MACROPHAGE POLARIZATION IN PLACENTAS OF GESTATIONAL DIABETIC MOTHERS: AN IMMUNOHISTOCHEMICAL STUDY OF CD68 AND CD163 EXPRESSION IN A TERTIARY CARE CENTRE

Abstract

Introduction: Gestational diabetes mellitus (GDM) is associated with metabolic and inflammatory alterations that can significantly impact structure and function of placenta. Placental macrophages including hofbauer cells play a key role in maintaining immune homeostasis, alterations in density and polarization which may contribute to pathophysiology of GDM. Materials and Methods: A case–control study was conducted at a tertiary care centre on 80 placenta (40 GDM, 40 controls). Placental tissues were processed for H&E staining and immunohistochemistry for CD68 and CD163 to quantify placental macrophages including hofbauer cells and assess macrophage polarization (CD163/CD68 ratio). Data were analyzed in SPSS version24 using Chi-square/Fisher’s exact tests and t-test/ANOVA; p < 0.05 was considered significant. Results: CD68-positive macrophages were significantly increased in GDM placentas compared to controls (23.1 ± 2.6 vs 10.2 ± 1.5 per 10 HPF; 64.0 ± 4.5 vs 29.8 ± 5.8 per 100 villi; p < 0.001). CD163-positive macrophages per 10 HPF were also significantly elevated in GDM cases (44.8 ± 5.3 vs 17.0 ± 2.7; p < 0.001). A significant positive correlation was observed between OGCT levels and macrophage markers (CD68 and CD163), indicating an association between maternal glycemic status and placental immune response. Conclusion: GDM is associated with increased macrophage infiltration along with preservation of anti-inflammatory M2 polarization, suggesting a state of adaptive yet dysregulated immune response. These findings highlight the role of macrophage mediated immune modulation in placental dysfunction in GDM and suggest potential avenues for therapeutic targeting.