Factors That Predict a Sustained Humoral Response to COVID-19 Vaccines in Kidney Transplant Recipients.

INTRODUCTION: Kidney transplant recipients (KTRs) produce a weak humoral response to coronavirus disease 2019 (COVID-19) vaccines. However, the factors associated with the quality of the serological response to three doses of COVID-19 vaccine have not been unambiguously identified. METHODS: We included KTRs followed in the Nephrology Department at Amiens University Hospital (Amiens, France) between June and December 2021 who had received three doses of a COVID-19 mRNA vaccine (or two doses plus an episode of polymerase chain reaction-confirmed COVID-19). The lack of a humoral response was defined as an antibody titer below 7.1 binding antibody units (BAU)/mL, and an optimal response was defined as an antibody titer above 264 BAU/mL. RESULTS: Of the 371 patients included, 246 (66.3%) were seropositive, and 97 (26.1%) had an optimal response. In a multivariate analysis, the only factor associated with seropositivity was a history of COVID-19 [odds ratio (OR) 87.2; 95% confidence interval (CI) (7.88-965.0); p < 0.0001], while the main factors associated with non-response were female sex [OR 0.28; 95%CI (0.15-0.51); p < 0.0001], less than 36 months between kidney transplantation and vaccination [OR 0.26; 95%CI (0.13-0.52); p < 0.0001], a higher creatinine level [OR 0.33; 95%CI (0.19-0.56); p < 0.0001], the use of tacrolimus [OR 0.23; 95%CI (0.12-0.45); p < 0.0001], the use of belatacept [OR 0.01; 95%CI (0.001-0.20); p = 0.002] and three-drug immunosuppression [OR 0.39; 95%CI (0.19-0.78); p = 0.015]. A history of COVID-19 was associated with an optimal response [OR 4.03; 95%CI (2.09-7.79); p < 0.0001], while an older age at vaccination [OR 0.97; 95%CI (0.95-0.99); p = 0.002], less than 36 months between kidney transplantation and vaccination [OR 0.35; 95%CI (0.18-0.69); p = 0.002], a higher creatinine level [OR 0.60; 95%CI (0.38-0.93); p = 0.02], three-drug immunosuppression [OR 0.45; 95%CI (0.27-0.76); p = 0.003] were associated with a poorer response. CONCLUSION: We identified factors associated with a humoral response to a COVID-19 mRNA vaccine in KTRs. These findings might help physicians to optimize vaccination in KTRs.

Intensity of de novo DSA detected by Immucor Lifecodes assay and C3d fixing antibodies are not predictive of subclinical ABMR after Kidney Transplantation.

De novo donor-specific antibodies (dnDSA) are associated with antibody-mediated rejection (ABMR) and allograft loss. We tested Immucor* (IM) Luminex Single-antigen beads (LSAB) assay and C3d-fixing antibodies in the setting of dnDSA and subclinical (s) ABMR. This retrospective multicentric study included 123 patients biopsied because of the presence of subclinical de novo DSA detected by One Lamda* Labscreen (MFI > 1000). In 112 patients, sera of the day of the biopsy were available and tested in a central lab with IM Lifecodes LSAB and C3d fixing antibodies assays. In 16 patients (14.3%), no DSA was detected using Immucor test. In 96 patients, at least one DSA was determined with IM. Systematic biopsies showed active sABMR in 30 patients (31.2%), chronic active sABMR in 17 patients (17.7%) and no lesions of sABMR in 49 KT recipients (51%). Intensitity criteria (BCM, BCR and AD-BCR) of DSA were not statistically different between these 3 histological groups. The proportion of patients with C3d-fixing DSA was not statistically different between the 3 groups and did not offer any prognostic value regarding graft survival. Performing biopsy for dnDSA could not be guided by the intensity criteria of IM LSAB assay. C3d-fixing DSA do not offer added value.

