Invasive Pulmonary Aspergillosis After Sars-CoV-2 Infection as Limitation of Contemporary Transplantology: A Case Report

Invasive fungal infections are uncommon in pediatric heart transplant recipients. Risk and mortality are highest in the first 6 months post-transplant, especially in patients with previous surgery and those requiring mechanical support. There is a possibility that prior SARS-CoV-2 infection may cause a more severe course of pulmonary aspergillosis, especially in immunosuppressed individuals. This report describes a female patient, eight years of age, who was admitted to the pediatric cardiac surgery department with symptoms of end-stage heart failure in urgent need of mechanical circulatory support (MCS). A left ventricular assist device (LVAD) was implanted as a bridge to transplantation. During over a year on the waiting list, LVAD was replaced twice due to the presence of fibrin on the inlet valve. While staying in the ward, the patient underwent SARS-CoV-2 infection. An orthotopic heart transplant was successfully performed after 372 days of MCS with LVAD. One month after transplantation, the girl developed severe pulmonary aspergillosis complicated by sudden cardiac arrest and implantation of venovenous extracorporeal membrane oxygenation (VV ECMO) used for 25 days. Unfortunately, a few days after weaning from VV ECMO, the patient died due to intracerebral bleeding.

ABSTRACT Invasive fungal infections are uncommon in pediatric heart transplant recipients. Risk and mortality are highest in the first 6 months post-transplant, especially in patients with previous surgery and those requiring mechanical support. There is a possibility that prior SARS-CoV-2 infection may cause a more severe course of pulmonary aspergillosis, especially in immunosuppressed individuals. This report describes a female patient, eight years of age, who was admitted to the pediatric cardiac surgery department with symptoms of end-stage heart failure in urgent need of mechanical circulatory support (MCS). A left ventricular assist device (LVAD) was implanted as a bridge to transplantation. During over a year on the waiting list, LVAD was replaced twice due to the presence of fibrin on the inlet valve. While staying in the ward, the patient underwent SARS-CoV-2 infection. An orthotopic heart transplant was successfully performed after 372 days of MCS with LVAD. One month after transplantation, the girl developed severe pulmonary aspergillosis complicated by sudden cardiac arrest and implantation of venovenous extracorporeal membrane oxygenation (VV ECMO) used for 25 days. Unfortunately, a few days after weaning from VV ECMO, the patient died due to intracerebral bleeding. I N end-stage heart failure, when all available treatment options have been used, and there are no contraindications to this form of treatment, orthotropic heart transplantation (OHT) is performed. Mechanical circulatory support (MCS) can be used as a bridge to such operation or, hopefully, recovery [1]. Patients in poor general condition, particularly solid-organ recipients on post-transplant immunosuppression, are more susceptible to infections. This case report presents a patient with a history of SARS-CoV-2 infection and OHT who developed a severe form of aspergillosis.

CASE REPORT
A female, eight years of age, was admitted to the hospital due to critical heart failure symptoms. Physical examination revealed shortness of breath, multiple peripheral edemas, hepatomegaly, and symmetrical parabasal lung cracking. Echocardiography showed an enlarged left ventricle with a 15% ejection fraction. Diagnosis of dilated cardiomyopathy prompted left ventricular assist device (LVAD) implantation as a bridge to transplantation. Berlin Heart Excor 25 mL was implanted successfully with subsequent improvement in cardiac function. The patient was added to the transplant waiting list. The LVAD was replaced twice due to the presence of fibrin on the inlet valve. After seven months, the patient got infected with SARS-CoV-2. After COVID-19 infection, several cannula-related infections caused by Enterobacter cloacae or Pseudomonas aerguinosa were noted. Four months later, apathy, fever, and profuse vomiting occurred. Blood culture confirmed the presence of P. aerguinosa. She was treated with vancomycin, which was complicated by pseudomembranous enteritis. The next month, after 372 days of mechanical circulation support with LVAD, OHT was performed. One month after OHT, the patient presented with a headache and 38.5°C fever. Voriconazole, piperacyline, and teicoplanin were administered. A swab test for galactomannan antigens was taken. As the patient's condition deteriorated with increasing dyspnea and her saturation dropped to 63%, treatment was modified to clarithromycin and meropenem. Based on a positive galactomannan test and the characteristic "butterfly sign" in computed tomography (CT), invasive pulmonary aspergillosis (IPA) was diagnosed. Caspofungin was added to the treatment. After planned endotracheal intubation, oxygen saturation increased to 85%. Twelve days after the first signs of infection, the patient's condition was still severe. Ventricular arrhythmias occurred, requiring magnesium sulfate infusion. Forty-two days after OHT, the patient had a sudden cardiac arrest with 30 minutes of successful resuscitation. It was decided to establish venovenous extracorporeal membrane oxygenation (ECMO), maintained for 25 days until chest radiography and respiratory parameters improved. On the second day after the removal of venovenous ECMO, a sudden drop in blood pressure to 60 mm Hg was observed. A CT scan of the head showed massive central nervous system bleeding. The patient was consulted for neurosurgery; however, due to the lack of cerebral circulation and features of brain herniation in the foramen magnum on the follow-up CT scan, the patient was disqualified from surgical treatment. Shortly after, a committee confirmed the patient's status as brain dead.

