Antibody-Mediated Rejection in Kidney Transplantation Without Evidence of Anti-HLA Antibodies?

INTRODUCTION

The definition of antibody-mediated rejection (AMR) is based on serologic (presence and/or development of donor-specific anti-HLA antibodies [DSAs]) and histologic (C4d deposition and endothelial damage) criteria. However, several cases of AMR have been described without C4d deposition, and other cases of histologic AMR without DSAs, which could be driven by other non-HLA alloantibodies such as anti-MICA or anti-angiotensin II type I receptor (AT1R). Here we studied clinical and histologic humoral rejection in kidney transplant recipients without evidence of anti-HLA antibodies.

MATERIALS AND METHODS

Fifteen kidney transplant recipients with AMR defined as C4d⁺ and/or histologic g+ptc without anti-HLA antibodies in screening test were studied. Sera at the moment of biopsy and 2 months earlier were studied for anti-HLA antibodies by Luminex, in neat, diluted 1/160, and sera after treatment with dithiothreitol (DTT) and confirmed by single-antigen test. The anti-AT1R was measured by enzyme-linked immunosorbent assay.

RESULTS

A lack of anti-HLA and MICA antibodies was confirmed after anti-HLA screening test in all conditions (neat, diluted, and DTT-treated) and de novo development of AT1R antibodies was ruled out. Nevertheless, after single-antigen test, 3 patients were identified with a weak reaction against class I antigen and another 4 patients against class II antigen. Due to the lack of locus-C typing in the donors, the DSA assignment cannot be confirmed, whereas anti-HLA class II antigens were DSA.

CONCLUSIONS

A low sensitivity in the screening of anti-HLA antibody testing was observed. Our results suggest performing single-antigen test in seronegative patients with clinical humoral rejection after screening to confirm the presence of DSA.

Implementation of a National Priority Allocation System for Hypersensitized Patients in Spain, Based on Virtual Crossmatch: Initial Results

Access to kidney transplantation for patients with high levels of antibodies against HLA is a major challenge. This issue makes it difficult to detect compatible donors for those patients in a certain geographical area. Consequently, hypersensitized patients remain on the waiting list for long periods and their quality of life deteriorates. Our purpose was to increase access to transplantation for highly sensitized patients by developing a national priority allocation system based on virtual crossmatch. Between June 15, 2015, and May 15, 2016, 675 patients on the kidney transplant waiting list with calculated panel-reactive antibodies ≥98% and undergoing dialysis for at least 12 months were included in the study; 86.1% of the patients had previously received at least one transplant. Solid-phase immunoassays were used to identify class I and II HLA antibodies in all patients. Participating hospitals assigned to the program one of the kidneys of every identified brain-dead real donor between 18 and 70 years old. Survival data were collected for the recipients transplanted between June 15, 2015, and December 31, 2015. In all, 475 (290 male and 185 female) brain-dead donors were assigned to the program. Virtual crossmatch was negative for 191 (41%) donors, 149 offers were accepted, and 102 (21.8%) kidneys were transplanted. At the end of the study, patient and graft survival were both 93.4%. The implementation of a national prioritization system based on virtual crossmatch increased access to transplantation for highly sensitized patients, with excellent results in terms of patient and graft survival.

Number of antihypertensive drugs at 1 year after kidney transplantation

High blood pressure (BP) affects up to 90% of kidney transplant recipients and is associated with lower patient and graft survival rates. Kidney Disease/Improving Global Outcomes (KDIGO) guidelines suggest maintaining BP at lower than 130/80 mm Hg. Multidrug therapy is usually required for the control of BP in this population. Our aim was to analyze the number of antihypertensive drugs used in our kidney transplantation population at 1 year after transplantation and their influence on graft and patient outcome. We included 411 deceased-donor kidney transplantation cases; data were obtained from a prospectively maintained institutional database. BP was measured at the outpatient clinic. Approximately 97 patients were not under antihypertensive therapy, whereas 130, 119, 52, and 13 received 1, 2, 3, or 4 antihypertensive drugs, respectively. The number of antihypertensive drugs was significantly related to lower patient survival rates independently of a previous diagnosis of hypertension and diabetes, recipient age and sex and renal function at 1-year. After multivariate linear regression analysis high body mass index, male gender of recipients, donor hypertension, previous acute rejection, and cyclosporine therapy were risk factors independently related to a higher number of antihypertensive drugs. To conclude, the number of antihypertensive drugs is an objective and easy-to-measure marker related to lower patient survival rates. Recipient body mass index, type of calcineurin inhibitor, and acute rejection are modifiable risk factors whose control can help to reduce the number of antihypertensive drugs needed to treat high BP in the kidney transplantation population.

High regulatory T-cell levels at 1 year posttransplantation predict long-term graft survival among kidney transplant recipients

INTRODUCTION

Regulatory T cells (Tregs) have gained an important role in mechanisms of tolerance and protection against the transplant rejection. However, only limited retrospective data have shown a relationship between peripheral blood Tregs and better long-term graft survival. The purpose of the present study was to investigate prospectively circulating Treg levels and their association with long-term graft survival.

METHODS

Ninety kidney transplant recipients underwent measurement of Treg levels in peripheral blood before as well as at 6 months and 1 year posttransplantation. Receiver operating characteristic curves were applied to test the sensitivity and specificity of Treg levels to predict prognosis.

RESULTS

Treg levels before transplantation correlated with those at 6 months and 12 months posttransplantation (P < .001 and P = .002, respectively). Patients who maintained high Treg levels (above 70th percentile) at both 6 and 12 months displayed better long-term graft survival at 4 and 5 years follow-up (P = .04 and P = .043 respectively). There was no effect on patient survival.

CONCLUSION

Detection of high levels of peripheral blood Tregs was associated with better graft survival possibly using as a potential marker of prognosis.

New-onset diabetes after transplantation: drug-related risk factors

INTRODUCTION

New-onset diabetes after transplantation (NODAT), an important complication of renal transplantation leads to reduced graft function and increased patient morbidity and mortality. Because of its high incidence and immense impact on clinical outcomes, prevention of NODAT is highly desirable. Several modifiable and nonmodifiable risk factors for NODAT have been described. The aim of this study was to analyze the influence of various drugs on the development of NODAT during the first year.

METHODS

A retrospective analysis was performed on 303 adult kidney transplant recipients free of previously known diabetes. NODAT was defined as a fasting plasma glucose level ≥ 126 mg/dL confirmed by repeat testing on a different day. We excluded patients with transiently elevated fasting plasma glucose during the first 3 months.

RESULTS

NODAT was diagnosed in 37 recipients (12.2%). Univariate analysis identified several variables related to NODAT: recipient age (P < .001), body mass index (P < .001), donor age (P = .005), family history of diabetes (P < .001), statin use (P = .005), diuretic use (P = .040) and tacrolimus therapy (P = .029). After multivariate analysis, recipient age (relative risk [RR] = 1.060, 95% confidence interval [CI] 1.019- 1.102, P = .004), family history of diabetes (RR = 3.562, 95% CI 1.574-8.058, P = .002), smoking habit (RR 2.514, 95% CI 1.118-5.655, P = .026) and diuretic use (RR = 2.496, 95% CI 1.087-5.733, P = .031) were independently associated with NODAT development.

