Contributions
Abstract: EP762
Type: E-Poster Presentation
Session title: Hematopoiesis, stem cells and microenvironment
Background
Patients with immunosuppression, including those with hematologic cancers, are at greater risk of developing SARS-CoV infection. The virus is capable of infecting monocytes, macrophages and dendritic cells in order to promote the secretion of cytokines, and IL-6 can contribute to the excessive activation of the effects of the acquired immune system (usually lymphocytes) and innate immunity (neutrophils, monocytes, NK cells, etc.).
Aims
The purpose of the study was an assessment of the immune status of patients with hematological cancers after multi-course chemotherapy, therapy with anti-CD20+ antibodies and PCR-confirmed COVID19.
Methods
The study included 12 adult patients with lymphoproliferative diseases with a history of PCR-confirmed COVID-19. All patients underwent 4 to 6 chemotherapy cycles. The BD FACSCanto II flow cytometer with Becton Dickinson reagents were used to assess the immune status of patients. The research group consisted of patients with non-Hodgkin’s large B-cell lymphomas. The blood plasma taken into a vacuum system with K2EDTA as an anticoagulant was used. The relative and absolute numbers of the main populations of T- and B-lymphocytes, the immunoregulatory index, and subpopulations of T-lymphocytes were assessed.
Results
Most patients showed a decrease in the relative number of lymphocytes, on average by 73%. The absolute and relative numbers of monocytes in half of the cases exceeded the norm or were similar to it. The immunoregulatory index in most cases (N=7) was decreased on average by 42%, compared to the norm. The absolute number of T-lymphocytes (CD3+) in 6 patients decreased on average by 42%±0.6. The population of T-helpers (CD3+CD4+) in 5 patients was reduced by an average of 44%±0.8. The number of double-positive (CD3+CD4+CD8+) T-lymphocytes in most cases (N=10) was reduced by 80%±0.8. At the same time, the number of double-negative (CD3+CD4-CD8-) T-lymphocytes increased by 177% in 7 patients. All patients showed a decrease in the B-cell immunity component. The relative number of B-lymphocytes (CD19+) was decreased on average by 78%, absolute number by 61%. The increase in all types of memory cells, both helper-inducer and cytotoxic populations, was registered.
Conclusion
Conclusions. Elevated numbers of various memory cells, together with a decrease in T-lymphocytes, could indicate the activation of the cellular adaptive immunity. A decrease in B-lymphocytes could indicate a decrease in the activity of the humoral component of adaptive immunity. The latter could also be a result of multi-course chemotherapy with anti-CD20+ monoclonal antibodies.
Keyword(s): COVID-19, Immunity, Microenvironment
Abstract: EP762
Type: E-Poster Presentation
Session title: Hematopoiesis, stem cells and microenvironment
Background
Patients with immunosuppression, including those with hematologic cancers, are at greater risk of developing SARS-CoV infection. The virus is capable of infecting monocytes, macrophages and dendritic cells in order to promote the secretion of cytokines, and IL-6 can contribute to the excessive activation of the effects of the acquired immune system (usually lymphocytes) and innate immunity (neutrophils, monocytes, NK cells, etc.).
Aims
The purpose of the study was an assessment of the immune status of patients with hematological cancers after multi-course chemotherapy, therapy with anti-CD20+ antibodies and PCR-confirmed COVID19.
Methods
The study included 12 adult patients with lymphoproliferative diseases with a history of PCR-confirmed COVID-19. All patients underwent 4 to 6 chemotherapy cycles. The BD FACSCanto II flow cytometer with Becton Dickinson reagents were used to assess the immune status of patients. The research group consisted of patients with non-Hodgkin’s large B-cell lymphomas. The blood plasma taken into a vacuum system with K2EDTA as an anticoagulant was used. The relative and absolute numbers of the main populations of T- and B-lymphocytes, the immunoregulatory index, and subpopulations of T-lymphocytes were assessed.
Results
Most patients showed a decrease in the relative number of lymphocytes, on average by 73%. The absolute and relative numbers of monocytes in half of the cases exceeded the norm or were similar to it. The immunoregulatory index in most cases (N=7) was decreased on average by 42%, compared to the norm. The absolute number of T-lymphocytes (CD3+) in 6 patients decreased on average by 42%±0.6. The population of T-helpers (CD3+CD4+) in 5 patients was reduced by an average of 44%±0.8. The number of double-positive (CD3+CD4+CD8+) T-lymphocytes in most cases (N=10) was reduced by 80%±0.8. At the same time, the number of double-negative (CD3+CD4-CD8-) T-lymphocytes increased by 177% in 7 patients. All patients showed a decrease in the B-cell immunity component. The relative number of B-lymphocytes (CD19+) was decreased on average by 78%, absolute number by 61%. The increase in all types of memory cells, both helper-inducer and cytotoxic populations, was registered.
Conclusion
Conclusions. Elevated numbers of various memory cells, together with a decrease in T-lymphocytes, could indicate the activation of the cellular adaptive immunity. A decrease in B-lymphocytes could indicate a decrease in the activity of the humoral component of adaptive immunity. The latter could also be a result of multi-course chemotherapy with anti-CD20+ monoclonal antibodies.
Keyword(s): COVID-19, Immunity, Microenvironment