Our findings demonstrate that IgD + CD38br AC, CD39+ CD8br%CD8br, CD28- CD127- CD25++ CD8br%T, CD28- CD127- CD25++ CD8br%CD8br, CD28+ CD45RA + CD8br%T, and CD28+ CD45RA + CD8br AC cells, CD27 on IgD- CD38- cells, and CD45 on lymphocytes contribute to an increased risk of HF. Here, CD28 is linked to hydrops fetalis.