CONCLUSIONS

In our population of kidney transplant recipients, the main nonmodifiable risk factors for NODAT were recipient age and a family history of diabetes. Diuretic use was a modifiable risk factor associated with the development of NODAT. To reduce NODAT incidence, it is necessary to consider not only immunosuppressive therapy, but also concomitant drugs such as diuretics.

Decreased plasma levels of clusterin in patients with psoriasis

INTRODUCTION AND OBJECTIVES

Psoriasis is a chronic inflammatory disease that has been linked to increased cardiovascular risk. The glycoprotein clusterin (apolipoprotein J) is a component of high-density lipoproteins and has a protective role in atherosclerosis. The aim of the present study was to evaluate the plasma levels of clusterin and the proinflammatory cytokine macrophage migration inhibitory factor (MIF) in patients with severe psoriasis, comparing groups of patients with different risks of cardiovascular disease.

MATERIAL AND METHODS

Twenty-one patients with severe psoriasis (psoriasis area severity index and body surface area>10) and 11 healthy controls with no dermatologic disease were studied. Cardiovascular risk factors were assessed according to the Adult Treatment Panel (ATP) III criteria. Subclinical carotid atheromatosis was assessed by Doppler ultrasonography of the carotid arteries. Plasma clusterin and MIF levels were measured by enzyme-linked immunosorbent assay.

RESULTS

ATP-III criteria for metabolic syndrome were met by 47% of the patients, and 33% had carotid atheromatous plaque. Mean (SD) clusterin plasma levels were significantly lower in patients with psoriasis compared with controls (81.39 [27.30] μg/mL for the 21 patients vs 117 [21.6] μg/mL for the 11 controls; P=.0017). MIF plasma levels (ng/ml) were significantly higher in patients with atheromatous plaque compared with controls (53.22 [29.02] for the 6 patients with plaque vs 34.21 [9.65] for the 11 controls; P=.0394).

CONCLUSIONS

The decreased plasma levels of clusterin in psoriatic patients suggested an association with the disease and might be an indicator of systemic inflammatory activity. Increased levels of MIF appear to be associated with cardiovascular risk factors and carotid atheromatous plaque.

[The 2013 Seville Consensus Document on alternatives to allogenic blood transfusion. An update on the Seville Document]

Since allogeneic blood transfusion (ABT) is not harmless, multiple alternatives to ABT (AABT) have emerged, though there is great variability in their indications and appropriate use. This variability results from the interaction of a number of factors, including the specialty of the physician, knowledge and preferences, the degree of anemia, transfusion policy, and AABT availability. Since AABTs are not harmless and may not meet cost-effectiveness criteria, such variability is unacceptable. The Spanish Societies of Anesthesiology (SEDAR), Hematology and Hemotherapy (SEHH), Hospital Pharmacy (SEFH), Critical Care Medicine (SEMICYUC), Thrombosis and Hemostasis (SETH) and Blood Transfusion (SETS) have developed a Consensus Document for the proper use of AABTs. A panel of experts convened by these 6 Societies have conducted a systematic review of the medical literature and have developed the 2013 Seville Consensus Document on Alternatives to Allogeneic Blood Transfusion, which only considers those AABT aimed at decreasing the transfusion of packed red cells. AABTs are defined as any pharmacological or non-pharmacological measure aimed at decreasing the transfusion of red blood cell concentrates, while preserving patient safety. For each AABT, the main question formulated, positively or negatively, is: « Does this particular AABT reduce the transfusion rate or not?» All the recommendations on the use of AABTs were formulated according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) methodology.

[The 2013 Seville Consensus Document on alternatives to allogenic blood transfusion. An update on the Seville Document]

Since allogeneic blood transfusion (ABT) is not harmless, multiple alternatives to ABT (AABT) have emerged, though there is great variability in their indications and appropriate use. This variability results from the interaction of a number of factors, including the specialty of the physician, knowledge and preferences, the degree of anemia, transfusion policy, and AABT availability. Since AABTs are not harmless and may not meet cost-effectiveness criteria, such variability is unacceptable. The Spanish Societies of Anesthesiology (SEDAR), Hematology and Hemotherapy (SEHH), Hospital Pharmacy (SEFH), Critical Care Medicine (SEMICYUC), Thrombosis and Hemostasis (SETH) and Blood Transfusion (SETS) have developed a Consensus Document for the proper use of AABTs. A panel of experts convened by these 6 Societies have conducted a systematic review of the medical literature and have developed the 2013 Seville Consensus Document on Alternatives to Allogeneic Blood Transfusion, which only considers those AABT aimed at decreasing the transfusion of packed red cells. AABTs are defined as any pharmacological or non-pharmacological measure aimed at decreasing the transfusion of red blood cell concentrates, while preserving patient safety. For each AABT, the main question formulated, positively or negatively, is: "Does this particular AABT reduce the transfusion rate or not?" All the recommendations on the use of AABTs were formulated according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) methodology.

Is proteinuria reversible, after withdrawal of mammalian target of rapamycin inhibitors?

Conversion to mammalian target of rapamycin inhibitors (mTORi) is an ever more frequent practice in renal transplant recipients, even if it is not always satisfactory, needing to be suspended for various reasons in certain patients. We analyzed the evolution of proteinuria as a marker of kidney damage after withdrawal of mTORi for any reason in order to assess conversion failure risk. Among 1633 renal transplant patients with 185 converted to mTORi, we considered the 52 (28%) who withdrew as result of intolerance or a bad evolution after at least 3 months use (median: 142 days after conversion). Four groups were defined according to the evolution of proteinuria: group 1 (G1), stable after conversion; group 2 (G2), increased with complete recovery (<1 g); group 3 (G3), increased with partial recovery (>1 g); or group 4 (G4), increased without recovery. The evolution according to the groups was: G1 (57.1%), G2 (17.2%), G3 (5.7%), and G4 (20%). There were no differences between the good (G1 and G2) and the bad evolution groups (G3 and G4) in proteinuria at the time of conversion (838 ± 641 vs 532 ± 404 mg/d) or renal function (1.95 ± 0.47 vs 1.90 ± 0.4 mg/dL). Six months after withdrawal, proteinuria was stable in G1 and G2 but worse in G3 and G4 (781 ± 643 vs 4479 ± 3235 mg/d); the same observation was noted for renal failure (2.1 ± 0.71 vs 2.8 ± 1.57 mg/dL). Among about 75% of patients in whom mTORi was withdrawn, no injury remained in the medium term whereas among the other 25%, there was a residual injury.

