18F-FDG PET/CT Metabolic Parameters and Circulating Tumour DNA Mutation Abundance in Diffuse Large B-Cell Lymphoma: Correlation and Survival Analysis / 中国实验血液学杂志

OBJECTIVE@#To investigate the correlation between 18Fluoro-deoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) metabolic parameters and peripheral blood circulating tumour DNA (ctDNA) in patients with diffuse large B-cell lymphoma (DLBCL), and the prognostic value of these two types of parameters in predicting progression-free survival (PFS).@*METHODS@#Clinical, PET/CT and ctDNA data of DLBCL patients who underwent peripheral blood ctDNA testing and corresponding PET/CT scans during the same period were retrospectively analyzed. At the time of ctDNA sampling and PET scan, patients were divided into baseline and relapsed/refractory (R/R) groups according to different disease conditions. CtDNA mutation abundance was expressed as variant allele frequency (VAF), including maximum VAF (maxVAF) and mean VAF (meanVAF). Total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG) were obtained by the 41% maximum normalized uptake value method, and the distance between the two farthest lesions (Dmax) was used to assess the correlation between PET parameters and ctDNA mutation abundance using Spearman correlation analysis. The receiver operating characteristic (ROC) curves were used to obtain the optical cut-off values of those parameters in predicting PFS in the baseline and R/R groups, respectively. Survival curves were outlined using the Kaplan-Meier method and log-rank test was performed to compare survival differences.@*RESULTS@#A total of 67 DLBCL patients ［28 males and 39 females, median age 56.0(46.0, 67.0) years］ were included and divided into baseline group (29 cases) and R/R group (38 cases). Among these PET parameters, baseline TMTV, TLG, and Dmax were significantly correlated with baseline ctDNA mutation abundance, except for maximum standardized uptake value (SUVmax) (maxVAF vs TMTV: r=0.711; maxVAF vs TLG: r=0.709; maxVAF vs Dmax: r=0.672; meanVAF vs TMTV: r=0.682; meanVAF vs TLG: r=0.677; meanVAF vs Dmax: r=0.646). While in all patients, these correlations became weaker significantly. Among R/R patients, only TMTV had a weak correlation with meanVAF (r=0.376). ROC analysis showed that, the specificity of TMTV, TLG and Dmax in predicting PFS was better than mutation abundance, while the sensitivity of ctDNA mutation abundance was better. Except R/R patients, TMTV, TLG, Dmax, and VAF were significantly different at normal/elevated lactate dehydrogenase in baseline group and all patients (all P<0.05). Survival curves indicated that high TMTV (>109.5 cm3), high TLG (>2 141.3), high Dmax (>33.1 cm) and high VAF (maxVAF>7.74%, meanVAF>4.39%) were risk factors for poor PFS in baseline patients, while only high VAF in R/R patients (both maxVAF and meanVAF >0.61%) was a risk factor for PFS.@*CONCLUSION@#PET-derived parameters correlate well with ctDNA mutation abundance, especially in baseline patients. VAF of ctDNA predicts PFS more sensitively than PET metabolic parameters, while PET metabolic tumour burden with better specificity. TMTV, TLG and VAF all have good prognostic value for PFS. PET/CT combined with ctDNA has potential for further studies in prognostic assessment and personalized treatment.

Correlations between monocyte immunosuppression and the inflammatory markers in patients with severe acute stroke / 中华神经医学杂志

Objective To explore the correlations between monocyte immunodepression andthe levels of C-reactive protein (CRP) and fibrinogen (Fg) in patients with severe acute stroke. MethodsThis prospective study involved 53 consecutive patients admitted in the neurological intensive care unit(NICU) within 24 h after stroke onset. Blood samples were collected serially on days 1, 2, 4, 6 and 14after stroke to determine monocytic HLA-DR expression using flow cytometry. CRP and Fg weredetected on day 2 after the admission, and Graph_Pad PRISM 4.0 software was used to analyze thecorrelations among the variables. Thirty-nine concurrent patients admitted in the general ward, whocomplained dizziness without magnetic resonance imaging evidence of acute stroke, were enrolled toserve as the control group. Results The levels of CRP and Fg in the stroke group were significantlyhigher than those in the control group (P<0.05). The CRP and Fg levels were both found to inverselycorrelate to monocytic HLA-DR expression at different observational points. The correlations of CRP andFg to HLA-DR expression were the most obvious on day 2 and 4 after admission (r=-0.419, P=0.001;r=-0.434, P=0.001), respectively. Conclusion Immunosuppression of the monocytes in patients withsevere acute stroke is probably associated with the inflammatory reaction after stroke.