Albumin and immunoglobulin-G in the cerebrospinal fluid and the diagnosis of multiple sclerosis.

Multiple sclerosis (MS) remains a diagnosis based mainly on clinical criteria. Definitive diagnostic tests are, despite numerous attempts, not available. However, some laboratory tests like electrophoresis of the cerebrospinal fluid proteins or the determination of immunoglobulin G in cerebrospinal fluid have proved useful in increasing the probability of MS. This paper describes how these laboratory tests have to be interpreted in relation to pathophysiological phenomena and how they correlate with each other. The electrophoresis of CSF proteins and the diagnostic quotients (Ralb and CSF-IgG-index) are valuable aids to the clinician. It especially can substantiate the diagnosis MS. The magnitude of the index cannot be correlated with the clinical stage of MS. The usefulness of these tests in terms of a possible gain of information in the diagnostic process is discussed.