Application of Immunocytochemistry to Monitor the T Cell Subset Counts in Patients with Sepsis

Abstract [Objective]: To evaluate the application significance of immunocytochemistry for monitoring peripheral blood CD3+ T cell subset (CD3+/CD3+CD4+/CD3+CD8+) counts in patients with sepsis. [Methodology]: 138 patients with sepsis, along with 20 healthy subjects for control purposes, were chosen for the research. On the first day of admission (D1), three peripheral blood samples from 20 healthy subjects and 20 patients with sepsis were collected for lymphocyte counts by routine blood tests and T cell subset counts by immunocytochemistry and flow cytometry. The remaining 118 patients with sepsis were asked to give two peripheral blood samples on the first day of admission and 20 of them were additionally required to give the peripheral blood samples on the fourth day of admission (D4), for lymphocyte counts by routine blood tests and T cell subset counts by immunocytochemistry. This was in order to analyze and compare the count levels of the lymphocyte and CD3+T cell subsets between the sepsis group and the healthy control group, and to explore the correlation and difference of CD3+ T cell subset counts obtained by flow cytometry and immunocytochemistry. [Results]: Lymphocyte counts by routine blood tests and CD3+T cell subset counts of the patients with sepsis were significantly lower than those in the healthy control group (P<0.01). The CD3+T cell subset counts of the surviving group of D4 increased significantly compared with D1, while the non-surviving group did not rebound significantly. Meanwhile, there was a significantly positive correlation between lymphocyte counts by routine blood tests and CD3+T lymphocyte subset counts in patients with sepsis and the healthy control subjects, with no significant difference between the two by t-test P <0.01). [Conclusion]: Detection of CD3+ T cell subsets counts by the immunocytochemistry method can reflect the cellular immune status of patients at the time, thus it can be used as one of the immune monitoring methods in patients with sepsis.