Estimation of Serum Levels of Heavy Metals in Patients with Chronic Invasive Fungal Rhinosinusitis Before the COVID-19 Era: A Pilot Study.

Objective: Various metals play role in the survival and pathogenesis of the invasive fungal disease. The objectives of this study were to compare the levels of heavy metals in patients with chronic invasive fungal rhinosinusitis (CIFR) and healthy controls, and to analyze their role in disease outcome.

Methods: Twenty-three patients (15 with invasive mucormycosis and 8 with invasive aspergillosis, Group 1), and 14 healthy controls (Group 2) were recruited. Blood samples were collected from each group into ion-free tubes and analyzed for serum levels of Nickel (Ni), Copper (Cu), Zinc (Zn), Gallium (Ga), Arsenic (As), Selenium (Se), Rubidium (Rb), Strontium (Sr), Cadmium (Cd), and Lead (Pb). The final outcome of the patients during their hospital stay was categorized clinico-radiologically as improved or worsened, or death.

Results: The levels of all metals were higher in Group 1 except for As and Pb. However, the differences in Cu (p=0.0026), Ga (p=0.002), Cd (p=0.0027), and Pb (p=0.0075) levels were significant. Higher levels of Zn (p=0.009), Se (p=0.020), and Rb (p=0.016) were seen in the invasive aspergillosis subgroup. Although Zn (p=0.035), As (p=0.022), and Sr (p=0.002) levels were higher in patients with improved outcome, subgroup analysis showed no differences.

Conclusion: The levels of some heavy metals in CIFR significantly differ from those of the general population and also vary with the type of the disease and its outcome. These levels may not have a direct effect on the outcome of the patient, but they do play a role in the pathogenesis of the invading fungus.