Apparent Immune Effect of Clostridium Difficile in Post-Heart Transplant Recipients.

Heart transplant patients develop many opportunistic infections due to chronic immunosuppression. One of the more common complications is that of Clostridium difficile (CDif) causing gastroenteritis, usually represented as diffuse diarrhea. It appears that these opportunistic infections such as CDif may have an impact on the immune system via the microbiome. It has not been demonstrated whether patients who develop CDif are at higher risk for the subsequent development of rejection or chronic rejection known as cardiac allograft vasculopathy (CAV) years after the event. Between 2010 and 2018, we assessed 69 heart transplant patients who developed CDif within the first year post-transplant. These patients were assessed for subsequent 3-year survival, 3-year freedom from CAV (stenosis ≥30% by angiography), 3-year freedom from non-fatal major adverse cardiac event (NF-MACE: MI, new CHF, PCI, ICD implant, stroke), and 1-year freedom from acute cellular rejection (ACR) and antibody-mediated rejection (AMR). These patients were compared to a group (case controlled for time from transplant, age, gender) who did not develop CDif. The average time of infection following transplant was 2.2 ± 3.0 months. The heart transplant patients who developed CDif had significantly lower subsequent 3-year survival, 3-year freedom from NF-MACE, and lower 1-year freedom from AMR compared to the control group. There was no significant difference in the development of CAV (see table). Assessment of specific immunosuppression, antibiotic prophylaxis, and specific CDif treatment did not have an impact on outcome. Heart transplant patients who developed first-year CDif appeared to have immune modulation that adversely affects subsequent outcome. Further investigation to study the microbiome is needed in order to elucidate the mechanisms that are in process. [ABSTRACT FROM AUTHOR]