After adjusting for age, sex, eGFR, proteinuria, diabetes, and cytomegalovirus seropositivity, decreased RTEs, which corresponded to decreased thymic output, significantly and monotonically increased the risk of poor renal outcome (p = 0.04), and decreased RTE% and increased highly differentiated CD28−/CD4+ T cells also tended to monotonically increase the risk (p = 0.074 and p = 0.056, respectively), but not CD28−/CD8+ T cells. Here, CD28 is linked to diabetes mellitus.