Real-time predictions of seabird distribution improve oil spill risk assessments.

Current knowledge of the distribution of sensitive seabirds is inadequate to safeguard seabird populations from impacts of oil spills in the Arctic. This gap is mainly driven by the fact that statistical models applied to survey data are coarse-scale and static with limited documentation of the distributional dynamics and patchiness of seabirds relevant to risk assessments related to oil spills. This paper describes a dynamic modelling framework solution for prediction of fine-scale densities and movements of seabirds in close-to-real time using fully integrated 3-D hydrodynamic models, dynamic habitat suitability models and agent-based models. The modelling framework has been developed and validated for the swimming migration of Brünnich's Guillemot Uria lomvia in the Barents Sea. The results document that the distributional dynamics of Brünnich's Guillemot and other seabird species to a large degree can be simulated with in-situ state variables and patterns reflecting the physical meteorology and oceanography and habitat suitability.

Calcineurin inhibitor avoidance with daclizumab, mycophenolate mofetil, and prednisolone in DR-matched de novo kidney transplant recipients.

BACKGROUND: Calcineurin inhibitor (CNI)-free regimens posttransplantation have been claimed to conserve graft function in addition to reduce the risk factors for cardiovascular and malignant disease in renal transplant recipients. METHODS: The primary aim of this prospective, open-label, randomized, parallel-group, single-center study was to compare the effect of complete CNI-avoidance posttransplant (daclizumab + mycophenolate mofetil + prednisolone: Dac-group, n=27) with the standard CNI-based immunosuppressive protocol at our transplant unit (cyclosporine A + mycophenolate mofetil + prednisolone: CsA-group, n=27) on renal function (glomerular filtration rate [GFR] determined as plasma clearance of 51Cr-EDTA) in a selected low immunogenic risk population (DR-matched, PRA-negative de novo cadaveric transplant recipients). RESULTS: There were no significant difference in GFR at week 10 (P=0.61), but GFR was significantly (P=0.029) lower in the Dac-group (52+/-20 ml/min) at month 12 than in the CsA-group (69+/-29 ml/min). One-year patient and graft survival did not differ between the two groups. Overall acute rejection rate was 70.4% (19/27) in the Dac-group and 29.6% (8/27) in the CsA-group (P=0.006). CONCLUSIONS: The strategy to select DR-matched, PRA-negative de novo cadaveric transplant recipients for a CNI-avoidance protocol was not successful. The incidence of acute rejection was unacceptable high even though anti-CD25 antibody induction as well as initial higher mycophenolate mofetil doses (3 g/day) were applied, and renal function was significantly lower in the CNI-avoidance patients at 1 year. Other strategies need to be examined for avoidance of CNI's in the early posttransplant period.

Two corticosteroid-free regimens-tacrolimus monotherapy after basiliximab administration and tacrolimus/mycophenolate mofetil-in comparison with a standard triple regimen in renal transplantation: results of the Atlas study.

BACKGROUND: The side effects associated with corticosteroids have led to efforts to minimize their use in renal transplant patients. In this study we compared two corticosteroid-free tacrolimus-based regimens with a standard triple therapy. METHODS: This was a 6-month, phase III, open-label, parallel-group, multicenter study. The total analysis set comprised 451 patients, randomized (1:1:1) to receive tacrolimus (Tac) monotherapy following basiliximab (Bas) administration (n=153), Tac/mycophenolate mofetil (MMF) (n=151), or, Tac/MMF/corticosteroids triple therapy as a control (n=147). RESULTS: The study was completed by 91.2% (triple therapy), 94.7% (Tac/MMF), and 82.4% (Bas/Tac) of patients. Patient baseline characteristics were similar in all groups. The incidences of biopsy-proven acute rejection were 8.2% (triple therapy), 30.5% (Tac/MMF), and 26.1% (Bas/Tac), p<0.001 (multiple test for comparison with triple therapy); Bas/Tac vs. Tac/MMF, p=ns. The incidences of corticosteroid-resistant acute rejection were 2.0%, 4.0%, and 5.2%, p=ns. Graft survival (95.9%, 96.7%, and 94.7%, p=ns) and patient survival (100%, 99.3%, and 99.3%, p=ns) were similar in all groups. Median serum creatinine at month 6 was 123.0 micromol/L (triple therapy), 134.7 micromol/L (Tac/MMF) and 135.8 micromol/L (Bas/Tac). The overall safety profiles were similar; differences (p<0.05) were reported for anaemia (24.5% vs. 12.6% vs. 14.5%), diarrhoea (12.9% vs. 17.9% vs. 5.9%), and leukopenia (7.5% vs. 18.5% vs. 5.9%) for the triple therapy, Tac/MMF, and Bas/Tac group, respectively. The incidences of new-onset diabetes mellitus were 4.6%, 7.1%, and 1.4%, respectively. CONCLUSION: Corticosteroid-free immunosuppression was feasible with the Bas/Tac and the Tac/MMF regimens. Both corticosteroid-free regimens were equally effective in preventing acute rejection, with the Bas/Tac therapy offering some safety benefits.

