Characterisation of lymphocyte subsets in asplenic patients - preliminary report

Introduction: Acquired asplenia is a common abnormality, following splenectomy due to splenic rupture from trauma, because of tumour or as a treatment for certain diseases, such as idiopathic thrombocytopenic purpura and spherocytosis. Asplenic patients are exposed to the long-term impairment of humoral and cellular immunity. Although the lack of humoral immunity is a well described issue, few studies have addressed the problem of alterations in T cell immunity in splenectomised individuals. Aim of study: Prospectively evaluate the impact of splenectomy on postoperative quantitative changes of circulating lymphocyte subsets as well as assessment of cell activation markers expression in patients after curative resection due to severe spleen injury, hereditary spherocytosis or immune thrombocytopenic purpura. Material and methods: A study group of 26 subjects, with an average age of 31.23 ±28.13 years, was recruited at the Department of Clinical Immunology and Immunotherapy of the Medical University of Lublin. 15 patients (57.70%) were splenectomised because of a blunt abdominal trauma with spleen injury, 7 persons (26.92%) because of hereditary spherocytosis and 4 patients (15.38%) due to thrombocytopenic purpura (ITP). Three-colour immunofluorescence analyses were performed using a FACS Calibur flow cytometer (Becton Dickinson) equipped with 488 nm argon laser. Statistical analysis was performed using Statistica 6.0 (Stat Soft Inc.) software. Results and conclusions: Between splenectomised patients, those who notified more frequent infections after splenectomy and those who did not observe any change in prevalence of upper respiratory tract infections (URTI), statistically significant differences in the percentages of lymphocyte activation markers were observed. Subjects, who did not suffer from common infections had more CD3+/CD69+, CD19+/CD69+, CD3+/CD25+, CD4+/CD69+ and CD8+/CD69+ cells. We did not indicate a statistically significant correlation between lymphadenopathy and frequency of URTI. The reason of splenectomy did not influence lymphocyte subsets (p > 0.1). The elapsed time after splenectomy positively correlated with the percentage of CD4+ lymphocyte subset (r = 0.670; p = 0.006) and negatively with HLA-DR+ T-cells (r = – 0.736; p = 0.002). In the group of examined patients, who had more frequent URTI, a positive correlation between the elapsed time after surgical treatment and percentage of CD8+/CD25+ cells (r = 0.613; p = 0.045) and a negative correlation between CD3+/HLA-DR+ lymphocytes (r = –0.847; p = 0.001) and a mentioned time was observed. Because of interesting preliminary observations, the present research will be expanded on a bigger group and the antigens which may activate lymphocytes in asplenic, otherwise healthy persons are going to be searched for.