P-chorionic gonadotropin in serum
Reference values of p-HG concentration in blood serum: adults - up to 5 IU / ml;at a pregnancy of 7-10 days - more than 15 IU / ml, 30 days - 100-5000 IU / ml, 10 weeks - 50 000-140 000 IU / ml, 16 weeks - 10 00050 000 IU / ml. The half-life is an average of 2.8 days.
HC is a hormone consisting of 2 subunits - a and p, non-covalently linked to each other;a-subunit is identical to the a-subunit of LH, FSH and TSH, the p-subunit is specific for HG.
P-XG is a glycoprotein secreted by the syncytial layer of trophoblast during pregnancy. It supports the activity and existence of the yellow body, stimulates the development of the embryoblast. Excreted in the urine. Detection of p-HG in serum serves as a method for early diagnosis of pregnancy and the pathology of its development. In oncology, the determination of p-HG is used to control the treatment of trophoblastic and germinogenic tumors. The half-life of p-HG is 3 days. In men and non-pregnant women, a pathological increase in p-CG concentration is a sign of a malignant tumor. Diseases and conditions in which the concentration of p-CG in the blood changes. Table
Table Diseases and conditions in which the concentration of p-CG in the blood changes
Table Diseases and conditions in which the concentration of p-CG in the blood changes
The sensitivity of the determination of p-HG in the blood for carcinoma of the ovary and placenta is 100%, for chorionadenoma 97%, for non-seminomatous germ-minomes 48-86%, for seminoma 7-14%.An increased concentration of P-XG is observed in 100% of patients with trophoblast tumors and in 70% of patients with non-seminiferous testicular tumors containing elements of syncytiotrophoblast.
Germs of the testicles are one of the most common oncological diseases of young men( 20-34 years).Due to the fact that the histological type of tumor can change during therapy, it is recommended to carry out a combined definition of b-CG and AFP in germinomas. Seven-nomes, disgerminomas and differentiated teratomas are always AFP-negative, yolk sac tumors in their pure form are always AFP-positive, while carcinomas or combined tumors, depending on the mass of the endodermal structures, can be either AFP-positive or AFP-negative. Thus, for germin, b-HG is a more important marker than AFP.The joint determination of AFP and b-CG is especially indicated in the course of treatment with germin. Profiles of these two markers may not coincide. The concentration of AFP is reduced to normal values within 5 days after radical surgery, reflecting a decrease in the total mass of the tumor. After chemotherapy or radiotherapy, on the contrary, the concentration of AFP will reflect only a decrease in the number of AFP-producing cells, and since the cellular composition is germin mixed, the determination of b-CG is necessary to evaluate the effectiveness of therapy.
Combined determination of AFP and p-CG allows to achieve a sensitivity of 86% in the diagnosis of recurrence of non-seminomatous testicular tumors. The increasing concentration of AFP and / or p-CG indicates( often several months earlier than other diagnostic methods) the progression of the tumor and, consequently, the need for treatment change. Initially, high values of AFP and p-HG in the blood indicate a poor prognosis.