Human humoral immune response to Dirofilaria species.

Dirofilaria immitis and D. repens, the agents of human pulmonary and subcutaneous dirofilariosis respectively, may coexist in areas of Southern Europe, and L3 and L4 of both species develop in subcutaneous tissue. Previous studies have shown that humans develop high levels of specific IgM, IgG and IgE anti-D. immitis. An antigen of approximately 22 kDa (Di22) is a marker of pulmonary dirofilariosis. In this work, we demonstrate that D. repens also induces IgG in infected humans. Polypeptides between 40 and 26 kDa from adult somatic antigenic complex of the later species, are specifically recognized by sera from individuals with subcutaneous dirofilariosis due to D. repens. These findings complement the previous studies on specific antigens for the serological diagnosis of pulmonary dirofilariosis.