Characteristics and outcomes of COVID-19 in hospitalized patients with and without diabetes.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a rapidly progressing pandemic, with four million confirmed cases and 280 000 deaths at the time of writing. Some studies have suggested that diabetes is associated with a greater risk of developing severe forms of COVID-19. The primary objective of the present study was to compare the clinical features and outcomes in hospitalized COVID-19 patients with vs without diabetes. METHODS: All consecutive adult patients admitted to Amiens University Hospital (Amiens, France) with confirmed COVID-19 up until April 21st, 2020, were included. The composite primary endpoint comprised admission to the intensive care unit (ICU) and death. Both components were also analysed separately in a logistic regression analysis and a Cox proportional hazards model. RESULTS: A total of 433 patients (median age: 72; 238 (55%) men; diabetes: 115 (26.6%)) were included. Most of the deaths occurred in non-ICU units and among older adults. Multivariate analyses showed that diabetes was associated neither with the primary endpoint (odds ratio (OR): 1.12; 95% confidence interval (CI): 0.66-1.90) nor with mortality (hazard ratio: 0.73; 95%CI: 0.40-1.34) but was associated with ICU admission (OR: 2.06; 95%CI 1.09-3.92, P = .027) and a longer length of hospital stay. Age was negatively associated with ICU admission and positively associated with death. CONCLUSIONS: Diabetes was prevalent in a quarter of the patients hospitalized with COVID-19; it was associated with a greater risk of ICU admission but not with a significant elevation in mortality. Further investigation of the relationship between COVID-19 severity and diabetes is warranted.

The association between body mass index class and coronavirus disease 2019 outcomes.

BACKGROUND/OBJECTIVES: A growing body of data suggests that obesity influences coronavirus disease 2019 (COVID-19). Our study's primary objective was to assess the association between body mass index (BMI) categories and critical forms of COVID-19. SUBJECTS/METHODS: Data on consecutive adult patients hospitalized with laboratory-confirmed COVID-19 at Amiens University Hospital (Amiens, France) were extracted retrospectively. The association between BMI categories and the composite primary endpoint (admission to the intensive care unit or death) was probed in a logistic regression analysis. RESULTS: In total, 433 patients were included, and BMI data were available for 329: 20 were underweight (6.1%), 95 have a normal weight (28.9%), 90 were overweight (27.4%), and 124 were obese (37.7%). The BMI category was associated with the primary endpoint in the fully adjusted model; the odds ratio (OR) [95% confidence interval (CI)] for overweight and obesity were respectively 1.58 [0.77-3.24] and 2.58 [1.28-5.31]. The ORs [95% CI] for ICU admission were similar for overweight (3.16 [1.29-8.06]) and obesity (3.05 [1.25-7.82]) in the fully adjusted model. The unadjusted ORs for death were similar in all BMI categories while obesity only was associated with higher risk after adjustment. CONCLUSIONS: Our results suggest that overweight (and not only obesity) is associated with ICU admission, but overweight is not associated with death.

Opportunistic Infections and Efficacy Following Conversion to Belatacept-Based Therapy after Kidney Transplantation: A French Multicenter Cohort.

Conversion from calcineurin-inhibitors (CNIs) to belatacept can help kidney-transplant (KT) recipients avoid CNI-related nephrotoxicity. The risk of associated opportunistic infections (OPIs) is ill-defined. We conducted a multicentric cohort study across 15 French KT-centers in a real-life setting. Between 07-2010 and 07-2019, 453 KT recipients were converted from CNI- to belatacept-based therapy at 19 [0.13-431] months post-transplantation. Most patients, i.e., 332 (79.3%), were converted after 6-months post-transplantation. Follow-up time after conversion was 20.1 +/- 13 months. OPIs developed in 42(9.3%) patients after 14 +/- 12 months post-conversion. Eight patients (19%) had two OPI episodes during follow-up. Incidences of CMV DNAemia and CMV disease were significantly higher in patients converted before 6-months post-KT compared to those converted later (i.e., 31.6% vs. 11.5%; p < 0.001; and 11.6% vs. 2.4%, p < 0.001, respectively). Cumulative incidence of OPIs was 6.5 OPIs/100 person-years. Incidence of CMV disease was 2.8/100 person-years, of pneumocystis pneumonia 1.6/100 person-years, and of aspergillosis 0.2/100 person-years. Multivariate analyses showed that estimated glomerular filtration (eGFR) < 25 mL/min/1.73 m2 at conversion was independently associated with OPIs (HR = 4.7 (2.2 - 10.3), p < 0.001). The incidence of EBV DNAemia was 17.3 events /100 person-years. At 1-year post-conversion, mean eGFR had significantly increased from 32.0 +/- 18 mL/min/1.73 m2 to 42.2 +/- 18 mL/min/1.73 m2 (p < 0.0001). Conversion to belatacept is an effective strategy with a low infectious risk.

