# Assessment of Systemic Inflammation as a Tool for Estimating the Risk of Death by Visceral Leishmaniasis

## TL;DR

This study shows that high levels of CRP and IL-6 in patients with visceral leishmaniasis are linked to a higher risk of death, helping to identify those needing urgent care.

## Contribution

The study introduces optimal cut-off values for CRP and IL-6 as prognostic tools in visceral leishmaniasis when used alongside the Kala-Cal® score.

## Key findings

- CRP and IL-6 levels were significantly elevated in patients with hemorrhage or fatal outcomes.
- CRP and IL-6 showed similar prognostic performance with AUCs of 0.85 and 0.87, respectively.
- Positive biomarker results in low-risk patients increased the probability of death.

## Abstract

Background: Visceral leishmaniasis (VL) is a life-threatening protozoan disease prevalent in tropical and subtropical regions and a frequent coinfection among people living with HIV. Early identification of patients at high risk of death may reduce case-fatality. This study evaluated the post-test prognostic value of C-reactive protein (CRP) and interleukin-6 (IL-6) as biomarkers of mortality in VL. Methods: A retrospective hospital-based cohort of 101 VL patients was analyzed. CRP and IL-6 concentrations at admission were correlated with clinical findings, the Kala-Cal® prognostic score, and in-hospital mortality. Results: Eight patients died, most presenting with hemorrhagic manifestations. At admission, 87.1% of patients had both biomarkers above the predefined cut-offs. CRP and IL-6 levels were markedly elevated in patients with hemorrhage or fatal outcomes. The AUC was 0.85 for CRP and 0.87 for IL-6, with no significant difference between markers. Optimal prognostic cut-offs were 150 mg/L for CRP and 90 pg/mL for IL-6. Conclusions: In this sample, CRP and IL-6 showed good prognostic performance in VL. In patients with low initial clinical risk, positive biomarker results substantially increased the probability of death. When combined with Kala-Cal®, these markers may improve risk stratification and guide referral decisions.