Surgical Complications in En Bloc Renal Transplantation.

En bloc pediatric transplantation (EBPT) began with the aim of increasing the donor pool due to the existing high demand for donors. At its inception, it was considered a type of suboptimal transplantation due to its association with a high incidence of vascular, urologic, and immunologic complications. The main objective of this study was to update information on EBPT with the largest case series that exists on a worldwide scale. In a retrospective study, the results obtained from brain-dead donors (BDDs; n = 770) were compared to those of EBPT (n = 100) from January 1990 to December 2012. The median of follow-up was 12.8 years (interquartile range 8.1 to 17.2). The variables collected for analysis were demographic factors (age and sex of recipients, age and weight of donors), renal function, graft survival, recipient survival, surgical complications (thrombosis, lymphocele, urologic complications, and renal artery stenosis and need for revascularization with angioplasty and/or stents). Subsequently in a second analysis, we studied the association between graft survival, thrombosis, angioplasty, stents, and appearance of lymphoceles with the different factors that were considered to be related in accordance with published literature and our own experience. Graft loss due to surgical complications was more frequent in EBPT than in BDD (15% vs 2.2 % in BDD; P < .001), and interstitial fibrosis and tubular atrophy were more frequent in BDD (13% vs 2%; P < .001). EBPT offers a good survival rate after overcoming the possible surgical complications that may arise.

Anemia in kidney transplants without erythropoietic agents: levels of erythropoietin and iron parameters.

AIM: To study the association between hemoglobin, endogenous erythropoietin (EPO) levels and ferric parameters in kidney recipients not treated with EPO-stimulating agents. MATERIALS AND METHODS: Transverse study of 219 kidney transplant outpatients. The median time after transplantation was 54 months (P(25-75), 23-107). We assessed blood counts, ferric parameters, EPO levels, renal function (MDRD-4), and adjuvant treatment. We performed a linear regression analysis to predict hemoglobin. RESULTS: Median EPO values were 14.05 mUI/mL (P(25-75) = 10.2-19.7). Applying the formulas described by Beguin, kidney transplant recipients showed a low observed/expected ratio of erythropoietin and of transferrin. Considering anemia to be an hemoglobin of < 12 g/dL in women and < 13 g/dL in men, 24.2% of subjects were anemic (n = 53), including 2.3% with hemoglobin < 11 g/dL. Anemic patients displayed worse renal function (49.2 ± 18.5 versus 55.46 ± 16.58 mL/min/1.73 m(2) in nonanemic; P = .021). There were no differences in C-reactive protein. The patients receiving a combination of angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor blockers (ARB) showed the highest prevalence of anemia compared with other groups (42.9%, P = .027). EPO levels were significantly lower among patients treated with these drugs (P = .041), without differences in transferrin and ferritin. The percentage of anemic patients treated with mammalian target of rapamycin inhibitors (mTORi) was 31% versus 22.2% among those not receiving these immunosuppressants (P = .23). Although there were no differences in hemoglobin levels, patients treated with mTORi, showed higher EPO levels (P = .005) and lower mean corpuscular volume (P < .001). Regarding the etiology of chronic kidney disease, less frequently anemic patients were those with polycystic kidney disease (8.6% versus 26.7% in the rest, P = .021). The formula obtained by multiple linear regression to calculate hemoglobin was: hemoglobin = 11829-0909 log (EPG level) - 0455 (if female) + 0.010 0.013 transferrin + 0.013 creatinine clearance (r = .424, P < .001). CONCLUSIONS: Treatment with ACEI and/or ARBs seemed to produce a defect in the synthesis of EPO, while those treated with mTORi, a hyporesponsive state.

De novo anti-HLA antibodies in renal allograft recipients: a cross-section study.

