Abstract
The demonstration of type-specific substances for Group I-III and Type II strains of meningococcus, 1 and the production of sera rich in precipitins for such substances but lacking in precipitins for the non-type-specific (C and P) fractions have led to the investigation of C.S.F. (cerebrospinal fluid) from meningococcal meningitis to ascertain whether this contains type-specific precipitinogens. Vincent and Bellot 2 , 3 and others have demonstrated precipitin reactions between C.S.F. and polyvalent antimeningococcal serum. Most of the investigators noted some inconsistencies, especially cross-precipitation with C.S.F. of other forms of meningitis, notably pneumococcal. The reason for this, no doubt, lies in the fact that the polyvalent serum contains non-specific antibodies, and that the antibody for the C polysaccharide of the meningococcus will react with the similar fraction from other organisms, especially the pneumococcus. Using polyvalent serum, there is, of course, no possibility of typing the organism involved. Marie, 4 however, states that cases of meningitis due to the meningococcus can be separated from those due to the parameningococcus by the use of monovalent serum prepared against these 2 types and used in the precipitin reaction with C.S.F.
The spinal fluid is cleared by rapid centrifugation. The precipitin test is made with equal parts of undiluted serum and spinal fluid for 2 hours at 37° C. and 15 to 18 hours in the ice-box. Both the ring method and the mixing method have been used. 0.1 cc. of each of the 3 type sera is placed in a small tube. 0.1 cc. of spinal fluid is layered on top of each specimen of serum so that the precipitate appears as a ring at the point of junction. A reading is made immediately and again after one hour at 37° C.
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