PRODIG (Prevention of new onset diabetes after transplantation by a short term treatment of Vildagliptin in the early renal post-transplant period) study: study protocol for a randomized controlled study

BACKGROUND

Post-transplant diabetes is a frequent and serious complication of kidney transplantation. There is currently no treatment to prevent or delay the disease. Nevertheless, identification of risk factors make it possible to target a population at risk of developing de novo diabetes. We hypothesized that a short-term treatment with vildagliptin may prevent new onset diabetes after transplantation (NODAT) in high-risk patients.

METHODS/DESIGN

This is a multicenter, double-blind, placebo-controlled randomized clinical trial. Patients undergoing first kidney transplantation will be included from ten French transplant centers. Included patients will be randomized (1:1) to receive either vildagliptin 100 or 50 mg/day (depending on glomerular filtration rate) during 2 months (the first dose being administered before entering the operating theatres) or placebo. Additional antidiabetic therapy could be administered according to glycemic control. The primary outcome is the proportion of diabetic patients 1 year after transplantation, defined as patients receiving a diabetic treatment, or having a fasting glucose above 7 mmol/l, and/or with an abnormal oral glucose tolerance test. Secondary outcomes include glycated hemoglobin, the occurrence of acute rejection, infection, graft loss and patient death at 3 months, 6 months, and 12 months after transplantation. Outcomes will be correlated to clinical and general characteristics of the patient, cardiovascular history, nephropathy, dialysis history, transplantation data, biological data, health-related quality of life, and the cost-effectiveness of prevention of diabetes with vildagliptin.

DISCUSSION

We have scarce data on the pharmacological prevention of post-transplant diabetes. If our hypothesis is verified, our results will have a direct application in clinical practice and could limit diabetes-associated morbidity, reduce cardiovascular complications, increase quality of life of renal transplant patients, and consequently promote graft and patient survival. Our results may possibly serve for non-transplant patients carrying a high-risk of diabetes associated with other co-morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02849899 . Registered on 8 February 2016.

Face Transplantation: Partial Graft Loss of the First Case 10 Years Later

Ten years after the first face transplantation, we report the partial loss of this graft. After two episodes of acute rejection (AR) occurred and completely reversed in the first posttransplantation year, at 90 months posttransplantation the patient developed de novo class II donor-specific antibodies, without clinical signs of AR. Some months later, she developed several skin rejection episodes treated with steroid pulses. Despite rapid clinical improvement, some months later the sentinel skin graft underwent necrosis. Microscopic examination showed intimal thickening, thrombosis of the pedicle vessel, and C4d deposits on the endothelium of some dermal vessels of the facial graft. Flow magnetic resonance imaging of the facial graft showed a decrease of the distal right facial artery flow. Three steroid pulses of 500 mg each, followed by intravenous immunoglobulins (2 g/kg), five sessions of plasmapheresis, and three cycles of bortezomib 1.3 mg/m² , were administered. Despite rescue therapy with eculizumab, necrosis of the lips and the perioral area occurred, which led to surgical removal of the lower lip, labial commissures, and part of the right cheek in May 2015. In January 2016, the patient underwent conventional facial reconstruction because during the retransplantation evaluation a small-cell lung carcinoma was discovered, causing the patient's death in April 2016.

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 blood pressure outcome after unilateral adrenalectomy for primary hyperaldosteronism]

OBJECTIVES

To evaluate long-term results of adrenalectomy for primary aldosteronism (PA) and to identify prognostic factors associated.

METHODS

Exhaustive retrospective review of all consecutive patients undergoing adrenalectomy for PA between 2002 and 2013 in our department. All patients underwent preoperative: clinical evaluation (age, sex, height, weight, systolic and diastolic BP under treatment, identification of anti-hypertension treatment), biological evaluation (potassium, renin, aldosterone) and radiological evaluation (CT and/or MRI). Blood pressure was assessed postoperatively at 1 month, 1 year, then at the date of the latest news. The patients were classified into three categories: cured (no antihypertensive therapy in postoperative associated with strictly lower blood pressures of 140/90mmHg), improved (decreased number of drugs or number unchanged but with better blood pressure control), and refractory (no change in the number of drug and blood pressure, or deterioration of one or other of these two parameters).

RESULTS

We evaluated 43 patients, 23 men and 20 women, with a median follow-up of 74.4 months [16.8 to 141]. Pathological analysis described 34 adenomas (79%), 7 hyperplasias (16%) (5 micro-nodular and 2 macro-nodular) and 2 adrenocortical carcinoma (5%). The postoperative long-term assessment found 20% of cured patients (n=8), 65% of improved (n=26) and 15% of refractory (n=6). Prognostic factors associated with favorable long-term blood pressure outcome were those typically associated with ARS score [preoperative number of anti-hypertension drugs (P=0.005), BMI<25kg/m² (P=0.009), and duration of hypertension (P=0.007)].

CONCLUSION

Adrenalectomy for PA is a long-term effective treatment for blood pressure control. Prognostic factors associated with long-term success are those conventionally described in ARS score.

LEVEL OF EVIDENCE

4.

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.

Vascular expression of annexin A2 in lupus nephritis

AIMS

To evaluate vascular expression of annexin A2 (ANXA2) and its subunit S100A10 in lupus nephritis (LN).

