Serum isotype responses in patients infected with Strongyloides stercoralis following treatment with ivermectin - abstract

ABSTRACT

Infections with Strongyloides stercoralis occur worldwide and can cause significant morbidity and mortality in man. They are often refractory to conventional chemotherapy especially in immunocompromised individuals. Recent studies have shown that Ivermectin is a safe and effective drug for use in uncomplicated infections. In this study, the profiles of parasite-specific IgG1, IgG4, IgE and IgA against a PBS soluble S. stercoralis filariform extract following treatment with ivermectin were investigated using the enzyme-linked immunosorbant assay (ELISA) technique. A series of 8 patients with parasitologically proven strongyloidiasis were treated with ivermectin and followed up for periods of 5 to 18 months. The predominant isotype found in the sera of patients from this series was IgG. High levels of IgG1 were recorded in young individuals while IgG4 was predominant in older persons. Levels of all isotypes declined following treatment and remained low up to eighteen months. Furthermore, no parasitological evidence of S. stercoralis infection was found after treatment, using agar plate and formalin-ether concentration methods. The reduction in antibody levels of post-treatment may be used as an indicator of adequate treatment and also demonstrate that patients are not exposed to drug-induced antigens following treatment. The study of S. stercoralis specific isotype profile will be useful in immuno-epidemiological studies in communities (AU)