Prediction of delayed graft function by means of a novel web-based calculator: a single-center experience

Renal failure persisting after renal transplant is known as delayed graft function (DGF). DGF predisposes the graft to acute rejection and increases the risk of graft loss. In 2010, Irish et al. developed a new model designed to predict DGF risk. This model was used to program a web-based DGF risk calculator, which can be accessed via http://www.transplantcalculator.com . The predictive performance of this score has not been tested in a different population. We analyzed 342 deceased-donor adult renal transplants performed in our hospital. Individual and population DGF risk was assessed using the web-based calculator. The area under the ROC curve to predict DGF was 0.710 (95% CI 0.653-0.767, p < 0.001). The "goodness-of-fit" test demonstrates that the DGF risk was well calibrated (p = 0.309). Graft survival was significantly better for patients with a lower DGF risk (5-year survival 71.1% vs. 60.1%, log rank p = 0.036). The model performed well with good discrimination ability and good calibration to predict DGF in a single transplant center. Using the web-based DGF calculator, we can predict the risk of developing DGF with a moderate to high degree of certainty only by using information available at the time of transplantation.

Characterization of bovine transcripts preferentially expressed in testis and with a putative role in spermatogenesis

Although the number of genes known to be associated with bovine spermatogenesis has increased in the past few years, regulation of this biological process remains poorly understood. Therefore, discovery of new male fertility genetic markers is of great value for assisted selection in commercially important cattle breeds, e.g., Nelore, that have delayed reproductive maturation and low fertility rates. The objective of the present study was to identify sequences associated with spermatogenesis that could be used as fertility markers. With RT-PCR, the following five transcripts preferentially expressed in adult testis were detected: TET(656) detected only in adult testis; TET(868) and TET(515) expressed preferentially in adult testis but also detected in fetal gonads of both sexes; and TET(456) and TET(262,) expressed primarily in the testis, but also present in very low amounts in somatic tissues. Based on their homologies and expression profiles, we inferred that they had putative roles in spermatogenesis. Detection of sequences differentially expressed in testis, ovary, or both, was a useful approach for identifying new genes related to bovine spermatogenesis. The data reported here contributed to discovery of gene pathways involved in bovine spermatogenesis, with potential for prediction of fertility.

Efficacy and safety of conversion from twice-daily to once-daily tacrolimus in a large cohort of stable kidney transplant recipients

Prolonged-release tacrolimus was developed to provide a more convenient once-daily dosing that could improve patient adherence. We conducted a multicenter, prospective, observational, 12-month study to describe the efficacy, safety and patient preference of conversion from tacrolimus twice-daily to once-daily formulation in stable kidney transplant recipients in routine clinical practice. Conversion was made on a 1 mg: 1 mg basis (1 mg: 1.1 mg in patients with trough levels <6 ng/mL). The study included 1832 patients (mean age (± SD): 50.0 ± 13.4 years; 62.7% male). After conversion, a modest reduction in tacrolimus trough levels, necessitating an increase in daily dose, was observed (mean changes at 12 months of -9.1% and +1.24%, respectively; p < 0.0001). Mean glomerular filtration rate did not change significantly (56.5 ± 19.7 mL/min at conversion vs. 55.7 ± 20.6 mL/min at 12 months). Proteinuria, blood pressure, lipid, hepatic and glucose parameters remained stable. Eight patients (0.4%) had acute rejection and 34 patients (1.85%) discontinued treatment. Almost all patients (99.4%) preferred the once-daily formulation, because of less frequent dosing (66%) and improved adherence (34%). In conclusion, at similar doses to twice-daily tacrolimus, once-daily formulation provided stable renal function, a low acute rejection rate, and good tolerability in stable kidney transplant recipients in the routine clinical practice setting.

Kidney transplant recipients show an increase in the ratio of T-cell effector memory/central memory as compared to nontransplant recipients on the waiting list

Studies of allotolerance in animal models do not usually consider the presence of preexisting memory T cells and activated immune status. However, humans are exposed throughout life to a multitude of external agents that enhance the immune memory. In this article, we consider the effect that a previous kidney transplant has on the number of regulatory T cells (Tregs), effector memory T cells (TEM), and central memory T cells (TCM). Sixty-three patients with end-stage renal disease were studied just before being transplanted (51 first transplants and 12 retransplants). The numbers of Tregs (CD4+ CD25highCD127lowCD27+CD62L+CD45RO+FOXP3+), TEM (CD3+CD45RO+CD62L+), and TCM (CD3+CD45RO+CD62L-) cell subsets were quantified in peripheral blood by flow cytometry. The absolute number of Tregs was slightly lower in patients with previous allografts (median, 95% confidence interval [CI]: 16.7 cells/mm3, 12-20.5) than in those who received their first transplants (median, 95% CI: 19.6 cells/mm3, 19.3-29.6; P-NS). Clearer differences were found with the number of CD3+ TCM, since the transplanted patients had lower numbers (238 cells/mm3, 153-323) than those who had not yet received transplants (378 cells/mm3, 317-439; P=.029). As a result, the TEM/TCM ratios of both CD4+ and CD8+ T cells in patients with previous allografts were higher than in those who received first transplants. In conclusion, the assessment of just the number of Tregs in renal transplant patients is not enough and must be read together with the number of TEM and TCM. The TEM:TCM ratio increases in patients with previous allografts, probably due to activation of the immune response in renal transplantation.

Chronic renal disease in renal transplant patients: management of cardiovascular risk factors

Kidney transplantation is the treatment of choice for patients with end-stage renal disease. Despite improvements in short-term patient and graft outcomes, there has been no major improvement in long-term outcomes. The aim of this study was to determine the prevalence of cardiovascular risk factors, such as hypertension, dyslipidemia, diabetes, chronic kidney disease, and obesity, and the impact of their control among 526 stable renal transplant recipients according to the guidelines in the general population. Mean blood pressure was 133 +/- 16/81 +/- 9 mm Hg. The proportion of patients on antihypertensive therapy was 75%, and on ACE inhibitors or angiotensin II receptor blockers, 26%. The mean cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides were 195 +/- 41, 115 +/- 32, 51 +/- 17, and 137 +/- 75 mg/dL, respectively. The proportion of patients on statin treatment was 49.7%, and those with body mass indices between 25 and 30, 30 and 35, and >35 kg/m(2) were 35%, 15%, and 4%. We observed a high prevalence of chronic kidney disease, hypertension, dyslipidemia, and obesity among renal transplant patients. Suboptimal control was frequent and control of some of these complications was far below targets established for nontransplant patients despite progressive intensification of therapy with functional graft decline. The findings of this study may have an impact on the management of renal transplant recipients.

Survival after dialysis initiation: a comparison of transplant patients after graft loss versus nontransplant patients

BACKGROUND

A substantial number of patients return to dialysis therapy after a renal transplant fails. It is not clear whether mortality increases among patients with graft failure relative to those who initiate dialysis but who have not yet received a kidney transplant.

PATIENTS AND METHODS

We compared the outcomes of an incident cohort of patients (n = 194) with a cohort of renal transplant patients who returned to dialysis after graft loss (n = 74). We analyzed the morbidity and mortality after dialysis initiation and the parameters during the year beforehand.

