The flow cytometric analysis of CD19+ B cells revealed no significant differences between the three groups before LVAD implantation (normal weight: 5.5 ± 2.7%; pre-obesity: 7.6 ± 5.4%; obesity: 7.3 ± 5.0%; p = 0.47), at 1st FU (normal weight: 4.1 ± 1.8%; pre-obesity: 5.7 ± 2.7%; obesity: 5.4 ± 3.0%; p = 0.26), 2nd FU (normal weight: 4.3 ± 2.0%; pre-obesity: 5.5 ± 2.3%; obesity: 5.8 ± 3.6%; p = 0.34) and 3rd FU after LVAD implantation (normal weight: 4.6 ± 2.0%; pre-obesity: 7.0 ± 3.1%; obesity: 6.7 ± 3.4%; p = 0.08). This evidence concerns the gene CD19 and obesity due to melanocortin 4 receptor deficiency.