While simple blood tests are used to test for hepatitis C, there can still be discrepancies in a patient's blood test results. Usually, these discrepancies arise from testing at the wrong time or due to other factors.
It is a major possibility to test negative for hepatitis C and still have it. If you test negative but still have the infection, the test result is described as false-negative. Discrepancies in blood testing results for hepatitis C usually take on the form of false-negative and false-positive results. False-negative and false-positive results can arise in all kinds of blood tests used to diagnose hepatitis C, including the anti-HCV antibody test and the HCV RNA test.
While getting false results on a blood test is worrisome, healthcare professionals often have an algorithm to eliminate the chances of getting a false result. These algorithms are designed to provide the most accurate results through the implication of a multi-tiered testing system.
AMBIGUOUS HEPATITIS C TEST RESULTS
As mentioned before, the tests routinely employed to detect hepatitis C are fairly simple. These tests are usually effective and accurately assess a person's HCV status. However, these tests can return a false assessment of a person's disease status and mislead the medical proceedings under certain circumstances.
The two most common tests for diagnosing hepatitis C are the anti-HCV antibody test and the HCV RNA test. These tests are employed in series to obtain an accurate assessment of a person's HCV status. However, both tests can return a false-negative or a false-positive test result.
ANTI-HCV ANTIBODY TEST
This test relies on a qualitative measure of antibodies that are produced in response to the hepatitis C virus entering the body. A positive antibody test is obtained when antibodies against the hepatitis C virus are present in a person's blood. A positive antibody test is also called a reactive anti-HCV antibody test.
However, a reactive antibody test does not always mean that a person has hepatitis C. According to WebMD, 1 in 5 people with positive antibody test results don’t actually have hepatitis C. One reason for this false-positive test result is that a person who has been exposed to the hepatitis C virus will have the circulating antibodies for a long time, even after the initial infection has been cleared. Sometimes, the testing kit mistakenly detects antibodies for other conditions, such as rheumatoid arthritis, as antibodies against the hepatitis C virus.
A non-reactive or negative anti-HCV antibody test means that a person does not have any circulating antibodies against the hepatitis C virus. However, a negative antibody test result does not mean that you don’t have hepatitis C. The testing kit usually returns false-negative results when testing is done during or before the window period.
HCV RNA test
The HCV RNA test is much more sensitive and specific for hepatitis C than the anti-HCV antibody test. However, false results are still possible with RNA testing.
A false-positive result with the HCV RNA test is obtained if your blood sample is contaminated. Similarly, a false-negative test result can be obtained if the viral load in your blood did not get time to multiply and become "detectable."
While false and ambiguous results are possible with the HCV RNA test, they are far more unlikely than in the anti-HCV antibody test.
WHAT TO DO IF MY HEPATITIS C TESTS ARE AMBIGUOUS?
Ambiguous hepatitis C tests are bothersome as they can impede the natural course of a diagnostic action. However, testing algorithms prevent these false results from ever influencing a person's diagnosis and treatment.
The first step toward accurate assessment of a person's HCV status is to test at the right time. While the HCV RNA test is a much more flexible diagnostic modality, the anti-HCV antibody test works best only when used after the window period. It takes time for antibodies to develop in a person's blood, and the anti-HCV antibody test only returns accurate results when employed at least after 12 weeks of initial infection. Therefore, multiple diagnostic algorithms recommend a repeat antibody test after six months of the initial antibody test.
Repeat testing is also useful when eliminating the possibility of false results. Different test results between two repeat tests often indicate the possibility of a false result and warrant the need for further testing.
While diagnostic tests often provide the most accurate assessment of a person's disease status, they are not the only thing a physician relies on to make an accurate diagnosis. Most diagnoses are entirely clinical and require no lab testing whatsoever.
Similarly, a physician looks for multiple clues for the diagnosis of hepatitis C. a combination of specific signs and symptoms of the disease, positive findings on physical examination, and lab testing confirmation is usually the mainstay of diagnosis. A physician’s discretion is also an important link in the chain of diagnosis of hepatitis C.
WHICH HEPATITIS C TEST IS THE MOST SENSITIVE?
Since the HCV RNA test detects the viral RNA present in a person's blood, it is said to measure a person's HCV status directly. A direct measure of a person's HCV status is directly related to a test's ability to diagnose the condition accurately. Therefore, the HCV RNA test is a far more sensitive and specific test for diagnosing hepatitis C than the anti-HCV antibody test.
IS HEPATITIS C TREATABLE?
Hepatitis C largely remained a dreaded diagnosis following its discovery. However, modern medicine has developed efficient and accurate tools for diagnosing and treating hepatitis C. Once a terrifying liver infection that was largely fatal has now been reduced to a mild to moderate inflammation of the liver than can be treated and cured completely using antiviral medication.
The drugs used to treat hepatitis C are Direct Acting Antivirals, or DAAs. These drugs are prescribed for 10-12 weeks and are taken regularly by the patient. After 12 weeks of regular therapy, a patient can be completely cured of hepatitis C in most cases without any long-term liver complications.