METHOD FOR DIFFERENTIAL DIAGNOSIS OF LEUKOPLAKIA AND SQUAMOUS CELL CARCINOMA OF THE ORAL MUCOSA AT THE PREOPERATIVE STAGE Russian patent published in 2022 - IPC G01N33/50 A61B5/00 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely oncology, and can be used for the differential diagnosis of leukoplakia and squamous cell carcinoma of the oral mucosa at the preoperative stage. The essence of the method: a fluorimetrical determination of the chymotrypsin-like activity of proteasomes (CTP) in blood serum is carried out, for which blood is taken from a vein into two 6 ml tubes, an hour after taking blood, it is centrifuged for 15 minutes at 3000 rpm, the resulting serum is pre-activated by 10% SDS, then CTP is determined by hydrolysis of fluorogenic oligopeptide Suc-LLVY-AMC (Sigma), utilized by chymotrypsin-like proteasome centers, a specific proteasome inhibitor is used to assess the activity of impurity proteases: MG132 (Sigma), a reaction mixture for determining the activity of proteasomes contains 20 mM Tris-HCl with a pH of 7.5, 1 mM dithiotreitol, 30 microns of fluorogenic substrate, 5 mM of MgCl₂ and 1 mM of ATP, the reaction is carried out at 37°C for 20 minutes, the resulting product is recorded on a multimode microplate reader-imager “Cytationl” (BioTek, USA) at Exi = 360 nm, Emi = 460 nm, the specific activity of proteasomes is expressed in units of activity per 1 ml of blood serum, CTP is estimated by the fluorescence intensity of the hydrolyzed substrate in units of the fluorimeter readings Eg/ml. When the value of the CTP indicator is reached in the range from 30.9 to 69.9, leukoplakia is diagnosed, and when the value is determined in the range from 70.0 to 126.4, squamous cell carcinoma of the oral mucosa is diagnosed.

EFFECT: use of the invention provides a reduction in invasiveness, an increase in the accuracy of early diagnosis.

1 cl, 2 ex