DISCUSSION
There are 2 main limitations of successful heart transplantation: graft rejection and infections. According to Pons, 81% of patients developed an infection within 180 days after OHT. Bacterial or fungal pneumonia were the most common infectious complications. Fungal infections account for 14%; aspergillosis infections, specifically, account for 5% [2]. Invasive pulmonary aspergillosis is a severe pulmonary infection with bronchopneumonia symptoms mainly caused by Aspergillus fumigatus, rarely by Aspergillus niger. Despite fluconazole prophylaxis, invasive pulmonary aspergillosis can develop in 5% to 10% of patients after transplantation [3]. Before the introduction of azoles as fungal prophylaxis, mortality rates reached 53% to 78% [4]. In 24 years, analysis incidence of IPA after OHT decreased from 8.7% to 3.5%, and mortality decreased from 46% to 0% after 2000 [5]. In a large retrospective study of patients who underwent OHT, among 23,101 transplanted patients who did not survive, only 1.23% died of aspergillosis [6]. Unfortunately, there are many reported cases of IPA after OHT in pediatrics. Saxena reported a 2.2% prevalence of invasive fungal infections in pediatrics after solid organ transplant, which seems to be a lower proportion than that found in the overall population [7].
According to the guidelines, the known risk factors for IPA in OHT recipients include isolation of A. fumigatus in respiratory tract cultures before OHT, reoperation, cytomegalovirus disease, post-transplant hemodialysis, and cases of IPA in the institution in the 2 months before transplantation [8]. Another risk factor should be considered. COVID-19−associated pulmonary aspergillosis is IPA occurring during or a few days/ weeks after COVID-19 infection. Infection develops, on average, 18 days after SARS-CoV-2 infection; Bhopalwala reported late manifestations of COVID-19−associated pulmonary aspergillosis within a few months after infection [9,10]. COVID-19−associated pulmonary aspergillosis risk factors involve old age, active smoking, chronic respiratory diseases, chronic renal failure, and chronic corticosteroids treatment. It does not completely fit the patient, but there could be some association with SARS-CoV-2 [11].
Sources report that COVID-19 infection has a major impact on the immune system during and for several months after infection. Immune system dysregulation is manifested through the functional debilitation of natural killer cells and T cells. This has been detected in COVID-19 patients through decreased levels of its markers, NK-G2A and PD-1 [12]. Reduced fungicidal activity of neutrophils from COVID-19 patients indicates that immune imbalance is an important risk factor for invasive fungal diseases. Alterations in the immune system can persist for more than six months after COVID-19 infection and include modifications in macrophages and neutrophils responsible for anti-fungal responses [13].
Furthermore, patients with long COVID-19 had highly activated innate immune cells, lacked naive T and B cells, and showed elevated interferon b and interferon λ1 expression that remained persistently high eight months after infection [14]. Ryan reported significant reductions in both CD4+ and CD8+ compartments, as well as in memory cells. Interestingly, despite an increase in total granulocytes, the CD14+ and CD16+ neutrophils were significantly decreased.
These changes could have affected our patients. After COVID-19 infection, even before OHT, she developed severe cannula-related infection and sepsis, both caused by P. aerguinosa. She developed IPA 31 days after OHT despite low levels of tacrolimus.
Also, according to Ryan, plated and megakaryocyte gene downregulation results in lower expression of platelet factor 4, platelet glycoprotein IX, thrombopoietin receptor, and coagulation factor XIII A chain [15]. This could explain the higher risk of intracranial bleeding in our patient. Bleeding remains one of the most common complications (33%) after ECMO. Werho reported intracranial hemorrhage as the most common hemorrhagic complication in cardiac and non-cardiac pediatric patients supported with ECMO [16]. Additionally, the female gender is a constitutional risk factor for intracranial bleeding [17].
Intracranial bleeding could also complicate central nervous system invasive aspergillosis [18]. Aspergillus fumigatus causes the angioinvasion phenomenon. It contributes to endothelial cell injury through its conidia and term tubes, which may result in massive intracranial hemorrhage [19]. At the other end of the spectrum, A. fumigatus causes tissue factor expression, which has a prothrombotic effect. Our patient did not show radiological signs of brain aspergillosis; however, in the literature, a case was reported of IPA with brain dissemination [20].

CONCLUSIONS
The direct cause of death in the patient seems to be intracranial hemorrhage as an ECMO complication. However, severe manifestations of IPA may be caused by alternations in the immune system (even eight months after COVID-19 infection), resulting in higher vulnerability to bacterial or fungal infections. Invasive pulmonary aspergillosis affecting cerebral vessels could result in vascular weakness and subsequent intracerebral hemorrhage.

DECLARATION OF COMPETING INTEREST
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.