Immune Responses in Post Kala-azar Dermal Leishmaniasis

Area of Science:

• Immunology
• Tropical Diseases
• Dermatology

Background:

• Visceral leishmaniasis (VL) elimination efforts in South Asia highlight the importance of Post Kala-azar Dermal Leishmaniasis (PKDL).
• PKDL is a skin manifestation following VL treatment, presenting as macular or polymorphic lesions.
• Understanding PKDL pathophysiology is vital for effective elimination strategies and treatment.

Purpose of the Study:

• To review and interpret existing literature on PKDL in Asia and Africa.
• To establish a potential correlation between immune responses and PKDL pathophysiology.
• To update the understanding of PKDL immunopathology for improved host-parasite interaction insights.

Main Methods:

• Literature review focusing on PKDL in Asian and African regions.
• Interpretation of histopathological findings in PKDL.
• Analysis of immune cell infiltrates and their expression levels.

Main Results:

• Histopathology reveals dense inflammatory infiltrates in PKDL lesions.
• Increased expression of alternatively activated CD68+ macrophages and CD20+ B cells observed.
• CD8+ T cells show exhaustion features, and CD1a+ dendritic cells are decreased.

Conclusions:

• The immunopathology of PKDL involves specific immune cell dysregulation.
• Insights into host-parasite interactions can be gained from studying these immune responses.
• Identifying markers for disease progression and treatment improvement is a potential outcome.