Association Between Leukocyte Subpopulations And Hematoma Expansion After Spontaneous Intracerebral Hemorrhage

Aims: To verify the association between leukocyte subpopulations and hematoma expansion(HE)determined by two definitions in Chinese individuals who experienced spontaneous intracerebral hemorrhage.Methods: 471 patients with spontaneous intracerebral hemorrhage confirmed by computed tomography(CT)were included in this study,and these patients had follow-up CT within 72 hours after the first CT scan.We use the formula(1/2ABC)to measure the volume of hematoma on the first CT and follow-up CT images,and calculate the difference and corresponding percentage between the volume of hematoma on the follow-up CT and the volume of hematoma on the first CT scan.The outcome was whether HE appeared within 72 h.We used Definition1(volume increase ≥ 6 m L or 33%)and Definition2(volume increase ≥ 12.5 m L or 33%)to define HE,respectively.This study used binary logistic regression analysis and established three models according to different adjustment strategies to evaluate the correlation between leukocyte subsets and HE.P < 0.05 indicates that the difference is statistically significant.We also conducted subgroup analysis for the leukocyte subpopulations that showed statistical significance in the binary logistic regression analysis to evaluate whether there were differences between subgroups.Results: Among 471 patients,131(27.81%)and 116(24.63%)patients experienced HE based on Definition1 and Definition2,respectively.After adjusting for confounding factors,elevated monocyte count was associated with a higher risk of HE-Definition1(adjusted odds ratio [a OR] 2.45,95% confidence interval [CI] 1.02–5.88,P=0.0450)and HE-Definition2(a OR 2.54,95% CI 1.04–6.20,P=0.0399).Additionally,we compared the results before and after adjusting for coagulation parameters(Thrombin time,plasma fibrinogen determination and activated partial thromboplastin time),Monocyte count was significantly correlated with HE only after adjusting for coagulation parameters;Increased neutrophil count was associated with a lower risk of HE-Definition1(a OR 0.91,95% CI 0.84–1.00,P=0.0463);No correlations were observed between lymphocyte and leukocyte counts and HE(P >0.05).and no subgroup interactions were observed in the subgroup analysis of monocyte and neutrophil counts(interaction P > 0.05).Conclusion: After excluding the influence of the coagulation parameters and other confounding factors.A higher monocyte count is associated with a higher HE risk regardless of the two definitions,which facilitates risk stratification.Moreover,only when HE is defined as volume increase ≥ 6 m L or 33%,the increase of neutrophil count is related to the reduction of HE risk,which reflects the importance of standardizing the definition of HE and it is necessary to conduct future research on the normalization and standardization of HE definition.