# Prognostic value of a new computed tomography severity score in hemorrhagic fever with renal syndrome

## TL;DR

A new CT severity score for HFRS correlates with disease severity and outcomes like kidney failure, offering a useful tool for predicting prognosis.

## Contribution

A novel CT severity score for HFRS is developed and validated for its prognostic value.

## Key findings

- The CT severity score strongly correlates with inflammation markers, thrombocytopenia, and proteinuria.
- Higher CT scores are associated with increased odds of requiring renal replacement therapy.
- The score has an 81.9% accuracy in predicting the need for renal replacement therapy.

## Abstract

To develop of a novel computed tomography (CT) severity score for hemorrhagic fever with renal syndrome (HFRS) and evaluate its correlation with disease severity and adverse outcomes.

This retrospective study included 37 patients diagnosed with HFRS from January 2012 to December 2023 who had available clinical laboratory and abdominal CT data during the acute phase. The CT severity score (range 0–5) was based on perirenal fat stranding, pararenal fascia thickening, anterior pararenal space fat stranding, ascites, and pleural effusion. Correlations between the score and markers of inflammation, thrombocytopenia, proteinuria, and adverse outcomes—including nephrotic range proteinuria and renal replacement therapy (RRT)—were analyzed.

The CT severity score exhibited moderate to strong correlations with markers of inflammation (white blood cell count, ρ = 0.65, p < 0.001), thrombocytopenia (platelet count, ρ = -0.54, p < 0.001), and proteinuria (urine protein-to-creatinine ratio, ρ = 0.56, p < 0.001). Higher scores were associated with increased nephrotic range proteinuria in Chi-squared test for trend (p-for-trend = 0.001). A one-point increase in the score significantly increased odds of requiring RRT in logistic regression analysis (odds ratio: 9.89, p = 0.047). The score achieved an area under the receiver operating characteristics curve of 0.819 for predicting RRT.

The CT severity score correlates well with disease severity and adverse outcomes in HFRS and can be assessed using noncontrast CT, making it a valuable prognostic tool in young male population. Further validation in diverse populations is warranted.

The online version contains supplementary material available at 10.1007/s10140-025-02322-9.