Studies of immunoglobulins, bentonite flocculation and IgE, IgG and IgM antibodies in serum from patients with trichinosis.

Serial serum samples were obtained from two patients from a family of four who ingested raw pork at a known time and in whom trichinosis developed. Single and occasionally two serum samples were obtained from other patients with proved trichinosis. Studies of these serum samples showed that elevations of serum immunoglobulin E (IgE) levels do occur but not in all serum samples and that even when these levels are elevated, they are not high enough to be of diagnostic value. This is also true for serum immunoglobulin M (IgM). Using a solid phase radioimmunoadsorbent test, IgE, IgG and IgM antibodies were detected in the serums. The IgE antibody activity appeared early but was not present in all samples. The IgM antibody activity appeared later than the IgE and IgG antibody activity, and there was a statistically significant correlation between IgM antibodies as determined by radioimmunoassay and the bentonite flocculation titers suggesting that the bentonite flocculation is due to IgM antibody. IgM antibodies detected by radioimmunoassay were positive in all serum samples from patients with trichinosis except for a sample obtained 3 days after the onset of symptoms. The early increase in IgG antibodies and the occurrence of these antibodies in all serum samples obtained more than 3 days after onset of symptoms suggest a potential diagnostic use if serial samples are available early in the course of the disease.