Liver biopsy is an invasive technique with associated major complications.
There is no information on the validity of 5 non-invasive indexes based on routinely available parameters.
There is also no information on these parameters estimated and validated in Hepatitis C monoinfected patients.
Furthermore, information on non-invasive indexes for patients coinfected with human immunodeficiency virus (HIV) and Hepatitis C is lacking.
Dr Macías and colleagues from Spain validated these predictive models of liver fibrosis in HIV/Hepatitis C coinfected patients.
A total of 357 of 398 patients from 5 hospitals were investigated, who underwent liver biopsy and who had complete data to validate all of the models considered.
The predictive accuracy of the indexes was tested by measuring areas under the receiver operating characteristic curves.
The research team calculated diagnostic accuracy by estimating sensitivity, specificity, and positive and negative predictive values.
| If both models were applied sequentially, 41% of liver biopsies could be spared|
The researchers found the models performed better when liver biopsies 15 mm were used as reference.
The Forns and Wai indexes, models aimed at discriminating significant fibrosis, showed positive predictive values of 94% and 87%, respectively.
Using these models, the team noted that 27 to 34% of patients could benefit from exclusion of liver biopsy.
The team observed that if both models were applied sequentially, 41% of liver biopsies could be spared.
The indexes aimed at predicting cirrhosis achieved negative predictive values of up to 100%.
However, they showed very low positive predictive values.
Dr Macías' team commented, “The diagnostic accuracy of these models was lower in HIV and Hepatitis C virus coinfected patients than in the validation studies performed in Hepatitis C virus monoinfected patients.”
“However, simple fibrosis tests may render liver biopsy unnecessary in deciding anti-Hepatitis C virus treatment in over a third of patients with HIV infection and chronic Hepatitis C.”