Variable degree of alternative complement pathway-mediated hemolysis in Indian visceral leishmaniasis induced by differential expression of 9-O-acetylated sialoglycans.

Abstract

BACKGROUND:

Increased expression of linkage-specific 9-O-acetylated sialoglycans (9-O-AcSGs) has been demonstrated on erythrocytes from patients with visceral leishmaniasis (VL) by use of Achatinin-H. We assessed the capacity of this glycotope to influence hemolysis via activation of the alternative complement pathway in patients with VL, compared with that in healthy control subjects.

METHODS:

The differential expression of 9-O-AcSGs on surfaces of erythrocytes was measured, 9-O-AcSGs were affinity purified, and the molecular determinants were identified by Western blotting. The degree of alternative complement pathway-mediated hemolysis was compared with expression of 9-O-AcSGs on erythrocytes.

RESULTS:

Enhanced expression of linkage-specific 9-O-AcSGs was demonstrated on erythrocytes from patients with active VL. Six distinct molecular determinants present only on diseased erythrocytes were affinity purified and were absent after elimination of parasite burden. A correlation (r2=0.9) was observed between the presence of 9-O-AcSGs and the degree of alternative complement pathway-mediated hemolysis.

CONCLUSION:

The 9-O-AcSGs expressed on erythrocytes from patients with VL are potent complement activators, causing enhanced hemolysis via activation of the alternative complement pathway, and may account for the anemia that is a common manifestation of VL.

• Authors: Anil Kumar Chava, Mitali Chatterjee, Vineeta Sharma, Shyam Sundar, Chitra Mandal
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 189 Issue 7 Pg. 1257-64 (Apr 01 2004) ISSN: 0022-1899 [Print] United States
• PMID: 15031795 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Lectins
• Polysaccharides
• Sialic Acids
• achatinin(H)
• 9-O-acetyl-N-acetylneuraminic acid

Topics

• Adolescent
• Adult
• Animals
• Blotting, Western
• Child
• Child, Preschool
• Complement Pathway, Alternative (immunology)
• Erythrocytes (immunology, metabolism, parasitology)
• Female
• Flow Cytometry
• Hemolysis (immunology)
• Humans
• India
• Lectins (immunology)
• Leishmania (immunology)
• Leishmaniasis, Visceral (blood, immunology)
• Male
• Middle Aged
• Polysaccharides (immunology)
• Sialic Acids (biosynthesis, blood, immunology)