DIAGNOSIS OF HEREDITARY SYPHILIS We have learned to recognize the great diagnostic value of the Rontgen ray examination of the long bones in fcetal syphilis, since Wegner's osteochondritis can easily be recognized, provided the foetus belongs to the second half of pregnancy.
Wassermann described a biologic test for the diagnosis of syphilis in 190G which is now considered one of the most important diagnostic aids in the detection of this disease. The Wassermann reaction is of great importance in the diagnosis of hereditary syphilis, latent syphilis in children and for syphilitic nerve disorders. The reaction depends on the following biologic principles: When a solution of the red blood corpuscles is mixed with the serum of an immunized animal the hasmo &bin is set free and the solution becomes pink in color. This is termed hmmolysis, and depends on the action of two distinct serum factors. One is termed a mboceptor. This can be produced in the serum of animals by means of repeated injections of foreign cells. The amboceptor is characterized by its specificity. The other is termed complement and is always present in fresh serum but disappears gradually on standing or is destroyed by heating at 56° C. If red cells are added to a serum con taining only amboceptor they absorb the amboceptor and retain it firmly. Such cells are said to have been sensitized. If complement is added to sensitized cells they promptly dissolve. The substances em ployed in producing antibodies are called antigens.
Wassermann uses extracts of syphilitic tissues in the active stage of the disease for the antigen. The serum of known syphilitics inactivated at 56° C. is used as antibody. When these are mixed. the complement is fixed and prevented from taking part in a subsequent haemolytic reaction. When serum of unknown origin is mixed with extracts of syphilitic tissues and if the complement is fixed, it can be stated that the unknown scrum contains the syphilitic antibody.
Noguchi simplified the technique for this test and his method is now in general use. The following apparatus will be needed: Several pipettes
of 1 c.c. capacity graduated to 0.01 c.c, two 10 c.c. pipettes graduated to 0.1 c.c., several 1 c.c. pipettes graduated to 0.01 c.c., small test tubes, flasks as containers of physiological salt solution and thin glass tubing for making capillary pipettes.
The necessary reagents are as follows: The complement is obtained from the blood serum of guinea-pigs. The serum must be fresh and kept in the refrigerator. The amboceptor is prepared from the blood serum of rabbit.s which have been injected with human blood cor puscles.
The antigen is an alcoholic extract of certain tissues such as heart, liver or kidney. It makes little difference whether the extract is derived from syphilitic or non-syphilitic organs. A corpuscle suspension can be prepared with the blood of the patient being examined. The corpuscles are washed with normal saline solution by centrifugaliza tion. The corpuscles are resuspended in normal salt solution, the standard amount for a test being 1 c.c. of a 1 per cent. solution of cor puscles.
To apply the test one drop from a capillary pipette (0.02 c.c.) of the scrum to be tested is placed in each of two small test tubes. The tubes should be placed in two rows and two sets of controls should be made, one using positive syphilitic serum, the other normal serum. To each of these tubes add two units of fresh complement and 1 c.c. of the 1 per cent. corpuscle suspension. Antigen is added only to the tubes of the first row. The rack holding these pairs of tubes is placed in a thermostat or warm place with a temperature not over 37° C. for an hour. Two units of amboceptor are then added to all the tubes and the rack incubated at 37° C. for two hours longer.
If the reaction is positive there will be no tuemolysis in the tubes of the front row. The corpuscles settle at the bottom of the tube and the supernatant fluid is clear. The tubes of the back row and those of the negative control will all show liTmolysis.