CELLULAR AND HUMORAL IMMUNE-RESPONSES OF HYDATIDOSIS PATIENTS TO ECHINOCOCCUS-GRANULOSUS PURIFIED ANTIGENS

The cellular and humoral immune responses of 41 hydatidosis patients, 12 healthy uninfected individuals, and seven patients with other paras itic diseases were determined using serologic and lymphoproliferative assays (LPAs), respectively. Echinococcal antigens were obtained by ge l filtration of crude hydatid cyst fluid (HCF) on a Sephadex G-200 col umn. The fractions contained either a mixture of antigens A plus B or antigen B alone that was further enriched by boiling. All the hydatido sis patients responded positively by LPA to either crude or purified e chinococcal antigens: 95% of them responded to either crude HCF, or a mixture of antigens A plus B and 83% to antigen B alone. The degree of the response to crude HCF (mean stimulation index [SI] = 75.3) was hi gher than that of purified antigens (SI = 39.1 for a mixture of antige ns A plus B and SE = 36.9 for antigen B alone). No positive LPA respon se was obtained with the control groups. Serologic examinations showed that 78% of cases were positive by immunoblot, 73% by indirect hemagg lutination, and 46% by immunoelectrophoresis. No correlation between t he degree of cellular and humoral responsiveness to both crude and pur ified echinococcal antigens was observed. Nine of the 41 patients exam ined who were serologically negative also developed a high lymphoproli ferative (LP) response to either crude or purified echinococcal antige ns. The LP response remained positive over a long period after success ful treatment. No relationship was observed between the results of tre atment and the LP response. The present study indicates that the LPA c ould be used as an additional tool for the diagnosis of hydatid diseas e, particularly in seronegative cases, although it is unsuitable for e ffective monitoring treatment/surgery.