RESULTS

Mortality among post-graft loss dialysis patients was higher than transplant-naive patients (relative risk [RR]: 2.05; 95% confidence interval [CI]: 1.26-3.35). Additionally, complications, such as the number of hospitalizations during the first year after dialysis initiation, were higher (29% vs 57%; P > .001). At dialysis initiation no differences were found in glomerular filtration rate, although hemoglobin and albumin levels were lower and C-reactive protein was higher in post-graft loss dialysis patients.

CONCLUSIONS

Mortality among patients on dialysis therapy after graft loss increased significantly compared with mortality among patients who initiated dialysis for the first time, despite specialty physicians being aware of them. Additional studies are urgently needed to define the mechanisms of the increased risk and strategies to decrease mortality.

Hemoglobin level variability in renal transplant patients treated with erythropoiesis stimulating agents

OBJECTIVE

Treatment with erythropoiesis stimulating agents (ESA) is associated with fluctuations in hemoglobin (Hb) levels. Recently, variability of Hb has been considered a factor that influences comorbidity and mortality among hemodialysis patients. The purpose of this analysis was to describe the phenomenon of Hb variability during ESA treatment, to study associated factors among kidney transplant patients, and to assess the impact on patient and graft survivals.

PATIENTS AND METHODS

Hb variability (defined as fluctuations of Hb +/- 1.5 g/dL) was assessed in 85 renal transplant patients treated with ESA for at least 3 months and with a minimum of 6 Hb measurements during 1 year.

RESULTS

Fifty-eight percent of the patients experienced Hb variability during follow-up. Only 3% of patients maintained stable Hb levels within the target range (11-13 g/dL), although 83% of patients maintained Hb levels >11 g/dL. Multivariate analysis showed that the clinical factors associated with variability were changes in ESA dose (relative risk [RR]: 2.92; 95% confidence interval [CI]: 1.0-8.5; P < .05), infectious events with hospitalization (RR: 1.95; 95% CI: 1.23-2.13; P < .05), and the use of sirolimus (RR: 1.1; 95% CI: 1.0-3.6; P < .05). When dose changes and hospitalization were excluded from the analysis, variability was an independent predictor of worsening graft function.

CONCLUSIONS

Hb variability is common in renal transplant patients treated with ESA. Only a few patients maintained Hb levels within the therapeutic range, although most had levels >11g/dL. Dose changes, inflammatory status, and worsening graft function are the determining factors of variability. Variability had no influence on patient survival, although it was a marker of worsening graft function.

T(H)17 versus Treg cells in renal transplant candidates: effect of a previous transplant

INTRODUCTION

The T(H)1 and T(H)2 cells were described several years ago. However, this dichotomy has been disrupted by the description of other CD4(+) T cell subsets: the proinflammatory interleukin (IL)-17-producing T cells (T(H)17) and regulatory T cells (Tregs). The latter group inhibits the immune responses driven by T(H)1, T(H)2, and T(H)17 cells. IL-6 is involved in T(H)17 development, down-regulating Treg differentiation. Our hypothesis suggested that an imbalance between T(H)17 and Tregs enhances immune responses among renal transplant patients.

MATERIALS AND METHODS

We studied 26 end-stage renal disease (ESRD) subjects and 10 patients awaiting a second renal transplant after previous graft dysfunction. We assessed the number of CD4(+)CD25(+)Foxp3(+) cells and serum levels of IL-17, the prototypic interleukin of T(H)17 cells.

RESULTS

We observed a lower number of CD4(+)CD25(+)Foxp3(+) T cells among patients with previous graft dysfunction than those with ESRD (median 3.37 vs 8.63 cells/mm(3), P = .008). In contrast, IL-17 serum levels were augmented in graft dysfunction (median 4.45 pg/mL) compared with ESRD patients (1.39 pg/mL, P = .036), suggesting a proinflammatory state in patients awaiting a second renal transplant.

CONCLUSION

The emerging alloresponse from a previous transplant favors the generation of T(H)17 instead of Treg cells. The enhanced activity of T(H)17 cells in retransplanted patients may down-regulate Treg cells, producing a proinflammatory environment that favors rejection of the next transplant.

Association between serum soluble CD30 and serum creatinine before and after renal transplantation

OBJECTIVE

There is increasing evidence that circulating levels of soluble CD30 (sCD30) may represent a biomarker for outcome in kidney transplantation. The aim of this study was to measure the pre- and posttransplantation serum levels of sCD30 in cadaveric kidney transplant recipients and correlate them with serum creatinine.

PATIENTS AND METHODS

Serum sCD30 was measured by a commercial enzyme-linked immunosorbent assay (ELISA) from prospective samples of 38 kidney allograft recipients serially transplanted at our center. Samples were collected at day 0 pretransplantation and at months 6, 12, 18, and 24 posttransplantation. We also studied sera from 29 patients with chronic kidney disease (CKD) at different stages of the K/DOQI guidelines, as a control group.

RESULTS

Serum levels of sCD30 decreased significantly in samples posttransplantation compared with pretransplantation. The significant decrease after transplantation may be related to the improvement in renal function since we observed a significant correlation between serum levels of sCD30 and creatinine (sCr) at all times of the study. In addition, the patients with chronic renal failure showed a significant association between serum sCD30 and sCr (r = .454; P = .013).

CONCLUSIONS

Our results did not suggest that the measurement of sCD30 may be used as a valuable biomarker in renal transplantation. Increased levels may be related to a decrease in its renal elimination.

Prevention of murine lupus disease in (NZBxNZW)F1 mice by sirolimus treatment

Sirolimus is a new immunosuppressive drug used to avoid allograft rejection. The immunosuppressive effect of sirolimus is due to inhibition of the mammalian target of rapamycin, necessary for the proliferation and clonal expansion of activated T-cells. Because T-cells play a central role in the pathogenesis of autoimmune disease developed in (NZBxNZW)F1 mice, we evaluated the therapeutic use of sirolimus in such mice. (NZBxNZW)F1 female mice received 1mg/kg/day of sirolimus from 12 to 37 weeks of age. The development of autoimmune disease was evaluated by measuring the serum levels of auto-antibodies (autoAbs) and their immunoglobulin isotypes, prevalence of glomerulonephritis and mortality rates. Sirolimus directly inhibited production of autoAbs, glomerular deposits of immunoglobulins and development of proteinuria; also the survival of these mice was prolonged. Our results demonstrate the beneficial effects of sirolimus in preventing the development of lupus disease in (NZBxNZW)F1 female mice.

Early sirolimus use with cyclosporine elimination does not induce progressive proteinuria

Proteinuria has been reported in several papers after conversion from calcineurin inhibitors to Sirolimus (SRL), but this complication has not been analyzed in randomized clinical trials using de novo SRL. It is not known whether de novo use of SRL is a risk factor for proteinuria. We analyzed a series of patients included in a big multicenter randomized trial (RMR trial) corresponding to all patients in Spain and Portugal with respect to this issue. We retrospectively evaluated 24-hour proteinuria in all the patients during the study period (5 years postransplant) for comparison between treatment arms group A, continuous cyclosporine (CyA) + SRL and group B SRL with CyA elimination at 3 months postransplant. The elimination of CyA after the third month was not followed by significant changes in proteinuria. Nevertheless, during the last year of follow-up (between 48 and 60 months postransplant) an impressive increase in proteinuria was observed in group A. This surprising finding seemed to be a consequence of a protocol amendment that recommended CyA elimination in patients of group A, due to poorer results in the intermediate analysis of the trial. This fact suggests that the hemodynamic changes induced by elimination of the vasoconstrictor CyA might be responsible for the proteinuria but only in the long term probably when significant pathological lesions are already present. This finding argues for earlier conversion.

