Human Placental Macrophages (Hofbauer Cells) in Severe Preeclampsia Complicated by HELLP Syndrome Immunohistochemistry of Chorionic Villi

OBJECTIVE: To evaluate Hofbauer cells in the placentas of women diagnosed with HELLP syndrome. STUDY DESIGN: The present study compared 20 patients with HELLP syndrome and 20 control patients with respect to demographics, hematological parameters and the presence of Hofbauer cells in placental samples. CD-68 antibody was used for immunohistochemical examination. The total number and size of Hofbauer cells were measured in the placental villi, and the proportion of Hofbauer cells relative to the vascular structure was also compared between groups. RESULT: The patient and control groups were similar according to baseline obstetric characteristics. White blood cell counts in patients with HELLP syndrome and the control group were 15,139 4,169 and 10,806 2,888, respectively, and were significantly increased among patients with HELLP syndrome (p < 0.001). Hofbauer cell numbers in the placental villi of patients with HELLP syndrome were significantly elevated in comparison to normotensive controls (p = 0.046). The proportion of Hofbauer cells in the placental villi according to proximity to the vascular structure were 3.85 +/- 1.66 in the HELLP group and 1.75 +/- 1.12 in controls (p < 0.001). Sizes of the Hofbauer cells were not statistically different between groups. CONCLUSION: Increased Hofbauer cells may be associated with increased inflammation or may have an adaptive mechanism at the fetal site of the placenta in patients with HELLP syndrome.