Vaccination coverage reinforced by an infectious disease consultation during pretransplant check-up in patients awaiting kidney transplantation: A randomized study

BACKGROUND

Vaccine coverage (VC) in patients awaiting kidney transplantation is insufficient.

METHODS

We performed a prospective, single-center, interventional, randomized, open-label study comparing a reinforced group (infectious disease consultation proposed) and a standard group (letter stating vaccine recommendations sent to the nephrologist) of patients in our institution awaiting renal transplantation.

FINDINGS

Out of the 58 eligible patients, 19 declined to participate. Twenty patients were randomized to the standard group and 19 to the reinforced group. Essential VC increased from. 10% to 20% in the standard group and from 15.8% to 52.6% in the reinforced group (p < 0.034). The main obstacles identified were lack of vaccination traceability, refusal of an additional consultation and the journey time between home and hospital.

CONCLUSION

While introduction of an infectious disease consultation during the pre-transplant check-up significantly improved VC in patients, it is time-consuming and failed to achieve a satisfactory rate of VC.

Cobalamin c deficiency associated with antifactor h antibody-associated hemolytic uremic syndrome in a young adult

Background

Thrombotic microangiopathy (TMA) syndromes are characterized by the association of hemolytic anemia, thrombocytopenia and organ injury due to arteriolar and capillary thrombosis.

Case presentation

We report the first case of adult onset cobalamin C (Cbl C) disease associated with anti-factor H antibody-associated hemolytic uremic syndrome (HUS).

A 19-year-old woman was admitted to the nephrology department owing to acute kidney failure, proteinuria, and hemolytic anemia with schizocytes.

TMA was diagnosed and plasma exchanges were started in emergency.

Exhaustive analyses showed 1) circulating anti factor H antibody and 2) hyperhomocysteinemia, hypomethioninemia and high levels of methylmalonic aciduria pointing towards Clb C disease. Cbl C disease has been confirmed by methylmalonic aciduria and homocystinuria type C protein gene sequencing revealing two heterozygous pathogenic variants.

The kidney biopsy showed 1) intraglomerular and intravascular thrombi 2) noticeable thickening of the capillary wall with a duplication aspect of the glomerular basement membrane and a glomerular capillary wall IgM associated with Cbl C disease related TMA.

We initiated treatment including hydroxycobalamin, folinic acid, betaine and levocarnitine and Eculizumab. Rituximab infusions were performed allowing a high decrease in anti-factor H antibody rate.

Six month after the disease onset, Eculizumab was weaning and vitaminotherapy continued. Outcome was favorable with a dramatic improvement in kidney function.

Conclusion

TMA with renal involvement can have a complex combination of risk factors including anti-FH autoantibody in the presence of cblC deficiency.

Reduction of Extended-Release Tacrolimus Dose in Low-Immunological-Risk Kidney Transplant Recipients Increases Risk of Rejection and Appearance of Donor-Specific Antibodies: A Randomized Study

The aim of this study (ClinicalTrials.gov, NCT01744470) was to determine the efficacy and safety of two different doses of extended-release tacrolimus (TacER) in kidney transplant recipients (KTRs) between 4 and 12 mo after transplantation. Stable steroid-free KTRs were randomized (1:1) after 4 mo: Group A had a 50% reduction in TacER dose with a targeted TacER trough level (C₀ ) >3 μg/L; group B had no change in TacER dose (TacER C₀ 7-12 μg/L). The primary outcome was estimated GFR at 1 year. Of 300 patients, the intent-to-treat analysis included 186 patients (group A, n = 87; group B, n = 99). TacER C₀ was lower in group A than in group B at 6 mo (4.1 ± 2.7 vs. 6.7 ± 3.9 μg/L, p < 0.0001) and 12 mo (5.6 ± 2.0 vs. 7.4 ± 2.1 μg/L, p < 0.0001). Estimated GFR was similar in both groups at 12 mo (group A, 56.0 ± 17.5 mL/min per 1.73 m²; group B, 56.0 ± 22.1 mL/min per 1.73 m²). More rejection episodes occurred in group A than group B (11 vs. 3; p = 0.016). At 1 year, subclinical inflammation occurred more frequently in group A than group B (inflammation score [i] >0: 21.4% vs. 8.8%, p = 0.047; tubulitis score [t] >0: 19.6% vs. 8.7%, p = 0.076; i + t: 1.14 ± 1.21 vs. 0.72 ± 1.01, p = 0.038). Anti-HLA donor-specific antibodies appeared only in group A (6 vs. 0 patients, p = 0.008). TacER C₀ should be maintained >7 μg/L during the first year after transplantation in low-immunological-risk, steroid-free KTRs receiving a moderate dose of mycophenolic acid.

