Autotaxin may be an effective noninvasive biomarker for the diagnosis and prognosis of primary biliary cholangitis (PBC), according to a study recently published in the journal Heliyon.
It may be particularly useful in patients who do not have anti-mitochondrial antibodies (AMA), or antibodies that attack small cell organelles called mitochondria.
“In some patients, especially those AMA negative, the diagnosis may be a challenge requiring liver biopsy. This study determined whether autotaxin, a secreted lysophospholipase D encoded by the exonucleotide pyrophosphatase phosphodiesterase 2 gene, can be used as a serum biomarker for PBC,” the study authors wrote.
The researchers collected plasma samples from 103 patients with PBC and 74 healthy volunteers. They used a complex laboratory test called enzyme-linked immunosorbent assay (ELISA) to determine the levels of autotaxin and analyzed its ability to detect PBC and predict outcomes. The relationship between autotaxin and clinical data was also assessed.
Read more about PBC testing and diagnosis
According to the results, patients with PBC had significantly higher levels of autotaxin compared with those of healthy individuals. The biomarker could detect PBC with a sensitivity of 54.3% and produced very few false positive results due to a specificity of 93.1%. It also had a positive predictive value of 84.4% and a negative predictive value of 74.8%.
“Anti-gp210 and anti-sp100 antibodies are complementary antibodies of PBC, particularly in AMA-negative cases, and might be associated with disease progression. However, both have low sensitivity for diagnosing patients with PBC,” the authors added.
The positivity rate of autotaxin (50.0%) was higher than that of anti-sp100 (16.7%) and anti-gp210 (11.1%) antibodies in AMA-negative patients with PBC.
Moreover, autotaxin levels were positively correlated with the level of antibody immunoglobulin M and Ludwig’s classification used to stage liver damage in patients with PBC.