Protocol Biopsies in Patients With Subclinical De Novo Donor-specific Antibodies After Kidney Transplantation: A Multicentric Study.

BACKGROUND: De novo donor-specific antibodies (DSAs) are associated with antibody-mediated rejection (AMR) and allograft loss. Whether monitoring of de novo DSA (dnDSA) paired with systematic kidney biopsy should become routine remains to be established. METHODS: A retrospective multicentric study (9 French kidney transplant units of the Spiesser group) included patients without graft dysfunction biopsied because of the presence of dnDSA (One Lambda, mean fluorescence intensity [MFI], >1000). RESULTS: One hundred twenty-three patients (85 male/38 female; mean age, 49.5 ± 13.1 y old) were biopsied after the detection of a dnDSA, 65.3 months (median) after kidney transplantation. Graft function was stable within 3 months before biopsy (estimated glomerular filtration rate, 55.3 ± 18.9 mL/min/1.73 m). Fifty-one subclinical AMRs (sAMRs) (41.4%) were diagnosed, of which 32 (26%) active and 19 (15.5%) chronic active sAMR. Seventy-two biopsies revealed no AMR (58.5%). Predictive factors associated with the diagnosis of active sAMR were MFI of immunodominant DSA >4000, MFI of the sum of DSA >6300, age of the recipient <45 years old, and the absence of steroids at biopsy. The presence of proteinuria >200 mg/g was predictive of chronic active sAMR. The decrease of estimated glomerular filtration rate at 5 years post-biopsy was significantly higher in patients with acute sAMR (-25.2 ± 28.3 mL/min/1.73 m) and graft survival significantly lower. CONCLUSIONS: Performing a kidney graft biopsy for the occurrence of dnDSA without renal dysfunction leads to the diagnosis of a sAMR in over 40% of cases. Nevertheless, we did not observe any effect of standard treatment in acute sAMR.

Opportunistic infections after conversion to belatacept in kidney transplantation.

BACKGROUND: Belatacept (bela) rescue therapy seems to be a valuable option for calcineurin inhibitor chronic toxicity in kidney transplantation. Nevertheless, the risk of infection associated with bela is not well reported. METHODS: We report the rate of opportunistic infections (OPI) after a switch to bela in a multicentric cohort of 280 kidney transplant patients. RESULTS: Forty-two OPI occurred in 34 patients (12.1%), on average 10.8 ± 11.3 months after the switch. With a cumulative exposure of 5128 months of bela treatment, we found an incidence of 0.008 OPI/month of exposure, and 9.8 OPI/100 person-years. The most common OPI was cytomegalovirus (CMV) disease in 18/42 OPI (42.9%) and pneumocystis pneumonia in 12/42 OPI (28.6%). Two patients presented a progressive multifocal leucoencephalopathy and two patients developed a cerebral Epstein-Barr virus-induced post-transplant lymphoproliferative disease. OPI led to death in 9/34 patients (26.5%) and graft failure in 4/34 patients (11.8%). In multivariate analysis, estimated glomerular filtration rate <25/mL/min/1.73 m2 on the day of the switch and the use of immunosuppressive agents before transplantation were associated with the occurrence of OPI. We found a higher rate of infection-related hospitalization (24.1 versus 12.3/100 person-years, P = 0.0007) and also a higher rate of OPI (13.2 versus 6.7/100 person-years, P = 0.005) in the early conversion group (within 6 months). CONCLUSIONS: The risk of OPI is significant post-conversion to bela and may require additional monitoring and prophylactic therapy, particularly regarding pneumocystis pneumonia and CMV disease. These data need to be confirmed in a larger case-control study.

