Alessandra Bachetoni

Continuous terlipressin versus vasopressin infusion in septic shock (TERLIVAP): a randomized, controlled pilot study.

IntroductionRecent clinical data suggest that early administration of vasopressin analogues may be advantageous compared to a last resort therapy. However, it is still unknown whether vasopressin and terlipressin are equally effective for hemodynamic support in septic shock. The aim of the present prospective, randomized, controlled pilot trial study was, therefore, to compare the impact of continuous infusions of either vasopressin or terlipressin, when given as first-line therapy in septic shock patients, on open-label norepinephrine requirements.MethodsWe enrolled septic shock patients (n = 45) with a mean arterial pressure below 65 mmHg despite adequate volume resuscitation. Patients were randomized to receive continuous infusions of either terlipressin (1.3 μg·kg-1·h-1), vasopressin (.03 U·min-1) or norepinephrine (15 μg·min-1; n = 15 per group). In all groups, open-label norepinephrine was added to achieve a mean arterial pressure between 65 and 75 mmHg, if necessary. Data from right heart and thermo-dye dilution catheterization, gastric tonometry, as well as laboratory variables of organ function were obtained at baseline, 12, 24, 36 and 48 hours after randomization. Differences within and between groups were analyzed using a two-way ANOVA for repeated measurements with group and time as factors. Time-independent variables were compared with one-way ANOVA.ResultsThere were no differences among groups in terms of systemic and regional hemodynamics. Compared with infusion of .03 U of vasopressin or 15 μg·min-1 of norepinephrine, 1.3 μg·kg-1·h-1 of terlipressin allowed a marked reduction in catecholamine requirements (0.8 ± 1.3 and 1.2 ± 1.4 vs. 0.2 ± 0.4 μg·kg-1·min-1 at 48 hours; each P < 0.05) and was associated with less rebound hypotension (P < 0.05). At the end of the 48-hour intervention period, bilirubin concentrations were higher in the vasopressin and norepinephrine groups as compared with the terlipressin group (2.3 ± 2.8 and 2.8 ± 2.5 vs. 0.9 ± 0.3 mg·dL-1; each P < 0.05). A time-dependent decrease in platelet count was only observed in the terlipressin group (P < 0.001 48 hours vs. BL).ConclusionsThe present study provides evidence that continuous infusion of low-dose terlipressin – when given as first-line vasopressor agent in septic shock – is effective in reversing sepsis-induced arterial hypotension and in reducing norepinephrine requirements.Trial registrationClinicalTrial.gov NCT00481572.

Phenylephrine versus norepinephrine for initial hemodynamic support of patients with septic shock: a randomized, controlled trial.

IntroductionPrevious findings suggest that a delayed administration of phenylephrine replacing norepinephrine in septic shock patients causes a more pronounced hepatosplanchnic vasoconstriction as compared with norepinephrine. Nevertheless, a direct comparison between the two study drugs has not yet been performed. The aim of the present study was, therefore, to investigate the effects of a first-line therapy with either phenylephrine or norepinephrine on systemic and regional hemodynamics in patients with septic shock.MethodsWe performed a prospective, randomized, controlled trial in a multidisciplinary intensive care unit in a university hospital. We enrolled septic shock patients (n = 32) with a mean arterial pressure below 65 mmHg despite adequate volume resuscitation. Patients were randomly allocated to treatment with either norepinephrine or phenylephrine infusion (n = 16 each) titrated to achieve a mean arterial pressure between 65 and 75 mmHg. Data from right heart catheterization, a thermodye dilution catheter, gastric tonometry, acid-base homeostasis, as well as creatinine clearance and cardiac troponin were obtained at baseline and after 12 hours. Differences within and between groups were analyzed using a two-way analysis of variance for repeated measurements with group and time as factors. Time-independent variables were compared with one-way analysis of variance.ResultsNo differences were found in any of the investigated parameters.ConclusionsThe present study suggests there are no differences in terms of cardiopulmonary performance, global oxygen transport, and regional hemodynamics when phenylephrine was administered instead of norepinephrine in the initial hemodynamic support of septic shock.Trial registrationClinicalTrial.gov NCT00639015

GLIBENCLAMIDE DOSE RESPONSE IN PATIENTS WITH SEPTIC SHOCK: EFFECTS ON NOREPINEPHRINE REQUIREMENTS, CARDIOPULMONARY PERFORMANCE, AND GLOBAL OXYGEN TRANSPORT

