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Quantification of key parameters accurately stages fibrosis in NAFLD

Dual-photon microscopy automated quantification of fibrosis-related parameters provided accurate assessments of fibrosis in patients with nonalcoholic fatty liver disease, according to data published in Gut.

“The dual-photon microscopy has been used to quantify fibrosis-related parameters (q-FP) with high accuracy in patients with chronic hepatitis B and NAFLD,” Yan Wang, MD, from the Southern Medical University, Guangzhou, China, and colleagues wrote. “The system identifies different morphological features of collagen fibril, which correlate well with fibrosis stages.”

Between November 2008 and November 2017, Wang and colleagues enrolled 344 patients with biopsy-proven NAFLD in the study and randomly assigned them to a training cohort (n = 206) or a validation cohort (n = 138). Approximately 43% had fibrosis between stage 2 and stage 4.

From the 70 q-FPs evaluated in the training cohort, 29 had an area under receiver operating characteristic higher than 0.9 for fibrosis stage 2 through stage 4 and 28 had an AUROC higher than 0.9 for fibrosis stage 3 and stage 4. The selected parameters included the total collagen content and features of collagen fibers such as their perimeter, length, width, area and numbers, either globally or at the perivessel area.

Perimeter of collagen fibers and number of long collagen fibers increased with fibrosis stage in a stepwise manner. A cut-off of 3.01 for perimeter had a sensitivity of 93.2%, specificity of 87.3%, positive predictive value (PPV) of 84.5%, and negative predictive value (NPV) of 94.5% for fibrosis stage 2 through stage 4. A cut-off of 0.0046 for number of long collagen fibers had a sensitivity of 90.9%, specificity of 88.1%, PPV of 85.1%, and NPV of 92.9%.

The researchers found similar results in the validation cohort with 27 q-FPs with an AUROC higher than 0.9 for fibrosis stage 2 through stage 4. The same cut-off of perimeter of collagen fibers had a sensitivity of 91.7%, specificity of 78.2%, PPV of 76.4%, and NPV of 92.4%. The cut-off for number of long collagen fibers had a sensitivity of 88.3%, specificity of 78.2%, PPV of 89.7%, and NPV of 89.7%.

During a median follow-up of 5.6 years, 12 patients developed liver-related events including hepatocellular carcinoma, cirrhotic complications and two deaths. Eleven patients had a perimeter of collagen fiber measurement of 3.77 or higher (P = .004) and number of long collagen fibers measurement of 0.0056 or higher (P < .001) compared with lower readings in the other patient.

“This automated platform can be used in future clinical trials and observational studies as objective and reliable evaluation of histological fibrosis,” Wang and colleagues concluded. “Features of vessel-bridging collagen fibers at baseline predict future fibrosis progression with modest accuracy. Future studies should refine the technique to evaluate the other histological features of NASH.” – by Talitha Bennett

Disclosures: Wang reports no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.