Levels of Indoxyl Sulfate in Kidney Transplant Patients, and the Relationship With Hard Outcomes.

BACKGROUND: Indoxyl sulfate (IS) is a protein-bound uremic toxin that is known to be associated with the risk of cardiovascular (CV) disease and death in both predialysis and dialysis patients. Data on levels of protein-bound uremic toxins in kidney transplant patients are scarce. The study's objective was to evaluate the levels of IS in kidney transplant patients and the relationship with hard outcomes. METHODS AND RESULTS: In 311 kidney transplant patients, IS levels were measured immediately before transplantation (T0), and 1 month (M1) and 12 months (M12) afterwards. Over a mean±standard deviation follow-up period of 113±29 months, a total of 55 deaths, 70 CV events and 71 graft losses were recorded. We observed a rapid significant decrease (below or near the normal value) in IS levels after kidney transplantation. Total and free IS levels at M12 were significantly higher in non-transplant patients than in transplant patients (P=0.003 and <0.0001 respectively), despite having similar estimated glomerular filtration rates. Lastly, IS levels were not associated with overall mortality, CV events or graft loss at T0, M1 or M12. CONCLUSIONS: IS levels were significantly lower in kidney transplant receipts than in non-recipients suggesting that kidney transplantation protects against an increase in IS levels. IS levels were not associated with hard outcomes in kidney transplant patients. (Circ J 2016; 80: 722-730).

[Fanconi syndrome in a 22-year-old African patient]. / Syndrome de Fanconi chez un patient de 22 ans d'origine africaine.

Acquired Fanconi syndrome can occur in patients with monoclonal gammopathy or after exposure to heavy metals or drug agents such as ifosfamide, and some antiretroviral therapies. Fanconi syndrome is characterized by a dysfunctional of the proximal tubular responsible in its complete form for polyuria, hypokalemia, glycosuria, hypophosphatemia and low molecular weight proteinuria. We report the case of a 22-year-old patient hospitalized with an acute renal failure secondary to a tubulo-interstitial nephritis associated with a complete Fanconi syndrome in a context of a poor general condition and fever. We described and analyzed the process leading to the diagnosis.

Thrombotic thrombocytopenic purpura due to anti-ADAMTS13 antibodies in multiple myeloma.

CONTEXT: Thrombotic thrombocytopenic purpura (TTP) is a particularly serious form of thrombotic microangiopathy (TMA) due to the risk of multiple organ dysfunction. Several etiological factors such as infection, auto-immune disease, certain medications and cancers have been associated with TTP. CLINICAL CASES: A 74-year-old hypertensive woman with a history of thromboembolic disease was hospitalized for acute kidney injury (AKI) associated with pneumonia. Initial investigations were suggestive of Pneumocystis jirovecii infection and myeloma cast nephropathy. Several days later, the patient presented features of TTP. Von Willebrand factor-cleaving protease activity was less than 5% with a high level of IgG antibody directed against ADAMTS13. Treatment consisted of monthly 4-day cycles of dexamethasone and melphalan in combination with plasmapheresis and resulted in a favorable outcome. Three years after ceasing treatment, the patient presented no signs of hemolysis, but required chronic hemodialysis. CONCLUSION: The association of TMA, especially TTP, and multiple myeloma is exceptional. The authors report such a case that induced irreversible renal damage, but with stable clinical and laboratory parameters with a follow-up of 4 years.

