An immunohistochemical study of CD83- and CD1a-positive dendritic cells in the decidua of women with recurrent spontaneous abortion

BACKGROUND There are more and more women with recurrent spontaneous abortion (RSA). The mechanism of RSA is still unclear. Immunological factors have been postulated to play a role in the etiology of RSA. Dendritic cells (DCs) are the most potent antigen-presenting cells in the immune system, and the decidual DCs may take part in the occurrence of RSA. The difference in maturity status of decidual DCs among women with RSA and women with normal pregnancies is worthy of studying for its application to prevention and therapy. METHODS The EnVision two-step immunohistochemical staining technique was used to detect the expression of CD83 and CD1a in the decidua of women with RSA (30 cases) and normal pregnancies (30 cases). The maturity status, distribution and quantity of DCs in the two groups were observed. Observation of the staining and cell counting were done using microscope within 30 randomly selected high-power fields (HPF, 40 × 10). All data analyses were conducted with SPSS 17.0 and the statistical significance was set at P <0.05. RESULTS The decidua from the two groups contained DCs that stained with the anti-CD83 and anti-CD1a antibody. Most of the decidual CD83(+)DCs from two groups were located in the stroma. There were more CD83(+)DCs clustered with other DCs in the stroma from women with RSA than normal pregnancies. Most of the CD1a(+)DCs in the decidua from the two groups are located close to maternal glandular epithelium. No difference in the location of CD1a(+)DCs was found in the decidua between two groups. The number of decidual CD83(+)DCs was statistically significantly higher in RSA women than in normal early pregnant women (14.20 ± 13.34/30 HPF versus 4.77 ± 2.64/30 HPF; t = 3.800, P = 0.001). The number of CD1a(+)DCs in the decidua was statistically significantly lower in RSA women compared with normal early pregnant women (3.97 ± 3.75/30 HPF versus 7.60 ± 6.08/30 HPF; t = 2.786, P = 0.008). CONCLUSIONS These findings suggest that the increase in the number of mature DCs and the decrease in the quantity of immature DCs in the decidua may be related to RSA. The maturation of decidual DCs may play an important role in the pathogenesis of RSA.