Development and Clinical Use of Antilonomic Serum

Abstract

Contact of Lonomia obliqua caterpillars results in skin local inflammation and a bleeding syndrome characterized by hemorrhage and blood incoagulability. Conventional therapy was incapable of alleviating the symptoms. A process for manufacturing a specific antilonomic serum (SALon) by immunizing horses with Lonomia caterpillar bristle extracts (LBE) was developed. LBE exhibited several protein bands on SDS‐PAGE, produced blood incoagulability and lethality in mice, and induced specific antibody production in horses. Sera obtained from immunized horses were rich in specific anti‐LBE antigens antibodies evenly distributed among the horse IgG isotypes. These antibodies were endowed with the ability to recognize various LBE antigens as well as neutralizing their coagulopathy‐inducing activity. The antivenom manufactured according the process was composed of purified and sterilized F(ab′)2 with ED50 = 38.61 μl; potency = 0.29 mg/ml, and a confidence limit of 95% of 0.20–1.36. In a clinical trial SALon was a specific and effective therapeutic agent to treat victims with lonomism. In a single dose of five ampoules (50 ml) it reverts the clinical symptoms, the hemostatic disturbances, and the hemorrhages resulting from the contact of the victims with the L. obliqua caterpillars. One strake observation was the significant reduction in rates of mortality, mainly of envenomed children.