Adenosine triphosphate-sensitive potassium channels are important regulators of arterial vascular smooth muscle tone and are implicated in the pathophysiology of catecholamine tachyphylaxis in septic shock. The present study was designed as a prospective, randomized, double-blinded, clinical pilot study to determine whether different doses of glibenclamide have any effects on norepinephrine requirements, cardiopulmonary hemodynamics, and global oxygen transport in patients with septic shock. We enrolled 30 patients with septic shock requiring invasive hemodynamic monitoring and norepinephrine infusion of 0.5 μg·kg−1·min−1 or greater to maintain MAP between 65 and 75 mmHg. In addition to standard therapy, patients were randomized to receive either 10, 20, or 30 mg of enteral glibenclamide. Systemic hemodynamics, global oxygen transport including arterial lactate concentrations, gas exchange, plasma glucose concentrations, and electrolytes were determined at baseline and after 3, 6, and 12 h after administration of the study drug. Glibenclamide decreased plasma glucose concentrations in a dose-dependent manner but failed to reduce norepinephrine requirements. None of the doses had any effects on cardiopulmonary hemodynamics, global oxygen transport, gas exchange, or electrolytes. These data suggest that oral glibenclamide in doses from 10 to 30 mg fails to counteract arterial hypotension and thus to reduce norepinephrine requirements in catecholamine-dependent human septic shock.

Once Daily Tacrolimus Formulation: Monitoring of Plasma Levels, Graft Function, and Cardiovascular Risk Factors

BACKGROUND Advagraf, an extended release formulation of tacrolimus, is administered once daily during the morning fast. Tacrolimus can be safely converted from the twice daily formulation (Prograf) to the same dose (1 mg:1 mg) of once daily dosing tacrolimus (m-Tac). The adverse effects of tacrolimus play important roles in posttransplant cardiovascular risk factors (CVR): hyperglycemia, posttransplant diabetes mellitus, dyslipidemia and hypertension. It has been suggested that avoiding high tacrolimus peak levels minimizes its diabetogenic effects leading to better glycemic control. The aim of our study was to observe the effects of conversion to m-Tac therapy on graft function and CVR among stable transplant kidney recipients. METHODS We selected 2 groups of 20 patients with stable kidney transplantation, who had been treated with Prograf for >6 months with a triple regimen. Group 1 were converted to once daily tacrolimus at the same dose (1 mg:1 mg); whereas in group 2, the therapy was maintained as a twice daily regimen. Blood pressure, creatinine and glomerular filtration rate levels evaluated by the Modification of Diet in Renal Disease formula, as well as urea, total, high- and low-density lipoprotein remained stable between the 2 groups as well as inside group 1 before and after conversion. RESULTS After conversion, glycemia and triglyceride values showed significant reductions in group 1 and between the 2 groups. These results were significant, as they may be associated with better long-term graft and patient survivals.

Improvement of Graft Function after Conversion to Once Daily Tacrolimus of Stable Kidney Transplant Patients

BACKGROUND Chronic renal dysfunction is present in about one quarter of kidney transplant patients at 1 year and in about 90% by 10 years. Nephrotoxicity caused by calcineurin inhibitors is among the most common factors. Elevated tacrolimus levels have been correlated with worse control of side effects including acute and/or chronic nephrotoxicity. The aim of this study was to observe the effects on graft function of conversion from the twice daily to the once daily extended release tacrolimus formulation in stable kidney transplant recipients within 5 years of grafting. METHODS Thirty-one stable kidney transplant patients were converted at the same dosage (1 mg:1 mg). Patients served as their own controls based on results before versus after conversion. RESULTS The trough levels of tacrolimus showed a slight albeit significant reduction after the conversion. Serum creatinine and glomerular filtration rate showed a significant improvement without an association with the tacrolimus trough levels. CONCLUSION We suggest that the immunosuppression with once daily tacrolimus may be a good option for kidney transplant patients.

Effector Th-1 cells with cytotoxic function in the intestinal lamina propria of patients with Crohn's disease

A large body of evidence points to a pivotal relationship between Th-1 cells and mucosal inflammation in Crohns disease (CD). The aim of the present study was to assess whether CD is associated with specific functional activity of lamina propria T lymphocytes (LPT), particularly purified CD4, such as cytotoxic activity and specific cytokine-secreted profile. The results showed that CD4 LPT in patients displayed a chronically activated memory-like surface phenotype and, when compared to controls, had a significantly enhanced antibody-redirected cytotoxicity. Interestingly, the ratio of perforin expression in CD4 LPT was higher compared to controls, and a redirected lysis of human RBC mediated by a CD4 subset of intestinal lamina propria was evident, suggesting a cytolytic pore-forming mechanism. Moreover, a unique Th-1 cytokine profile pattern in the CD4 cells from CD was defined. These effector cells produced 12 times more IFN-γ, two times more TNF-α, and three times less IL-4 than controls. In contrast, no increase in IL-2 was detected, while IL-5 was undetectable. Our studies suggest that these preexisting in vivo activated CD4 LPT may play an important role in the inflammatory process in CD, thus directly contributing to the intestinal lesions.

