Major Vault Protein/Lung Resistance-Related Protein: A Novel Biomarker for Inflammation and Acute Infections

Introduction: Vault particles are large cytoplasmic ribonucleoprotein particles that participate in inflammation. The aim of this study was to assess the diagnostic and prognostic value of major vault protein (MVP) in patients with inflammation, in order to determine whether MVP could be used as a biomarker for infection or inflammation. We also aimed to compare the diagnostic impact of MVP compared to other conventional measurements, such as CRP or white blood cell (WBC) counts. Methods: CRP and MVP levels were measured in 111 sera samples from 85 patients with inflammation admitted to a tertiary-care hospital and 26 healthy individuals during an 18-month period (2019–2020), using nephelometry and a custom MVP sandwich ELISA assay, respectively. In addition, WBC counts were measured using a commercial assay. Results: MVP levels were found to be elevated in patients with inflammation compared to healthy individuals (p < 0.0001). Moreover, MVP levels were higher in patients with inflammation due to an infectious etiology compared to those with non-infectious etiology (p = 0.0006). MVP levels significantly decreased during the first four days of infection in response to antibiotic treatment, while CRP levels showed a less-sensitive decline. An ROC curve analysis demonstrated that MVP and CRP have similarly high diagnostic accuracy, with AUCs of 0.955 and 0.995, respectively, followed by WBCs with an AUC of 0.805. Conclusions: The ROC curves demonstrated that MVP has the potential to serve as a diagnostic biomarker for inflammation and infection. Additionally, MVP levels may reflect the efficacy of antibiotic treatment.