Impact of Everolimus and Low-Dose Cyclosporin on Cytomegalovirus Replication and Disease in Pediatric Renal Transplantation

In order to investigate the hypothesis that the mammalian target of rapamycin inhibitor everolimus (EVR) shows anticytomegalovirus (CMV) activity in pediatric patients, we analyzed the impact of EVR-based immunosuppressive therapy on CMV replication and disease in a large cohort (n = 301) of pediatric kidney allograft recipients. The EVR cohort (n = 59), who also received low-dose cyclosporin, was compared with a control cohort (n = 242), who was administered standard-dose cyclosporin or tacrolimus and an antimetabolite, mostly mycophenolate mofetil (91.7%). Multivariate analysis revealed an 83% lower risk of CMV replication in the EVR cohort than in the control cohort (p = 0.005). In CMV high-risk (donor+/recipient-) patients (n = 88), the EVR-based regimen was associated with a significantly lower rate of CMV disease (0% vs. 14.3%, p = 0.046) than the standard regimen. In patients who had received chemoprophylaxis with (val-)ganciclovir (n = 63), the CMV-free survival rates at 1 year and 3 years posttransplant (100%) were significantly (p = 0.015) higher in the EVR cohort (n = 15) than in the control cohort (n = 48; 1 year, 75.0%; 3 years, 63.3%). Our data suggest that in pediatric patients at high risk of CMV, an EVR-based immunosuppressive regimen is associated with a lower risk of CMV disease than a standard-dose calcineurin inhibitor-based regimen.

Premature ageing of the immune system relates to increased anti-lymphocyte antibodies (ALA) after an immunization in HIV-1-infected and kidney-transplanted patients

Low-affinity immunoglobulin (Ig)G with potential autoreactivity to lymphocytes and hypergammaglobulinaemia have been described previously in HIV-1-infected patients. Whether such antibodies increase after challenging the immune system, for example with an immunization, is not known. In the present study, the modulation of antibodies with low affinity and potential autoreactivity was evaluated after 2012-13 seasonal flu vaccination with a simple empirical laboratory test measuring the titres of anti-lymphocyte antibodies (ALA) in two different models of secondary immunodeficiency: HIV-1 vertically infected patients (HIV) and patients treated with immunosuppressive therapies after kidney transplantation (KT) compared to healthy individuals (HC). In parallel, the activation status of B cells and their degree of immune senescence was evaluated by measuring the B cell interleukin (IL)-21R expression/plasma IL-21 levels and the frequencies of mature-activated (MA) and double-negative (DN) B cells. A significant increase of ALA titres was observed after vaccination in HIV and KT but not in HC, and this correlated directly with the frequencies of both MA and DN and inversely with the B cell IL-21R expression. This suggests that the quality of an immune response triggered by flu vaccination in HIV and KT may depend upon the activation status of B cells and on their degree of immune senescence. Further investigations are needed to verify whether high frequencies of MA and DN may also relate to increase autoimmunity after immunization in high-risk populations.

Quantitative bone ultrasonography at phalanges in patients with high-risk monoclonal gammopathy of unknown significance (MGUS) and myeloma treated with zoledronic acid

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Background: Bisphosphonates are commonly used for metastatic bone disease in order to prevent skeletal-related events, to reduce bone pain and to improve quality of life. Zoledronic acid is commonly used in myeloma patients (pts), but additional studies are needed to determine the optimal timing, schedule and duration of treatment. Aim of the present study is to assess bone mineral density (BMD) in patients with high-risk MGUS and myeloma receiving zoledronic acid, using quantitative ultrasound analysis in transmission through phalanges. Methods: DBM Sonic Bone Profiler is the only ultrasound device that applies the method of signal analysis in transmission through phalanges. This technique has proven to be particularly effective in the diagnosis and treatment monitoring of post-menopausal osteoporosis. Measurements of BMD were performed by ultrasonography at distal metaphysis of the first phalanx of the II, III, IV and V hand finger, at baseline and at 1, 3, 6, 9, 12, 15 and 18 months. Results: 12 pts with high-risk MGUS (8 IgG k, 4 IgG lambda) and 4 pts with myeloma IIIA (3 IgG k, 1 IgA lambda), 6 males/ 10 females, median age 69 years, received zoledronic acid 4 mg intravenously every 4 weeks for at least 12 courses. All subjects took daily oral supplements containing elemental calcium (1 g) and vitamin D (400 IU). Myeloma patients also received chemotherapy. 4/6 males (66%) and 5/10 females (50%) improved amplitude-dependent speed of sound (AD-SoS) over the least significant change after 6 months. Mean difference from baseline value of AD-SoS shows a trend after 4 months of treatment, and became significant after 16 months (p<0.005). Conclusions: Densitometric-structural evaluation of bone tissue at phalanges is safe and useful to evaluate bone quality changes during treatment with zoledronic acid, that determines a significant and sustained increase in ultrasonographic parameters of bone density and structure.

No significant financial relationships to disclose.