Predictive Modeling of Tacrolimus Dose Requirement Based on High-Throughput Genetic Screening

Any biochemical reaction underlying drug metabolism depends on individual gene-drug interactions and on groups of genes interacting together. Based on a high-throughput genetic approach, we sought to identify a set of covariant single-nucleotide polymorphisms predictive of interindividual tacrolimus (Tac) dose requirement variability. Tac blood concentrations (Tac C₀ ) of 229 kidney transplant recipients were repeatedly monitored after transplantation over 3 mo. Given the high dimension of the genomic data in comparison to the low number of observations and the high multicolinearity among the variables (gene variants), we developed an original predictive approach that integrates an ensemble variable-selection strategy to reinforce the stability of the variable-selection process and multivariate modeling. Our predictive models explained up to 70% of total variability in Tac C₀ per dose with a maximum of 44 gene variants (p-value <0.001 with a permutation test). These models included molecular networks of drug metabolism with oxidoreductase activities and the multidrug-resistant ABCC8 transporter, which was found in the most stringent model. Finally, we identified an intronic variant of the gene encoding SLC28A3, a drug transporter, as a key gene involved in Tac metabolism, and we confirmed it in an independent validation cohort.

Long-Term Clinical Impact of Adaptation of Initial Tacrolimus Dosing to CYP3A5 Genotype

Pretransplantation adaptation of the daily dose of tacrolimus to CYP3A5 genotype is associated with improved achievement of target trough concentration (C0 ), but whether this improvement affects clinical outcomes is unknown. In the present study, we have evaluated the long-term clinical impact of the adaptation of initial tacrolimus dosing according to CYP3A5 genotype: The transplantation outcomes of the 236 kidney transplant recipients included in the Tactique study were retrospectively investigated over a period of more than 5 years. In the Tactique study, patients were randomly assigned to receive tacrolimus at either a fixed dosage or a dosage determined by their genotype, and the primary efficacy end point was the proportion of patients for whom tacrolimus C0 was within target range (10-15 ng/mL) at day 10. Our results indicate that the incidence of biopsy-proven acute rejection and graft survival were similar between the control and the adapted tacrolimus dose groups, as well as between the patients who achieve the tacrolimus C0 target ranges earlier. Patients' death, cancer, cardiovascular events, and infections were also similar, and renal function did not change. We conclude that optimization of initial tacrolimus dose using pharmacogenetic testing does not improve clinical outcomes.

Effect of an Early Switch to Belatacept Among Calcineurin Inhibitor-Intolerant Graft Recipients of Kidneys From Extended-Criteria Donors

Transplant recipients receiving a kidney from an extended-criteria donor (ECD) are exposed to calcineurin inhibitor (CNI) nephrotoxicity, as demonstrated by severe delayed graft function and/or a low GFR. Belatacept is a nonnephrotoxic drug that is indicated as an alternative to CNIs. We reported 25 cases of conversion from a CNI to belatacept due to CNI intolerance within the first 6 mo after transplantation. The mean age of the recipients was 59 years, and 24 of 25 patients received ECD kidneys. At the date of the medication switch, 12 of 25 patients displayed a calculated GFR (cGFR) <15 mL/min, six patients remained on dialysis, and the biopsies showed evidence of acute tubular damage associated with severe vascular or tubulointerstitial chronic lesions. Three patients did not recover renal function, and three patients died during the follow-up period. Among the remaining patients, renal function improved: The cGFR was 18.28 ± 12.3 mL/min before the medication switch compared with 34.9 ± 14.5 mL/min at 1 year after conversion to belatacept (p = 0.002). Tolerance of and compliance with belatacept were good, and only one patient experienced acute rejection. Belatacept is an effective therapy that preserves renal function in kidney transplant patients who are intolerant of CNIs.

Pre-transplant end-stage renal disease-related immune risk profile in kidney transplant recipients predicts post-transplant infections

BACKGROUND

End-stage renal disease (ESRD) is associated with premature aging of the T-cell system. Nevertheless, the clinical significance of pre-transplant ESRD-related immune senescence is unknown.

METHODS

We studied whether immune risk phenotype (IRP), a typical feature of immune senescence, may affect post-transplant infectious complications. A total of 486 patients were prospectively studied during the first year post transplant. IRP was defined as positive cytomegalovirus serology with at least 1 of the following criteria: CD4/CD8 ratio <1 and/or CD8 T-cell count >90th percentile.