Use of the New Proliferation Signal Inhibitor Everolimus in Renal Transplant Patients in Spain: Preliminary Results of the EVERODATA Registry

Everolimus (Eve) has shown good efficacy and safety profiles in clinical trials in combination with low doses of cyclosporine but there is limited experience in other modes, especially with calcineurin inhibitor elimination. We developed a retrospective study to analyze its clinical use after approval in Europe in 2005. Herein we have presented the results of a series of 272 patients followed for the first 6 months after Eve introduction. In 93.8% of cases Eve was introduced after the first month posttransplantation (conversion use), and 6 months after introduction, the CNI had been eliminated in 75% of cases. The main indication for Eve introduction was the diagnosis of a malignant neoplasm (42%), whereas the combined indication of prevention and/or treatment of toxicity, especially nephrotoxicity, accounted for 46.3% of cases. Initial doses were low (1.37 mg/d), but were progressively increased up to 2 mg/d at 6 months. Renal function remained unchanged during the follow-up period, whereas proteinuria moderately increased. Only 5 cases (2%) of acute rejection episodes were observed with excellent patient and graft survivals at 6 months after conversion. Further analysis of this extensive series of patients with a longer follow-up is needed.

Cytokine Polymorphisms and Risk of Infection After Kidney Transplantation

INTRODUCTION

Infection remains a significant cause of morbidity and mortality after solid organ transplantation. Genetic background has an influence on the incidence of infection. The aim of our study was to analyze the relationship between cytokine polymorphisms and infection in our kidney transplant recipients.

METHODS

DNA from 255 kidney transplant recipients was isolated routinely. Polymerase chain reaction sequence-specific primer was performed using commercially available cytokine genotyping primer packs to determine polymorphisms of interleukin (IL)-10, transforming growth factor-beta, tumor necrosis factor-alpha, interferon-gamma, IL-6, IL-4, IL-2, IL-12, IL-4R alpha, IL-1RA, IL-1R, IL-1 beta, and IL-1 alpha. The appearance and number of infections within the first year after transplantation were identified retrospectively.

RESULTS

One hundred twenty-two patients experienced at least one episode of infection in the first year after transplant. The frequency of the -511 IL-1beta CC genotype and the frequencies of the -1188 IL-12 CA and CC genotypes were significantly higher among the infected patients compared with the noninfected patients. We failed to observe significant differences in the genotype distribution of the other analyzed cytokines regarding the incidence of infection. After adjusting, recipient IL-1beta (-511 CC) genotype (relative risk [RR] 2.67, 95% confidence interval (CI) 1.30 to 5.49, P = .007) and recipient IL-12 (-1188 CA and CC) genotypes (RR 2.57, 95% CI 1.22 to 5.38, P = .012) predicted independently the risk of infection in the first year after kidney transplantation.

CONCLUSION

Kidney transplant recipients with -511 IL-1beta CC genotype or with -1188 IL-12 CA and CC genotypes were at higher risk of developing infections in the first year after transplantation. Patients with genetic susceptibility to infection may benefit from less potent immunosuppressive therapy and more intense preventive measures.

Conversion to everolimus in kidney transplant recipients: a safe and simple procedure

To date there is a substantial experience with rapamycin conversion in stable renal transplant recipients with respect to the procedure of conversion, initial doses, and target blood levels as well as adverse events, but in the case of Everolimus there is almost no experience with conversion and calcineurin inhibitor (CNI) withdrawal. We describe an initial experience among 32 renal transplant recipients who were converted to Everolimus with complete suspension of CNI in two Spanish transplant centers. Our results emphasised the procedure for conversion, the target levels, the adverse events, and the initial efficacy, over the first month after conversion. Our conclusions were that conversion from CNI to Everolimus was a simple, safe procedure with a predictable profile of adverse events, which were, in general, of mild intensity. There was a good correlation between initial dose and blood level. Initial doses of about 3 mg/d combined with rapid reduction in CNI exposure seemed to be adequate. The target range levels between 5 and 10 ng/mL seemed to be sufficient for complete CNI elimination, especially in patients also receiving antiproliferative drugs (such as mycophenolate mofetil or azathioprine) in whom levels near the lower end of the range might be adequate.

Calcineurin inhibitors affect circulating regulatory T cells in stable renal transplant recipients

INTRODUCTION

Immunosuppression, although crucial for short-term management, has been described in renal transplantation to be a major hurdle for long-term graft survival. Efforts have been directed at achieving a true state of allotolerance, thereby reducing the load of immunosuppression. Recently, increased frequencies of CD4(+)CD25(high) regulatory T cells (Tregs) have been described as an additional mechanism to induce alloimmune tolerance.

MATERIALS AND METHODS

We assessed 64 renal transplant recipients with stable renal function for at least 1 year, divided into two groups: one composed of patients receiving rapamycin but not calcineurin inhibitors (CNIs), and another, of those receiving CNIs but not rapamycin.

RESULTS

We demonstrated that T cells with a regulatory phenotype were decreased in peripheral blood of renal transplant recipients under CNI therapy compared to those who were CNI-free. The Tregs in our patients showed a modest association with renal function as measured by the delta serum creatinine, which was not significant.

CONCLUSIONS

CNIs, but not rapamycin, reduce the frequencies of circulating Tregs in renal transplant recipients. The use of rapamycin might be further exploited in strategies reducing immunosuppression in renal transplantation. Furthermore, quantification of blood Tregs may be a suitable tool to identify those recipients who are candidates for reducing immunosuppression.

[Abscess colon diverticular disease produced for Actinomyces israelii in a renal transplant recipient]

We present the case of a 53 years old man with a cadaveric kidney transplant under cyclosporin A and prednisolone therapy. Clinical transplant course was uneventful until 15 years after transplant, when he was admitted in our hospital with fever and a perirenal mass of unknown origin. Cyclosporin A was removed and a left sided colon was carried out and a abscess colon diverticular disease produced for Actinomyces israelii was diagnosed. The development was satisfactory after medical and surgical treatment.

Acute renal failure associated with use of inhaled tobramycin for treatment of chronic airway colonization with Pseudomonas aeruginosa

Aminoglycoside nephrotoxicity is a well-known clinical entity that complicates the course of infectious diseases treated under this antibiotic regime. Recently, a new administration form of tobramycin, inhaled tobramycin (TOBI), has been approved to improve the antibacterial activity and reduce nephrotoxicity. We describe the clinical case of a 73-year-old woman with chronic-obstructive pulmonary disease (COPD) who developed acute renal failure (ARF) after using TOBI. Clinical presentation and biochemical parameters were compatible with aminoglycoside-induced renal failure. Based on the clinical findings presented here, a surveillance program should be established to monitor the presence of factors predisposing to renal failure, and to measure serum levels of tobramycin.

