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Updated: May 5, 2026

Isolation of Exosomes from the Plasma of HIV-1 Positive Individuals
Published on: January 5, 2016
Elevated serum fibroblast growth factor 21 levels correlate with immune recovery but not mitochondrial dysfunction in
Brendan Ai Payne1, David Ashley Price, Patrick F Chinnery
1Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle-upon-Tyne NE1 3BZ, UK. brendan.Payne@ncl.ac.uk.
Background:
Anti-retroviral treated HIV-infected patients are at risk of mitochondrial toxicity, but non-invasive markers are lacking. Serum FGF-21 (fibroblast growth factor 21) levels correlate strongly with muscle biopsy findings in inherited mitochondrial disorders. We therefore aimed to determine whether serum FGF-21 levels correlate with muscle mitochondrial dysfunction in HIV-infected patients.
Findings:
We performed a cross-sectional study of anti-retroviral treated HIV-infected subjects (aged 29 - 71 years, n = 32). Serum FGF-21 levels were determined by quantitative ELISA. Cellular mitochondrial dysfunction was assessed by COX (cytochrome c oxidase) histochemistry of lower limb skeletal muscle biopsy. Serum FGF-21 levels were elevated in 66% of subjects. Levels correlated significantly with current CD4 lymphocyte count (p = 0.042) and with total CD4 count gain since initiation of anti-retroviral therapy (p = 0.016), but not with the nature or duration of past or current anti-retroviral treatment. There was no correlation between serum FGF-21 levels and severity of the muscle mitochondrial (COX) defect.
Conclusions:
Serum FGF-21 levels are a poor predictor of muscle mitochondrial dysfunction in contemporary anti-retroviral treated patients. Serum FGF-21 levels are nevertheless commonly elevated, in association with the degree of immune recovery, suggesting a non-mitochondrial metabolic disturbance with potential implications for future comorbidity.

