Human giardiasis as an etiology of skin allergy: the role of adhesion molecules and interleukin-6.

The role of adhesion molecules; the intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) as mediators in development of skin allergy caused by giardiasis and the controlling role of the cytokine interleukin (IL)-6 over these adhesion molecules were studied. The work included 25 symptomatic giardiasis patients with skin allergy manifested by diffuse urticaria, pruritus, wheal and erythema, and had positive serum anti-Giardia immunoglobulin (Ig) E measured as mean optical density (OD) value by enzyme linked immunosorbent assay (ELISA), employed as an evidence of allergic sensitization (G.I). They were compared with 30 symptomatic giardiasis patients (G.II) and 20 apparently healthy control subjects (G.III), both latter groups had negative serum anti-Giardia IgE. The mean OD value of anti-Giardia IgE was significantly increased in G.I (P < 0.01) & insignificantly different in GIII (P > 0.05) compared with G.III. Serum levels of soluble forms of adhesion molecules; sICAM-1 & sVCAM-1, and IL-6 were determined by ELISA. sICAM-1 & sVCAM-1 serum levels were significantly increased (P < 0.001) in G.I compared with G.III and showed insignificant difference (P > 0.05) between Gs. II & III. Serum IL-6 significantly increased in G.I (P < 0.001) & G.II (P < 0.05) compared with G.III, and was significantly higher (P < 0.001) in G.I than G.II. Serum IL-6 correlated positively with serum sICAM-1 (P < 0.01) and sVCAM-1 (P < 0.001) in G.I. The results are discussed.