|Adhesion Molecules In Human Schistosomiasis:
I. Adhesion molecules correlate with protection against Schistosoma
|Maklad SS; Mobdy HR; El-Refaei MM; 1Galal N; 2Phillips
SM and El-Sheikh N.
|Microbiology Department, Faculty of Medicine For Girls, Al-Azhar University;
1Institute of Tropical Medicine, and 2Allergy and
Immunology Division, University of Pennsylvania, USA.
The present study addresses the relationship between expression of adhesion
molecules and resistance to reinfection with Schistosomiasis mansoni. Fifty
six children and adolescence from Monofia Governorate were studied. Twenty
of them were susceptible to reinfection and 36 resistant. Expression of
ICAM-1, LFA-1, MAC-1 and L-Selectin by in vitro granuloma cells (IVGCs)
and peripheral blood mononuclear cells (PBMCs) were assessed using image
analyzer. Significant expression was observed when IVGCs were cultured
with soluble egg antigen (SEA) coated as compared to uncoated beads (P
< 0.01). The frequency % (mean + SEM) of ICAM-1, LFA-1 and MAC-1 positive
IVGCs was significantly higher in resistant (10.7 ± 1.2, 11.3 ±
1.1 and 13.2 ± 1.4) than susceptible (6.1 ± 1.2 ±
6.2 ± 1.8 and 3.4 ± 0.7) groups of patients respectively.
The basal expression by PBMCs was also significantly higher among resistant
(13.5±1.7, 15.7±2.2, and 17.7±1.9) than susceptible
(4.8±0.8, 4.5±0.6 and 4.6±0.7) groups respectively.
In contrast, L-selectin expression by PBMCs showed no significant difference
between the two groups of patients. Analysis of the intensity of expression
(unit area/cell) also revealed no significant difference in the expression
of the four molecules between the two groups of patients. Clinical and
sonographic studies revealed significant decrease in LFA-1 expression by
IVGCs in patients with organomegally (P < 0.05). Correlation studies
revealed no significant correlation between granuloma index (GI) and ICAM-1
and LFA-1 (r = 0.281 and r = 0.031 respectively). In conclusion the study
emphasizes the role of adhesion molecules in human Schistosomiasis and
suggests that an adhesion molecule mediated mechanism is probably operating
in concomitant immunity and resistance to reinfection.