CD4 and hip fracture: The frequency of senescent CD28-ve (p = .001), CD57+ve (p = .001), KLRG1+ve (p = .03) CD8 T cells, as well as senescent CD28-ve CD4+ve (p = .01) and CD57+ve CD4+ve (p = .003) T cells were higher in depressed hip fracture patients compared with healthy controls and the frequency of CD28-ve CD8 T cells was also higher when compared to patients with hip fracture alone (p = .01).