[The role of ceruloplasmin in the differential diagnosis of neuropsychiatric disorders].

The blue copper protein ceruloplasmin has been of interest to psychiatrists for decades following Heilmeyer's observation of elevated serum copper levels in schizophrenic patients. Immunoturbidimetry, however, does not yield elevated serum ceruloplasmin concentrations in schizophrenia while ceruloplasmin-related oxidase activity appears to be elevated in patients with schizophrenia and reduced in patients with Alzheimer's disease. Low serum concentrations of immuno-turbidimetrically measured ceruloplasmin, and of oxidase activity, are typical of Wilson's disease, Menkes' disease, and aceruloplasminemia, three familial neurodegenerative disorders of pronounced variability, with regard to both genotype and phenotype. Especially patients with Wilson's disease may exhibit behavioural symptoms only over a long period. Heterozygous carriers of Wilson's disease and aceruloplasminaemia may have low serum ceruloplasmin concentrations; they will not develop somatic symptoms, but the significance of these carrier states, or of "hypoceruloplasminaemia", with regard to mental disorders is unknown.