As an autoimmune disorder, vitiligo has been associated with anticipated increased risk of disease severity among patients infected with SARS-CoV-2 since the beginning of the pandemic. Conversely, recent study outcomes prove that COVID-19 hospitalization and mortality risk may be significantly decreased among patients with vitiligo. 

A team of US investigators from West Virginia University School of Medicine discovered that vitiligo was associated with such a decreased likelihood of severe COVID-19 outcomes among infected patients that investigators suggested vitiligo may confer “protective effects against worse outcomes in a severe course” of the pandemic virus.

The team conducted their retrospective analysis using the 80 million-patient TriNetX federal database, which spans 58 health care organizations. They identified adult patients ≥18 years old diagnosed with COVID-19 from January 20, 2020 to December 1, 2021; patients vaccinated against the virus prior to infection were excluded from analysis. The initial recruitment identified 1,390,646 patients.

Compared with the control cohort, patients with vitiligo were older (51.0 years old), with a greater rate of females (59.0%), Black patients (20.0%) and comorbid diseases. Investigators reported that patients with vitiligo had a 23.4% reduced risk of hospitalization, and 38% reduced risk of mortality compared to the non-vitiligo cohort. 

“While the pathophysiological reasoning is unclear, a previous review hypothesized that non-segmental vitiligo shifts the body's immune system to a more adaptive type 1 (IFN-γ and CD8+ T cells) and that innate immune responses increase interferon signaling,” they wrote. Investigators also supported the idea of increased antiviral immunity in patients with vitiligo due to “certain single nucleotide polymorphisms in their genetic profile.” 

“Further studies examining outcomes of COVID-19 in patients with other autoimmune diseases and whether vitiligo patients are also protected from the long-term effects of COVID-19, if infected, are warranted,” they wrote.