Test Catalog

Test ID: APPI    
Amyloid Precursor Protein (APP) Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Aids in the identification of amyloid precursor protein present in Alzheimer disease

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

For the initial technical component only immunohistochemical (IHC) stain performed, the appropriate bill-only test ID will be reflexed and charged (IHTOI). For each additional technical component only IHC stain performed, an additional bill-only test ID will be reflexed and charged (IHTOA).

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Amyloid precursor protein (APP) is present in Alzheimer disease-associated plaques, large pyramidal cells as well as smaller neurons, astrocytes, and microglia. Histologic features of Alzheimer disease include the presence of abundant neurofibrillary, tangles, neuropil threads, and neuritic ("senile") plaques. The main component of senile plaque amyloid is a 39- to 42-amino acid segment referred to as beta amyloid, which is derived from APP.

Interpretation Provides information to assist in interpretation of the test results

The positive and negative controls are verified as showing appropriate immunoreactivity. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request. Contact 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen-dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Ahlgren S, Li GL, Olsson Y: Accumulation of beta-amyloid precursor protein and ubiquitin in axons after spinal cord trauma in humans: immunohistochemical observations on autopsy material. Acta Neuropathol 1996;92(1):49-55

2. Craggs LJ, Yamamoto Y, Ihara M, et al: White matter pathology and disconnection in the frontal lobe in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Neuropathol Appl Neurobiol 2014;40:591-602

3. Dermaut B, Kumar-Singh S, De Jonghe C, et al: Cerebral amyloid angiopathy is a pathogenic lesion in Alzheimer's disease due to a novel presenilin 1 mutation. Brain 2001;124:2383-2392

4. Reichard RR, White CL 3rd, Hogan RN, et al: Beta-amyloid precursor protein immunohistochemistry in the evaluation of pediatric traumatic optic nerve injury. Ophthalmology 2004;111(4):822-827

5. Sawaguchi T, Franco P, Kadhim H, et al: Investigation into the correlation in SIDS victims between Alzheimer precursor protein A4 in the brainstem and sleep apnea. 2004;10:161-166