CD8A and immunodeficiency disease: In this study, the level of blood urea nitrogen, PCT, and CRP in the poor prognosis group were significantly higher than those in the survival group; the peripheral blood CD8 count level in the poor prognosis group were significantly lower than those in the survival group; in the overall presentation of patients with TM bloodstream infection, although they have immunodeficiency, poor prognosis patients are often in an extremely severe immunodeficient state and have poor nutritional status compared with the survival patients.