Weinberg Reaction

WEINBERG REACTION, proposed in 1906 by Ghedini for the recognition of echinococcal disease and developed by M. Weinberg (Paris, Pasteur Institute). This reaction is a specific case of the Bordet-Gengou complement fixation reaction (see Bordet-Gengou reaction). The high specificity of the Weinberg reaction, which yields only 18% negative results, has made it popular for the recognition of echinococcus. The reaction is based on the fact that antibodies to the anti-echinococcal antigen appear in the blood serum of a patient with echinococcus, which specifically bind to the latter in vitro. The complex formed by them with the antigen adsorbs the complement (alexin) of the serum. A positive complement fixation reaction indicates the presence of echinococcus in the organism. The reaction remains positive for several weeks after the removal of the echinococcus, which must be kept in mind, including in cases of recurrence. In this reaction, the quality of the antigen is of great importance. According to Weinberg, the fluid from echinococcal cysts of the liver or lungs of a sheep (worse—of a bull) possesses the best antigenic properties. The fluid collected from the cyst is used in the reaction in its entirety. The antigen remains active in a cold place (without antiseptic agents) for several years. Weinberg employs two methods of the reaction—the rapid and the slow. In the rapid method, the test serum of the patient is used active (without heating), without a hemolytic amboceptor and without complement, and the experiment is set up as follows: to 0.1 cubic cm of the test serum are added 0.1-0.2 cubic cm of echinococcal fluid and 0.1-0.3 cubic cm of physiological saline. The mixture is placed for 1 hour in a thermostat at 37°, after which a 5% emulsion of sheep erythrocytes is added, and the entire mixture is placed for half an hour at 37°. Since the amount of hemolysins in the investigated serum is indefinite, Weinberg recommends determining the hemolytic titer of the test serum in parallel with the experiment separately. This method is completely inapplicable with a negligible amount of hemolysins in the serum or a low content of complement. Therefore, the slow method has gained the greatest distribution, in which the serum is used inactivated and complement is added. Erythrocytes are added sensitized, with an accurate accounting of the serum's own hemolysins. The reaction is set up in the following manner: to 0.3 cubic cm of inactivated serum are added 0.2-0.8 cubic cm of echinococcal antigen and 0.1 cubic cm of complement (diluted by half) with 1.1-2 cubic cm of physiological saline. The mixture is placed in a thermostat at 37° for 1 hour, after which sensitized erythrocytes (1 cubic cm) are added, and the mixture is again placed in a thermostat at 37° for half an hour. The total volume of all ingredients must be equal to 3 cubic cm; in this method, too, Weinberg attaches great importance to the determination of the quantity of hemolytic amboceptors of the heated serum. For this, Weinberg titrates the heated serum, adding to 0.1 cubic cm of the latter 0.1-1 cubic cm of 5% emulsion of erythrocytes, 0.1 cubic cm of complement (diluted by half), and 0.1-1 cubic cm of physiological saline. The entire mixture is placed in a thermostat at 37° for 1 hour. In the main experiment, the hemolytic serum is introduced in such an amount as to account for its own hemolysins: the latter are subtracted from the quantity of introduced hemolysins. It is recommended to set up the reaction in parallel by both methods; in case of discrepancy, it is necessary to take other antigens.