Progression of pulse pressure in kidney recipients durably exposed to CsA is a risk factor for epithelial phenotypic changes: an ancillary study of the CONCEPT trial.

In this ancillary study of the CONCEPT trial, we studied the role of CsA withdrawal at 3 months (3M) post-transplant on the intensity of epithelial phenotypic changes (EPC, an early marker for kidney fibrogenesis) on the 12 M surveillance biopsy. Although conversion from CsA to sirolimus (SRL) at 3M was reported to have improved mean graft function at 12 M, it did not reduce the score of EPC (1.73 ± 1.15 in the SRL group vs. 1.87 ± 1 in the CsA group, P = 0.61). Acute rejection, which had occurred twice more frequently in SRL-converted patients included here, was associated with 12 M EPC. Interestingly, we observed that the patients durably exposed to CsA and who developed 12 M EPC had a significant progression of blood pulse pressure (pp) from 1 to 6M post-transplantation (Δpp = +12.3 mmHg, P = 0.0035). Pulse pressure at 4, 6, and 9 M and pp progression from 1 to 6M were significantly associated with the development of EPC at 12 M in renal grafts. Logistic regression analysis revealed that a high 6M pp (≥ 60 mmHg) was an independent risk factor for 12 M EPC with an odds ratio of 2.25 per additional 10 mmHg pp (95%CI: 1.14-4.4, P = 0.02) after adjustment with recipient's and donor's age, acute rejection incidence and immunosuppressive regimen. A post hoc analysis of the data collected in the whole population CONCEPT study revealed that pp was significantly higher at 6 months in patients maintained on CsA and that at this time point pp correlated negatively with GFR at 1 year.

Comparison of UW and Celsior: long-term results in kidney transplantation.

BACKGROUND: The aim of this study was to compare 2 preservation solutions in kidney transplant recipients in the same center during the same period since initiation of the use of High Na+; low K+ solution (Celsior). MATERIAL AND METHODS: From January 1999 to April 2011, 610 consecutive renal transplantations were done in our department with deceased donor kidneys. Data were collected prospectively. Organ procurement was performed in our center for 305 kidneys. We washed and preserved 409 kidneys in UW, and 201 in Celsior solution. RESULTS: Donors criteria were worse in the Celsior group for age, male sex, creatinemia, and cold ischemia. Populations of recipients were comparable. There were no differences at 1 and 12 months in creatinine levels (p=0.9 and 0.8, respectively) and in number of delayed graft functions (DGF) (p=0.8 and relative risk =0.9) between groups. There were no differences in post-transplantation outcomes for all variables. At 5 years, graft survival was 90.4% for UW and 93.5% for Celsior (p=0.44). CONCLUSIONS: Our retrospective study did not succeed in demonstrating superiority of a High Na+; low K+ solution compared to a UW type reference solution. Celsior has the same effectiveness as UW during kidney cold storage.

The high rate of de novo graft carcinomas in renal transplant recipients.

BACKGROUND: To investigate the incidence, the clinical characteristics and outcomes of renal graft carcinomas in the same renal transplant population. METHODS: From April 1989 to April 2012, 1,037 consecutive renal transplantations were performed in our department. Data were collected prospectively in an extensively maintained database. For all recipients, monitoring consisted of clinical examination and an abdominopelvic CT scan or ultrasonography at least once a year. RESULTS: After 1,037 renal transplantations, 48 men and 14 women (sex ratio 3:4) with a mean age of 54 years (25.1-78.9) were included for urological malignancies. Eight graft carcinomas were identified: 7 renal cell carcinomas (5 papillary carcinomas and 2 clear cell carcinomas of the renal graft) and 1 transitional cell carcinoma of the ureteral graft (incidence 0.78%). Nephron-sparing surgery was chosen for 5 patients with good outcomes. All graft renal cell carcinomas were classified as pT1a and the mean size of tumors was 28.4 mm (range 6-45). The 5-year specific survival rate was 100%. No recurrence was observed with a mean follow-up of 36.8 months (4.1-84.3). CONCLUSION: Thus confirming an increased risk of de novo graft cancer, close monitoring of renal transplant recipients should be discussed with at least an abdominopelvic ultrasonography and PSA measurement once a year. Renal cell graft carcinomas seemed to be mostly small and of papillary type and low grade.

