Study of specific IgG subclass antibodies for diagnosis of Gnathostoma spinigerum.

ABSTRACT

Gnathostoma spinigerum infection is endemic in Thailand and many Asian countries. Current diagnosis is the skin test and enzyme-linked immunosorbent assay (ELISA) for IgG antibody against the G. spinigerum third-stage larvae (L3), but cross-reactivity is common. We evaluated the sensitivity and specificity of anti-G. spinigerum L3 IgG subclass antibodies for diagnosis of 43 patients with gnathostomiasis. The majority of patients with gnathostomiasis (91%) had eosinophilia. While the anti-G. spinigerum L3 IgG1 antibody provided the highest sensitivity (98%), the anti-G. spinigerum L3 IgG2 antibody had the highest specificity (88%). The ELISA that detected anti-G. spinigerum L3 IgG1 antibody could be a reliable laboratory screening test, while anti-G. spinigerum L3 IgG2 antibody could be used to confirm the diagnosis.