Increase in the numbers of CD163+ and also CD169+ cells in the endometrium could be explained by an influx of blood monocytes differentiating into both cell populations as a result of a marked inflammatory process driven not only by PRRSV, but also by significant tissue damage associated with vasculitis, necrosis of uterine glands, and apoptosis. This evidence concerns the gene SIGLEC1 and vasculitis.