Factors influencing transfusion‐associated HLA sensitization in patients bridged to heart transplantation using ventricular assist device

Abstract

Background:Bridging heart failure patients with mechanical ventricular assist devices (VAD) enables access to transplantation. However, VAD is associated with increased risk for anti-HLA antibodies associated with rejection of subsequent allografts.Factors determining alloantibody formation in these patients remain undefined. Methods:We performed a single-center retrospective cohort study of 164 patients undergoing heart transplantation from 2014 to 2017. Medical records including use of VAD, transfused blood products, anti-HLA antibody testing, crossmatch, and time to transplant were evaluated. Results:Patients received an average of 13.8 red blood cell and 1.9 single-donor platelet units associated with VAD. There was a 28.7% increase in the incidence of anti-HLA antibodies after VAD. Development of anti-HLA antibodies did not correlate with volume or type of blood products, but with pre-VAD HLA sensitization status; relative risk of new alloantibodies in patients with pre-VAD antibodies was 3.5-fold higher than those without prior antibodies (P = .008). Development of new anti-HLA antibodies was associated with an increased time to transplant (169 vs 330 days, P = .013). Conclusions:Our findings indicate that the presence of anti-HLA antibodies pre-VAD was the most significant risk factor for developing additional antibodies post-VAD, suggesting that a subset of patients may be predisposed to alloantibody formation. K E Y W O R D Santibodies, heart transplant, HLA, sensitization, transfusion, ventricular assist device

De Novo Human Leukocyte Antigen Allosensitization in Heartmate 3 Versus Heartmate II Left Ventricular Assist Device Recipients

“…Single center studies have demonstrated that de novo HLA sensitization on LVAD support is associated with longer times to transplantation as well as increased risk of acute cellular and humoral rejection in the posttransplant period. 5,14,15 A recent analysis of the UNOS registry suggested pretransplant allosensitization (PRA > 10%) was not associated with increased 5-year posttransplant mortality in patients bridged with MCS devices, but it is difficult to draw conclusions from this study as it remains unclear whether allosensitization occurred after implantation of LVAD or if patients were already sensitized before device implant. 16 Aside from HLA sensitization, LVAD implantation is associated with development of polyreactive natural IgG antibodies (Nabs) which are associated with primary graft dysfunction but not rejection.…”

Crossing low/moderate‐level donor‐specific antibodies during heart transplantation

“…It is not known if patients with low/moderate levels (MFI < 10 000) of pre‐transplant DSA have acceptable post‐transplant outcomes. Currently, the number of sensitized patients awaiting heart transplantation has been increasing, primarily due to blood transfusions, pregnancies, prior organ transplantations, and increasing implantation of mechanical circulatory support devices 5,6 . Patients implanted with ventricular‐assist devices (VAD) as a bridge to transplant especially carry a significant risk of sensitization and possibly a higher risk of post‐transplant antibody‐mediated rejection (AMR), allograft failure, and mortality 6 …”

A retrospective view of the relationship of soluble Fas with anemia and outcomes in chronic kidney disease

“…Even so, the blood transfusion required to treat anemia in patients with CKD continues to be widely used, especially in patients with inflammation status who progress to kidney failure with replacement therapy requirements [13,14]. Moreover, red blood cell (RBC) transfusion presents risks and complications, such as infections and increased sensitization to HLA antigens for kidney transplantation [15,16].…”