Marco Formica

Coupled Plasma Filtration Adsorption

Sepsis is one of the main causes of death in critically ill patients worldwide, and in many cases it is associated with renal and/or other organ failure. However, we do not have a unique efficient therapy to reduce this extremely high mortality rate. In the last years interest around the use of extracorporeal blood purification techniques has increased. One of the emerging treatments in patients with severe sepsis and septic shock is coupled plasma filtration adsorption (CPFA), a novel extracorporeal blood purification therapy aimed at a nonselective reduction of the circulating levels and activities of both pro- and anti-inflammatory mediators. Early experimental studies and the following clinical trials have demonstrated impressive results regarding hemodynamics and respiratory parameters, even in patients without concomitant acute renal injury, paralleled by a quick tapering of vasoactive drugs. Considering the still high morbidity and mortality rates in septic shock patients, this new blood purification technique seems to have benefits when applied early in the course of sepsis, also without renal indications, suggesting that it might be performed to prevent rather than to treat acute kidney injury.

Renal replacement therapy in intensive care units: a survey of nephrological practice in northwest Italy

BACKGROUND Few reports have addressed how current practice reflects uncertainty as to the optimal management of renal replacement therapy (RRT) in Western countries. Current dialytic practice for 2007 in the northwest of Italy was assessed. METHODS A total of 24 nephrology and dialysis centers covering all of the RRT provided in the intensive care units (ICUs) in northwest Italy took part in the survey. Consultant nephrologists of each center reported their own activities throughout the year 2007 by an e-mailed questionnaire. RESULTS RRT for a total of 7,842 days was provided by 24 dialysis centers in 79 ICUs for 1,118 patients. RRT median duration (5.76 days/patient) increased with the increasing number of hospital ICU beds. Of the RRT cases, 69.9% were due to acute kidney injury, 23.6% for continuation of a treatment in chronic dialysis patients and 4.2% for extrarenal indications. More than 90% of the patients were treated with high permeability membranes, at a median target dosage of 35.0 ml/kg per hour in continuous (39.4%) or extended modality (6-14 hours, 38.5%). Unfractionated heparin was the most common anticoagulant used (67.5%, median 500 IU/hour). In patients at high risk of bleeding, RRT without or with heparin at low-dose + saline flushes was the most commonly adopted line of treatment, followed by citrate (18% of days of dialysis). The decision to start RRT was made by nephrologists alone or in collaboration with intensivists, whereas dose prescriptions were given by nephrologists alone. CONCLUSIONS This survey may represent a useful starting point for further research into changes in RRT practice and the adoption of common, shared protocols.

Study protocol: the DOse REsponse Multicentre International collaborative initiative (DO-RE-MI)

IntroductionCurrent practices for renal replacement therapy in intensive care units (ICUs) remain poorly defined. The DOse REsponse Multicentre International collaborative initiative (DO-RE-MI) will address the issue of how the different modes of renal replacement therapy are currently chosen and performed. Here, we describe the study protocol, which was approved by the Scientific and Steering Committees.MethodsDO-RE-MI is an observational, multicentre study conducted in ICUs. The primary end-point will be the delivered dose of dialysis, which will be compared with ICU mortality, 28-day mortality, hospital mortality, ICU length of stay and number of days of mechanical ventilation. The secondary end-point will be the haemodynamic response to renal replacement therapy, expressed as percentage reduction in noradrenaline (norepinephrine) requirement. Based on the the sample analysis calculation, at least 162 patients must be recruited. Anonymized patient data will be entered online in electronic case report forms and uploaded to an internet website. Each participating centre will have 2 months to become acquainted with the electronic case report forms. After this period official recruitment will begin. Patient data belong to the respective centre, which may use the database for its own needs. However, all centres have agreed to participate in a joint effort to achieve the sample size needed for statistical analysis.ConclusionThe study will hopefully help to collect useful information on the current practice of renal replacement therapy in ICUs. It will also provide a centre-based collection of data that will be useful for monitoring all aspects of extracorporeal support, such as incidence, frequency, and duration.

