Rethinking ME/CFS diagnostic reference intervals via machine learning, and the utility of activin B for defining symptom severity, by Brett A. Lidbury, Badia Kita, Alice M Richardson, Donald P Lewis, Edwina Privitera, Susan Hayward, David de Kretser and Mark Hedger in Diagnostics 2019, 9(3), 79; https://doi.org/10.3390/diagnostics9030079
Biomarker discovery applied to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a disabling disease of inconclusive aetiology, has identified several cytokines to potentially fulfil a role as a quantitative blood/serum marker for laboratory diagnosis, with activin B a recent addition.
We explored further the potential of serum activin B as a ME/CFS biomarker, alone and in combination with a range of routine test results obtained from pathology laboratories.
Previous pilot study results showed that activin B was significantly elevated for the ME/CFS participants compared to healthy (control) participants. All the participants were recruited via CFS Discovery and assessed via the Canadian/International Consensus Criteria.
A significant difference for serum activin B was also detected for ME/CFS and control cohorts recruited for this study, but median levels were significantly lower for the ME/CFS cohort. Random Forest (RF) modelling identified five routine pathology blood test markers that collectively predicted ME/CFS at ≥62% when compared via weighted standing time (WST) severity classes.
A closer analysis revealed that the inclusion of activin B to the panel of pathology markers improved the prediction of mild to moderate ME/CFS cases. Applying correct WST class prediction from RFA modelling, new reference intervals were calculated for activin B and associated pathology markers, where 24-h urinary creatinine clearance, serum urea and serum activin B showed the best potential as diagnostic markers.
While the serum activin B results remained statistically significant for the new participant cohorts, activin B was found to also have utility in enhancing the prediction of symptom severity, as represented by WST class.
Australian researchers explored a potentially effective method of identifying ME/CFS by using a combination of cytokines. By grouping activin B with 24-hour urinary creatinine clearance and serum urea together for analysis, the results show good potential for use in diagnosing ME/CFS. Activin B is a complex protein found to have biological effects in numerous bodily functions.
A previous pilot study showed a significant increase of activin B in ME/CFS patients as compared to healthy controls. The researchers found that including activin B in the panel of pathology markers improved prediction rates for mild and moderate cases of ME/CFS. Additionally, activin B was also found to help with the prediction of symptom severity as represented by weighted standing time tests.
**This paper is from the Emerge Australia sponsored issue of Diagnostics