The relationship of the possible allergic response to jellyfish envenomation and serum antibody titers.

The sera of patients envenomated by the sea nettle (Chrysaora quinquecirrha) or the Portuguese man-o'war (Physalia physalis) were investigated for immune specific and cross-reacting antibodies. Crude or partially purified (SP-Sephadex column chromatography) nematocyst venom was used as antigen in an enzyme-linked immunosorbent assay (ELISA) designed to detect IgG and IgE antibodies. The sera of 66 patients who exhibited strictly cutaneous, extracutaneous or anaphylactoid reactions to envenomation were studied. Most of the subjects developed an IgG antibody and many developed an IgE antibody to the venom of the offending animal. The titer of both immunoglobulins correlated directly with the severity of symptoms. Cross-reacting antibodies to these two jellyfish were apparent in a significant number of patients, but detectable cross-reacting IgE antibodies were rare in patients severely stung by the sea nettle. The titer of specific IgG antibody was higher against the partially purified lethal sea nettle venom than fractions lacking lethal activity. These results may support the hypothesis that some of the visible response to jellyfish envenomation may be allergic in nature and that cross-reactivity to these venoms may be clinically important.