Curr HIV/AIDS Rep. 2018;15(2):172–181.
---
Slide 2 — What this presentation answers
· How to analyse combinations of hepatitis serological markers and explain what different patterns indicate
· How to identify potentially confusing profiles that can mislead interpretation
· When an additional molecular test such as viral nucleic acid testing provides useful information
---
Slide 3 — First principle: each marker answers a different question
· Antigen: a viral component is present — often indicates current infection
· Antibody: the host has responded — from exposure or from vaccination
· Nucleic acid: the virus is replicating now
· Rule: interpret the pattern, the timeline, and the patient — never one marker in isolation
---
Slide 4 — HBV: start with the triple panel
· HBsAg: current infection — acute or chronic
· Total anti-HBc: exposure to natural HBV — past or current; not produced by vaccination
· Anti-HBs: immunity — from vaccination or resolved infection
· Anti-HBc positive with HBsAg negative and anti-HBs negative = isolated anti-HBc
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Slide 5 — Confusing profile: isolated anti-HBc
Pattern: HBsAg negative, anti-HBs negative, total anti-HBc positive
· Resolved infection with waned anti-HBs — most common
· False-positive anti-HBc — repeat with a second assay
· Occult HBV — HBsAg negative but HBV DNA detectable
· Window period — IgM anti-HBc may be positive
· HBsAg escape mutant not detected by standard assay
· Passive maternal anti-HBc in infants — do not test before 24 months
---
Slide 6 — Confusing profiles: window period and occult HBV
· Window period: HBsAg negative, IgM anti-HBc positive, anti-HBs negative — HBV DNA confirms acute infection
· Occult HBV: HBsAg negative but HBV DNA detectable — anti-HBc raises suspicion but cannot diagnose alone
· HBsAg positive with anti-HBc negative: consider very early acute infection, false result, or mutant — repeat serology and consider HBV DNA
· These are the profiles where serology alone is insufficient
---
Slide 7 — HCV: antibody is exposure, RNA is current infection
· Anti-HCV positive: exposure — does not prove current infection
· HCV RNA positive: current infection
· Anti-HCV positive with HCV RNA negative: past cleared or treated infection, or false-reactive antibody
· After cure, anti-HCV usually stays positive — use RNA to detect reinfection
---
Slide 8 — HDV and a note on HAV and HEV
· HDV requires HBsAg to assemble and propagate
· Anti-HDV indicates exposure — but can persist after clearance
· HDV RNA confirms active viraemia — reflex te
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This guide provides a comprehensive approach to understanding serological markers in hepatitis B and C. It begins by defining key terms such as antigens and antibodies, and emphasises the importance of patient context in interpreting HBV results. It addresses the complexities of marker profiles, particularly isolated anti-HBc, and clarifies the distinction between window periods and occult infections. Finally, it outlines methods to confirm active viral infections, including the use of HDV...