Longitudinal Cohort Study on Invasive Fungal Disease After Allogeneic Hematopoietic Stem Cell Transplantation

Invasive fungal disease refers to a severe infection caused by fungi invading human tissues, blood or body fluids, mainly affecting people with weakened immune systems. Under the background of HSCT, due to the transplantation recipients undergoing high-dose chemotherapy pretreatment, graft-versus-host disease (GVHD), and the use of immunosuppressants, the immune function of the body is severely impaired, and the risk of IFD occurrence significantly increases. The clinical manifestations of IFD after HSCT are diverse, which can involve multiple organs and systems such as the lungs, blood, central nervous system, and skin. It is difficult to diagnose, challenging to treat, and has a poor prognosis, seriously affecting the long-term survival and quality of life of transplant patients.

In recent years, the epidemiological characteristics of IFD after HSCT have undergone significant changes. According to the CAESAR 2.0 study, among 2015 Chinese patients who received allo-HSCT, the cumulative one-year incidence of IFD (proven + probable) was 6.3%. It is worth noting that compared with the CAESAR study ten years ago, the pathogen spectrum has undergone a significant transformation, which is closely related to the evolution of antifungal prevention strategies - ten years ago, fluconazole was mainly used for prevention, while currently about three quarters of patients use antifungal active drugs such as voliconazole or posaconazole. Although this shift in preventive strategies has reduced the occurrence of aspergillosis, it may increase the risk of infection from drug-resistant pathogens such as Mucor.

IFD after HSCT remains a major clinical challenge affecting the prognosis of patients. The current research has the following deficiencies: (1) There is still a lack of multi-center, large-sample prospective cohort studies in China; (2) The dynamic changes in the pathogen spectrum and clinical characteristics of IFD require continuous monitoring. (3) The diagnosis and treatment strategies and prognostic factors of different types of IFD need in-depth research. Based on the above background, this study intends to establish a longitudinal observational cohort that combines retrospective and prospective approaches to systematically evaluate the epidemiological characteristics, treatment strategies, and short-term and long-term outcomes of IFD patients after HSCT.

• Proportion of participants with invasive fungal disease who have overall response at 1 year [Time frame: 1 year after diagnosis of invasive fungal disease]
• Cumulative incidence of proven or probable invasive fungal disease within 1 year after allo-HSCT [Time frame: From date of allo-HSCT to first diagnosis of invasive fungal disease, death, last contact, or 1 year after allo-HSCT, whichever occurs first]
• Number and percentage of participants with post-transplant complications within 5 years after allo-HSCT [Time frame: From date of allo-HSCT to death, last contact, or 5 years after allo-HSCT, whichever occurs first]
• Number and percentage of participants with treatment-related adverse events as assessed by CTCAE v5.0 [Time frame: From initiation of systemic antifungal therapy to 30 days after the last dose, death, or last contact, whichever occurs first]
• Total length of hospital stay within 5 years after allo-HSCT, measured in inpatient days [Time frame: From date of allo-HSCT to death, last contact, or 5 years after allo-HSCT, whichever occurs first.]