Visceral Leishmaniasis in Immunocompetent Hosts in Brescia: A Case Series and Analysis of Cytokine Cascade

Alice Mulè ¹, Verena Crosato ¹, Douglas Byron Kuhns ²

⁰Unit of Infectious and Tropical Diseases, Department of Clinical and Experimental Sciences, University of Brescia and ASST Spedali Civili di Brescia, 25123 Brescia, Italy.

Microorganisms +

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February 24, 2024

View abstract on PubMed

Summary

Three immunocompetent patients developed visceral leishmaniasis (VL) in Italy. Analysis revealed an imbalanced immune response, with T-helper-2 pathway activation, potentially explaining VL development in these individuals.

Area Of Science

Immunology
Parasitology
Infectious Diseases

Background

Visceral leishmaniasis (VL) is a neglected parasitic zoonosis typically affecting immunocompromised individuals.
VL is not endemic to Brescia, Italy, making three cases in immunocompetent patients in late 2021 unusual.

Observation

Three immunocompetent patients in Brescia, Italy, presented with human VL.
Epidemiological investigations in the region did not identify the source of infection.
Serum cytokine analysis was performed on patients during acute and recovery phases.

Findings

All patients showed elevated levels of CXCL-10, CCL-4, and IL-6.
During the acute phase, IL-1α, IL-5, IL-10, and IL-12 were elevated.
The recovery phase showed increased TNF-α and IL-7.
A predominant T-helper-2 pathway activation was observed during the acute phase, with less T-helper-1 pathway cytokine representation.

Implications

The findings suggest an imbalanced immune response, specifically a predominant T-helper-2 bias, may contribute to VL development in immunocompetent hosts.
This study highlights the potential for VL to occur in non-endemic areas and in immunocompetent individuals.
Understanding these immune dysregulations could inform future diagnostic and therapeutic strategies for VL.

Keywords:

Brescia IFN-γ Leishmania Th1 Th2 cytokines immunocompetent host neglected disease parasitic zoonosis visceral leishmaniasis