Correction of postkidney transplant anemia reduces progression of allograft nephropathy.

Retrospective studies suggest that chronic allograft nephropathy might progress more rapidly in patients with post-transplant anemia, but whether correction of anemia improves renal outcomes is unknown. An open-label, multicenter, randomized controlled trial investigated the effect of epoetin-ß to normalize hemoglobin values (13.0-15.0 g/dl, n=63) compared with partial correction of anemia (10.5-11.5 g/dl, n=62) on progression of nephropathy in transplant recipients with hemoglobin <11.5 g/dl and an estimated creatinine clearance (eCrCl) <50 ml/min per 1.73 m(2). After 2 years, the mean hemoglobin was 12.9 and 11.3 g/dl in the normalization and partial correction groups, respectively (P<0.001). From baseline to year 2, the eCrCl decreased by a mean 2.4 ml/min per 1.73 m(2) in the normalization group compared with 5.9 ml/min per 1.73 m(2) in the partial correction group (P=0.03). Furthermore, fewer patients in the normalization group progressed to ESRD (3 versus 13, P<0.01). Cumulative death-censored graft survival was 95% and 80% in the normalization and partial correction groups, respectively (P<0.01). Complete correction was associated with a significant improvement in quality of life at 6 and 12 months. The number of cardiovascular events was low and similar between groups. In conclusion, this prospective study suggests that targeting hemoglobin values ≥13 g/dl reduces progression of chronic allograft nephropathy in kidney transplant recipients.

Early steroid withdrawal and optimization of mycophenolic acid exposure in kidney transplant recipients receiving mycophenolate mofetil.

BACKGROUND: Early posttransplant steroid withdrawal may increase the risk of acute rejection and the occurrence of subclinical acute rejection (SCAR). We assessed the feasibility and safety of early steroid withdrawal in low-risk patients receiving cyclosporine A (CsA) and the impact of optimization of mycophenolic acid exposure on steroid withdrawal success. METHODS: De novo, low-immunological risk kidney recipients received an anti-interleukin-2-receptor-α antibody induction, a short course of 7 days of corticosteroids, and CsA with 2-hr postdose concentration monitoring. They were randomized to adjusted dose (AD) of mycophenolate mofetil (MMF) using therapeutic drug monitoring (TDM) or a fixed-dose (FD) regimen. MMF 3 g was initiated posttransplant and then adjusted starting at week 2 to a 0 to 12 hr area under the concentration time curve of 40 mg · h/L versus 2 g daily, respectively. The primary endpoint was a composite of the proportion of patients experiencing biopsy-proven acute rejection (BPAR) and those with SCAR identified on the 3-month protocol biopsy. RESULTS: Among 247 analyzed patients, only 22 in the AD group and 17 in the FD group experienced BPAR or SCAR (P=0.46). The rate of SCAR was low: 4% (AD) and 2.5% (FD). No between-group difference in the incidence of BPAR was observed. TDM yielded MMF doses ranging from 1 to 4 g/d and significantly reduced interpatient variability at weeks 26 and 52 in the AD group. CONCLUSIONS: In low-immunological risk kidney recipients, MMF combined with CsA allows early corticosteroid discontinuation with good tolerability. In this group of patients, TDM of MMF does not improve clinical outcome.

Localized amyloidosis of the genitourinary tract: report of 5 new cases and review of the literature.

