Peripheral double negative T: A look at senescent Cubans.

INTRODUCTION

Age-related changes in the immune system are called immunosenescence. Within the T lymphocytes is the subpopulation of double negative (DNT) peripheral lymphocytes that are immunomodulators of the immune response, based on their ability to suppress the functions of simple positive T cells and their cytotoxicity for tumor cells and those infected by viruses.

OBJECTIVE

To determine the frequency of peripheral DNT lymphocytes in older Cuban adults.

METHODS

A cross-sectional study was carried out in 30 older adults, residents in Cuba. DNT lymphocytes in peripheral blood were quantified by flow cytometry. A Beckman Coulter Gallios flow cytometer was used for data reading and analysis. Percentage values mean and standard deviation were used. The Chi-square was used to relate the percentage values of DNT and comorbidities. It was considered statistically significant if p ≤ 0.05.

RESULTS

There was a predominance of women who represented 70 %. No older adult with low values of DNT lymphocytes was reported. Women with high percentage and absolute values of DNT lymphocytes prevailed in relation to men. In the group ≥80 years, high values in % and absolute values of DNT lymphocytes predominated. The high percentage values of DNT cells were mainly related to cardiovascular disease, and predominated in the elderly of ≥80 years old; who presented respiratory and skin infections, fundamentally. The percentage normal value in the group < 80 years was significant (p = 0.0198). The Chi-square value was 0,5995.

CONCLUSIONS

Most older adults who exhibited high percentage and absolute values of DNT lymphocytes, or a tendency to them, had some associated comorbidity, an idea that suggests that DNT cells participate in immune surveillance, defense and homeostasis based on their double identity, that is, its pathogenic or immunosuppressive phenotype according to the specific immunological microenvironment.