Alterations in the Kinetics of CD4+ T Cell Responses with Aging / 대한류마티스학회지

OBJECTIVE: Alterations in the immune system occur with aging, and these contribute to an increased risk of infection and malignancy. The age-associated changes in T cell immunity range from single cell function to the maintenance of cell populations. We investigated the kinetics of CD4+ T cell activation and proliferation in young and elderly subjects after stimulating their peripheral blood mononuclear cells with anti-CD3 and anti-CD28 antibodies (Abs). METHODS: The expressions of the activation markers CD69, CD40L and CD25 on the CD4+ T cells from young (n=14) and elderly (n=19) were analyzed at 6, 24 and 48 hours (hrs) of T cell receptor (TCR) stimulation by using flow cytometry. In the same individuals, the CD4+ T cell proliferation was determined at 48 and 96 hrs of TCR stimulation by using the CFSE dilution method. RESULTS: The elderly had decreased CD69 and CD40L expressions on the CD4+ T cells at 6 hrs of stimulation, as compared to that of the young patients. The elderly also had a decreased CD25 expression on the CD4+ T cells at 24 hrs of stimulation. However, the two groups had similar levels of the CD25, CD69 and CD40L expressions at 48 hrs of stimulation. The elderly had decreased CD4+ T cell proliferation at 96 hrs of stimulation, as compared to that of the young, although both groups had similar levels of CD4+ T cell proliferation at 48 hrs of stimulation. CONCLUSION: Our findings suggest that the elderly have altered kinetics of CD4+ T cell activation and proliferation in response to anti-CD3 and -CD28 Ab stimulation, and that such an altered response is governed by the duration of stimulation.

Revascularization of Popliteal Artery Injury in Trauma Around Knee Joint

Popliteal artery injury in blunt trauma of knee joint is not common but poses high rate of amputation due to anatomical characteristics or delayed diagnosis and treatment. The aim of the present study is to review the authors' experiences with this condition and identify factors contributing to disability. We reviewed 7 cases of popliteal artery injury in trauma around knee. Injury mechanism, type of vessel damage, associated injuries, mangled extremity severity scores (MESS), ischemic time and additional treatments were analyzed. Tibial fracture, distal femoral fracture and serious soft tissue defect were combined. Mean MESS was 9.9 point and mean time of revascularization was 7.1 hours. Transfemoral amputation was performed in 2 cases due to vascular insufficiency and devastating infection, and 4 patients were able to walk without any support at the last follow up. Age, the severity of soft tissue injury, ischemic time and MESS are thought to be related to prognosis, and young patients with short ischemic time show best results, but authors experienced one exceptional case. We have to consider multiple factors related to the prognosis in popliteal artery injury with fractures around knee, and careful decision is needed regarding to early amputation.