BACKGROUND: The occurrence of anti-HLA antibodies plays a well established role in solid organ rejection. The development of x-MAP multiple bead technology (Luminex) has enabled more accurate detection and definition of these alloantibodies. METHODS: In 267 kidney transplant patients with stable allograft function for ≥3 years, we analyzed the presence of anti-HLA antibodies by Luminex technology. These patients had no alloantibodies before transplantation, and the immunosuppression treatment was: tacrolimus, cyclosporine, mycophenolate mofetil, prednisone, everolimus, and/or sirolimus. RESULTS: Fifteen of the 267 patients showed anti-HLA class I antibodies and 12 showed anti-HLA class II antibodies, Seven patients had donor-specific antibodies (DSA): 1 anti-HLA class I, 5 anti-HLA class II, and 1 with both classes. No differences were found between DSA and the use or not of any specific therapy. However, in the retrospective review, we found a higher incidence of acute rejection episodes in the immediate posttransplant period among patients who developed class II DSA than those without DSA. CONCLUSIONS: The prevalence of patients with normal renal function who develop DSA beyond 3 years after transplantation was relatively low. Steroid or withdrawal replacement of calcineurin inhibitors with inhibitors of mammalian target of rapamycin seem to not be risk factors to increase the development of DSA. The finding that patients who developed DSA showed a higher rate of previous acute rejection episodes suggested that they should be monitored more frequently for HLA antibodies.

Changes in magnesium and potassium homeostasis after conversion from a calcineurin inhibitor regimen to an mTOR inhibitor-based regimen.

BACKGROUND: Transplant recipients treated with calcineurin inhibitors (CNIs) frequently show hyperkalemia, metabolic acidosis, and hypomagnesemia which could be deleterious for some patients. Conversion to inhibitors of mammalian target of rapamycin (mTOR) could improve these electrolytic disturbances. OBJECTIVE: To evaluate the potassium and magnesium changes due to converting patients from CNIs to mTOR inhibitors. METHODS: Retrospective review of 138 renal transplant patients who were converted from CNIs to mTOR inhibitors over a 6-month observation period. The following parameters were determined: potassium, sodium, chloride, magnesium, urea, glucose, and creatinine in blood and urine. We also analyzed plasma bicarbonate and calculated plasma and urine anion gap and plasma osmolarity. RESULTS: One month after conversion, a decrease was observed in serum creatinine (1.75±0.68 vs 1.61±0.61 mg/dL; P=.01), plasma potassium (4.60±0.52 vs 4.39±0.53 mEq/L; P<.001), calculated plasma osmolarity (308.7±8.5 vs 307.4±8.4 mOsm/L; P<.036), fractional excretion of sodium (1.55±0.69 vs 1.29±0.65%; P<.003), and fractional excretion of magnesium (7.15±4.08 vs 15.84±3.64%; P<.001), with an increase in serum magnesium (1.77±0.24 vs 1.95±0.29 mg/dL; P<.001). At 3 and 6 months, these differences remained unchanged. The transtubular potassium gradient did not change. CONCLUSIONS: We observed a decrease in serum magnesium due to renal magnesium wasting before switching from CNIs to mTOR inhibitors. After conversion, an increase in serum magnesium was observed together with a drop in the fractional excretion of this cation. A decrease in plasma potassium levels, plasma osmolarity, and fractional excretion of sodium consistent with minor aldosterone resistance was also detected after changing the immunosuppressive treatment.

Comparative analysis of adverse events requiring suspension of mTOR inhibitors: everolimus versus sirolimus.

