Relationships Between Invasive Fungal Infection and Rejection Post Heart Transplantation

Abstract

<h3>Purpose</h3> Rejection and infections are leading threats in patients undergoing heart transplantation (HTx). While invasive fungal infections (IFI) have decreased due to antifungal prophylaxis and optimised immunosuppressant therapy, IFI remains the most threatening infection after HTx. We performed a single-centre retrospective study on the epidemiology of IFI post HTx. <h3>Methods</h3> All HTx were reviewed from January 2013-December 2020. In accordance with Infectious Disease Society of America (IDSA) guidelines, we looked at IFI seeking histo/cytological, molecular and microbiological findings for aspergillosis; real time PCR for <i>Pneumocystis jirovecii</i> pneumonia (PJP); positive cultures in sterile sites for candidiasis. We compared these findings with the occurrence of ≥ 2R cellular (ACR) and ≥ pAMR1 humoral (AMR) rejections, defined by positive endomyocardial biopsies (EMB), as stated by the International Society for Heart and Lung Transplantation (ISHLT). Appropriate parametric and non-parametric tests were used to analyse the data. <h3>Results</h3> A total of 115 patients underwent HTx from January 2013-December 2020. Median age was 57 years (IQR= 21,50), 75 (65%) male and 34 (29,6% female. Overall, 64 (55%) received a diagnosis of rejection, 57 (89%) ACR, 29 (45%) AMR and 22 (34%) had both types of rejection, occurred a median of 29 days (IQR= 62) after transplant. 15 (23%) of them had at least one episode of IFI, while 4 patients had IFI without rejection (7,8%) (p= 0,04; Fisher), totalling 26 episodes in all. The IFI episodes occurred a median of 45 days (IQR= 214) after the first episode of rejection and a median of 87 days (IQR= 242) after the transplant (p= 0,08). The most common infection was Aspergillosis with 9 episodes (60%); candidiasis was diagnosed 6 times (40%). There were 2 cases of mucormycosis (13%) and 1 case of PJP (7%). <h3>Conclusion</h3> The risk of developing IFI post HTx is considered low. In our single-centre study IFI occurred in almost a quarter of patients following a rejection episode, with aspergillosis being the most common infection. These findings support the consideration of antifungal prophylaxis after treated rejection episodes.