Neutrophil gelatinase-associated lipocalin and cystatin C in cirrhosis and portal hypertension: Relations to organ extraction and dysfunction.

BACKGROUND AND AIMS: Early detection of renal dysfunction in cirrhosis is important, and several renal biomarkers have been put forward. Neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C are markers of renal dysfunction, but relations to splanchnic and systemic hemodynamics and kinetics are sparsely studied in cirrhosis. In patients with cirrhosis and portal hypertension, we studied plasma levels and renal, hepatic, and peripheral extraction of NGAL and cystatin C and relations to patients characteristics, liver dysfunction, and hemodynamics. METHODS: Forty-five cirrhotic patients (Child class A/B/C:15/15/15) and 15 controls were evaluated with a full clinical, biochemical, and hemodynamic assessment. Urine and regional plasma concentrations of NGAL and cystatin C were measured. RESULTS: There was no significant difference in circulating or hepatic NGAL or cystatin C between all patients and controls but a trend towards increased levels with increasing Child class. In addition, there was a significant renal but no hepatic or systemic extraction of both NGAL and cystatin C (P < 0.001). Plasma NGAL correlated with glomerular filtration rate (r = -0.56, P < 0.0001), and hepatic venous pressure gradient (r = 0.34,P = 0.02) and urinary NGAL correlated with heart rate (r = 0.58, P= 0.007), blood pressure (r = -0.46, P < 0.05), cardiac output (r = 0.45, P < 0.05), and systemic vascular resistance (SVR) (r = -0.48, p < 0.05). Plasma cystatin C correlated with hepatic venous pressure gradient (r = 0.45, P < 0.005), blood pressure (-0.40, P < 0.01), and glomerular filtration rate (r = 0.98, P < 0.000). CONCLUSIONS: Extractions of NGAL and cystatin C levels seem largely unaffected by the severity of liver disease in cirrhosis with a renal extraction. These biomarkers therefore have the potential of being both valuable in diagnosing renal failure and reflecting the degree of portal hypertension and systemic haemodynamic changes.

Soluble urokinase plasminogen activator receptor (suPAR) in acute care: a strong marker of disease presence and severity, readmission and mortality. A retrospective cohort study.

OBJECTIVE: Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker associated with presence and progression of disease and with increased risk of mortality. We aimed to evaluate the unspecific biomarker suPAR as a prognostic marker in patients admitted to acute care. METHODS: This registry-based retrospective cohort study included 4343 consecutively admitted patients from the Acute Medical Unit at a large Danish university hospital. Time to readmission and death were analysed by multiple Cox regression. Results were reported as HRs for 30-day and 90-day follow-up. RESULTS: During 30-day follow-up, 782 patients (18.0%) were readmitted and 224 patients (5.2%) died. Comparing 30-day readmission and mortality between patients in the highest and lowest suPAR quartiles yielded HRs of 2.11 (95% CI 1.70 to 2.62) and 4.11 (95% CI 2.46 to 6.85), respectively, when adjusting for age, sex, Charlson score and C reactive protein. Area under the curve for receiver operating characteristics curve analysis of suPAR for 30-day mortality was 0.84 (95% CI 0.81 to 0.86). Furthermore, in the entire cohort, women had slightly higher suPAR compared with men, and suPAR was associated with age, admission time, admission to intensive care unit and Charlson score. CONCLUSIONS: In this large unselected population of acute medical patients, suPAR is strongly associated with disease severity, readmission and mortality after adjusting for all other risk factors, indicating that suPAR adds information to established prognostic indicators. While patients with low suPAR levels have low risk of readmission and mortality, patients with high suPAR levels have a high risk of adverse events.

Identifying the potential of changes to blood sample logistics using simulation.

Using simulation as an approach to display and improve internal logistics at hospitals has great potential. This study shows how a simulation model displaying the morning blood-taking round at a Danish public hospital can be developed and utilized with the aim of improving the logistics. The focus of the simulation was to evaluate changes made to the transportation of blood samples between wards and the laboratory. The average- (AWT) and maximum waiting time (MWT) from a blood sample was drawn at the ward until it was received at the laboratory, and the distribution of arrivals of blood samples in the laboratory were used as the evaluation criteria. Four different scenarios were tested and compared with the current approach: (1) Using AGVs (mobile robots), (2) using a pneumatic tube system, (3) using porters that are called upon, or (4) using porters that come to the wards every 45 minutes. Furthermore, each of the scenarios was tested in terms of what amount of resources would give the optimal result. The simulations showed a big improvement potential in implementing a new technology/mean for transporting the blood samples. The pneumatic tube system showed the biggest potential lowering the AWT and MWT with approx. 36% and 18%, respectively. Additionally, all of the scenarios had a more even distribution of arrivals except for porters coming to the wards every 45 min. As a consequence of the results obtained in the study, the hospital decided to implement a pneumatic tube system.

