Changes And Significance Of Lymphocyte Perforin And Granzynfle B In Children With Infectious Mononucleosis Disease

Objective:To detect lymphocytes and the expression of perforin(PRF)and granzyme B(GRzB)in lymphocytes of children with infectious mononucleosis,To analyze the correlation between the expression of PRF and GRzB and the occurrence and severity of the disease.The aim of this study is to provide a new clue for the diagnosis and treatment of IM.Methods:This is a prospective study(1)A total of 26 cases(A1-A26) of children with IM diagnosed and admitted to DALIAN MUNICIPAL WOMEN AND CHILDREN’S MEDICAL CENTER from July 2020 to February 2021 were collected and included in the experimental group for the study,including 16 males and 10 females,with a male-female ratio of 1.6:1.A total of 30 healthy children(P1-P30)who underwent physical examination in the pediatric outpatient department of our center during the same period and excluded other immunodeficiency diseases were included in the normal healthy control group,including 15 males and 15 females,with a male to female ratio of 1:1.Relevant clinical information was collected: gender,age,length of hospital stay,fever days,as well as pharynx pain,respiratory tract obstruction,hepatosplenomegaly,cervical lymph node swelling and pain,increased liver enzymes,whether there were some complications.(2)2 ml of peripheral venous blood was collected and placed in an EDTA anticoagulant tube.Hemolysin was added to destroy red blood cells.After low-speed centrifugation,the supernatant was discarded.After conventional membrane breaking,washing,fixation,and multiple low-speed centrifugation,peripheral blood monocytes(PBMC)were obtained.Then 50 ul was added into PRF tube and GRzB tube separately,and APC-A labelled performin and PE labelled GRzB antibody were added.The cells were incubated at room temperature for30 minutes and then washed,the level of PRF or GRzB was expressed by the positive cell rate of PRF or GRzB in Flow cytometry.(3)Group and comparison methods: 1)IM group(n=26)and healthy control group(n=30);2)According to the number of atypical lymphocytes(AT),they were divided into two groups: 10%≤AT<15% group(n=11)and AT≥15% group(n=15);3)According to clinical characteristics,the patients were divided into mild and severe groups: severe group(n=13),mild group(n=13);4)IM acute stage group and convalescence stage group.Flow cytometry was used to detect lymphocyte subsets and the expression levels of granulocase and perforin in lymphocytes,and SPSS26.0 statistical software was used to analyze the data.Results:1.The expression of PRF and GRzB in patients with mild and severe IM was significantly higher than that in controls(p < 0.05).There was no significant difference in the expression of PRF and GRzB in lymphocyte group(P > 0.05).2.The expression of PRF and GRzB in acute IM group was significantly higher than that in control group and convalescent group(p < 0.05),and the expression of PRF and GRzB in convalescent group was slightly higher than that in normal group(p< 0.05).3.Between different AT groups,there was no significant difference in the expression of PRF and GRzB in lymphocyte(P<0.05).4.The level of CD8+T lymphocyte in IM group was significantly higher than that in control group(p < 0.05),the level of CD4 + T lymphocyte was significantly lower(p<0.05),CD4 +/CD8 + was significantly lower(p<0.05),while the level of NK cells was not significantly changed(P<0.05).Conclusion:1.PRF and GRzB were significantly higher in IM children than in healthy children,which can be considered as a laboratory index to assist IM diagnosis.2.PRF and GRzB had no significant difference between the severe IM group and the mild IM group,which could not be used as an indicator to judge the severity of the disease.3.PRF can monitor the prognosis of the disease,and it can be used as an index to evaluate the effectiveness of clinical treatment.4.The number of lymphocyte as a criterion for judging the degree of immune dysfunction needs to be further explored.