Intradialytic Cytokine Gene Expression

Along with the numerous technological improvements in molecular biology, polymerase chain reaction, which permits analysis of sequences of a very small amount of biological material, enables evaluation of hemodialysis-induced gene transcription of inflammatory cytokines. Blood samples drawn from 22 hemodialysis patients, treated with cellulose- derived or synthetic membranes, were collected at 0 and 15 min of hemodialysis. Total RNA, purified from mononuclear cells, was reverse transcribed and cDNA amplified by polymerase chain reaction primed with specific oligomers in order to determine tumor necrosis factor α (TNFα), interleukin (IL) 1β and IL6 gene expression. Plasma samples were collected at 0 and 180 min for detection of mature cytokines by enzyme immunoassay with plates pre-coated with monoclonal antibodies to TNFα, IL1β and IL6. A significant increase in TNFα mRNA was detected at 15 min of hemodialysis in 12 of 22 patients: 5 of 9 treated with cuprophan; 3 of 3 with cellulose triacetate; 3 of 5 with polysulfone, and only 1 of 5 treated with polymethylmethacrylate membranes. A parallel increase in IL1β or IL6 mRNA was detected, and significant relationships were found between TNFα and IL1β (p < 0.001), and IL1β and IL6 gene expression (p < 0.05). Increased levels of mature TNFα and IL1β molecules in plasma were detected in the majority of patients showing an increased cytokine gene expression. However, the absolute amount of cytokine mRNA transcription at 15 min did not predict the levels of mature molecules reached in plasma at 180 min. Cytokine mRNA transcription is quite common at the beginning of a dialysis run. Possibly due to intracellular degradation of critical sequences of cytokine mRNA, gene expression does not necessarily imply translation into mature protein. It is suggested that mechanisms related to cell-to-cell interaction, which may possibly involve procytokine biology, are needed to drive phenomena of cytokine activation to clinical effectiveness.

The prevalence of peripheral neuropathy in hemodialysis patients.

BACKGROUND/AIMS Uremic Neuropathy (UN) highly limits the individual self-sufficiency causing near-continuous pain. An estimation of the actual UN prevalence among hemodialysis patients was the aim of the present work. METHODS We studied 225 prevalent dialysis patients from two Italian Centers. The Michigan Neuropathy Score Instrument (MNSI), already validated in diabetic neuropathy, was used for the diagnosis of UN. It consisted of a questionnaire (MNSI_Q) and a physical-clinical evaluation (MNSI_P). Patients without any disease possibly inducing secondary neuropathy and with MNSI score ≥ 3 have been diagnosed as affected by UN. Electroneurographic (ENG) lower limbs examination was performed in these patients to compare sensory conduction velocities (SCV) and sensory nerve action potentials (SNAP) with the MNSI results. RESULTS 37 patients (16.4%) were identified as being affected by UN, while 9 (4%) presented a score < 3 in spite of neuropathic symptoms. In the 37 UN patients a significant correlation was found between MNSI_P and SCV (r2 = 0.1959; p < 0.034) as well as SNAP (r2 = 0.3454; p = 0.027) both measured by ENG. CONCLUSIONS UN is an underestimated disease among the dialysis population even though it represents a huge problem in terms of pain and quality of life. MNSI could represent a valid and simple clinical-instrumental screening test for the early diagnosis of UN in view of an early therapeutic approach.

WHAT IS THE ROLE OF SENSITIZATION IN UREMIC PRURITUS ? : AN ALLERGOLOGIC STUDY

Patch tests were carried out to evaluate the presence of a sensitization to some components of dialytic circuits in 17 uremic patients complaining of pruritus of unknown origin. Fragments of different dialyzer membranes, of tubing sets, of dialyzer membranes recently resterilized with ethylene oxide and the International Contact Dermatitis Research Group standard series substances were tested. Neither patients nor healthy subjects reacted positively to patch tests, which leads us to question the role of contact allergy in the determination of uremic pruritus.

Clinical effects of online dialysate and infusion fluids

Online hemodiafiltration appears to be the most effective technique of renal replacement therapy in many respects. Removal of small and high‐molecular weight substances is enhanced. Modern technology ensures a safe, online production of reinfusion fluids. Nonetheless, stringent maintenance rules are required for the production of sterile and nonpyrogenic‐dialysate solutions. In this review, we will critically review the state of the art of the clinical effects derived from the use of ultrapure dialysate and the online production of dialysate fluids in high‐flux hemodiafiltration.

