Immunity Tests in Coccidioidal Granuloma. 35 



and Saxon is apparently a cholesterol-free diet and perhaps the 

 same can be said for casein and lard, although the writer is by no 

 means certain on this point. This is merely suggestive and further 

 investigation along this line may prove it erroneous. 



20 (952) 



Immunity tests in coccidioidal granuloma. 



By Jean V. Cooke. 



[From the Pathological Laboratory of the University of California 

 Hospital, San Francisco.] 



In a case of coccidioidal granuloma studied no specific com- 

 plement-fixing bodies or agglutinins could be found in the blood 

 serum using cultures of Coccidioides immitis and emulsions of the 

 same organism from human lesions as antigens. No specific skin 

 reaction could be demonstrated. Precipitins, however, could be 

 demonstrated in the serum even when diluted 1-160, when an 

 extract of dried cultures of the organisms was used as precipiti- 

 nogen. The precipitins were apparently specific since they could 

 not be demonstrated when normal serum was tested with the same 

 antigen or when the specific immune serum was tested with an 

 antigen similarly prepared from the closely related organism 

 Blastomyces. 



The presence of specific precipitins in this infection must be 

 verified by the examination of other cases. It is suggested that 

 this reaction might be applied as a means of diagnosis in cases of 

 deep seated infection where there are no discharging lesions from 

 which the spherical doubly-contoured bodies can be demon- 

 strated. It might also serve as a means of differentiating coc- 

 cidioidal granuloma from blastomycosis in obscure cases. 



Experiments are now being carried out to determine whether 

 specific immune substances are formed in infected animals. 



