Objective: To study whether an algorithm that includes additional diagnostic information could increase the specificity of the 14-3-3 protein testing in patients suspected to suffer from Creutzfeldt-Jakob disease (CJD).
Design: The development of a diagnostic algorithm.
Method: The 14-3-3 protein was tested in the cerebrospinal fluid from 69 consecutive patients suspected of having CJD. On the basis of a former study and literature research, a diagnostic algorithm was constructed, which restricted the indication for performing the 14-3-3 protein test.
Results: By taking into consideration the findings of neuroimaging and routine cerebrospinal fluid examination prior to 14-3-3 testing, the specificity increased to 97% (95%-CI: 85.5-99.9) thus changing the prior probability of having CJD of 35% to a posterior probability of 75-100%, in the case of a positive test result.
Conclusion: Determining the presence of 14-3-3 protein is a highly sensitive and specific marker for sporadic CJD when used in combination with imaging and cerebrospinal fluid examination.