Objective:To investigate the correlation between the number of circulating DLBCL cell and the marrow tumor cell burden and the prognostic indicators in patients with DLBCL, and to evaluate the feasibility of circulating DLBCL cell reflecting the marrow tumor burden and disease progression. Optimization of FCM for screening circulating DLBCL cell was done to monitor MRD and recurrence.Methods:We conducted a retrospective study in 75 diagnosed DLBCL patients in the First Affiliated Hospital of Zhengzhou University from June 2020 to February 2021, including 43 males and 32 females aged 61 (37-85) years. According to the diagnosis and treatment criteria, the patients were divided into initial and recurrence group ( n = 53), partial response(PR)group ( n=14) and complete response(CR)group ( n=8). According to the positive criteria of circulating DLBCL cells, 48 cases were divided into circulating DLBCL positive group and 27 cases were negative group. 30 anemia patients with non-B-cell tumor-related diseases were selected as the control group, including 16 males and 14 females, aged 52 (30-79) years. 70 healthy subjects, including 36 males and 34 females, aged 39 (25-57), were selected for methodology optimization. FCM was used to detect the ratio of marrow and circulating DLBCL cells in each group, and analyze the connection between circulating DLBCL cells and clinical indicators. Statistical analysis was performed using t test, χ 2 test, Kruskal-Wallis H test, Spearman rank correlation, and Logistic regression. Results:(1) Bone marrow and circulating DLBCL cells were not detected in CR group and control group; The positive rate of circulating DLBCL cells in the initial/recurrent group and PR groups was 75.47% and 57.14%, respectively. The proportion of bone marrow and circulating DLBCL cells was positively correlated in the two groups ( P value was <0.001 and 0.020, respectively). (2) The proportion of bone marrow and circulating DLBCL cells in the initial and recurrent groups, PR group, CR group and control group decreased successively ( P<0.05). The proportion of DLBCL cells was 27.72% (initial and recurrent bone marrow group), 26.92% (initial and recurrent circulating group), 3.23% (bone marrow PR group) and 1.67% (circulating PR group), respectively. (3) Compared with the negative group, the circulating DLBCL cell positive group had increased LDH, β 2-MG, and CMYC expression(≥80%), with decreased LYM, HGB<100 g/L, B symptoms, PD-L1 expression, and age ≥60 years, showing higher ECOG, aaIPI/IPI scores and Ann staging ( P<0.05). Age ≥60, B symptoms, and PD-L1 expression were independent risk factors for circulating DLBCL cells ( P<0.05). Conclusions:The detectable rate of circulating DLBCL cell could be improved by optimizing the preoperative treatment conditions of FCM. Circulating DLBCL cells can reflect the tumor burden and disease progression. Detecting circulating DLBCL cells may improve patients′ compliance.

Objective:To summarize the morphological characteristics of diffuse large B-cell lymphoma (DLBCL) cells and investigate the prognosis value of the characteristics and the number of DLBCL cells in bone marrow.Methods:Retrospective study. We collected 79 cases newly diagnosed with DLBCL in the First Affiliated Hospital of Zhengzhou University from January 2020 to August 2022. 30 cases newly diagnosed without bone marrow involvement were selected as controls, whose mean age 58 years (30-82 years). The DLBCL cells were evaluated by the bone marrow smear, biopsy and flow cytometry separetely.The detection rate of DLBCL cells in the bone marrow was compared, to analyse the relationship between the morphological characteristics of DLBCL in the smear, clinical characteristics and flow cytometry parameters, and the prognostic value of DLBCL detected in the bone marrow smear and its quantity was analyzed. Logistic regression was used to analyze the correlation between the detection of DLBCL cells in bone marrow smears and the age, clinical stage, and the number of extraderules involved organs. Multivariate Cox regression was used to analyze the influence of DLBCL cells detection and its number on the prognosis of patients.Results:(1) The positive rates of DLBCL cells in bone marrow biopsy, bone marrow smear and flow cytometry were 4.86%, 5.14% and 9.27% respectively. (2) The morphological characteristics of 79 cases in bone marrow smears were described: more than 2 times the volume of the cell body of the lymphocyte, the shape was different, round or quasi-round or irregular shape, can be seen pseudopodia or protrusion; The volume of cytoplasm was moderate, vacuoles were visible, and a few perinuclear areas were visible. The nucleus were different in shape, round or quasi-round or irregularly shaped, with a majority of them having multiple nuclei and a few of them having delicate and loose chromatin. Most nucleoli were medium or large obviously, with a majority of them having 1-2 nucleoli and a few having more than 3.Sergiosomes and hemophagocytosis were observed in some DLBCL cases, tumor cell aggregation phenomenon was observed in a few DLBCL cases, occasionally pathological mitosis.(3) DLBCL cells in bone marrow smear was positively related to the age of patients, clinical stage and the number of extranodal organs involved(regression coefficient were 2.012, 2.754, 2.028, P<0.05);The volume of DLBCL cells in bone marrow smear was positively correlated with the ratio of CD4 and CD8(regression coefficient is 2.545, P<0.05);The vacuoles in cytoplasm and the pseudopod of tumor were both negative relationship with the quantity of CD38 expressed on DLBCL cells(regression coefficient was -2.465, -3.045, P<0.05); (4) DLBCL cells in bone marrow smear was an independent risk factor for PFS and OS( RR=7.059, P<0.05); RR=5.409, P<0.05). Conclusion:The appearace of DLBCL cells in bone marrow smear with prognosis, and could be used for clinical staging.