pr20
Forum Senior
Topics: 18
Posts: 161
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A 34-year old accountant returns home after a trip to calcutta,complaining of fatigue,malaise,and loss of appetite.Three months after the initial diagnosis,the results of the serological tests reveal:
HBcAb-positive
HBeAb-positive
HBeAg-negative
HBsAg-negative
HBsAb-negative
The absence of HBsAg and HBsAb from the serum of this patient is reflective of which of the following?
1.The patient has been successfully vaccinated against Hepatitis B
2.The patient is anergic to Hepatitis B
3.The patient is immune to Hepatitis B
4.The patient is making an excess of HBsAb
5.The patient is making an excess of HBsAg
6.The patient is making equivalent amounts of HBsAb and HBsAg
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| angel23
Forum Guru
Topics: 34
Posts: 667
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6.the patient is making equal amount of Ag and Ab....window pwriod
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| Misrati
Forum Junior
Topics: 10
Posts: 48
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I would say , its the window phase "serologic gap " since after months he had high HBcAB which correlates which disappearance of HBsAg , and also has high HBeAb as well.
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| new_n_lost
Politically InCorrect
Topics: 650
Posts: 6,058
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yup this is the window period and choice 6 is the only one that fits as a correct answer but what about choice 2 just for discussion.
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| Tiff
Forum Guru
Topics: 54
Posts: 563
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#6 - only one that makes sense to me. Window period just before the Antibody becomes detectable.
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| mediocre
Forum Elite
Topics: 37
Posts: 229
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good work guys..check this out ,
Explanation of Viral Hepatitis Tests
Test Abbreviation
Interpretation ofResults and Comments
b
(Anti-HAV IgM or HAV IgM Ab)
Positive result defines a recent HAV infection.
May be negative in early infection (if collected within 5 to 7 days after onset of symptoms)
Present for 3 to 6 months after onset of acute infection.
b
(Anti-HAV Ab or HAV Ab)
Of extremely limited value in the diagnosis of acute infection.
Positive result indicates past infection and immunity to HAV.
Individuals given serum immune globulin for HAV prophylaxis may test as positive for at least six months.
b
(HBsAg)
Used to diagnose an acute or chronic infection.
First marker to appear in an acute infection.
Disappearance indicates recovery from infection.
Persistence for > 6 months indicates chronic infection (carrier).
Individuals tested within 72 hours after administration of the vaccine may test as positive. (See anti-HBs, anti-HBc IgM and HBeAg.)
b
(Anti-HBs or HBs Ab)
Only test which can be used to assess presence of protective immunity after immunization with hepatitis B vaccine.
Levels of 10 MIU/mL (10 IU/L) are usually considered protective. Routine monitoring of levels in individuals who have received the complete course of vaccine is not considered necessary.
Some individuals, e.g. healthcare workers, who are believed to have been exposed to the virus by a needlestick injury, should have their anti-HBs levels tested to determine whether they require administration of hepatitis B immune globulin (HBIG) and hepatitis B vaccine booster.
Positive result in individuals with recent acute HBV infection indicates convalescence.
Usually NOT detected when HBsAg is also present.
In some cases of chronic hepatitis B infection, both HBsAg and anti-HBs can be detected. These antibodies are heterotypic and likely not protective.
Antibody levels may decline with time.
b
(Anti-HBc IgM or HBc IgM Ab)
This test is expensive and should primarily be used if there is a high index of suspicion to indicate that the patient is in the early convalescence “window period” (2 to 16 weeks post infection) when HBsAg has disappeared and anti-HBs levels are not yet detectable.
Positive result in patients who are also HBsAg positive usually indicates acute infection.
Usually detectable for 3 to 12 months.
Depending upon the threshold level of sensitivity, low levels may be detected in patients with chronic infection and reactivation.
b
(HBeAg)
Marker of active HBV replication.
Also a marker of infectivity. However, the absence of HBeAg in a person who is HBsAg-positive does not imply that the individual is NOT infectious.
Can be used to monitor therapy of patients with chronic HBV infection.
b
(Anti-HBe or HBe Ab)
Appears as HBeAg disappears.
In chronic hepatitis B infection, a positive result indicates resolving or minimal liver disease.
However, individuals who are HBsAg-positive and have anti-HBe present must still be considered infectious.
b
(Anti-HBc or HBc Ab)
A positive result indicates past infection with hepatitis B virus.
Usually persists for life.
This antibody is absent in individuals who are immune solely as a result of vaccination.
Up to 10% false-positive rate has been described in individuals with no documented infection to HBV. If uncertain, presence of one other marker, e.g., anti-HBs or anti-HBe would confirm previous exposure with HBV. Alternatively a negative repeat test later may indicate an earlier false-positive result.
b
(HBV DNA)
Available by special request only. Of very limited value in the diagnosis of HBV infection.
Used to determine the presence of HBV DNA circulating in the blood which is a measure of virus replication in the liver.
Primary use is in monitoring treatment and clarifying some complex situations.
b
(Anti-HCV or HCV Ab)
Enzyme immunoassay (EIA) tests are the most common screening tests used to detect antibody.
• With present EIA tests, a reactive result may be obtained after 8 to 12 weeks to several months following infection with HCV. Earlier generations of EIA tests often gave negative antibody results for up to 1 year.
False-positive results are found in patients with autoimmune chronic active hepatitis, alcoholic liver disease and other disorders relating to hypergammaglobulinemia.
Presence of antibody can be due to acute or chronic infection. It may represent only evidence of an infection with HCV.
Persistently elevated ALT levels suggest chronic infection. Repeatedly normal levels do not exclude chronic infection, but suggest low grade inflammation.
ALT values in some patients with HCV infection are within normal ranges.
b
(RIBA)
Supplementary test for the verification of EIA reactive results to HCV.
Indeterminate results may be found in early seroconversion, immunosuppressed patients or those unable to mount a complete antibody response. Some of the conditions which give false-positives in the EIA may well give an indeterminate or non-specific result in the RIBA.
b
(PCR for HCV)
Available by special request only, as it is a research tool.
Used to determine the presence of HCV RNA circulation in the blood which is a measure of virus replication in the liver.
Can be used to assess the infectivity of the patient and monitor therapy.
May be of use in early infection when antibody to the virus is undetectable, and in immunocompromised patients who may not seroconvert.
Can be of use in resolving indeterminate RIBA results.
b
(Anti-HDV or HBV Ab)
HDV occurs as a co-infection with HBV or super-infection of a chronic HBsAg carrier.
Antibodies appear late during the course of acute infection.
HDV is uncommon in Alberta.
b
(Anti-HEV or HEV Ab)
Routine tests not presently available for detection of this agent.
This test may be available by special request only from reference laboratories.
b
alanine aminotransferase
Liver enzyme test
Used to assess extent of liver inflammation
Can be used to monitor resolution of inflammation following acute or chronic infection
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| pr20
Forum Senior
Topics: 18
Posts: 161
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Answer is 6...window period
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| Ig F
Forum Elite
Topics: 3
Posts: 431
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pt is in the window period....when the amount os HBsAg is equal to HBsAb....so there is no detactable Ab in the blood
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