METHODS

The present histological study included 14 patients with LN and 11 controls (patients with non-lupus kidney diseases). Kidney biopsies from patients with lupus were scored for lupus glomerulonephritis (according to the International Society of Nephrology/Renal Pathology Society 2003 classification) and vascular lesions (such as microthrombi and antiphospholipid syndrome nephropathy (APSN)). ANXA2 and S100A10 expression in glomerular and peritubular capillaries was evaluated by immunohistochemistry on tissue sections. The staining intensity score ranged from 0 (no expression) to 4 (intense expression).

RESULTS

In patients with LN, the median age (range) at first kidney biopsy was 36 (18-49). Vascular lesions were observed in six patients (including two with APSN). We observed intense expression of ANXA2 in glomerular and peritubular capillaries while expression of S100A10 was weaker. However, one of the patients with APSN showed strong S100A10 expression. Patients with LN and controls differed significantly in terms of S100A10 expression in peritubular capillaries. We also observed a statistical difference between patients who had LN with renal vascular lesions and those without renal vascular lesions in terms of ANXA2 expression in peritubular capillaries.

CONCLUSIONS

The presence of vascular lesions in LN appears to be associated with significant differences in the vascular expression of ANXA2. Vascular expression of ANXA2 was somewhat higher in LN. Vascular expression of S100A10 was somewhat lower in LN (except one of the two patients with APSN). Further studies of ANXA2's putative value as a biomarker of active LN or of vascular lesions in LN are required.

[Significance of the urine strip test in case of stunted growth]

Observation of stunted growth in children usually leads the general practitioner to refer the patient to endocrinologists or gastroenterologists. In most cases, after a complementary check-up, the diagnosis is made and treatment is initiated. However, certain cases remain undiagnosed, particularly renal etiologies, such as proximal tubulopathy. The urine strip test at the initial check-up would be an easy and inexpensive test to avoid delayed diagnosis. The aim of the present paper is to increase general physicians' and pediatricians' awareness of the significance of questioning the parents and using the urine strip test for any child presenting stunted growth. We report a patient case of a 20-month-old child admitted to the emergency department for severe dehydration. He had displayed stunted growth since the age of 5 months and showed a negative etiologic check-up at 9 months of age. Clinical examination at admission confirmed stunted growth with loss of 2 standard deviations and signs of dehydration with persistent diuresis. Skin paleness, ash-blond hair, and signs of rickets were also observed and the urine strip test showed positive pads for glycosuria and proteinuria. Polyuria and polydipsia were also revealed following parents' questioning, suggesting proximal tubulopathy (Fanconi syndrome). Association of stunted growth, rickets, polyuria and polydipsia, glycosuria (without ketonuria and normal glycemia), and proteinuria suggest nephropathic cystinosis. Ophthalmic examination showed cystine deposits in the cornea. The semiotic diagnosis of nephropathic cystinosis was confirmed by leukocyte cystine concentrations and genetic investigations. This case report clearly illustrates the significance of the urine strip test to easily and quickly concentrate the diagnosis of stunted growth on a renal etiology (glycosuria, proteinuria), especially on proximal tubulopathy for which the most frequent cause is nephropathic cystinosis. Specificity of nephropathic cystinosis treatment is that the age of treatment initiation is crucial and determinant for the prognosis of the disease and the onset of final stage renal failure. Therefore, the urine strip test should be included in the systematic check-up of stunted growth to identify any renal etiology.

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.

Circulating endothelial cells and progenitors as prognostic factors during autoimmune thrombotic thrombocytopenic purpura: results of a prospective multicenter French study

BACKGROUND

Autoimmune thrombotic thrombocytopenic purpura (AI-TTP) is characterized by an excess of circulating ultralarge von Willebrand factor (VWF) caused by anti-ADAMTS-13 autoantibodies. Animal studies, however, have shown that endothelial cell activation may also be an important trigger of AI-TTP.

OBJECTIVES

To prospectively study circulating biomarkers of endothelial lesion and activation, such as circulating endothelial cells (CECs), soluble P-selectin (sP-selectin), or VWF, and of endothelial repair, such as circulating progenitor cells (CPCs) and endothelial progenitor cells (EPCs), in AI-TTP, in relation to disease severity and prognosis.

RESULTS

Twenty-two patients were included in this study. CEC (P < 0.01), VWF (P < 0.05) and sP-selectin (P < 0.01) levels were significantly increased during crisis, and returned to baseline levels during remission. Both CEC (P < 0.05) and sP-selectin (P < 0.05) levels were significantly higher in patients who died or developed neurologic sequelae. CPC levels were substantially increased during the acute phase of the disease (P < 0.001), and returned to baseline levels during remission. Among CPCs, EPC levels were also increased during crisis (P < 0.05) and significantly decreased during remission. Patients who received < 16 plasma exchanges (PEs) had significantly higher EPC counts (P < 0.05) than those who needed more numerous PEs to obtain remission, suggesting that initial EPC counts may be associated with faster endothelial repair.

CONCLUSION

The profile of circulating endothelial markers shows massive endothelial activation and repair/remodeling during AI-TTP, and suggests that CECs and EPCs may be promising prognostic biomarkers of the disease.