Serum ferritin as a predictive marker of pulmonary fibrosis in post-COVID-19

Abstract

Background: Pulmonary fibrosis is characterized by excessive matrix formation, which destroys typical lung architecture and increases the chances of comorbidity. It is essential to look into potential serum indicators for the early identification of individuals who may develop such severe fibrotic consequences since there is currently no specific marker for the early diagnosis of post-COVID-19 pulmonary fibrosis. The study is aimed at examining potential serum markers that could be used for early detection of pulmonary fibrosis in patients with COVID-19.

Methods: It is a cross-sectional retrospective observational study that included male (n = 26) and female (n = 10) patients who were confirmed positive for COVID-19 using the Reverse transcription polymerase chain reaction (RTPCR) test. Various hematological parameters, such as platelet count, white blood cell count (WBC count), platelet-to-lymphocyte ratio (PLR), white blood cell count to mean platelet volume ratio (WMR), red cell distribution width (RDW), plateletcrit (PCT), mean platelet volume (MPV), platelet distribution width (PDW), serum ferritin level, and CT severity scores (CT-SSs) were recorded. The association between hematological parameters, serum ferritin level, and CT-SS was assessed by the Pearson correlation test using the GraphPad Prism software (version 10). p < 0.05 was considered statistically significant.

Results: The descriptive analysis revealed no significant correlation between platelet count (r = 0.1610, p = 0.3483), WBC count (r = -0.1381, p = 0.4217), PLR (r = 0.2262, p = 0.1847), WMR (r = -0.1093, p = 0.5258), RDW (r = 0.05982, p = 0.7289), PCT (r = -0.059, p = 0.752), MPV (r = 0.046, p = 0.788), and PDW (r = -0.06, p = 0.699) with CT-SS. However, a significant positive correlation was observed between CT-SS and serum ferritin levels in COVID-19 patients (r = 0.5452, p = 0.0006).

Conclusions: As there was a significant positive correlation between serum ferritin level and CT-SS, the serum ferritin level could be considered as a simple and cost-effective biomarker for predicting the development of lung fibrosis in long COVID-19 conditions after controlling the confounders.

Keywords: COVID-19; CT severity score; Ferritin; Platelet Distribution Width; Plateletcrit; Red cell Distribution Width.

Figure 1

Demographic features of recruited patients. (A) indicates the gender-wise distribution of patients. (B) indicates the number of patients based on the severity of COVID-19. (C) indicates the number of patients based on the past history of comorbidities. (D) indicates the number of patients based on the age-wise distribution of patients.

Figure 2

Correlation of CT-SS (CO-RADS) with platelet count in COVID-19 patients, r = 0.1610, p = 0.3483 (A), and WBC count, r = −0.1381, p = 0.4217 (B). The correlation is insignificant.

Figure 3

Correlation of CT-SS (CO-RADS) with PLR in COVID-19 patients, r = 0.2262, p = 0.1847 (A), and WMR, r = −0.1093, p = 0.5258 (B). The correlation is insignificant.

Figure 4

Correlation of CT-SS (CO-RADS) with RDW in COVID-19 patients, r = 0.05982, p = 0.7289 (A), and PCT, r = −0.059, p = 0.752 (B). The correlation is insignificant.

Figure 5

Correlation of CT-SS (CO-RADS) with MPV in COVID-19 patients, r = 0.046, p = 0.788 (A), and PDW, r = −0.06, p = 0.699 (B). The correlation is insignificant.

Figure 6

Correlation of CT-SS (CO-RADS) with serum ferritin level in COVID-19 patients, r = 0.5452, p = 0.0006. There is a significant positive correlation between ferritin level and CT severity score.

Figure 7

Representative images of axial high-resolution chest CT of the mild, moderate, and severe conditions of a diagnosed COVID-19 patient with CO-RAD 6 (A) indicates the axial HRCT showing bilateral fibrotic bands (red arrowheads) with predominantly peripheral distribution with a CT-SS of 6/25 (mild). (B) indicates the axial HRCT showing consolidations in both the lung fields (yellow arrows) and fibrotic bands (red arrowheads) with predominantly peripheral distribution with a CT-SS of 15/25 (moderate). (C) indicates axial HRCT showing bilateral patchy ground glass opacities (yellow arrowheads) with predominantly peripheral and peribronchovascular distribution with a CT-SS of 21/25 (severe).