Relevance of Chronic Kidney Disease Classification (K/DOQI) in Renal Transplant Patients

The National Kidney Foundation has developed guidelines for diagnosis and classification of chronic kidney disease (CKD) but it is not known whether they are applicable to renal transplant patients. This study analyzed the prevalence, the complications, and the influence of the CKD stage on the presence of complications in 506 stable transplant recipients. The mean age of the patients was 52.9 +/- 12 years, 34% were men, and the mean time after transplantation was 9.56 +/- 6.18 years. CKD was present in 90.3% with 9.9% were in CKD stages 4 or 5 with glomerular filtration rates lower than 30 mL/min per 1.73 m(2). The prevalence of anemia, phospho-calcium metabolism disorders, hypertriglyceridemia, and hypertension increased with the stage of CKD. We concluded that CKD and the complications of CKD were highly prevalent in renal transplant recipients. The classification of renal transplant patients by CKD stage may help clinicians to identify patients at increased risk and to target appropriate therapy to improve outcomes.

Clinical significance of antiphospholipid antibodies on allograft and patient outcome after kidney transplantation

INTRODUCTION

Antiphospholipid antibodies (APA) have acquired great relevance as atherogenic factors. Kidney graft recipients have a higher prevalence of cardiovascular disease (CVD) than the general population, which is not fully explained by the classical vascular risk factors. The aim of this study was to assess the influence of APA on kidney graft and patient outcomes with special focus on CVD.

MATERIALS AND METHODS

One hundred ninety seven cadaveric kidney graft recipients with functioning grafts for more than 1 year underwent determination of serum APA titres (anti-cardiolipin and anti-beta-2 glycoprotein I IgG and IgM antibodies) in one pretransplant serum and in second one obtained at least 1 year after transplantation. In the case of postransplant CVD, the postransplant serum was always chosen before the cardiovascular event. The enzyme linked immunosorbent assay (ELISA) for anti-cardiolipin antibodies was performed in the presence of cofactor.

RESULTS

Twenty-seven percent of patients had pretransplant APA, whereas 15.7% developed postransplant APA de novo. The presence of pretransplant serum APA was not associated with a higher risk of postransplant CVD. The development of postransplant APA de novo showed a relationship to an acute rejection episode (ARE): the frequency of patients who had APA de novo was higher among patients who suffered ARE (18.8% vs 7%, P = .01). In addition, in patients who suffered any ARE, the production of postransplant APA was associated with a higher frequency of postransplant CVD.

CONCLUSIONS

The detection of APA is not an independent risk factor for CVD after kidney transplantation. The inflammatory phenomena secondary to an ARE may be responsible for the de novo production of postransplant APA, which may be associated with the development of postransplant CVD. The control of cardiovascular risk factors should be intensified in this special group of patients.

Higher initial tacrolimus blood levels and concentration-dose ratios in kidney transplant recipients who develop diabetes mellitus

Posttransplantation diabetes mellitus (PTDM) is a common complication of kidney transplantation, associated with poorer graft and patient outcomes. Tacrolimus is a strong immunosuppressive drug associated with low acute rejection rates, but a higher risk for PTDM. High trough levels of tacrolimus during the first month after transplantation have been found to be a significant risk factor for the development of PTDM. The aim of this single-center study was to identify the risk factors for the development of PTDM among kidney transplant recipients under tacrolimus therapy. We examined 73 cadaveric kidney transplant recipients receiving tacrolimus between 1994 and 2003. Age, donor and recipient gender, dialysis method, body mass index (BMI), first year weight gain, mismatches, incidence of acute rejection and delayed graft function, hepatitis C serology, first year cumulative steroid dose, first tacrolimus blood level, first tacrolimus blood level <15 ng/mL, and corresponding tacrolimus daily doses and concentration/dose ratios (CDR) were also collected. PTDM was defined as at least 2 fasting blood glucose values > or =126 mg/dL, according to the World Health Organization criteria. Incidence of first year PTDM was 27.4%. Patients with PTDM showed significantly higher age, BMI, first tacrolimus blood level, first tacrolimus CDR, and CDR with tacrolimus blood level <15 ng/mL as well as less 1-year weight gain. After logistic regression, age (relative risk [RR] 1.060, confidence interval [CI] 95%, 1.001-1.122; P = .043) and first tacrolimus blood level (RR 1.154; CI 95%, 1.038-1.283; P = .008) remain significant risk factors for developing PTDM. Older age and initial tacrolimus blood levels were the main risk factors for PTDM among our group of patients. Kidney transplant recipients who develop PTDM maintain a high CDR of tacrolimus.

Prevalence of anemia in renal transplant patients: results from MOST, an observational trial

INTRODUCTION

Anemia is one of the most common complications of chronic renal disease. However, the incidence or prevalence of anemia in kidney transplant recipients has not been well studied. The aim of this study was to assess the prevalence of anemia in renal transplant in early and late posttransplant period and the influence of drugs (immunosuppressive and antihypertensive).

METHODS

MOST is an observational, prospective trial of renal transplant receiving cyclosporine-based immunosuppressive regimen under condition of normal practice in de novo or maintenance recipients. We analyzed the Spanish data from 397 de novo recipients and 2102 maintenance recipients.

RESULTS

In maintenance recipients mean hemoglobin levels were 12.8 +/- 1.6 g/dL (13.2 +/- 1.7 in men and 12 +/- 1.4 in women); 22.73% of men and 20.19% of women were found to be anemic. There was a significant correlation between hemoglobin and graft function (r = .14, P < .0001). The percentage of patients with anemia increased with the severity of chronic renal disease according to the KDOQI classification. Therapy with mycophenolate mofetil was also associated with a higher likehood of anemia as compared with other immunosuppressive therapies (azathioprine or sirolimus). There were no differences with angiotensin-converting enzyme inhibitors or ARB II. In de novo patients postransplant anemia was a frequent complication during the first 3 to 6 months. In patients with delayed graft function the recovery of anemia was slower.

CONCLUSION

The prevalence of anemia in transplant recipients was remarkably high, especially in the early postransplant period, and appeared associated with impaired renal function and with immunosuppressive treatment.

Impact of HLA Antibodies on Transplant Glomerulopathy

The influence of humoral rejection on the development of chronic allograft nephropathy (CAN) is controversial, especially in relation to transplant glomerulopathy. The aim of our study was to analyse the influence of anti-HLA antibodies on the development of transplant glomerulopathy (cg0, cg1, cg2, and cg3; Banff'97). We selected all renal transplants patients from 1975 to 2003 who had a functioning graft for at least 6 months and a clinically indicated graft biopsy with CAN and chronic glomerular changes (case group). We studied the presence of anti-HLA antibodies (Ab) in the last serum taken while the graft was functioning and divided them into three groups according to the severity of glomerular lesions. We also selected 52 contemporary and comparable cases without transplant glomerulopathy (control group). A total of 77 case had transplant glomerulopathy: 39 cg1, 29 cg2, and 9 cg3. Pretransplant Ab titers and number of previous blood transfusions were higher among the subgroup with the most severe glomerulopathy. Patients who developed posttransplant anti-HLA Ab more frequently showed transplant glomerulopathy. Serum creatinine and proteinuria were higher among cases with chronic glomerulopathy, and more grafts were lost in that group. Thus, the presence of HLA-Ab is a key factor in the development of transplant glomerulopathy and chronic allograft rejection.

