Photobiomodulation Improves Serum Cytokine Response in Mild to Moderate COVID-19: The First Randomized, Double-Blind, Placebo Controlled, Pilot Study.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 35874678 · doi:10.3389/fimmu.2022.929837
What was done
In a randomized, double-blind, placebo-controlled pilot study conducted in the second half of 2021, 52 hospitalized patients with mild-to-moderate COVID-19 were assigned to standard medical treatment plus photobiomodulation (PBM; n = 24) or standard treatment plus placebo (n = 28). The PBM intervention delivered 620–635 nm light via 8 LEDs (energy density 45.40 J/cm², power density 0.12 W/cm²) twice daily for three days. Blood samples were collected four times across the three days to assess serum IL-6, IL-8, IL-10, and TNF-α.
What was found
Patients receiving PBM experienced significant reductions in serum IL-6 (-82.5% ± 4%, P < 0.001), IL-8 (-54.4% ± 8%, P < 0.001), and TNF-α (-82.4% ± 8%, P < 0.001), along with improvement in the IL-6/IL-10 ratio. IL-10 did not change significantly in the PBM group. The placebo group showed no decrease or an increase in these cytokine levels. No complications or adverse events were reported.
Why it matters
This pilot trial provides early randomized evidence that non-invasive photobiomodulation may rapidly reduce key circulating pro-inflammatory cytokines in mild-to-moderate COVID-19, presenting a potential adjunctive tool to mitigate hyperinflammation.
Limits
The trial had a small sample size (n = 52) and a very short observation window (3 days). The abstract does not report clinical endpoints such as progression to severe disease, ICU admission, length of hospital stay, or mortality.