BACKGROUND: Inhibitors of mammalian target of rapamycin (mTORi) have been suggested as an alternative to calcineurin inhibitors (CNIs) to treat stable renal transplant recipients. However, their use has been significantly limited owing to a high incidence of side effects. OBJECTIVE: To compare the rate of dropout (mTORi elimination and CNI reintroduction) caused by side effects among renal transplant patients converted to everolimus (EVL) or sirolimus (SRL). METHODS: Between October 1999 and February 2010, 409 subjects were converted to an mTORi at least 3 months after transplantation, including 220 (53.8%) to EVL and 189 (46.2%) to SRL. Most patients were under CNI therapy. Patients were followed for a median of 35 months (interquartile range [IQR], 18-50 months). RESULTS: mTORi treatment was prematurely eliminated due to adverse events in 112 patients. The median time between the initiation of mTORi and discontinuation was 5.7 months (IQR, 1.9-15.7 months; range, 0.2-48 months): 5.5 (IQR, 1.6-16.3) in the EVL group and 7.4 (IQR, 2.6-15.6) in the SRL group. In the EVL group, the drug was stopped in 69 patients (31.4%), and in the SRL group in 43 patients (22.8%; P=.051). The most important causes of discontinuation were severe infections (2.3% in EVL group and 4.8% in SRL group; P=.17), pneumonitis (6.8 % in EVL group and 4.8 in SRL group; P=.38), acute rejection episode (4.1% in EVL group and 1.6% in SRL group; P=.13), proteinuria (4.1% in EVL group and 1.6% in SRL group; P=.13), renal function deterioration (2.3% in EVL group and 2.1% in SRL group; P=.91), and severe dermal eruption (2.3% in EVL group and 0.5% in SRL group; P=.14). CONCLUSIONS: Although the overall incidence discontinuations due to side effects was higher in the EVL group, there was no greater frequency of severe side effects, such as pneumonitis, proteinuria, acute rejection episodes, renal function deterioration, or dermal eruptions.

Effect of the brain-death process on acute rejection in renal transplantation.

INTRODUCTION: Growing experimental evidence suggests that the state of brain death (BD) activates surface molecules on peripheral organs by the massive release of macrophage- and T cell-associated cytokines as well as adhesion molecules into the circulation. The question is whether the sequelae of the BD process substantially influences the quality of the donor organ, the ensuing host response, or the ultimate transplant outcome. Our aim was to compare explosive BD with gradual-onset injury in terms of a trigger of the host immune mechanisms accelerating acute rejection processes. MATERIALS AND METHODS: This retrospective study included 149 cadaveric donors whose kidneys were transplanted in to 264 recipients. Exclusion criteria were previous transplants and hyperimmmunized patients. Donor variables were: sex, age, etiology of death, and hemodynamic conditions during the 24 hours prior to death. The recipient variables included, all possible conditions known to induce rejection. RESULTS: Cox analysis revealed the following factors to be predictive of acute vascular rejection: initial immunosuppression without induction (risk ratio [RR] 1.83; 95% confidence interval [CI] 1.02 to 3.25; P = .039) which there was a trend to an impact of a regimen without tacrolimus (RR 1.84; 95% CI 0.85 to 3.98; P = .099), or of recipient age < 30 years (RR 2.17; 95% CI 1.06 to 4.48); P = .053) or lower mean donor blood pressure during the 3 hours prior to death (RR 1.17; 95% CI 1.00 to 1.37; P = .054). CONCLUSIONS: Greater sympathetic activity during brain death produces nonspecific endothelial damage and increases organ immunogenicity, promoting rejection.

Cytomegalovirus infection in seronegative patients treated with prophylaxis: case-controlled study.

Primary cytomegalovirus (CMV) infection is common in infancy with approximately 90% to 95% of subjects developing antibodies against this virus. CMV seronegative renal allograft recipients generally receive this infection with a graft or with blood transfusions, showing a high morbidity and mortality. Prophylaxis in these patients has shown good results; however, the published studies have included a small number of patients. Our case-controlled study evaluated 163 kidney transplant recipients: 76 seronegatives for CMV and 87 seropositive for CMV as controls. The evaluated parameters were: CMV infection, CMV disease, renal function, and survival of the patient and graft. We studied our experience among CMV seronegative patients treated with various prophylaxis guidelines. Our conclusions were that CMV prophylaxis in seronegative patients was effective because it showed a risk of infection that was equal (or even less) than that in seropositive patients and revealed a delay in the onset of the disease. CMV seronegativity may be a positive prognostic factor for graft survival.