Critical reviews in clinical laboratory sciences
-
Crit Rev Clin Lab Sci · Jan 2015
ReviewHow many biomarkers to discriminate neurodegenerative dementia?
A number of cerebrospinal fluid (CSF) biomarkers are currently used for the diagnosis of dementia. Opposite changes in the level of amyloid-β(1-42) versus total tau and phosphorylated-tau181 in the CSF reflect the specific pathology of Alzheimer's disease (AD) in the brain. This panel of biomarkers has proven to be effective to differentiate AD from controls and from the major types of neurodegenerative dementia, and to evaluate the progression from mild cognitive impairment to AD. ⋯ Other biomarkers included in the common clinical practice do not clearly relate to the underlying pathology: progranulin (PGRN) is a selective marker of frontotemporal dementia with mutations in the PGRN gene; the 14-3-3 protein is a highly sensitive and specific marker for Creutzfeldt-Jakob disease, but has to be used carefully in differentiating rapid progressive dementia; and α-synuclein is an emerging candidate biomarker of the different forms of synucleinopathy. This review summarizes several biomarkers of neurodegenerative dementia validated based on the neuropathological processes occurring in brain tissue. Notwithstanding the paucity of pathologically validated biomarkers and their high analytical variability, the combinations of these biomarkers may well represent a key and more precise analytical and diagnostic tool in the complex plethora of degenerative dementia.
-
Severe hyperkalemia is a potentially life-threatening condition requiring immediate medical intervention. Pseudohyperkalemia can be misleading and result in incorrect interpretation and inappropriate patient management. Immediate recognition and appropriate interpretation of pseudohyperkalemia, on the other hand, prevents misdiagnosis and unnecessary intervention. ⋯ Reverse pseudohyperkalemia has recently been reported in leukemic patients in whom the plasma potassium levels are greater than the serum potassium levels because of heparin-induced cell membrane damage. Although pseudohyperkalemia has long been recognized and understood, it continues to be misinterpreted. To improve patient care, an algorithm for investigation of pseudohyperkalemia and preventive measures should be established and implemented in the clinical laboratory.