Plasma adiponectin in patients with active, early, and chronic rheumatoid arthritis who are steroid- and disease-modifying antirheumatic drug-naive compared with patients with osteoarthritis and controls.

OBJECTIVE: Rheumatoid arthritis (RA) is a systemic chronic inflammatory joint disease, whereas osteoarthritis (OA) is a local joint disease with low-level inflammatory activity. The pathogenic role of the adipocytokine adiponectin is largely unknown in these diseases. We hypothesized (1) that plasma adiponectin concentrations differ in healthy controls and patients with early disease-modifying antirheumatic drug (DMARD)-naive RA, chronic RA, and OA; (2) that changes in adiponectin are observed during methotrexate (MTX) treatment of chronic RA; and (3) that adiponectin correlates to disease activity measures in RA. METHODS: Plasma adiponectin was analyzed with a validated in-house immunoassay. We measured adiponectin in healthy controls (n = 45) and patients with early DMARD-naive RA (n = 40), chronic RA (n = 74), and OA (n = 35). In a subgroup of patients with chronic RA (n = 31), the longitudinal effect of MTX treatment on adiponectin (Week 0 vs Week 28) was investigated. RESULTS: Adiponectin differed significantly between healthy controls (mean 4.8 +/- SD 2.7 mg/l) and the 3 groups, with 8.9 +/- 4.8 mg/l in early RA, 11.6 +/- 5.6 mg/l in chronic RA, and 14.1 +/- 6.4 mg/l in OA. Longitudinally, MTX treatment increased adiponectin significantly from 9.7 +/- 4.5 mg/l at Week 0 to 11.0 +/- 4.5 mg/l at Week 28 in chronic RA. No correlations to disease activity measures were found. CONCLUSION: Both early DMARD-naive and chronic RA were associated with higher plasma adiponectin compared to healthy controls, but lower plasma adiponectin than OA. Adiponectin increased 13% during MTX treatment. In patients with RA and OA body mass index, age, sex, and disease activity measures failed to explain the findings.

Patients with rheumatoid arthritis treated with methotrexate (MTX): concentrations of steady-state erythrocyte MTX correlate to plasma concentrations and clinical efficacy.

OBJECTIVE: To investigate the accumulation of methotrexate (MTX) in circulating erythrocytes and the association with pharmacokinetic variables, weekly dose, and clinical efficacy in 2 cohorts of patients with chronic active rheumatoid arthritis (RA) undergoing MTX monotherapy. METHODS: Seventy-six patients with RA were included in this open prospective study: 40 were included before initiation of MTX therapy. Laboratory analyses, intracellular MTX concentrations in erythrocytes (Ery-MTX), and clinical examinations including toxicity data were performed prospectively for 52 weeks. Plasma concentrations of MTX were measured and area under the plasma concentration versus time curve (AUC) was estimated along with other pharmacokinetic variables in a population based software model. RESULTS: Ery-MTX rose after initiation of therapy and reached a steady state after 6-8 weeks. The correlation between steady-state Ery-MTX and dose was poor (r(2) = 0.16), whereas steady-state Ery-MTX levels correlated strongly with the estimated AUC (r(2) = 0.51, log-transformed variables). Both steady-state Ery-MTX levels and estimated AUC were significantly higher in patients responding to MTX therapy than in patients classified as nonresponders according to American College of Rheumatology core criteria and were similar to patients on longterm MTX therapy. CONCLUSION: Our results indicate that clinical efficacy and Ery-MTX may have a causal relation and that measurement of Ery-MTX or estimation of AUC in a software model provides useful guidelines to the clinician when starting MTX therapy in patients with RA. The latter can be performed immediately after initiation of therapy.

[Uniform reference intervals and harmonised results in clinical biochemistry in Scandinavia--light ahead]. / Ens referenceintervaller og harmoniserede resultater inden for klinisk biokemi i de nordiske lande--der er lys forude.

Danish laboratories are introducing identical reference intervals for a number of biochemical components in accordance with a Nordic agreement and recommendations during 2007. Danish doctors will consequently experience both changes in reference interval limits as well as adjustments of patients' levels of reported results for some components.

The calcineurin activity profiles of cyclosporin and tacrolimus are different in stable renal transplant patients.