RESULTS

We found that 47 patients (9.7%) had pre-transplant IRP. IRP+ patients did not differ from IRP- patients for any clinical characteristics, but exhibited more pronounced immune senescence. Both opportunistic infections (43% vs. 6%, P < 0.001) and severe bacterial infection (SBI) (40% vs. 25%, P = 0.028) were more frequent in IRP(+) patients. In multivariate analysis, IRP was predictive of both opportunistic infection (hazard ratio [HR] 2.97 [95% confidence interval {CI} 1.53-5.76], P = 0.001), and SBI (HR 2.33 [95% CI 1.34-3.92], P = 0.008). Acute rejection rates were numerically much lower in IRP+ patients. A total of 418 patients (86%) had biological evaluation 1 year post transplant. Among 41 IRP+ patients, 35 (85%) remained IRP+ 1 year post transplant.

CONCLUSION

Pre-transplant IRP is associated with an increased risk of post-transplant infection.

Kidney transplant recipients carrying the CYP3A4*22 allelic variant have reduced tacrolimus clearance and often reach supratherapeutic tacrolimus concentrations

CYP3A4*22 is an allelic variant of the cytochrome P450 3A4 associated with a decreased activity. Carriers of this polymorphism may require reduced tacrolimus (Tac) doses to reach the target residual concentrations (Co). We tested this hypothesis in a population of kidney transplant recipients extracted from a multicenter, prospective and randomized study. Among the 186 kidney transplant recipients included, 9.3% (18 patients) were heterozygous for the CYP3A4*22 genotype and none were homozygous (allele frequency of 4.8%). Ten days after transplantation (3 days after starting treatment with Tac), 11% of the CYP3A4*22 carriers were within the target range of Tac Co (10-15 ng/mL), whereas among the CYP3A4*1/*1 carriers, 40% were within the target range (p = 0.02, OR = 0.19 [0.03; 0.69]). The mean Tac Co at day 10 in the CYP3A4*1/*22 group was 23.5 ng/mL (16.6-30.9) compared with 15.1 ng/mL (14-16.3) in the CYP3A4*1/*1 group, p < 0.001. The Tac Co/dose significantly depended on the CYP3A4 genotype during the follow-up (random effects model, p < 0.001) with the corresponding equivalent dose for patients heterozygous for CYP3A4*22 being 0.67 [0.54; 0.84] times the dose for CYP3A4*1/*1 carriers. In conclusion, the CYP3A4*22 allelic variant is associated with a significantly altered Tac metabolism and carriers of this polymorphism often reach supratherapeutic concentrations.

Recent progress in elucidating signalling proteolytic pathways in muscle wasting: potential clinical implications

AIMS

Muscle wasting prevails with disuse (bedrest and immobilisation) and is associated with many diseases (cancer, sepsis, diabetes, kidney failure, trauma, etc.). This results first in prolonged hospitalisation with associated high health-care costs and second and ultimately in increased morbidity and mortality. The precise characterisation of the signalling pathways leading to muscle atrophy is therefore particularly relevant in clinical settings.

DATA SYNTHESIS

Recent major papers have identified highly complex intricate pathways of signalling molecules, which induce the transcription of the muscle-specific ubiquitin protein ligases MAFbx/Atrogin-1 and MuRF1 that are overexpressed in nearly all muscle wasting diseases. These signalling pathways have been targeted with success in animal models of muscle wasting. In particular, these findings have revealed a finely tuned crosstalk between both anabolic and catabolic processes.

CONCLUSIONS

Whether or not such strategies may be useful for blocking or at least limiting muscle wasting in weight losing and cachectic patients is becoming nowadays a very exciting clinical challenge.

Kidney biopsy in the critically ill patient, results of a multicentre retrospective case series

BACKGROUND

The impact of a contributive result of kidney biopsy on the management of patients in the intensive care unit (ICU) has not been extensively investigated yet.

METHODS

This was a retrospective study conducted between 2000 and 2011 in five French ICUs. The study included 56 patients. They had at least one non-renal organ failure, as defined by a Sequential Organ Failure Assessment (SOFA) score ≥3 on ICU admission, and kidney biopsy was performed during ICU stay. Kidney samples were obtained by percutaneous (N.=55) or transjugular biopsy (N.=1).