Evolution of Proteinuria After Conversion From Calcineurin Inhibitors (CNI) to Sirolimus (SRL) in Renal Transplant Patients: A Multicenter Study

Conversion from calcineurin inhibitors (CNI) to sirolimus (SRL) has become an option in patients with chronic allograft nephropathy or other conditions. However, in some cases an increase of proteinuria has been reported after such therapeutic intervention. The aim of this study was to characterize the clinical course of this so far unexplained proteinuria after conversion. We performed a retrospective analysis evaluating 94 renal transplant patients from various Spanish centers. Proteinuria (629 determinations) and clinical developments were analyzed between 6 months before and 6 months after conversion. Patients were divided into three groups according to mean proteinuria before conversion (group A: <300 mg/d; group B: 300 to 2000 mg/d; and group C: >2 g/d). The mean proteinuria level was 1.69 g/24 h (n = 312 determinations) before and 2.36 g/24 h after conversion (n = 317 determinations; P = .006), which corresponds to an overall increase of 25% (1.55 to 1.69 g/24 h considering only determinations of 1 month before and 1 month after conversion; P = NS). We could not detect any clear correlation between proteinuria and serum creatinine nor between changes of proteinuria and changes of serum creatinine. A variance analysis for repeated measures showed an increase in proteinuria compared to the preconversion values (P = .003), and when the three groups of preconversion proteinuria were evaluated separately it could be observed that this change in the evolution of proteinuria was almost completely dependent of an increase in the group C (preconversion proteinuria greater than 2 g/d; P = .03), whereas in the other two groups changes were almost irrelevant. Finally, the switch to SRL in renal transplant recipients is followed by an increase in the level of proteinuria predominantly dependent of an increase in patients with high levels of preconversion proteinuria, whereas it seems to be irrelevant in patients without or with light or moderate proteinuria. These results suggest that this might not be a direct effect of SRL.

The macrophage infiltration index and matrix metalloproteinase-II expression as a predictor of chronic allograft rejection

The presence of macrophages on renal biopsy specimens is considered an important cofactor in the development of chronic allograft nephropathy (CAN). Macrophages can activate the expression of matrix metalloproteinases (MMP), which induce glomerulosclerosis, arteriosclerosis, and interstitial fibrosis. The aim of our study was to demonstrate if they were related to the development of CAN. We analyzed matrix metalloproteinase (MMP) expression with specific monoclonal antibodies on 53 kidney biopsies performed due to the suspicion of a first acute rejection (AR) episode: 24 of the grafts have been lost due to CAN and the rest are still functioning. The group with CAN showed worse graft function and greater proteinuria from the beginning. The macrophage infiltration index (MI) expression was significantly higher in that group also (18.8 +/- 12 vs 12.5 +/- 9.15; P < .05), with a more important presence of macrophages in the interstitium and tubules. We observed a positive correlation between MI and tubular infiltration (r(2) = 0.52; P < .001) and between MMP-II and MI in the interstitium (r(2) = 0.3; P < .05) and with the global MI (r(2) = 0.3; P < 0.05). The last correlation was more powerful in the group with CAN (r(2) = 0.4; P < .05). According to our experience, global MI and tubular infiltration during an AR episode are good markers of long-term graft survival. The correlation between MI and MMP-II supports the role of macrophages in the development of CAN, although further studies are needed to clarify the nature of this relationship.

[Current role of hormone replacement therapy in the prevention of postmenopausal osteoporosis: gynecologic point of view]

Hormonal Replacement Therapy (HRT) of the menopause has already proved to be effective in preventing bone loss and reducing the risk of fractures in postmenopausal women. Up until 2002, HRT was widely proposed and prescribed by French practitioners, in particular with regard to the prevention of osteoporosis. The results of two major studies, one American, the Women's Health Initiative (WHI) Study, and the other British, the Million Women Study (MWS), published in July 2002 and August 2003, have called into question the hitherto favourable benefits/risks ratio of HRT after finding an increased incidence of breast cancer and heart disease amongst women undergoing this treatment. Following these studies, the European and French health authorities have issued new recommendations regulating and restricting the use of HRT with a drastic restriction on the indications for its use in the prevention of osteoporosis. These new recommendations are the subject of controversy and pose new problems for practitioners.

Markers of Fibrosis in Early Biopsies of Renal Transplants

Many factors are involved in the development of chronic allograft nephropathy (CAN). Extracellular matrix turnover depends on the balance between fibrogenic and antifibrogenic cytokines. The aim of our study was to analyze the presence of transforming growth factor beta-1 (TGF-beta1), matrix metalloproteinase-2 (MMP-2), and mast cells in 53 early transplant biopsies using immunochemistry with specific monoclonal antibodies. We divided the patients into two groups depending on graft evolution (lost due to CAN versus functioning), renal function, presence of proteinuria, and graft survival. There were no differences in the demographic or immunological data. Renal function was worse and proteinuria greater among the group with CAN. The presence of mast cells was similar in both groups, but TGF-beta1 was expressed more and MMP-2 less in the CAN group. We observed a negative correlation between donor age and mast cells, and a positive correlation between TGF-beta1 and MMP-2. Grafts from younger donors showed better renal function, less proteinuria, greater graft survival, and less frequent development of CAN. According to our experience, cytokines involved in matrix turnover are expressed in early stages, correlating with donor age. The expressions of TGF-beta1 and MMP-2 seem to be important for the development of fibrosis in CAN.

Change in Serum Creatinine Levels Between 6 and 12 Months and Kidney Graft Survival: Influence of Proteinuria

Renal function within the first year after transplantation has been shown to be an important parameter influencing long-term survival. In this study, we examined the relationship between long-term outcome in 365 renal transplants and renal function in the first year, expressed as serum creatinine (SCr) level at 6 months and at 1 year as well as namely deltaCr, the change in SCr between 6 months and 1 year. In addition, we examined the influence of the presence of proteinuria as a predictive factor for a worse evolution. Graft survival was worse among patients with higher deltaCr, especially among those who developed proteinuria. In a Cox regression analysis of long-term graft survival, both deltaCr and proteinuria were important predictors of half-life. The risk of graft loss when deltaCr >0.3 was 2.65 (1.8-3.8; P < .000), whereas the risk increased to 5.67 (3.3-9.4; P < .00) when proteinuria was present. In conclusion, deltaCr values predict long-term graft survival. Patients who developed proteinuria were at higher risk for graft loss compared with those without proteinuria. By using a combination of SCr and deltaCr with proteinuria, it is possible to identify a subset of transplant recipients with a predictably shortened half-life.

