THE ALLERGENIC PROPERTIES OF FRESH AND PRESERVED HEVEA-BRASILIENSIS LATEX PROTEIN PREPARATIONS

The allergenic properties of the proteins of two lyophilized fractions of fresh natural rubber latex obtained by ultracentrifugation, the C serum and the sedimented bottom or lutoid fraction, have been compared with those of the serum proteins of two samples of high ammonia latex (HAL), [A]HALS obtained from HAL stored for more than 1 year, and [IM ]HALS derived from HAL stored for 6 weeks before ultracentrifugation a nd lyophilization. The most potent source of allergenic polypeptides b oth for skin prick testing of latex-sensitive patients and for immunob lots of their blood serum was the lutoid fraction of fresh latex. Skin prick tests and immunoblots of patients' sera showed that the allerge nicity of the ammoniated latex decreased during storage. Skin prick te sts using fractions of [A]HALS, C serum and lutoid proteins obtained a fter passage through a Sephacryl S300 column showed that the component s of all three preparations which eluted in the largest volumes were a lmost equally effective in provoking the largest number of responses. Immunoblots of the sera of 43 latex-sensitive individuals showed that the majority (66%) of sera of the adult allergic patients reacted with a polypeptide of 19 kD. No characteristic pattern of binding latex po lypeptides could be recognized in the sera from patients who were also asthmatic or from those who had had an anaphylactic response to latex proteins.