Falsely elevated tacrolimus concentrations measured using the ACMIA method due to circulating endogenous antibodies in a kidney transplant recipient

BACKGROUND Therapeutic monitoring of whole-blood concentration of tacrolimus, a potent immunosuppressive drug used after organ transplantation, is essential to avoid toxic effects and to maintain the correct dosage. Although the reference method for the determination of tacrolimus concentrations is LC-MS/MS, several certified immunoassays are widely used for routine examinations. We report falsely elevated blood tacrolimus concentrations using the antibody-conjugated magnetic immunoassay (ACMIA) from Siemens Healthcare Diagnostics for the analysis of a patient who had undergone renal transplantation. METHODS Whole-blood samples from a patient with elevated tacrolimus concentrations not consistent with the clinical picture were analysed with an alternative immunoassay and were investigated for interference by performing double dilution tests, by incubating in heterophilic blocking tubes and by evaluating plasmatic interfering factors. RESULTS Double dilution tests showed a clear nonlinearity, suggesting that antibody interference not related to heterophilic antibodies had occurred; false-positive concentrations of cyclosporin obtained when using an antibody-conjugated to β-galactosidase suggested the presence of endogenous antibodies directed against β-galactosidase. CONCLUSION In patients receiving tacrolimus, continued surveillance by laboratory staff and clinicians is necessary when using a method not requiring external pre-treatment, such as the Siemens ACMIA method.

Enhanced production of interferon-γ by T lymphocytes cloned from rejected kidney grafts

Seventy-seven T cell clones were generated from cell blasts infiltrating rejected kidney allografts. All clones, either CD4 or CD8, displayed cytolytic activity evaluated by lectin-dependent cell-mediated cytotoxicity (LDCC) and natural killer activities. Furthermore, both types of clones were able to produce IFN-gamma following PHA stimulation. These data suggest that the graft infiltrate is characterized by T cell clones with cytolytic potential responsible for the killing of graft cells. The production of IFN-gamma, enhancing the class II MHC expression, may amplify the recipient immune response.

Diltiazem impairs maturation and functions of human dendritic cells

The aim of this study was to define the effects of diltiazem, a calcium antagonist drug used in cardiology and in clinical transplantation, on the differentiation and maturation of human dendritic cells (DC). Herein, we demonstrate that diltiazem, in association with granulocyte macrophage-colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), induces monocytes to differentiate into cells with many of the characteristic of DC. However, diltiazem-induced DC express high levels of mannose receptor and Fc gamma RII and, consequently, manifest a higher endocytic activity compared with GM-CSF+IL-4-induced DC. Importantly, diltiazem-induced DCs have an impaired responsiveness to lipopolysaccharide and CD40 ligand because they produce decreased levels of IL-12 and reveal a reduced ability to stimulate alloreactive T-cell responses as well as in inducing interferon-gamma producing Th1 cells. These effects may contribute to a decreased DC-dependent T-cell activation and may help to explain the immunoregulatory function of diltiazem and its effectiveness in preventing transplant rejection.

Presepsin as a potential marker for bacterial infection relapse in critical care patients. A preliminary study.

Abstract Background: Systemic bacterial infection carries a high risk of mortality in critical care patients. Improvements in diagnostic procedures are required for effective management of sepsis. Recently, the soluble CD14 subtype, or presepsin, has been suggested as a reliable marker of sepsis, and we set out to compare its diagnostic performance with that of procalcitonin (PCT). We focused on a cohort of septic patients who, during their hospitalization, relapsed after a period of clinical relief from symptoms. Methods: In total 21 adult patients were studied during their hospitalization in the Critical Care Unit of Policlinico Umberto I hospital; 74 plasma samples were collected at multiple time points, and presepsin levels were measured using a PATHFAST® analyzer. Results: Presepsin and PCT were significantly lower in healthy controls than in sepsis or severe sepsis (p<0.001), both enabled a significant difference to be detected between systemic inflammatory response syndrome (SIRS) and severe sepsis (p<0.05). The area under the curve (AUC) calculated from the receiver operating characteristic (ROC) curve analysis was 0.888 for presepsin and 0.910 for PCT. In those patients in whom a clinical recurrence of sepsis was observed, while PCT levels normalized during the transient remission phase, presepsin levels (>1000 pg/mL) remained high. Conclusions: This study confirms the importance of monitoring a combination of several biomarkers in order to obtain a reliable diagnosis. Maximal presepsin levels could alert clinicians not to suspend antibiotic treatments and to carefully monitor septic patients’ state of health, even after clinical symptoms have disappeared and PCT levels returned to normal.