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

Retrospective and Prospective Longitudinal Observational Study on Invasive Fungal Disease After Allogeneic Hematopoietic Stem Cell Transplantation

Invasive fungal disease (IFD) is one of the serious complications after hematopoietic stem cell transplantation (HSCT), characterized by high incidence and high mortality. According to the data from a multi-center study in China (CAESAR 2.0), even with the extensive use of antifungal active drugs for prevention, the cumulative incidence of IFD one year after HSCT still reached 6.3%, and the IFD-related mortality rate was 48.28%. In recent years, with the improvement of transplantation techniques, the application of new antifungal drugs and the optimization of diagnostic methods, the pathogen spectrum and clinical characteristics of IFD have undergone significant changes. Compared with ten years ago, the proportion of non-Aspergillus pathogens (such as Candida and Mucophora) has significantly increased, while the proportion of Aspergillus has relatively decreased. In addition, different types of invasive mycosis (such as invasive aspergillosis and invasive fusarium) show significant differences in clinical manifestations, onset time and prognosis. However, at present, large-scale prospective cohort studies on IFD after HSCT in China are still relatively scarce, and the diagnosis and treatment norms and prevention strategies in clinical practice still need to be further optimized. This study intends to conduct a multi-center retrospective and prospective combined longitudinal cohort study to comprehensively register the basic information, diagnosis, treatment and prognosis of IFD patients after HSCT, providing evidence-based medical basis for establishing new clinical diagnosis and treatment technologies and improving the long-term survival rate of patients.

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.

Inclusion Criteria:

Since January 1, 2014, patients who underwent allo-HSCT at Peking University People's Hospital and other assistance centers.

Exclusion Criteria:

1. For any reason, such as the occurrence of severe mental disorders, the follow-up information may be unavailable;
2. Patients deemed unsuitable for the study by the researchers.