[Pharmacotherapy of sepsis]

Despite an increasingly understanding of the pathogenetic mechanisms of sepsis, its mortality remains extremely high, caused mainly by hemodynamic impairment-related alterations frequently present in severe sepsis. Currently, treatment of sepsis is based on hemodynamic support, antibiotic therapy, surgical excision of infectious foci and immunomodulatory therapy. In fact, a massive host inflammatory infection response has recently emerged to substantially contribute to the development of septic shock and multiple organ dysfunction. Many clinical trials on various pharmacological agents have been conducted: glucocorticoids, nonsteroidal anti-inflammatory drugs (NSAIDs), antithrombin III (AT III), anti-endotoxin monoclonal antibodies, nitric oxide inhibitors, interleukin-1 receptor antagonist, anti-tumor necrosis factor (TNF) antibodies. Apart from some likely favourable findings connected to low doses of glucocorticoids, most studies yielded disappointing results. Nevertheless, the use of recombinant human activated protein C (drotrecogin-alpha) has recently proven to have a mortality reduction effect particularly in patients with severe sepsis and dysfunction of at least two organs. Furthermore, the early treatment of hemodynamic instability with volume expanders and vasopressors (early goal-directed therapy), and a strict glycemic control represent important measures in order to significantly reduce mortality from severe sepsis and septic shock, and are fundamental guidelines recommended by most scientific societies (Surviving Sepsis Campaign).

[Pharmacokinetic principles and drug-dosing adjustments during continuous renal replacement therapies (CRRT)]

In the critically ill, acute renal failure (ARF) and "Multiple Organ Dysfunction Syndrome" (MODS) can be associated with significant modifications of many pharmacokinetic parameters, such as protein binding, volume of distribution and total body clearance. The start of renal replacement therapy (RRT) represents an additional variable to take in consideration for drug-dosing adjustments. Drugs significantly eliminated by the kidney are likely to be removed during RRT and a supplemental dose or further dosing adjustments are required if extracorporeal clearance is more than 25-30% of total body clearance. The impact of RRT on plasma drug concentrations can be substantially different in relation to the type of treatment (diffusive, convective or both), membrane characteristics (low-flux or high-flux), filter surface area and prescribed dialysis dose. The molecular weight cut-offs of high-flux membrane are much higher than the molecular weight of most drugs. Therefore, molecular size will not be a limitation for the removal of the unbound fraction of the drugs most commonly used in the critically ill undergoing continuous renal replacement therapy (CRRT). However, diffusive clearance could be significantly lower than convective clearance for drugs in the middle molecular weight range. In any case, the extracorporeal clearances report-ed with the use of high-volume CRRT (>50-60 L/2 h) are often surprisingly elevated and can lead to drug underdosing in clinical conditions where adequate antibiotic treatment is essential.

[Acute renal failure following cardiac surgery]

Acute renal failure (ARF) develops in 1-30% of patients who undergo cardiac surgery and is associated with a high mortality rate (15-30%). Several risk factors (pre- and intra-operative) for ARF have been identified. Pre-operative factors are strictly related to cardiovascular disease, advanced age and baseline renal dysfunction, while intra-operative factors are linked with the type of cardiac surgery, the duration of cardiopulmonary bypass and aortic cross-clamping. These factors provide an opportunity to quantify the risk of ARF based on pre-operative data, and for this purpose a clinical score to predict post-operative ARF has recently been developed. Moreover, this score could allow the identification of those patients who may take advantage of preventive strategies. Mortality in patients who develop severe ARF requiring dialysis is particularly high (50-80%). Therefore, an early diagnosis of ARF and a timely and aggressive renal replacement therapy could improve the outcome.

Efficiency of different hollow-fiber hemofilters in continuous arteriovenous hemodiafiltration

Low dialysate to blood flow rate ratios are a unique characteristic of continuous arteriovenous hemodiafiltration (CAVHDF) that should allow complete saturation of dialysis fluid with small-molecular-weight blood solutes. The aim of the investigation was to evaluate the performance of different hemofilters in CAVHDF. In 10 critically ill patients with acute renal failure, the efficiency of four hollow-fiber hemofilters, polyamide 0.6 m(2), polyacrylonitrile (PAN) 0.3 and 0.6 m(2), acrylonitrile sodium methallylsulfonate (AN69HF) 0.6 m(2), has been evaluated. For comparison, dialysate flow rates (Q(di)) were standardized to 16.6 and 25 ml/min. Samples for urea nitrogen were obtained from the arterial blood line (C(bi)) and from the dialysate exit port (C(do)) within 24-hour running time. Outflowing dialysate (Q(do)) was also measured at the same time. Blood flow (Q(b)) was calculated by the bubble transit time technique. Diffusive and total urea clearances were determined. AN69HF and PAN hemofilters provided higher clearances than the polyamide hemofilter. Despite the smaller surface area, PAN 0.3 m(2) had a total urea clearance comparable to that of PAN 0.6 m(2) and AN69HF at Q(di) = 16.6 ml/min. While at Q(di) = 16.6 ml/min equilibrium between blood and dialysate (C(do)/C(bi) congruent with 1) occurred with the AN69HF and PAN hemofilters, at Q(di) = 25 ml/min the equilibrium was obtained only with the AN69HF hemofilter. In conclusion, almost complete urea saturation of dialysis fluid has not been obtained with all hemofilters tested here. In our experience, membrane characteristics play an important role in determining diffusive efficiency in CAVHDF.