Electrophoretic determination of aqueous and serum neuron-specific enolase in the diagnosis of retinoblastoma.
OBJECTIVE
Neuron-specific enolase (NSE) of containing gamma-enolase is considered valuable in the diagnosis of tumours of neuroectodermal origin.


METHODS
We used rapid electrophoretic method on cellulose acetate plate to determine the pattern of enolase isoenzymes in 21 aqueous humor and 23 serum specimens from retinoblastoma (Rb) and 21 aqueous and 25 serum specimens from 25 control cases to evaluate NSE in the diagnosis of Rb. The assay allowed assessment of all three major isoenzymes (alpha alpha, alpha gamma and gamma gamma), and NSE relative activity and its percentage in the total relative activity of the three enolase isoenzymes were assessed by means of fluorometer.


RESULTS
Aqueous from all patients with Rb contained alpha alpha, alpha gamma and gamma gamma isoenzymes and presented strong positive, the positive rate of NSE being 100% and its relative activity accounting for 45 +/- 9% of the total relative activity of the 3 enolase isoenzymes; No enolase was detectable in control aqueous with cataract, glaucoma and Coats's diseases (4 cases), but in two patients with traumatic hyphema alpha alpha and faint alpha gamma and gamma gamma were presented in aqueous. The control serum contained only an alpha alpha band, while the sera form patients with Rb contained alpha alpha, alpha gamma and gamma gamma bands in 18 of 23 specimens, the positive rate being 78.2%, and only alpha alpha bands in the rest 5 specimens (21.8%). In patients with Rb, the NSE relative activity and its percentage in the total relative activity of the 3 isoenzymes in serum (36 +/- 9%) were significantly lower lever than those in aqueous.


CONCLUSIONS
The amounts of NSE increase significantly in both serum and aqueous from patients with Rb, and the immunoelectrophoretic assay for determination of enolase patterns is valuable in the diagnosis of Rb and differential diagnosis of Rb. In addition, the method is rapid, simple and requires only a little amount (< 5 microL) of samples.
Wu
Z
Z
Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China.
Yang
H
H
Pan
S
S
Chen
Z
Z
D001082:Aqueous Humor / Q000201:enzymology*; D004796:Clinical Enzyme Tests; D004588:Electrophoresis, Cellulose Acetate; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D019572:Retinal Neoplasms / Q000175:diagnosis*; D012175:Retinoblastoma / Q000175:diagnosis*
D007527:Isoenzymes; D010751:Phosphopyruvate Hydratase