Cyclosporin and tacrolimus remain the cornerstone immunosuppressive drugs in organ transplantation. Dosing and monitoring these drugs is based on pharmacokinetic protocols, but measuring a pharmacodynamic parameter, calcineurin phosphatase (CaN) activity, could be a valuable supplement in determining optimal doses. Forty stable renal transplant patients were investigated three times in a 6-month period. Blood samples were drawn at 0, 1, 2, 3 and 4 h after oral intake of tacrolimus (FK) or cyclosporin at days 1 and 180. At day 90, one blood sample at trough level (FK) or C2 level (cyclosporin A, CsA) was drawn. CaN activity was determined in whole blood as the release of 32P from a phosphorylated peptide. Activity of the 32P was quantitated by liquid scintillation and results converted to Units CaN, utilizing a calibration curve with CaN. We demonstrated that calcineurin activity profiles at days 1 and 180 were the same for both drugs. Furthermore, we found that patients treated with tacrolimus or cyclosporin displayed different calcineurin activity profiles. We found that cyclosporin displayed greater calcineurin inhibition than tacrolimus. We have demonstrated that the two drugs exert significantly different effects on calcineurin activity in renal transplant patients with stable, well-functioning grafts and that tacrolimus-treated patients can maintain good, stable graft function with minimal CaN inhibition.

Correlations between calcineurin phosphatase inhibition and cyclosporine metabolites concentrations in kidney transplant recipients: implications for immunoassays.

Cyclosporine exhibits a wide spectrum of metabolites that vary considerably in the extent to which they interfere with the various parent drug monitoring immunoassays. There is no consensus regarding the clinical significance of metabolites. Cyclosporine exerts its immunosuppressive action by inhibiting the enzyme calcineurin phosphatase. Determination of the enzyme's activity is one of the most promising pharmacodynamic markers. It is unknown how calcineurin phosphatase inhibition correlates with various cyclosporine monitoring assays and what is the potential impact of metabolites in this perspective? The aim of the present study was to determine the concentration of cyclosporine (by means of three different assay methods) and the four most significant metabolites (AM1, AM4N, AM9, and AM1C) in relation to calcineurin phosphatase inhibition. Twelve randomly selected cyclosporine-treated renal transplant patients were included in the study. Blood samples were drawn before, 1, 2, 3, 4, 6, 8, and 12 hr after oral intake of cyclosporine. Parent drug and metabolites were determined by liquid chromatography/tandem mass spectrometry (LC/MSMS). Additionally, cyclosporine concentration was determined by the enzyme multiplied immunoassay technique (EMIT) and by the polyclonal fluorescence polarization immunoassay (pFPIA). Calcineurin phosphatase activity was measured by its ability to dephosphorylate a previously phosphorylated 19-amino acid peptide. We found that calcineurin phosphatase inhibition correlates strongly with parent cyclosporine metabolites concentrations determined by all three assay methods. Determination methods that took metabolites into consideration exhibit stronger correlations with calcineurin phosphatase inhibition (sum of cyclosporin plus metabolites r=-0.93, LC/MSMS; pFPIA r=-0.94, P

Randomized, concentration-controlled trial of topiramate in refractory focal epilepsy.

OBJECTIVE: To establish the concentration response of topiramate in patients with refractory focal epilepsy. METHODS: Sixty-five patients with more than eight seizures during an 8-week baseline were randomized to three prespecified plasma levels (low, 6 micromol/L [2 mg/L]; medium, 31 micromol/L [10.5 mg/L]; and high, 56 micromol/L [19 mg/L]). Topiramate treatment was titrated to one of the prespecified plasma levels during an 8-week titration period, followed by a 12-week observation period. RESULTS: The overall median (25th to 75th percentile) reduction in seizures during the observation compared with baseline was 50% (9.5 to 90%). In the individual groups, the median reduction was as follows: low, 39% (13 to 70%); medium, 85% (41 to 96%); and high, 39% (2.0 to 81%). The primary outcome of the trial was the comparison of seizure reduction (Mann-Whitney U test) between the low and the medium group (p = 0.03). Comparisons between the other groups were as follows: medium vs high (p = 0.05) and low vs high (p = 0.81). Psychiatric adverse events and adverse events related to the CNS were the most frequently encountered. Most adverse events showed concentration response, particularly between low and medium levels. CONCLUSIONS: Patients assigned to the medium plasma level (31 micromol/L [10.5 mg/L]) had the best seizure outcome. Patients in the medium and high groups experienced more adverse events than patients in the low group. Optimal treatment response is thus most likely found at plasma concentrations higher than 6 micromol/L (2 mg/L), but no further increase in efficacy seems to occur at concentrations above 31 micromol/L (10.5 mg/L).