Staphylococcal Protein A column: correlation of mitogenicity of perfused plasma with clinical response.

Eleven patients with advanced breast cancer and four with astrocytoma were treated with plasma perfused over columns containing staphylococcal Protein A (SPA). Doses of 5 to 20 mg of SPA were bound to collodion charcoal particles, and this treatment resulted in partial remissions in one patient with astrocytoma and in two patients with breast cancer. Remission duration was 6 wk to 6 mo. Resolution of lymphadenopathy and a decrease in carcinoembryonic antigen were noted in an additional two breast cancer patients. Systemic reactions to infused plasma consisted of fever, chills, and rigors. In brain cancer patients, increased intracranial pressure was also noted. A mitogenic substance was generated in plasma of 11 patients after it was perfused over the SPA charcoal matrix. The mitogenic material induced lymphoproliferation comparable to concanavalin A and required the presence of SPA on the collodion charcoal but was not due to leakage of SPA from the column during plasma perfusion. Of considerable significance was that only patients whose column perfused plasma contained this mitogenic activity exhibited systemic reactions, and five of these patients obtained antitumor responses. This striking correlation implies that the mitogenic factor is an active component of SPA therapy. The ability to demonstrate mitogenicity in column perfused plasma might also be useful for selecting patients amenable to SPA therapy. These findings attest to the therapeutic value of this mode of treatment and provide an initial definition of a mediator of SPA antitumor activity.