L. Poli

Detection of T suppressor cells in patients with organ allografts.

Specific immunosuppression of hosts immune response to donor HLA antigens has been a major goal to clinical transplantation. Recent evidence has been accumulating to show that a distinct population of T cells expressing the CD8(+) CD28(-) phenotype display suppressor function and inhibit Th activation and proliferation by modulating the APC function. To assess the presence of Ts in transplant recipients circulation, we have developed a flow cytometry method that measures the expression of costimulatory molecules on donor APC exposed to recipient Th and Ts. Our results demonstrate that quantitation of the capacity of CD8(+) CD28(-) T cells from patient circulation to suppress the activation of costimulatory molecules (CD80, CD86) on donor APC offers a reliable tool for monitoring specific immunosuppression against the graft in solid organ transplantation.

RIFLE Criteria and Hepatic Function in the Assessment of Acute Renal Failure in Liver Transplantation

Renal dysfunction in cirrhotic patients is primary related to disturbances of circulatory function, triggered by portal hypertension with chronic intrarenal vasoconstriction and hypoperfusion. Pretransplant renal function is an important factor implicated in the development of acute renal failure (ARF) after liver transplantation (OLT), but other factors mostly related to liver function seem to influence the development of ARF. The Acute Dialysis Quality Initiative workgroup developed the RIFLE classification to define ARF. We sought to evaluate the incidence of ARF among patients undergoing OLT, to evaluate the association of ARF with pre-OLT renal and hepatic functions, and to evaluate the influence of ARF on chronic kidney disease (CKD) at 1 month post-OLT. Clinical, renal, hepatic function, and donor risk index data of 24 patients who underwent deceased donor OLT were collected before transplantation, in the perioperative period and in the first month post-OLT. ARF occurred in 37.5% of patients with 56% developing the R grade and 44% the I grade; no patient showed the F grade. An association was observed between ARF and a higher Model for End-Stage Liver Disease (MELD) score and between ARF and a reduced pre-OLT serum albumin. No association was noted between ARF and other pre-OLT parameters. In cirrhotic patients serum creatinine is a bias for renal function assessment and the Modification of Diet in Renal Disease formula overestimates GFR. Post-OLT CKD was present in 6.7% of patients without ARF and in 44.4% of patients with ARF. The R grade developed more frequently among patients with viral cirrhosis. The association of ARF with MELD and hypoalbuminemia may be the result of a close relationship between renal and hepatic functions among cirrhotic patients. Post-OLT CKD may be the result of unrecognized, preexisting CKD and/or the effects of not fully resolved acute damage to an injured kidney.

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.

Immunoadsorption with protein A in humoral rejection of kidney transplants

The presence of alloantibodies may play a role in accelerated or acute humoral rejection. Different therapeutic strategies based on a removal of anti donor antibodies and prevention of their resynthesis have been used in the management of transplant rejection episodes. Immunoadsorption with staphylococcal protein A, a method to selectively remove immunoglobulin G, may represent a new treatment to reverse humoral rejection in kidney transplantation. From 1991 to January 1996, such a method was used in 23 patients in whom an acute humoral rejection developed over a mean period of 14.1 +/- 9.5 days after operation. Twenty-two patients had been transplanted from living donors and one from a cadaveric donor. The ages ranged from 23 to 58 years (mean, 34 +/- 10 years). All transplants were performed according to a negative direct crossmatch. Basic immunosuppression included cyclosporine, steroids, azathioprine, and antilymphocyte globulin or monoclonal antibodies (OKT3). Rejection was diagnosed on the basis of hematochemical tests, Doppler ultrasonography, and kidney biopsy. Only steroid and monoclonal and polyclonal antibody resistant rejections with > 165% positive direct crossmatches against the donor were treated with Protein A immunoabsorption. The procedure used is based on the treatment of 2-3 plasma volumes for the first 2 days and then every other day until a negative crossmatch is obtained, together with improvement in clinical status (mean treatments, 7.3 +/- 4.5 [range, 4-23]; mean duration of treatment, 12.3 +/- 10.2 days [range, 3-44]). From the start of treatment, azathioprine is replaced by cyclophosphamide at a dose of 1-2 mg/kg/day. During treatment, a remarkable fall in immunoglobulin G levels is achieved on the first day, whereas immunoglobulin M titers remain constant, with a slight decrease in serum albumin. Immediately after treatment, a negative crossmatch was found in 22 (95.6%) of 23 patients. In six patients (26%), graft function did not recover, and one patient (4.3%) died. Preliminary results show that immunoabsorption with staphylococcal protein A may be an effective support in the treatment of humoral acute rejection, particularly when it is performed as soon as an early diagnosis of humoral rejection is made. In fact, such treatment has a highly selective adsorption, allows treatment of large volumes of plasma, and can achieve a rapid decrease in the titer of circulating immunoglobulins.

