Evaluation of the Relationship between CRP/Albumin Ratio and Pulmonary Function Parameters in Patients with Post-Acute COVID-19

Background: Novel coronavirus disease 2019 (COVID-19), which has been a global pandemic for nearly 2 years, presents with highly variable clinical manifestations in both the acute and post-acute periods. This study evaluat-ed the relationship between CRP/albumin ratio and pulmonary function at 12 weeks in patients with post-acute COVID-19. Methods: The study included 157 patients with a previous diagnosis of COVID-19 pneumonia who presented to our outpatient clinic with symptoms of post-acute COVID-19 (12 weeks after first testing positive) between July 2021 and October 2021. Patients who had non-severe pneumonia were included in group 1, severe pneumonia that did not require intensive care in group 2, and severe pneumonia that required intensive care in group 3. Results: At 12 weeks, group 3 had significantly lower percent predicted forced expiratory volume in 1 second (FEV1%), percent predicted forced vital capacity (FVC%), percent predicted diffusing capacity of the lungs for carbon monoxide (DLCO%), and oxygen saturation (SO2) compared to patients in groups 1 and 2 (p = 0.001, 0.04, 0.001, and 0.001, respectively). CRP/albumin ratio was significantly lower in group 2 compared to groups 1 and 3 (p = 0.001). Correlation analysis independent of age and comorbidity showed that CRP/albumin ratio was nega-tively correlated with SO2, FEV1%, FVC%, and DLCO%. Conclusions: CRP and albumin levels have prognostic significance during acute COVID-19 infection. The nega-tive correlation between CRP/albumin ratio and respiratory function observed in our study suggest this parame-ter may be used in the follow-up of patients presenting at 12 weeks with post-acute COVID-19 symptoms. (Clin. Lab. 2022;68:xx-xx. DOI: 10.7754/Clin.Lab.2021.211102)