ABSTRACT
AIMS: The widespread use of immune checkpoint inhibitors (ICIs) has demonstrated significant survival benefits for cancer patients and also carry the risk of immune-related adverse events (irAEs). ICIs-associated myocarditis is a rare and serious adverse event with a high mortality rate. Here, we explored the mechanism underlying ICIs-associated myocarditis. METHODS AND RESULTS: Using the peripheral blood of patients with ICIs therapy and ICIs treated mice with transplanted tumors, we dissect the immune cell subsets and inflammatory factors associated with myocarditis. Compared to the control group, patients with myocarditis after ICIs therapy showed an increase in NK cells and myeloid cells in peripheral blood, while T cells significantly decreased. Among T cells, there was an imbalance of CD4/CD8 ratio in the peripheral blood of myocarditis patients, with a significant decrease in central memory CD4+ T (CD4+ TCM) cells. RNA-Seq revealed that CD4+ TCM cells in myocarditis patients were an immunosuppressive cell subset, which highly express the immunosuppressive factor IL4I1. To elucidate the potential mechanism of the decrease in CD4+ TCM cells, protein array was performed and revealed that several inflammatory factors gradually increased with the severity of myocarditis in the myocarditis group, such as IL-1B/CXCL13/CXCL9, while the myocardial protective factor IL-15 decreased. Correlation analysis indicated a positive correlation between IL-15 and CD4+ TCM cells, with high expression of IL-15 receptor IL15RA. Furthermore, in vivo studies using an anti-PDL1 antibody in a mouse tumor model indicated a reduction in CD4+ TCM cells and an increase in CD8+ TEMRA cells, alongside evidence of cardiac fibrosis. Conversely, combining anti-PDL1 antibody treatment with IL-15 led to a resurgence of CD4+ TCM cells, a reduction in CD8+ TEMRA cells, and a mitigated risk of cardiac fibrosis. CONCLUSIONS: Our data highlight CD4+ TCM cells as a crucial role in cardiac protection during ICIs therapy. IL-15, IL4I1 and CD4+ TCM cells can serve as therapeutic targets to reduce ICIs-associated myocarditis in cancer patients.
ABSTRACT
BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a multiethnic inherited disease with a particularly high prevalence in tropical and subtropical regions including southern China. A convenient and reliable method is required to detect common G6PD mutations in the Chinese population. METHODS: We developed a reverse dot blot (RDB) assay for the expanded screening of eleven mutations (c.95A>G, c.392G>T, c.871G>A, c.1004C>T, c.1004C>A, c.1024C>T, c.1360C>T, c.1376G>T, c.1381G>A, c.1387C>T, c.1388G>A). The method consists of a single-tube multiplex PCR amplification of four fragments in the G6PD target sequence of wild-type and mutant genomic DNA samples followed by hybridization to a test strip containing allele-specific oligonucleotide probes. We applied our method to a group of 213 unrelated Chinese patients. RESULTS: The test had a detection rate of 95.8%, validated by direct sequencing in a blind study with 100% concordance. CONCLUSIONS: The results demonstrate that our reverse dot blot assay is an easy, reliable, high-yield and cost-effective method for genetic screening to identify G6PD patients and carriers among the Chinese population.
