#4229 SECONDARY BACTERIAL AND FUNGAL INFECTIONS IN COVID-19 PATIENTS WITH ACUTE KIDNEY INJURY AND RELATION WITH CYTOKINE STORM SYNDROME
Authors: Daniela Radulescu , David Cristiana , Cuiban Elena , Onofrei Simona-Daniela , Florina Feier Larisa , Turcu Flavia Liliana , Vacaroiu Ileana Adela 
Published: June 2023

Abstract

Background and Aims
Both COVID-19 and acute kidney injury (AKI) are associated with impaired host immunity. Virus-induced immunosuppression, overuse of antibiotics and corticosteroids are COVID-19 related factors, while dysregulation of the inflammatory response, increased volemia, hemodialysis catheters are AKI-related factors which favor secondary infections. We aimed to search the relation between markers of cytokine storm syndrome (interleukin-6 – IL-6; ferritin; C-reactive protein – CRP) and incidence of secondary infections and to identify the microorganisms involved in secondary infections in patients admitted with acute kidney injury and COVID-19 patients.

Method
Patients with both COVID-19 and AKI admitted in the 2nd and 3rd waves of the COVID-19 pandemic (May-December 2021) in an COVID-only hospital were included in this retrospective analysis. Diagnosis of AKI was established according to KDIGO creatinine-based criteria. Obstructive AKI cases were excluded. AKI was classified as A-AKI when it was diagnosed at the moment of admission and HA-AKI when it developed during hospitalization. Bacterial and/or fungal infections and the sites of positive cultures were registered in all patients. Colonizations with nonpathogenic microorganisms were excluded. Median values of IL-6, ferritin and CRP (maxim levels recorded during hospitalization) were compared between infected and non-infected patients.

Results
A total of 247 patients with AKI+COVID-19 were included in the study: 146 had A-AKI and 101 had HA-AKI. Secondary bacterial and fungal infections were registered in 111 patients (44.93%) cumulating 161 positive urine, blood, hemodialysis catheter tip, sputum, wounds, feces and tracheal intubation tubes cultures. Secondary infections were noted significantly more frequent in HA-AKI cases than in A-AKI cases: 61.38% (62 patients) vs 33.56% (49 patients) – Fischer exact test, p&lt;0.001. The responsible microorganisms and the sites of positive culture are presented in Table 1. Median values of IL-6, ferritin and CRP (maximum levels recorded during hospitalization) were significantly higher in infected patients than in non-infected patients (Table 2) in the entire study group. IL-6 was significantly higher in infected HA-AKI patients when compared with infected A-AKI (231.40 pg/mL vs 124 pg/mL; p = 0.015), but no significant difference was found between the two subgroups of infected AKI patients regarding median ferritin levels (2481.5 ng/mL vs 1785 ng/mL; p = 0.324) or regarding median CRP values (206.27 mg/L vs 179.59 mg/L; p = 0.546).

Conclusion
Incidence of secondary bacterial and/or fungal infections in patients admitted with AKI and COVID-19 was very high in our study and it was associated with more severe altered markers of cytokine storm syndrome. Secondary infections in COVID-19 patients are important drivers of hospital-acquired AKI or they can aggravate its evolution.