A call for promoting living kidney donation in France in 2023 / Pourquoi développer la greffe de rein à partir de donneurs vivants en France en 2023 ?

Kidney transplantation from living donors is particularly under-developed in France in comparison with the US and most European countries. Among others, the lack of a proactive and evidence-based communication from French health providers is a potential cause that has been overlooked thus far. With this as a backdrop, the SFNDT Commission of transplantation has elaborated a 10 points-call for promoting living kidney transplantation in France in 2023 with the aims at (1) providing the entire nephrology community with a scientific rationale and (2) strenghtening the conviction of health providers, patients, and their relatives regarding the relevance of this modality of kidney transplantation.

La transplantation rénale à partir de donneur vivant est une activité qui reste insuffisamment développée en France. Ceci est particulièrement vrai en comparaison à la majorité des pays nord-américains et européens. Les raisons en sont multiples et incluent un défaut de communication proactive et argumentée par les acteurs de soins. La communication, l'information et finalement la promotion de la greffe à partir de donneurs vivants sont l'affaire de l'ensemble de la communauté néphrologique et, au premier rang, des néphrologues non spécifiquement impliqués en transplantation. C'est dans cet esprit que la Commission Transplantation de la Société francophone de néphrologie, dialyse et transplantation (SFNDT) a travaillé à l'élaboration d'un plaidoyer en tentant de répondre, en dix points, à la question « Pourquoi faut-il développer la transplantation rénale à partir de donneurs vivants en France en 2023 ? ¼. L'objectif est double : (1) fournir les principales bases d'une information scientifiquement argumentée et (2) renforcer la conviction de l'ensemble des acteurs de soins et des patients du bien-fondé de cette modalité de greffe.

The Clinical Frailty Scale as a triage tool for ICU admission of dialysis patients with COVID-19: an ERACODA analysis.

BACKGROUND: Several guidelines recommend using the Clinical Frailty Scale (CFS) for triage of critically ill coronavirus disease 2019 (COVID-19) patients. This study evaluates the impact of CFS on intensive care unit (ICU) admission rate and hospital and ICU mortality rates in hospitalized dialysis patients with COVID-19. METHODS: We analysed data of dialysis patients diagnosed with COVID-19 from the European Renal Association COVID-19 Database. The primary outcome was ICU admission rate and secondary outcomes were hospital and ICU mortality until 3 months after COVID-19 diagnosis. Cox regression analyses were performed to assess associations between CFS and outcomes. RESULTS: A total of 1501 dialysis patients were hospitalized due to COVID-19, of whom 219 (15%) were admitted to an ICU. The ICU admission rate was lowest (5%) in patients >75 years of age with a CFS of 7-9 and highest (27%) in patients 65-75 years of age with a CFS of 5. A CFS of 7-9 was associated with a lower ICU admission rate than a CFS of 1-3 [relative risk 0.49 (95% confidence interval 0.27-0.87)]. Overall, mortality at 3 months was 34% in hospitalized patients, 65% in ICU-admitted patients and highest in patients >75 years of age with a CFS of 7-9 (69%). Only 9% of patients with a CFS ≥6 survived after ICU admission. After adjustment for age and sex, each CFS category ≥4 was associated with higher hospital and ICU mortality compared with a CFS of 1-3. CONCLUSIONS: Frail dialysis patients with COVID-19 were less frequently admitted to the ICU. Large differences in mortality rates between fit and frail patients suggest that the CFS may be a useful complementary triage tool for ICU admission in dialysis patients with COVID-19.

Histological Scores Validate the Accuracy of Hepatic Iron Load Measured by Signal Intensity Ratio and R2* Relaxometry MRI in Dialysis Patients.

Almost all haemodialysis patients are treated with parenteral iron to compensate for blood loss and to allow the full therapeutic effect of erythropoiesis-stimulating agents. Iron overload is an increasingly recognised clinical situation diagnosed by quantitative magnetic resonance imaging (MRI). MRI methods have not been fully validated in dialysis patients. We compared Deugnier's and Turlin's histological scoring of iron overload and Scheuer's classification (with Perls' stain) with three quantitative MRI methods for measuring liver iron concentration (LIC)-signal intensity ratio (SIR), R2* relaxometry, and R2* multi-peak spectral modelling (Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation (IDEAL-IQ®)) relaxometry-in 16 haemodialysis patients in whom a liver biopsy was formally indicated for medical follow-up. LIC MRI with these three different methods was highly correlated with Deugnier's and Turlin's histological scoring (SIR: r = 0.8329, p = 0.0002; R2* relaxometry: r = -0.9099, p < 0.0001; R2* relaxometry (IDEAL-IQ®): r = -0.872, p = 0.0018). Scheuer's classification was also significantly correlated with these three MRI techniques. The positive likelihood ratio for the diagnosis of abnormal LIC by Deugnier's histological scoring was > 62 for the three MRI methods. This study supports the accuracy of quantitative MRI methods for the non-invasive diagnosis and follow-up of iron overload in haemodialysis patients.

[Renal transplantation: Procedure and early follow-up]. / Transplantation rénale : réalisation et suivi précoce.

