Different cell death mechanisms are involved in leprosy pathogenesis

Area of Science:

• Immunology
• Cell Biology
• Dermatology

Background:

• Leprosy is a chronic granulomatous disease with diverse clinical presentations.
• The relationship between cell death and leprosy outcomes is not fully understood.
• Investigating cell death mechanisms is crucial for understanding disease progression.

Purpose of the Study:

• To investigate autophagy and cell death pathways (apoptosis, necroptosis, pyroptosis) in leprosy skin lesions.
• To determine the role of these mechanisms in the clinical progression of different leprosy forms.
• To correlate cell death markers with leprosy classifications (lepromatous, tuberculoid, indeterminate).

Main Methods:

• Cross-sectional analytical study of 30 leprosy patients (10 LL, 10 TT, 10 II).
• Histopathological analysis of skin biopsies using H&E staining.
• Immunostaining for apoptotic (FasL, caspase 3, BAX) and necroptotic (caspase 8, RIP1, RIP3, MLKL) markers.
• Analysis of autophagy marker (Beclin-1) and pyroptosis marker (caspase 1).

Main Results:

• FasL, caspase 8, RIP1, RIP3, MLKL, BAX, and caspase 3 expression were highest in the lepromatous (LL) form.
• Beclin-1 expression was highest in the tuberculoid (TT) form and low in LL and indeterminate (II) forms.
• Caspase 1 expression was highest in LL, followed by TT and II forms.

Conclusions:

• Different cell death mechanisms are implicated in the pathophysiology of various leprosy forms.
• Apoptosis, necroptosis, and pyroptosis play significant roles, particularly in lepromatous leprosy.
• Findings suggest potential therapeutic targets for controlling host response and disease progression in leprosy.