Primary localized amyloidosis of the genitourinary tract is a rare entity characterized by small pseudotumors localized in the renal pelvis, ureters, or bladder. Amyloid fibrils are derived from immunoglobulin light chains, but no systemic plasma cell proliferation is detected. The clinical and radiologic features mimic urinary tract cancer, and local treatment is indicated. The prognosis is excellent in most cases, although disease recurrence is possible. We report 5 new cases of localized amyloidosis of the urinary tract, with lambda (4/5), or kappa (1/5) chain amyloid protein, involving the bladder (5/5), and the ureter and renal pelvis (1/5), with multiple, bilateral lesions in 1 case. The presenting complaint was painless hematuria in 4 cases. All cases were of primary (AL)-type amyloidosis. All patients underwent extensive investigation, and none presented any signs of generalized amyloidosis. A favorable outcome was observed in every case. We performed a comprehensive review of the literature, and summarize the data.

[TREAT or not to treat: anemia in type 2 diabetes and chronic kidney disease at stages 3 and 4]. / TREAT or not to treat: anémie du patient diabétique de type 2 aux stades 3 et 4 de la maladie rénale chronique.

Anemia is associated with an increased risk of cardiovascular and renal events among patients with type 2 diabetes and chronic kidney disease (CKD). Although erythropoiesis-stimulating agents (ESA) can effectively increase hemoglobin (Hb) levels, their effect on clinical outcomes has not been demonstrated in CKD patients. The TREAT study is the first randomized, double-blind, placebo-controlled trial with the aim to evaluate the effect of a Hb level of 13 g/dL on the risk of death, cardiovascular events and progression to end-stage renal disease (ESRD) in type 2 diabetes with stage 3 to 4 CKD. Four thousand and thirty-eight patients were included. Death, cardiovascular events and progression to ESRD were not different between the two groups. Stroke occurred in 101 patients assigned to DA and 53 patients assigned to placebo (p<0.001), and red-cell transfusions were administered in 14.8% patients in the DA group and in 24.5% patients assigned to placebo (p<0.001). There was a modest improvement in patient-reported fatigue in the DA group. Studies performed in CKD patients who were not undergoing dialysis failed to show a benefit of the use of ESA to target a Hb level of 13 g/dl or more, on the risk of death, cardiovascular morbidity and progression to ESRD. Post hoc analysis of randomized studies suggest that the increase cardiovascular risk induced by targeting a high Hb level is more related to the resistance state of patients who failed to increase their Hb level under high ESA doses and by the rate of change in Hb concentration over time. After the release of the TREAT study, the recommendations of a Hb level of 10 to 12 g/dl in CKD patients seems adequate. This target needs to be tailored for each patient taking into account the comorbidity, age and physical activity.

[Factors affecting the response to erythropoiesis-stimulating agents]. / Facteurs de résistance a l'action des agents stimulant l'erythropoïèse.

Recombinant human erythropoietin (rHuEPO) has transformed the management chronic renal failure (CKD) and considerably improved the outcome of patients on regular chronic dialysis. However, a significant number of patients fail to respond to high of Erythropoiesis-stimulating agents (ESAs) and several causes of inadequate response to epoetin therapy have been identified. Some factors, such as gender, age, length of time on dialysis, type of dialysis and co-morbidities such as hemoglobinopathy, are not susceptible to clinical intervention. However, many other factors can be adjusted. Iron deficiency, whether functional or absolute, is the most common factor that limits the response to rHuEPO. Monitoring of iron parameters and a large use of iron supplementation result in an efficient epoetin response. Infection and inflammation have been shown to reduce responsiveness to ESAs by disrupting iron metabolism and increasing the release of pro-inflammatory cytokines that inhibit erythropoiesis. Increase dialysis dose is associated with improvements in anemia correction and reduced requirements for ESAs. Severe hyperparathyroidism and aluminum overload lead to a reduced number of responsive erythroid progenitor cells. Finally, a number of nutritional factors, such as deficiencies of carnitine, vitamin B12, folic acid, and vitamin C, are susceptible to alter erythropoiesis. Optimizing patient response to ESAs therefore requires consideration of many of well-established factors and is important for both patient outcomes and cost of treatment.