Individualized T cell monitored administration of ATG versus OKT3 in steroid-resistant kidney graft rejection.

Acute steroid-resistant rejection episodes are recommended to be treated with set doses of anti-thymocyte globulin (ATG) or anti-CD3 monoclonal antibody (OKT3). Individualized T cell monitoring has been proposed as a tool for dose finding. A randomized study comparing the efficacy and safety of ATG (n = 27) with OKT3 (n = 28) in the treatment of biopsy verified acute steroid-resistant rejection (ASRR) when both drugs were administered on the basis of daily individualized T cell measurements. A drop to below 50 cells/mm3 CD2+ T cells was considered adequate and used to guide the dose of ATG/OKT3. Demographic, clinical and histopathological severities of rejections were equal in the two groups. During the 10 days of T cell monitoring and antibody treatment, 13 patients were in need of dialysis (ATG = 7/OKT3 = 6). Two grafts did not respond to antibody treatment and were lost due to rejection (ATG = 1/OKT3 = 1). There were 26 biopsy verified re-rejections (ATG = 12/OKT3 = 14) within the first 3 months following antibody treatment. Mean serum creatinine (micromol/L) was similar in the two groups (ATG/OKT3: before rejection 157 +/- 72/151 +/- 88, at start of antibody treatment 308 +/- 125/330 +/- 94, end of antibody treatment 254 +/- 122/246 +/- 144 and at follow-up after a mean of 32 months 166 +/- 55 (n = 24)/164 +/- 57(n = 23)). To keep the T cell count below 50 cells/mm3, average dose ATG given was 354 +/- 151 mg (2.3 administrations, range 1-4) and average OKT3 was 32.5 +/- 6.8 mg in 10 doses. In conclusion, individualized T cell monitored administration of ATG and OKT3 is safe and seems as effective as a standard set dose in treatment of ASRR. Tailoring the dose for each individual patient lowers the cost.

The impact of cytomegalovirus infection and disease on rejection episodes in renal allograft recipients.

Cytomegalovirus (CMV) infection and disease are potential risk factors for acute allograft rejection in renal transplant recipients. The present study specifically addresses this issue. From October 1994 to July 1997, 477 consecutive renal allograft recipients (397 first transplants and 80 retransplants) were included in the study. CMV infection (cytomegalovirus pp65 antigen in leukocytes) and disease (infection and clinical symptoms or signs of disease) were examined prospectively for 3 months. No CMV prophylaxis was given, and CMV disease was treated with intravenous (i.v.) ganciclovir. The retransplantation of four patients transplanted twice during the study and 22 patients receiving kidneys from human leucocyte antigen (HLA)-identical siblings were excluded from statistical analysis. Rejections were evaluated clinically [277(61%)] and 173 (38%) also had a biopsy verified rejection. CMV infection occurred in 64% of the patients and 24% experienced CMV disease. In a multiple time-dependent Cox analysis, CMV infection and CMV disease were independent significant predictors for clinical acute rejections, RR = 1.6 (1.1-2.5, p = 0.02) and RR = 2.5 (1.2-5.1, p = 0.01), respectively. Among 173 patients with biopsy verified rejection, 72% of the patients had tubulointerstitial rejection whereas 28% had a vascular rejection. CMV disease, but not CMV infection was a predictor of tubulointerstitial rejection, RR = 3.1 (1.1-9.3, p = 0.04). CMV infection and disease are independent risk factors for clinical acute rejection in kidney allograft recipients. CMV disease is an independent risk factor for biopsy verified acute tubulointerstitial rejection in kidney allograft recipients.