Sensitization-Associated Post-COVID-19 Symptoms at 6 Months Are Not Associated with Serological Biomarkers at Hospital Admission in COVID-19 Survivors: A Secondary Analysis of a Cohort Study

Individuals who survived coronavirus disease, 2019 (COVID-19), often have symptoms of sensitization, but the extent to which these symptoms relate to serological biomarkers remains unclear. Therefore, this secondary analysis evaluated the association between serological biomarkers at hospital admission with sensitization-associated post-COVID-19 symptoms in a sample of previously hospitalized COVID-19 survivors. Sixty-seven individuals hospitalized due to SARS-CoV-2 infection in one urban hospital of Madrid (Spain) during the first wave of the pandemic were assessed a mean of 6.0 (SD 0.8) months after hospital discharge. The Central Sensitization Inventory (CSI) was used as rough tool to estimate the presence of sensitization-associated post-COVID-19 symptoms (≥40/100 points). Levels of 16 serological biomarkers collected at hospital admission were obtained from medical records. Twenty-four (35.8%) patients reported sensitization-associated post-COVID-19 symptoms (CSI ≥ 40 points). Subjects reporting sensitization-associated symptoms had lower ferritin and hemoglobin levels than those not reporting sensitization-associated post-COVID-19 symptoms; however, these differences were small. We observed significant but small negative associations of the CSI score with ferritin (r: -0.251, p = 0.04) and hemoglobin (r: -0.292, p = 0.017) levels. No other significant difference was found. In conclusion, this secondary analysis did not find significant associations between the investigated serological biomarkers at hospital admission and sensitization-associated post-COVID-19 symptoms at 6 months after hospitalization in COVID-19 survivors.