BACKGROUND AND PURPOSE:

• Dysregulated inflammation may provide a biological mechanism for post-acute sequelae of severe acute respiratory coronavirus 2 (SARS-CoV-2) infection (PASC)
• Ng et al. (Menopause et al, 2025) examined the association of inflammatory markers, measured ~25 years prior to the pandemic with PASC

METHODS:

• Long-term cohort study
  •  Data from Women’s Health Initiative
• Population
  • Postmenopausal
  • Blood specimens collected pre-pandemic (1993 through 1998)
  • Completed a COVID-19 survey in 2021 or 2022
• Exposures
  • Leukocyte count
  • High-sensitivity C-reactive protein (hsCRP) concentrations
• Study design
  • Multivariable regression models were used with adjustment for patient characteristics
• Primary outcome
  • PASC
  • PASC severity
    • Defined as the sum of PASC symptoms
  • PASC associated cognitive outcomes

RESULTS:

• 1237 women
• Both log e-transformed leukocyte count (used to normalize data) and leukocyte count ≥5.5 × 1,000 cells/µL were associated with more severe PASC
  • Leukocyte count
    • β=0.27 (95% CI, 0.07 to 0.47) | P=0.009
  • Leukocyte count ≥5.5 × 1,000 cells/µL
    • β=0.13 (95% CI, 0.02 to 0.23) | P=0.02
• Leukocyte count was not associated with PASC occurrence or PASC-related cognitive outcomes
• Concentration of hsCRP was not associated with PASC outcomes but was underpowered due to only 27% of participants having this marker available for analysis

CONCLUSION:

• Higher leukocyte count is an inflammatory marker that is associated with more severe long COVID in postmenopausal women
• The authors state

Our study extends the evidence that low-grade inflammation is not only a correlate or an outcome of PASC severity, but also precedes the acute COVID-19 infection leading to this debilitating outcome, further supporting a role of inflammation in the etiology of PASC

Learn More – Primary Sources:

Pre-pandemic leukocyte count is associated with severity of post-acute sequelae of SARS-CoV-2 infection among older women in the Women’s Health Initiative