Elevated Plasma Immunoglobulin Levels Prior to Heart Transplantation Are Associated with Poor Post-Transplantation Survival.

Cardiac allograft vasculopathy (CAV) and antibody-mediated rejection are immune-mediated, long-term complications that jeopardize graft survival after heart transplantation (HTx). Interestingly, increased plasma levels of immunoglobulins have been found in end-stage heart failure (HF) patients prior to HTx. In this study, we aimed to determine whether increased circulating immunoglobulin levels prior to transplantation are associated with poor post-HTx survival. Pre-and post-HTx plasma samples of 36 cardiac transplant recipient patients were used to determine circulating immunoglobulin levels. In addition, epicardial tissue was collected to determine immunoglobulin deposition in cardiac tissue and assess signs and severity of graft rejection. High levels of IgG1 and IgG2 prior to HTx were associated with a shorter survival post-HTx. Immunoglobulin deposition in cardiac tissue was significantly elevated in patients with a survival of less than 3 years. Patients with high plasma IgG levels pre-HTx also had significantly higher plasma levels after HTx. Furthermore, high pre-HTX levels of IgG1 and IgG2 levels were also significantly increased in patients with inflammatory infiltrate in CAV lesions. Altogether the results of this proof-of-concept study suggest that an activated immune response prior to transplantation negatively affects graft survival.

Soluble ST2 in end-stage heart failure, before and after support with a left ventricular assist device.

BACKGROUND: The interleukin-33 (IL-33)/suppressor of tumorigenicity 2 (ST2) pathway is suggested to play an important role in fibrosis, remodelling and the progression of heart failure (HF). Increased soluble (sST2) levels are associated with adverse outcome in the average HF population. Less is known about sST2 levels in end-stage HF. Therefore, we studied sST2 levels in end-stage HF and the effect of unloading by left ventricular assist device (LVAD) support on sST2 levels. METHOD AND RESULTS: Serial plasma measurements of sST2 were performed pre-implantation and 1, 3 and 6 months after (LVAD) implantation in 38 patients. sST2 levels were elevated in end-stage HF just prior to LVAD implantation (74.2 ng/mL [IQR 54.7-116.9]; normal <35 ng/mL) and decreased substantially during LVAD support, to 29.5 ng/mL [IQR 24.7-46.6](P < .001). Patients with INTERMACS profile I had significantly higher sST2 levels compared to patients in profile II and profile III. A moderate correlation was found between sST2 and C-reactive protein (r = .580, P < .010). CONCLUSION: Levels of sST2 are elevated in end-stage HF patients with variability that suggests multiple inputs to a pro-inflammatory and pro-fibrotic pathway. Cardiogenic shock and increased C-reactive protein levels are associated with higher sST2 levels. LVAD support results in a significant drop in sST2 levels with normalization within 3 months postimplantation. This suggests that LVAD support leads to lessening of fibrosis and inflammation, which might eventually be used to target medical policy: explantation of the LVAD versus permanent use or cardiac transplantation.

The composition of ectopic lymphoid structures suggests involvement of a local immune response in cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is a multifactorial pathology limiting the survival of cardiac transplants. The etiology of CAV is unclear, but antibody-mediated and cellular-mediated responses have been implicated. We, and others, have observed ectopic lymphoid structures (ELS) surrounding epicardial coronary arteries with CAV. The potential contribution of these ELS to CAV has not been elucidated. METHODS: Epicardial coronary arteries were collected from 59 transplant patients at 2 centers and studied for ELS presence and composition using immunohistochemistry. The intima and ELS were isolated, and the expression of the genes involved in tertiary lymphoid organ (TLO) formation was measured by quantitative polymerase chain reaction. RESULTS: ELS presence was related to survival after transplantation (p = 0.013) and histologic composition of CAV (p < 0.001). ELS contain B and T lymphocytes, macrophages, and antibody-producing (immunoglobulin [Ig] M and/or IgG) plasma cells. A sub-population of B lymphocytes appeared to be cluster of differentiation (CD)20(+)CD27(+) memory B lymphocytes. The messenger RNA expression of TLO markers (lymphotoxin-ß, and chemokine [C-C motif] ligand 19 and 21) was significantly higher in ELS than in the neointimal lesions. The ELS observed in this study exhibited some TLO markers but did not exhibit the distinct areas rich in B and T lymphocytes that are normally found in classic TLOs. CONCLUSIONS: The cellular composition of the ELS differs from the cellular infiltrate in CAV intimal lesions. The presence of memory B lymphocytes and plasma producing IgM and IgG cells suggests that ELS are related to local antibody production, potentially contributing to antibody-mediated CAV. ELS associated with coronary vessels containing CAV show features of underdeveloped TLOs; classic TLOs may not develop due to patient immunosuppression.

Proteomic profiling of the human failing heart after left ventricular assist device support.

BACKGROUND: Left ventricular assist device (LVAD) support is commonly used in patients with heart failure as a bridge to heart transplantation. Whereas myocardial gene expression profile changes have been well established after LVAD support, the consequences on the protein level largely remain unclear. METHODS: Pre-LVAD and post-LVAD myocardial tissue specimens from dilated cardiomyopathy (DCM) and ischemic heart disease (IHD) patients were analyzed by fluorescent 2-dimensional difference gel electrophoresis, and differentially expressed proteins were identified by mass spectrometry. RESULTS: In the DCM group, 16 proteins were detected that showed statistically significant downregulation from pre-LVAD to post-LVAD tissue. In IHD patients, 50 alterations were found, including upregulated (n = 12) and downregulated (n = 38) proteins. The identified proteins in both groups partially overlapped and included proteins from cytoskeleton and mitochondrial energy metabolism. The latter changes were paralleled by severe abnormalities in mitochondrial morphology, as shown by electron microscopy. Post-LVAD proteomes of both DCM and IHD patients largely mimicked the protein profiles of non-failing hearts. Downregulation of the serine protease inhibitor α-1-antichymotrypsin in both DCM and IHD patients after LVAD support was confirmed by immunosorbent assay. CONCLUSIONS: LVAD-induced cardiac remodeling in DCM and IHD patients is associated with downregulation of α-1-antichymotrypsin and specific atrophic changes in protein expression profiles predominantly involved in cytoskeleton integrity and mitochondrial energy metabolism.