Is Serum Ferritin an Early Marker for COVID-19-Associated Mucormycosis?

Abstract

Background Coronavirus disease 2019 (COVID-19) is a hyperinflammatory disease caused by severe acute respiratory syndrome coronavirus 2, which makes critically ill patients susceptible to invasive fungal infections. Invasive fungal infections such as mucormycosis are associated with high morbidity and mortality. This study aimed to determine the serum ferritin levels in COVID-19-associated mucormycosis (CAM) patients and isolate and identify the fungi causing secondary fungal infections in patients with suspected CAM. Methodology This cross-sectional study was conducted from June to September 2021 among CAM patients admitted to Bowring and Lady Curzon Hospital. After obtaining approval from the institutional ethics committee and valid consent, data regarding demographic details, past medical history, and serum ferritin levels, along with other blood investigations, were carefully collected from patients presenting with clinical features of mucormycosis and a history of COVID-19. Samples were examined under a bright field microscope using wet mounts of samples in KOH, cultured on Sabouraud's dextrose agar, and examined under a microscope after staining with lactophenol cotton blue for the isolation and correct identification of fungi. Statistical analysis was done using Microsoft Excel (Microsoft Corp., Seattle, WA, USA) and SPSS version 26.0 (IBM Corp., Armonk, NY, USA). A p-value less than <0.05 was considered statistically significant. Results A total of 95 patients with CAM were included in this study, comprising 70 males and 25 females. The mean age of presentation was 49.83 ± 12.41 years, with 73% males and 26% females. Type 2 diabetes mellitus was noted in 69% of patients, hypertension in 29%, and steroid use in 42%. The mean serum ferritin level was 537.38 ± 468.88 ng/mL. We found a significant association between increased serum ferritin and a history of diabetes. Serum ferritin levels had a statistically significant correlation with samples of patients who were positive for Mucorales under KOH microscopy. The fungal culture showed the growth of Aspergillus, Mucor, Rhizopus, and Candida. The mean value of serum ferritin in patients who showed mucor growth was 842.09 ng/mL. Conclusions We found a significant increase in serum ferritin levels in CAM patients. Ferritin can be used as an early marker for screening mucormycosis in COVID-19 patients. Monitoring patients with elevated serum ferritin levels in severe COVID-19, glycemic control, judicious use of corticosteroids, early diagnosis, and appropriate treatment can aid in better management of the disease.

Keywords: covid-19; fungal culture; mucorales; mucormycosis; serum ferritin.

Figure 1. Mean serum ferritin in patients with diabetes mellitus and a history of steroid use.

Figure 2. Serum ferritin levels in different age groups.

Figure 3. Mucor growth on Sabouraud’s dextrose agar.

Figure 4. Fungal culture growth.