RESULTS

The mean Simplified Acute Physiology Score II and total SOFA scores on ICU admission were 52±19 years and 10.3±3.6, respectively. ICU mortality was 23%. The median (interquartile range) time between ICU admission and kidney biopsy was 9 days (5-21). Pathologic findings in the 54 analyzable kidney biopsies were acute tubular necrosis (N.=26), glomerulonephritis (N.=14), acute vascular nephritis (N.=11), acute interstitial nephritis (N.=6), and deposit disease (N.=3). Kidney biopsy was contributive to the management of 40 patients. In 23 of these, new treatments were started, in 13 ongoing treatments were stopped, including four life-sustaining therapies, and in 13 it was decided to start chronic renal replacement. Severe bleeding was observed in 7 patients, with fatal outcome in one case.

CONCLUSION

Kidney biopsy may have a significant impact on the management of critically ill patients. Further studies should be done to identify the groups of ICU patients likely to benefit from the procedure with minimum risk.

Optimization of initial tacrolimus dose using pharmacogenetic testing

Retrospective studies have demonstrated that patients who are expressors of cytochrome P4503A5 (CYP3A5) require a higher tacrolimus dose to achieve a therapeutic trough concentration (C(0)). The aim of this study was to evaluate this effect prospectively by pretransplantation adaptation. We randomly assigned 280 renal transplant recipients to receive tacrolimus either according to CYP3A5 genotype or according to the standard daily regimen. The primary end point was the proportion of patients within the targeted C(0). Secondary end points included the number of dose modifications and the delay in achieving the targeted C(0). In the group receiving the adapted dose, a higher proportion of patients had values within the targeted C(0) at day 3 after initiation of tacrolimus (43.2% vs. 29.1%; P = 0.03); they required fewer dose modifications, and the targeted C(0) was achieved by 75% of these patients more rapidly. The clinical end points were similar in the two groups. Pharmacogenetic adaptation of the daily dose of tacrolimus is associated with improved achievement of the target C(0). Whether this improvement will affect clinical outcomes requires further evaluation.

Efficacy on renal function of early conversion from cyclosporine to sirolimus 3 months after renal transplantation: concept study

Sirolimus (SRL) allows to minimize the use of cyclosporine (CsA), but de novo administration after transplantation is associated with various complications. We report a prospective, open-label, multicenter randomized study to evaluate conversion from a CsA-based regimen to a SRL-based regimen 3 months after transplantation. One hundred ninety-two of a total of 237 patients were eligible at 3 months to be converted to SRL (n = 95) or to continue CsA (n = 97). All patients were also given mycophenolate mofetil (MMF) and oral steroids, planned to be discontinued at month 8. The primary endpoint, the clearance estimated according to Cockcroft and Gault at week 52, was significantly better in the SRL group (68.9 vs. 64.4 mL/min, p = 0.017). Patient and graft survival were not statistically different. The incidence of acute rejection episodes, mainly occurring after withdrawal of steroids, was numerically but not statistically higher in the SRL group (17% vs. 8%, p = 0.071). Sixteen patients discontinued SRL, mainly for adverse events (n = 11), and seven patients discontinued CsA for renal failure or acute rejection. Significantly, more patients in the SRL group reported aphthous, diarrhea, acne and high triglyceride levels. Conversion CsA to SRL 3 months after transplantation combined with MMF is associated with improvement in renal function.

Sirolimus versus cyclosporine in kidney recipients receiving thymoglobulin, mycophenolate mofetil and a 6-month course of steroids

To evaluate the efficacy and tolerance of a calcineurin inhibitor (CNI)-free regimen, 145 renal recipients were prospectively randomized to receive either sirolimus (n = 71) or cyclosporine (CsA; n = 74). All patients received polyclonal antilymphocyte antibodies, mycophenolate mofetil (MMF) and steroids (6 months). The primary endpoint, estimated glomerular filtration rate (eGFR) was not significantly different at 12 months comparing sirolimus- and CsA-treated patients (60 +/- 27 vs. 57 +/- 21 mL/min). At 12 months, patient and graft survival, incidence of biopsy-proven rejection and rates of steroid withdrawal were not statistically different (97% vs. 97%; 90% vs. 93%; 14.3% vs. 8.6% and 82.8% vs. 84.1%, respectively). Delayed and slow graft function (SGF) was not significantly different (18.6% vs. 12.3% and 11.4% vs. 13.7%, respectively). In patients who remained on treatment according to protocol at 12 months, eGFR was significantly higher with sirolimus (69 +/- 19 vs. 60 +/- 14 mL/min, p = 0.01). Overall study drug discontinuation rates were 28.2% with sirolimus and 14.9% with CsA. Adverse events (wound complications, mouth ulcers, diarrhea, hypokalemia, bronchopneumonia) and proteinuria >0.5 g/24h (38.8% vs. 5.6%, p < 0.001) were significantly more frequent in sirolimus-treated patients. Cytomegalovirus (CMV) infections were significantly less frequent with sirolimus (6% vs. 23%, p < 0.01). A CNI-free regimen using sirolimus-MMF can achieve excellent renal function, but patients on sirolimus experienced a high rate of adverse events and study drug discontinuation.