Similar Impact of Slow and Delayed Graft Function on Renal Allograft Outcome and Function

Kidney transplant patients can be divided into three groups, according to the initial graft function. First-week dialyzed patients form the delayed graft function (DGF) group. Nondialyzed patients are divided into slow graft function (SGF) or immediate graft function (IGF) according to whether the day 5 serum creatinine was higher versus lower than 3 mg/dL, respectively. SGF patients showed worse graft survival, above higher incidence of acute rejection and lower renal function than IGF patients, although few reports have analyzed outcomes in these groups. We analyzed the impact of SGF on graft survival, first-year renal function, and incidence of acute rejection in 291 renal transplant patients. Creatinine was significantly worse at 12 months for SGF and DGF than for IGF patients (1.9 +/- 0.8 mg/dL, 1.8 +/- 0.7 mg/dL, 1.5 +/- 0.5 mg/dL, respectively; P < .05). There was no difference in first-year renal function between SGF and DGF. The acute rejection rate was higher among the SGF than the IGF group (45% vs 21%, P < .05), but not different from DGF patients (42%, P < .05). Graft survival was better among IGF than SGF or DGF patients, with no significant difference between the last two groups (3-year graft survival, 82%, 71%, 70%, respectively; log-rank test, P < .05). Kidney transplant recipients who develop SGF have a worse outcome than patients with IGF, similar to DGF patients. SGF patients show worse graft survival, worse renal function, and higher acute rejection rates than IGF patients, despite not needing dialysis.

High Initial Blood Levels of Tacrolimus in Overweight Renal Transplant Recipients

For the purpose of both efficacy and safety, exposure to tacrolimus and other immunosuppressive drugs must be monitored, since initial levels influence the development of acute rejection episodes, nephrotoxicity, and posttransplantation diabetes mellitus. The aim of this study was to identify risk factors for developing high initial tacrolimus blood levels. We analyzed clinical and biochemical parameters of 85 renal transplant recipients receiving tacrolimus-based immunosuppressive therapy by stratifying into subgroups of patients who displayed first tacrolimus concentrations higher and lower than 15 ng/mL. Patients with a first level of tacrolimus higher than 15 ng/mL were older (52 +/- 13 vs 40 +/- 12 years, P < .05) and had a larger body mass index (27 +/- 4 vs 23 +/- 3 kg/m2, P < .05) than patients with lower levels, despite receiving a lower weight-adjusted cumulative steroid dose (8.2 +/- 2.2 vs 9.3 +/- 2.5 mg/kg, P < .05). Upon logistic regression, age (RR 1.047, 95% CI 1.007 to 1.08, P = .021) and body mass index (RR 1.176, 95% CI 1.009 to 1.371, P = .036) remained significant risk factors for high initial blood levels of tacrolimus. As these subgroups of patients are most prone to develop posttransplantation glycemic disorders, attention must be paid to avoid high tacrolimus blood levels by diminishing initial tacrolimus doses or estimating them from ideal body weight.

Insulin-like growth factor I correlates with lean body mass in cystic fibrosis patients

BACKGROUND

A major consequence of malnutrition in cystic fibrosis (CF) patients is the loss of lean body mass (LBM) and the subsequent impairment of respiratory muscle function.

AIM

To determine whether insulin-like growth factor I (IGF-I) could be related to the LBM depletion and the evolution of respiratory disease in CF patients.

METHODS

LBM was evaluated by dual energy x ray absorptiometry; serum concentrations of IGF-I were measured in 24 CF patients twice with a one year interval. Both values were expressed as SD score (SDS) calculated from normal data for age, sex, and pubertal stage and analysed with respect to anthropometric evaluation and disease related conditions.

RESULTS

At the initial evaluation, IGF-I SDS had a mean value of -0.98 (range -3.6 to 3.2) and correlated with weight for age index, LBM SDS, and lung disease related conditions. Multiple regression analysis showed that only LBM remained independently related to IGF-I, suggesting that the relation of IGF-I to LBM was independent of weight and that the correlation between IGF-I and the respiratory conditions was related to the level of LBM. IGF-I SDS at the first evaluation was lower for the patients who lost > or =5% of weight for age index or > or =1 SD of LBM between the two evaluations.

CONCLUSION

Low levels of IGF-I could be crucial for clinical outcome by impairing LBM and respiratory function. IGF-I could be a tool for nutritional evaluation by identifying the CF patients at risk of LBM depletion.

De novo hemolytic-uremic syndrome/thrombotic microangiopathy in renal transplant patients receiving calcineurin inhibitors: role of sirolimus

The aim of this study was to evaluate the outcome of ten renal transplant recipients who developed de novo hemolytic uremic syndrome/thrombotic microangiopathy (DnHUS) after treatment with calcineurin inhibitors among 3,862 patients transplanted during the period 2000-2001 in Spain, and the results of switching to sirolimus for resolution of this pathologic condition. No patient had end-stage disease due to primary HUS. The criteria of diagnosis were decreased renal function, biopsy-proven thrombotic microangiopathy, and no signs of acute rejection. Calcineurin inhibitors were completely removed and immediate treatment with sirolimus started after diagnosis. The follow-up period was 19.0+/-4.3 months, at least 12 months after diagnosis. One patient died of sepsis shortly after starting sirolimus therapy. The serum creatinine level in the series decreased from 5.2+/-2.6 mg/dL at the time of biopsy to 2.15+/-1.9 mg/dL 1 month later (P=.011). All but one of the nine recipients, who lost his graft 3 months later (80% success) maintained function, with a serum creatinine of 2.1+/-1.4 mg/dL and Cockroft index of 61.3+/-34 mL/min at the end of follow up. During this time, none of the patients experienced an acute rejection episode and sirolimus was maintained without any remarkable secondary effect. Sirolimus seems to be a promising alternative for the treatment of renal transplant patients who develop calcineurin inhibitor-induced DnHUS.

Early elimination of cyclosporine in kidney transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions

Cyclosporine elimination in a regimen including sirolimus has been shown to be a safe and effective approach to improve graft function. Nevertheless, it is still unknown whether the functional benefit of CyA withdrawal coincides with a subsequent reduction in histologic lesions of chronic damage or development of chronic allograft nephropathy. This consideration would forecast a reduction in the rate of long-term graft loss. We analyzed 114 graft biopsies from a subgroup of 57 patients that had been included in a randomized study to eliminate CyA at 3 months posttransplant from a regimen including sirolimus either in group A CyA + SRL vs group B of SRL with CyA elimination at 3 months. Every patient had two biopsies, one at transplantation and another at 1 year. The biopsy reading was performed in a blinded manner by a central pathologist using the Banff 1997 and the CADI classifications. A significantly lower rate of progression of tubular and interstitial chronic lesions between basal and 1-year biopsies was observed for group B patients. In addition, the incidence of new cases of chronic allograft nephropathy during the first year was significantly lower in the group in which CyA had been eliminated at 3 months posttransplant. We conclude that early elimination of CyA in the first months posttransplant, when SRL is used as the main immunosuppressant, reduces the appearance or worsening of chronic histologic lesions, probably as a consequence of long-term CyA toxicity prevention.