@article {Huangjclinpath-2021-207926, author = {Jinfa Huang and Xiaochun Liu and Yi Hou and Yixuan Liu and Kedan Liao and Ning Xie and Kaixian Deng}, title = {Macrophage polarisation in caesarean scar diverticulum}, elocation-id = {jclinpath-2021-207926}, year = {2022}, doi = {10.1136/jclinpath-2021-207926}, publisher = {BMJ Publishing Group}, abstract = {Aims To determine immunohistochemical features and correlations between M1/M2 polarisation status with disease severity of post-caesarean scar diverticulum (CSD).Methods Histological and immunohistological stainings were performed and inflammatory (CD16, CD163 and tumour necrosis factor-α (TNF-α)), fibrosis (α-smooth muscle actin (α-SMA)) and angiogenic (CD31) markers were examined in uterine tissues collected from patients with uterine scar diverticula (CSD) (n=37) and caesarean section (CS) (n=3).Results CSD tissues have higher expression of α-SMA, TNF-α, CD16 and CD31 and lower expression of CD163 than CS tissue (p\<0.05). Compared with adjacent tissues, thick-walled blood vessels, glands and fibrotic sites have higher expression of α-SMA, TNF-α and CD16. Statistical correlation was observed between the expression of CD16 and TNF-α (R=0.693, p\<0.001), α-SMA (R=0.404, p\<0.05) and CD31 (R=0.253, p\<0.05) in CSD tissues, especially with the ratio of CD16/CD163 (R=0.590, p\<0.01). A more significant difference was observed between the expression of CD16/CD163 and α-SMA (R=0.556, p\<0.001), TNF-α (R=0.633, p\<0.0001) and CD31 (R=0.336, p\<0.05).Conclusions In this study, TNF-α, α-SMA, CD16 and CD31 proteins were overexpressed in all CSD cases, and CD16/CD163 was positively correlated with tissue inflammation, fibrosis and neovascularisation. Abnormal mononuclear macrophage infiltration may be involved in the origin and progression of CSD.Data are available upon reasonable request. All data relevant to the study are included in the article or uploaded as supplementary information.}, issn = {0021-9746}, URL = {https://jcp.bmj.com/content/early/2022/01/03/jclinpath-2021-207926}, eprint = {https://jcp.bmj.com/content/early/2022/01/03/jclinpath-2021-207926.full.pdf}, journal = {Journal of Clinical Pathology} }