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.

Clinical Results of Treatment of Postsurgical Endotoxin-Mediated Sepsis With Polymyxin-B Direct Hemoperfusion

We evaluated the possibility of preventing the evolution of endotoxin-mediated sepsis in severe septic shock using early treatment of critical endotoxemia with polymyxin-B direct hemoperfusion (PMX-DHP). Thirty-eight postsurgical patients who fulfilled at least 2 criteria for systemic inflammatory response syndrome were stratified on the basis of the value of the endotoxin activity assay. Seventeen patients who demonstrated high risk of endotoxin activity (>or=0.6) received standard therapy plus PMX-DHP every 24 hours to lower the endotoxin activity level to less than 0.4, and the remaining 21 patients with endotoxin activity levels less than 0.6 received standard therapy only. Seven patients required 2 courses of PMX-DHP therapy, 8 required 3 courses, and 2 required 4 courses. After treatment, mean arterial pressure increased, from 69.00 mm Hg to 81.35 mm Hg (P < .01); heart rate decreased, from 105.40 bpm to 78.12 bpm (P < .01); white blood cell count decreased, from 20,700 cells/mm(3) to 9740 cells/mm(3) (P < .01); arterial oxygen tension-fraction of inspired oxygen ratio increased, from 273.82 to 305.82 (P < .01); and Sequential Organ Failure Assessment score decreased, from 7 to 4 (P < .01). Length of stay was longer for transplant recipients (16 days) than for other surgical patients (8(1/2) days). All patients survived to 28-day follow-up, and 15 of 16 patients (94%) had survived at 60-day follow-up. Despite the small number of patients included in the study, the encouraging results suggest that PMX-DHP is a useful therapeutic strategy for lowering sepsis-related mortality.

Pathfast presepsin assay for early diagnosis of bacterial infections in surgical patients: preliminary study.

BACKGROUND Various biomarkers have been studied for diagnosing bacterial infections, seeking to stop the sepsis cascade. Presepsin, which is ∼13 kDa in size, has been identified to increase specifically in the blood of sepsis patients. Additionally, measurement of presepsin is useful to evaluate the severity of infection and monitor clinical responses. We evaluated the analytical and clinical performance of the Pathfast presepsin (PFP) assay system for early diagnosis of infection. MATERIALS AND METHODS From November 2011 to June 2012 we studied 70 adult patients, including 35 cadaveric organ transplant recipients and 35 abdominal surgery patients. The 32 female and 38 male subjects had a mean age of 56.1 years (range, 19-70). Heparinized whole blood for PFP assay was tested at 48 hours after surgery together with blood cultures. RESULTS The mean presepsin level (PL) in the 50 positive patients was 3,957.45 pg/mL (range 255-20,000). For transplant patients, PL was 3,034.43 ± 2,880.791 pg/mL, with 30 positive results. Microbiologic findings confirmed the presence of bacterial infections within 69 ± 2.5 hours from enrollment despite that when the test was performed, 70% showed no sign or symptom of infection. In 15 abdominal surgery patients, the PFP test was negative with negative blood cultures. The positive PFP test in 20 other abdominal surgery patients showed PL of 2,363 ± 7,988.47 pg/mL in the absence of signs or symptoms of infection in 25% of them. The 20 positive patients showed positive blood cultures within 67 ± 1.8 hours from enrollment. CONCLUSIONS The PFP test had a (100%) sensitivity to show the presence of infection in a short time (15 min), confirmed by positive blood cultures.

