Flaws in testing for cirrhosis/fibrosis

  • Contaminated Blood Campaign
  • It is clear that liver disease is not the only effect of HCV, but even if it was, it would not be fair to base eligibility for financial assistance on the available tests for cirrhosis or fibrosis when none of them are totally reliable.
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Flaws in testing for cirrhosis/fibrosis

It is clear that liver disease is not the only effect of HCV, but even if it was, it would not be fair to base eligibility for financial assistance on the available tests for cirrhosis or fibrosis when none of them are totally reliable. Of ninety-four research articles referenced in the review document, roughly a quarter dealt with progression to fibrosis/cirrhosis and its subsequent effect on quality of life and morbidity. Clearly this subject was considered an important issue, therefore it was surprising to find that none of the research was in relation to the reliability of testing for the extent of liver damage.

Even if liver damage was the only effect of HCV it seems impossible to measure it with accuracy, so it is grossly unfair to withhold financial help on this basis. Research on the methods used to assess liver damage reveals the following flaws:

  1. A liver biopsy is the 'Gold Standard' method but even that is not 100% accurate. This fact was confirmed at the Penrose Inquiry, when Professor James, Medical Assessor to the Inquiry, said "there is a tremendous opportunity for what's called sampling error in the liver biopsy". (1 October 2011. Page 121, lines 7-13 of transcript.)
  2. Liver biopsy is dangerous for people with a bleeding disorder. Again, this was confirmed at the Penrose Inquiry by Professor Thomas who reported that his personal experience included fatality in people with haemophilia undergoing liver biopsy. (Referred to by Ms Dunlop on 12 October. Page 9, lines 15-22 of transcript.)
  3. AST/ALT ratio, as set out on the Skipton application form, is not a reliable way of measuring cirrhosis in the case of hepatitis C. Evidence of this is shown below.
  4. Fibroscan is geographically discriminatory because it is not available in all areas. Furthermore, it is even less reliable than the so-called 'Gold Standard' biopsy.
  5. Even if fibroscan was available to all and 100% reliable, it would be nonsense to expect people to have one on a regular basis just to find out when they cross the boundary into the Stage 2. The same applies to biopsies. A campaigner was informed recently by his hepatologist that fibroscans would only be carried out every 3 years.
  6. Some people prefer to remain in ignorance as to the extent of their liver damage, therefore it is wrong to set this as a criteria. Furthermore, the rules of the Skipton fund state that a liver biopsy must not be undertaken purely to prove eligibility for the payment.

Evidence of unreliability of AST/ALT ratio to predict fibrosis

A study comparing non-invasive tests with liver biopsy, reported inPubMed in February 2011, shows that Fibroscan is not a reliable measure of cirrhosis. It is stated in the results of the study that: "Even though from its beginning, Fibroscan is proved to be best with high AUROCs (> 0.90) in all studies, no single noninvasive marker is able to differentiate all fibrosis stages from end stage cirrhosis."

An article in Hepatology Journal entitled 'Predictive value of ALT levels for histologic findings in chronic hepatitis C: A European collaborative study' indicates the inaccuracy of using the AST/ALT ratio to measure fibrosis in HCV patients.

"The receiver operating characteristics analysis indicates that the ALT threshold for the best compromise sensitivity-specificity was about 2.25 times the upper limit of normal (ULN). In conclusion, almost all HCV RNAñpositive patients with elevated ALT levels have some degree of fibrosis. However, an important proportion of patients with persistently normal ALT levels also show some histologic signs of fibrosis; the degree of fibrosis is usually mild but is sometimes more marked, and in rare cases cirrhosis may be present."

The extract below originates from 'Clinical and histologic spectrum of nonalcoholic fatty liver disease associated with normal ALT values'

"the absence of any obvious symptoms, signs, or ALT values suggestive of liver disease does not guarantee the absence of clinically significant liver disease, i.e., advanced stage chronic liver disease. In this respect, these data corroborate and extend the existing literature regarding other chronic liver diseases, e.g., hepatitis C and normal ALT values."