BK Polyomavirus-Specific 9mer CD8 T Cell Responses Correlate With Clearance of BK Viremia in Kidney Transplant Recipients: First Report From the Swiss Transplant Cohort Study.

BK polyomavirus (BKPyV) causes premature kidney transplant (KT) failure in 1-15% of patients. Because antivirals are lacking, most programs screen for BKPyV-viremia and, if positive, reduce immunosuppression. To evaluate the relationship of viremia and BKPyV-specific immunity, we examined prospectively cryopreserved plasma and peripheral blood mononuclear cells at the time of transplantation (T0) and at 6 mo (T6) and 12 mo (T12) after transplant from 28 viremic KT patients and 68 nonviremic controls matched for the transplantation period. BKPyV IgG seroprevalence was comparable between cases (89.3%) and controls (91.2%; p = 0.8635), but cases had lower antibody levels (p = 0.022) at T0. Antibody levels increased at T6 and T12 but were not correlated with viremia clearance. BKPyV-specific T cell responses to pools of overlapping 15mers (15mer peptide pool [15mP]) or immunodominant CD8 9mers (9mer peptide pool [9mP]) from the early viral gene region were not different between cases and controls at T0; however, clearance of viremia was associated with stronger 9mP responses at T6 (p = 0.042) and T12 (p = 0.048), whereas 15mP responses were not informative (T6 p = 0.359; T12 p = 0.856). BKPyV-specific T cells could be expanded in vitro from all patients after transplant, permitting identification of 78 immunodominant 9mer epitopes including 50 new ones across different HLA class I. Thus, 9mP-responses may be a novel marker of reconstituting CD8 T cell function that warrants further study as a complement of plasma BKPyV loads for guiding immunosuppression reduction.

Quality of life after acute type B dissection in the era of thoracic endovascular aortic repair.

BACKGROUND: Conservative management of acute type B aortic dissection is currently being challenged by primary thoracic endovascular aortic repair. Aim was to assess outcome and quality of life after these different approaches using an adjusted standard population as benchmark. PATIENTS AND METHODS: Observational study of a prospectively collected (January 2000 to December 2005) consecutive series of 87 patients with acute type B aortic dissection. Patients were 63 +/- 13 years old and 68 were men (78.2 %). Seventy-two were managed conservatively (83 %) and 15 invasively (12 by endovascular aortic repair). Follow-up was 36 +/- 19 months. Endpoints were early and late morbidity and mortality, and long-term quality of life as assessed by the Short Form health survey questionnaire. RESULTS: Patient cohorts were similar regarding age, risk profile and local disease. In the conservative cohort, four patients died during early (5.6 %) and eight during long-term follow-up (cumulative four years survival rate 79 %). Thirty-two patients needed secondary surgical management (44 %), i.e. delayed aortic repair (n = 11), or interventions on adjacent aortic sections or major branches (n = 21). In the surgical cohort no patient died, and no repeated interventions were necessary after the peri-operative period. Long-term quality of life scores were 100 (69-115) in conservatively and 94 (75-124) in invasively managed patients. Normal scores range from 85 to 115. CONCLUSIONS: Primary endovascular management of uncomplicated acute type B dissection is safe and leads to excellent long-term results, whereas secondary interventions were required with high incidence after initial conservative management. Long-term quality of life, however, returned to normal with any successful treatment strategy.