Model for end-stage liver disease score versus simplified acute physiology score criteria in acute renal failure after liver transplantation

Hepatic function and renal failure are closely related among patients with end-stage liver disease (ESLD) due to splanchnic hemodynamic mechanisms that characterize advanced decompensated cirrhosis. Acute renal failure (ARF) is a frequent complication that occurs immediately post-orthotopic liver transplantation (OLT). The Model for End-stage Liver Disease (MELD) score describes the survival of patients with ESLD awaiting OLT related to the severity of liver disease. The Simplified Acute Physiology Score (SAPS II) is a mortality prediction model that scores the severity of illness among intensive care unit patients. In a previous study we observed an association between ARF post-OLT and a higher MELD score, but it was not clear whether this association depends on the grade of ESLD or on the critical condition of liver transplant patients. The aim of this study was to evaluate the association of ARF with MELD score and/or SAPS II criteria among liver transplant patients. We analyzed 46 patients with ESLD who underwent deceased donor OLT. All patients were evaluated at baseline and in the first 7 days post-OLT. According to the RIFLE classification, the incidence of the worst grade of ARF post-OLT was 19.2%. These patients showed significantly higher MELD scores, while there was no association with systemic parameters related to the critical patients condition or with the mortality score as evaluated by SAPS II criteria. We confirmed the association between renal failure and hepatic function among liver transplant patients. A more severe degree of hepatic dysfunction before OLT was associated with a greater incidence of ARF that can adversely affect patient survival.

Meaning of early polyomavirus-BK replication post kidney transplant.

Polyomavirus BK (BKV) infection is ubiquitous in the human population. Under immunosuppression, BKV can undergo reactivation resulting in viral replication. What really happens in the early hours posttransplantation is not clearly defined; the meaning of early viremia and viruria is not clear. BKV viremia is considered a marker of infection. The aim of our study was to investigate the prevalence of early BKV infection in kidney transplant patients, to evaluate the relationship to infections at 3 and 6 months and the association with recipient, donor, and graft features. We enrolled 36 kidney transplanted patients from May 2006 to April 2007. BKV load was measured on plasma and urine samples by Q-PCR at 12 hours (T(0)/early) as well as 3 (T(3)) and 6 (T(6)) months thereafter. A high percentage of BKV infections were detectable in the first hours after transplantation (33.3%), which remained unchanged to month 6 post transplantation. Moreover, patients who were positive at T(0) had a high probability of remaining positive thereafter. The number of copies in plasma samples tended to increase at 3 months and to decrease thereafter, whereas the urine viral load tended to steadily increase. Among BKV-positive patients, we identified 2 groups according to viremic state at T(0): 9 patients (group A); who were already positive and remained so to T(6) 5 and 3 patients who turned positive at 3 or at 6 months, respectively (group B). Group A included 75% of positive patients at T(0) and 90% of positive patients at either T(3) or T(6) (P = .007). The most important contribution of our study was to highlight the presence of BKV infection in renal transplant recipients from the first hours posttransplantation. This condition seemed to be the most important risk factor for persistent infection in the first 6 months.

Acute Renal Failure in Liver Transplant Recipients: Role of Pretransplantation Renal Function and 1-Year Follow-Up

Chronic renal failure and acute renal failure (CRF and ARF) are common complications after orthotopic liver transplantation (OLT) that adversely affect patient survival. Many factors influence the development of ARF in the OLT setting. In a previous study we reported an association between ARF and the development of CRF at 1 month after OLT. The aims of our study were to evaluate the influence of ARF on short-, middle-, and long-term renal function after OLT and its influence on 1-year survival of patients and grafts. Fourty-four patients who underwent deceased donor OLT between August 2008 and August 2010 were evaluated pretransplantation, in the perioperative period, and at 1, 6, and 12 months posttransplantation. ARF was associated with CRF at 1 month post-OLT, whereas no association was observed at 6 and 12 months post-OLT. The development of CRF at 6 months post-OLT was associated with pre-OLT renal dysfunction and 1 month post-OLT CRF. Four patients died in the ARF group, whereas 3 patients died in the group without ARF. We confirmed ARF to be a predictive event for short-term renal dysfunction. The majority of patients recovered renal function after the first month. Although many pre-, peri-, and post-OLT factors may contribute to the development of posttransplantation CRF, pre-OLT CRF seemed to be the most important risk factor.