Outcome of dialysis patients submitted to coronary revascularization

Cardiovascular disease accounts for almost half of the total mortality in patients with end stage renal disease (ESRD). It has recently been debated whether coronary revascularization has the same rate of risks and successes in this cohort of patients compared to patients without renal disease. Since 1991, 17 dialysis patients were submited to coronary revascularization in our center. Seven patients were following peritoneal, 10 hemodialytic treatment. Four patients were submitted to percutaneous transluminal coronary angioplasty (PTCA) and 13 to surgical revascularization (CABG). In 2 patients the coronary lesion was unique, in the others stenosis of multiple vessels were found. Six patients were diabetic. The mean age at the onset of the coronary artery disease (CAD) was 57.17 ± 11.6 years. The mean time elapsed from the onset of the CAD and the performance of the PTCA or CABG was 30.1 ± 35.4 months. The mean time from beginning of dialysis treatment to revascularization was 48.2 ± 39.6 months. Mean hemoglobin values were 9.7 ± 1 g/dL, mean phosphorus values were 5.2 ± 8.7 mg/dL, mean cholesterol values were 211 ± 49.5 mg/dL. The procedure was technically successful in all patients. Mean survival was 25.09 ± 28.12 months. Twelve patients died, 5 of whom within one month. Survival at one month was 70.5%, at 6 months 58.8%, at one year 52.9%, at 2 years 47%. There was neither significant difference patients submitted to PTCA and those submitted to CABG, nor between diabetic and non-diabetic patients. In conclusion, coronary revascularization in our experience is a high risk procedure in dialysis patients. The reasons for this could be the severe general conditions of these patients affected with diffuse vasculopathy and the long time elapsed since the onset of the ischemic cardiopathy. Thus, our results could suggest the opportunity of performing earlier screening of coronary situation and revascularization treatment in CAD dialysis patients.

N-Acetylcysteine in hemodialysis diabetic patients resets the activation of NF-kB in lymphomonocytes to normal values.

BACKGROUND Oxidative stress pathways are activated in diabetes, particularly when dialysis is required (DD). NF-kB is activated in this clinical condition. Since N-Acetyl-cysteine (NAC) is an anti-oxidant, we aimed at investigating its effect in modulating NF-kB activation in lymphomonocytes (PBMC) of DD patients. METHODS Twenty-five DD patients were enrolled in a cross-over designed study. Tests were performed at T0 and after one month (T1) of treatment with NAC and three months after NAC withdrawal. We assessed NF-kB activation by EMSA, levels of advanced oxidation protein products (AOPP) by spectral analysis, total antioxidant capacity (TAC) by colorimetry, and apoptosis by FACS. RESULTS At T0 a statistically significant increased activation of the subunits of NF-kB, p50/p65, was detected in PBMC of DD patients in comparison to controls (both P<.0001). After one month of NAC both p50-p50/p50-p65 dimers were significantly reduced (P<.004 and .006). Three months after drug withdrawal NF-kB increased again to basal levels (P<.002 and P<.001 vs. end of treatment with NAC). AOPP and TAC levels and the percentage of apoptotic PBMC revealed modifications in accordance with NFkB activation. In a multivariate linear regression model using delta AOPP as the dependent variable and delta p50-p50, delta TAC, and delta APO as independent variables, we found that all three dependent parameters all retained an independent correlation with delta AOPP. CONCLUSIONS Our data indicate in vivo a modulation by NAC of parameters indicating a redox imbalance in DD patients on hemodialysis. The use of NAC might suggest a potential clinical benefit.

A solid phase enzyme immunoassay for the measurement of urinary albumin and the detection of microalbuminuria

A test for the measurement of trace urinary albumin concentrations, which is suitable for the detection of microalbuminuria, was developed. The technique is an indirect enzyme-linked assay (ELISA) in which a fixed amount of anti-albumin antibody is placed into polystyrene tubes coated with human albumin, together with the urine sample to be tested. The albumin in the test specimen competes with the solid-phase albumin for binding to the added antibody. The test is precise (inter- and intra-assay coefficients of variation were 8.2% and 7.8%, respectively), accurate (mean recovery 102-106% for two human albumin preparations), and sensitive (detection limit 0.9 micrograms/ml). These characteristics are not dissimilar from those of the radioimmunoassay reported in the literature, with the advantages of being completely safe, easy to perform, and not requiring expensive equipment. Using this assay the urinary albumin excretion in 20 normal subjects was found to be 2.5 +/- 2.2 micrograms/min (range 0.9-7.5 micrograms/min) after 8 hours of bed rest and 4.5 +/- 5.7 micrograms/min (range 1.5-2.0 micrograms/min) after 8 hours of moderate physical activity.