Sirolimus versus cyclosporine in kidney recipients receiving thymoglobulin, mycophenolate mofetil and a 6-month course of steroids

To evaluate the efficacy and tolerance of a calcineurin inhibitor (CNI)-free regimen, 145 renal recipients were prospectively randomized to receive either sirolimus (n = 71) or cyclosporine (CsA; n = 74). All patients received polyclonal antilymphocyte antibodies, mycophenolate mofetil (MMF) and steroids (6 months). The primary endpoint, estimated glomerular filtration rate (eGFR) was not significantly different at 12 months comparing sirolimus- and CsA-treated patients (60 +/- 27 vs. 57 +/- 21 mL/min). At 12 months, patient and graft survival, incidence of biopsy-proven rejection and rates of steroid withdrawal were not statistically different (97% vs. 97%; 90% vs. 93%; 14.3% vs. 8.6% and 82.8% vs. 84.1%, respectively). Delayed and slow graft function (SGF) was not significantly different (18.6% vs. 12.3% and 11.4% vs. 13.7%, respectively). In patients who remained on treatment according to protocol at 12 months, eGFR was significantly higher with sirolimus (69 +/- 19 vs. 60 +/- 14 mL/min, p = 0.01). Overall study drug discontinuation rates were 28.2% with sirolimus and 14.9% with CsA. Adverse events (wound complications, mouth ulcers, diarrhea, hypokalemia, bronchopneumonia) and proteinuria >0.5 g/24h (38.8% vs. 5.6%, p < 0.001) were significantly more frequent in sirolimus-treated patients. Cytomegalovirus (CMV) infections were significantly less frequent with sirolimus (6% vs. 23%, p < 0.01). A CNI-free regimen using sirolimus-MMF can achieve excellent renal function, but patients on sirolimus experienced a high rate of adverse events and study drug discontinuation.

Centropontine myelinolysis after correction of hyponatremia: role of associated hypokalemia

BACKGROUND

Patients with severe hyponatremia have a high risk for centropontine myelinolysis (CPM) during treatment, but the incidence rate and risk factors have not been well-assessed.

METHODS

This study was conducted in a medical intensive care unit (ICU) of a university teaching hospital. All patients with a serum sodium concentration < 120 mmol/l and a serum osmolality level < 250 mosmol/kg upon ICU admission were enrolled in this prospective study and were included if they underwent a baseline brain computerized tomography scan (CT scan) and a follow-up brain magnetic resonance imaging 1 month after admission. The diagnosis of CPM was based on cerebral magnetic resonance imaging findings, i.e. T1-weighted images with T2-weighted images showing hyperintense signal in the corresponding areas which were not apparent on the initial cerebral CT scan. RESULTS. Of the 22 patients included, 12 were considered as having acute hyponatremia and 8 were chronic alcoholics. In 12 patients, the increase in serum sodium level was < 12 mmol/I in any 24-hour period. CPM was diagnosed in 7/22 patients (31.8%) and was asymptomatic in 4 of them. CPM was present in 4 patients with acute hyponatremia and in 4 chronic alcoholics. It was associated with a lower baseline potassium level (p = 0.05) and NaCl administration during the first 24 hours (p = 0.005). However, non-acute hyponatremia, chronic alcoholism and rapid correction of serum sodium did not appear as risk factors.

CONCLUSION

The incidence rate of CPM following severe hyponatremia is high and can develop even when there is a slow correction of serum sodium level. Hypokalemia is a predisposing factor.

PUVA apoptotic response in activated and resting human lymphocytes

In extracorporeal photopheresis (ECP) collected cells are treated by 8 methoxypsoralen and UVA (PUVA) which induced apoptosis. The mechanism of action of reinfused cell is unclear. A vaccination model postulates an efficient presentation of apoptotic alloreactive cells to the patient immune system. The efficiency may depend upon a predominance of apoptotic alloreactive cells after PUVA. Such selectivity could result from their activation. We studied apoptosis in resting and PHA-activated lymphocytes. Both were equally susceptible. Changes in early apoptosis were possibly missed. We evaluated the effect of preincubation before PUVA. During preincubation monocyte could affect lymphocytes susceptibility to apoptosis as an increase of number of apoptotic cells was observed after 72 hours in stimulated and resting cells. Our findings do not preclude a selectivity of other PUVA effects since expression of membrane marker also targets to PUVA is modified by activation.