Pulmonary Aspergillosis in Solid Organ Transplant

Aspergillosis represents clinical disease due to Aspergillus species, including allergic, chronic pulmonary infection, and tissue-invasive disease. Invasive aspergillosis (IA) most often occurs in immunocompromised hosts, such as solid organ transplant (SOT) patients or those with underlying hematologic malignancy. Among solid organ transplant (SOT) recipients, the incidence of IA is up to 30% and is dependent upon transplant type and level of immunosuppression. Prevention strategies are important in high-risk SOT transplant groups (i.e. lung), where chemoprophylaxis, either as universal prophylaxis or preemptive therapy with azoles, is employed. The most common type of aspergillosis is invasive pulmonary aspergillosis (IPA). Clinical manifestations of IPA in SOT patients are nonspecific and may be subtle, making clinical suspicion and early investigation essential to diagnosis. Fever, cough, and nodular infiltrates on lung imaging are suggestive of IPA. Diagnosis is confirmed by histopathology, culture data, or the use of biomarkers such as Aspergillus galactomannan testing. Treatment of IPA has improved over the past decades, with the availability of safe and effective therapies. Azole antifungals such as voriconazole, isavuconazole, or posaconazole are first-line agents. However, with an increase in Aspergillus resistance to azole therapies, drug toxicities, or interactions with transplant-related medications, alternative therapies such as lipid amphotericin B products or echinocandins may be necessary. This chapter will discuss invasive pulmonary aspergillosis in solid organ transplant patients.