99P - Quantitative indicators of TREC and KREC excision rings in malignant neoplasms

Background

The excisional rings of the T cell receptor rearrangement (TREC) and the κ-deletion element (KREC) are extrachromosomal DNA structures formed during V(D)J-recombination. A decrease in the number of TREC and KREC below age-related values may be a manifestation of immunodeficiency conditions, which can be caused by oncological and hematological diseases.

Methods

To study the change in the amount of TREC and KREC in malignant neoplasms. Methods. For the study, blood was taken from patients with malignant neoplasms in the main group and group of healthy individuals of various ages. At the stage of intermediate evaluation 206 studies were performed out of 700 planned. Of these 26 healthy individuals and 180 patients with malignant neoplasms. Sex distribution: 22.8% (46/206) men, 77.2% (159/206) women, median age 54 years (Q1-Q3: 44-66 years). From MN: breast cancer 35% (63/180), ovarian cancer 21.1% (38/180), melanoma 15.6% (28/180), lymphoma 11.1% (20/180), lung cancer 8.9%(16/180), colorectal cancer 8.3%(15/180). Quantification of TREC and KREC was performed by real-time PCR using the IMMUNO-BIT reagent kit (ABV-test LLC) in accordance with the instructions for the kit. DNA extraction from whole blood was performed using the AmpliPrime RIBO-prep reagent kit (NextBio LLC).

Results

According to our study, in healthy individuals, the TREC level is 75.6/105 PBMC (Q1-Q3: 19.2-135.3), the KREC level is 317.3/105 (Q1-Q3: 118.1-565.9). Whereas in patients with MN, the level of TREC is 4.6/105 PBMC (Q1-Q3: 0.9-17.3), the level of KREC is 111.9/105 (Q1-Q3: 29.3-339.28). When comparing the TREC and KREC indicators in different groups, statistically significant differences were established (p<0.001, p=0.006). The levels of TREC and KREC in the healthy population were significantly higher than among patients with cancer (median TREC were 75.6 and 4.6, median KREC 317.3 and 111.9, respectively).

Conclusions

The data obtained demonstrate significant changes in T- and B-cell lymphopoiesis in patients with cancer. Quantitative determination of TREC and KREC makes it possible to assess the state of the T- and B-cell link of the immune system in patients with malignant neoplasms.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.