Serum Uromodulin Could Indicate Acute Kidney Injury in COVID-19 Patients

Acute kidney injury (AKI) is a common complication in COVID-19 patients, contributing to a higher risk of mortality. Early detection of kidney-related issues in COVID-19 cases is crucial for improving patient outcomes. Traditional markers of kidney function, such as creatinine and cystatin C, often lack the specificity and sensitivity needed for accurate diagnosis. These markers can be influenced by factors like muscle mass, sex, nutrition, and other variables, while the estimated glomerular filtration rate (eGFR) can vary based on the method used. Now, a new study suggests that serum uromodulin (sUmod) could serve as a promising biomarker for diagnosing AKI in COVID-19 patients.

The study conducted by EUROIMMUN (Lübeck, Germany), St George Hospital (Leipzig, Germany), and various other research institutes, has found that sUmod may overcome the limitations of traditional kidney function markers. Uromodulin, a glycoprotein produced exclusively in the kidneys, is directly linked to kidney function. Compared to creatinine and cystatin C, sUmod offers greater sensitivity, allowing for earlier detection of kidney injury. The study analyzed the relationship between sUmod levels and AKI, as well as in-hospital mortality, in a cohort of 378 COVID-19 patients, including subsets with various comorbidities. AKI was diagnosed using standard laboratory parameters and sUmod, with serum uromodulin levels measured through a sensitive ELISA technique based on monoclonal antibodies, which is CE-marked for serum analysis (EUROIMMUN). Out of the 378 patients, 151 (40%) developed AKI, with 116 of these patients showing AKI at hospital admission, and 35 developing it during their stay.

The study revealed that patients with AKI had significantly lower mean sUmod levels (125 ng/ml) compared to those without AKI (215 ng/ml). Additionally, there was a strong correlation between sUmod and other AKI markers, such as serum creatinine and cystatin C. AKI patients had a higher probability of in-hospital death, with a mortality rate of 15%. Among those who died, the mean sUmod levels were significantly lower (129 ng/ml) compared to survivors (188 ng/ml). This study, published in Scientific Reports, further emphasizes the association between AKI and in-hospital death in COVID-19 patients and underscores the importance of early detection and management of AKI. The stable nature of sUmod and its analytical advantages over traditional kidney markers make it a promising candidate for clinical use. Further research is needed to explore its full clinical potential and improve risk stratification in this patient group.