5. When a syphilitic fluid does not give the strong “paretic reaction,” it is good presumptive evidence that the case is not general paresis; and this test offers a very valuable differential diagnostic aid between general paresis, tabes and cerebrospinal syphilis.
6. The term “syphilitic zone” is a misnomer, as non-syphilitic as well as syphilitic cases give reactions in this zone; but no fluid of a case with syphilitic central nervous system disease has given a reaction out of this zone (test thus valuable negatively). Any fluid giving a reaction outside of this zone may be considered non-syphilitic.
7. Light reactions may occur without any evident significance, while a reaction of no greater strength may mean marked inflammatory reaction.
8. Tuberculous meningitis, brain tumor and purulent meningitis fluids characteristically, though not invariably, give reactions in higher dilutions than syphilitic fluids.
9. The unsupplemented gold sol test is insufficient evidence on which to make any diagnosis, but used in conjunction with the Wassermann reaction, chemical and cytological examinations, it offers much information looking toward the differential diagnosis of general paresis, cerebrospinal syphilis, tabes dorsalis, brain tumor, tuberculous meningitis, purulent meningitis.
10. We believe that no cerebrospinal fluid examination is complete for clinical purposes without the gold sol test.
The Wassermann reaction as carried out in the Wassermann Laboratory is based on the principles of the original method—the only essential modification consists in the employment of cholesterinized alcoholic extracts of human hearts as antigen instead of aqueous extracts of foetal livers from cases of congenital syphilis. Experience has shown that properly standardized antigens made from human hearts are much more sensitive in the detection of true cases of syphilis.
Antigens. Three antigens are used, each being an alcoholic extract of human heart which is saturated at room temperature with cholesterin. These antigens differ slightly in their sensitiveness. Before the test is made each antigen is diluted with 0.85% salt solution in the proportion of four parts of the cholesterinized antigen extract to sixteen parts of 0.85% salt solution. The amount to be used, the dosage, is carefully determined by testing each antigen against a large number of known positive and known negative specimens of blood. The dosage of the antigens employed is less than one-half the amount which inhibits hemolysis when the antigen is incubated for one hour with the hemolytic system which consists of complement, amboceptor and cells in the proper proportions. These antigens are designated as A, B, and C. Antigen A is the most sensitive. B and C are very similar to each other quantitatively and qualitatively.
Specimens to be tested. The serum which separates from the clot is withdrawn, centrifugalized if necessary, and then heated at 55 degrees for thirty minutes. 0.1 cc. of serum is used in the test and 0.2 cc. of each specimen is used as a control to exclude the presence of anti-complementary substances. Spinal fluids are tested in two ways. As a routine 0.5 cc. of the spinal fluid is used in the test and 1.0 cc. is used in the control; or when especially requested spinal fluids are titrated by using respectively 1.0, 0.7, 0.5, 0.3, and 0.1 cc. of the spinal fluid for each test and 1.0 cc. of spinal fluid for the control. Spinal fluids are not inactivated.
Complement. The complement is obtained from the serum of guinea pig’s blood. No complement is used when older than eighteen hours. A 10% solution and 0.85% salt solution is used in the test. The amount used is twice the minimum quantity necessary to hemolyze the sensitized cells.