CD4 and Atrophy: We examined the cross-sectional association between thymic atrophy, evaluated as the number of CD3+CD4+CD45RA+CD31+ cells [recent thymic emigrants (RTE)/μL], and MBD-related factors [(serum PTH, FGF23, and alkaline phosphatase (ALP) level] in 125 patients with non-dialysis dependent CKD.