More than fifty years after the success of the two first renal transplantations in Boston and in Necker hospital in Paris, renal transplantation became the treatment of choice of end stage renal failure, because it improves not only the quality of life of the patients but also their long-term survival. In France, more than 3,700 kidney transplantations are performed every year and more than 40,000 patients are living with a functioning kidney allograft. This treatment of end stage renal disease requires a fine-tuned pre-transplant evaluation and a multidisciplinary post-transplant care in order to prevent, to detect and to treat comorbidities and complications of immunosuppression. The ambition of this manuscript is not to describe in an exhaustive way all the aspects of renal transplantation but starting from the experience of a team, recently published data, and national and international guidelines, to try to provide a synthetic and chronological view of the early post-transplant monitoring.

Management of Kaposi sarcoma after solid organ transplantation: A European retrospective study.

BACKGROUND: Systemic therapeutic management of post-transplant Kaposi sarcoma (KS) is mainly based on 3 axes: reduction of immunosuppression, conversion to mammalian target of rapamycin (mTOR) inhibitors, chemotherapy, or a combination of these. OBJECTIVE: To obtain an overview of clinical strategies about the current treatment of KS. METHODS: We conducted a multicenter retrospective cohort study including 145 solid organ transplant recipients diagnosed with KS between 1985 and 2011 to collect data regarding first-line treatment and response at 6 months. RESULTS: Overall, 95%, 28%, and 16% of patients had reduction of immunosuppression, conversion to mTOR inhibitor, and chemotherapy, respectively. Patients treated with chemotherapy or mTOR inhibitor conversion were more likely to have visceral KS. At 6 months, 83% of patients had response, including 40% complete responses. LIMITATIONS: The retrospective design of the study. CONCLUSION: Currently available therapeutic options seem to be effective to control KS in most patients. Tapering down the immunosuppressive regimen remains the cornerstone of KS management.

Liver Iron Load Influences Hepatic Fat Fraction in End-Stage Renal Disease Patients on Dialysis: A Proof of Concept Study.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a spectrum of diseases including steatosis, nonalcoholic steatohepatitis (NASH), cirrhosis, and end-stage liver failure. Hepatic iron accumulation has been linked to hepatic fibrosis severity in NASH and NAFLD. Iron overload induced by parenteral (IV) iron therapy is a potential clinical problem in dialysis patients. We analyzed the hypothetical triggering and aggravating role of iron on NAFLD in patients on dialysis. METHODS: Liver iron concentration (LIC) and hepatic proton density fat fraction (PDFF) were analyzed prospectively in 68 dialysis patients by magnetic resonance imaging (MRI). Follow up of LIC and PDFF was performed in 17 dialysis patients during iron therapy. FINDINGS: PDFF differed significantly among dialysis patients classified according to LIC: patients with moderate or severe iron overload had increased fat fraction (PDFF: 7.9% (0.5-14.8%)) when compared to those with normal LIC (PDFF: 5% (0.27-11%)) or mild iron overload (PDFF: 5% (0.30-11.6%); P = 0.0049). PDFF correlated with LIC, and ferritin and body mass index. In seven patients monitored during IV iron therapy, LIC and PDFF increased concomitantly (PDFF: initial 2.5%, final 8%, P = 0.0156; LIC: initial 20 µmol/g, final 160 µmol/g: P = 0.0156), whereas in ten patients with iron overload, PDFF decreased after IV iron withdrawal or major dose reduction (initial: 8%, final: 4%; P = 0.0098) in parallel with LIC (initial: 195 µmol/g, final: 45 µmol/g; P = 0.002). INTERPRETATION: Liver iron load influences hepatic fat fraction in dialysis patients. Iron overload induced by iron therapy may aggravate or trigger NAFLD in dialysis patients. TRIAL REGISTRATION NUMBER (ISRCTN): 80100088.

Outcome of second kidney transplantation in patients with previous post-transplantation Kaposi's sarcoma: A French retrospective study.

This retrospective study concerned 8 patients with post-transplantation Kaposi's sarcoma (pt-KS) after a first kidney transplant who later had a second kidney transplantation. Pt-KS was widespread, with lymph node or visceral involvement in 7 cases. Complete remission was observed in 6 cases and partial remission in 2. After the second kidney transplantation, only 2 cases showed recurrence of skin KS, one with previous complete remission of KS and one with partial remission. The mean delay between stability or complete remission of KS and retransplantation was 2.0 and 7.3 years in patients with and without relapse, respectively. Both recurrent cases showed complete KS remission after tapering immunosuppression therapy and/or switching a calcineurin inhibitor to a mammalian target of rapamycin inhibitor. We compared these 8 cases to 24 controls who had undergone 2 kidney transplantations but did not have KS, matching on sex, age and phototype. Cases and controls did not differ in graft function or survival. A second kidney transplantation may be possible after pt-KS and has acceptable risk, especially after a long complete remission of pt-KS.

Signal-intensity-ratio MRI accurately estimates hepatic iron load in hemodialysis patients.

BACKGROUND: Iron overload, diagnosed by means of magnetic resonance imaging (MRI), is an increasingly recognized disorder in hemodialysis patients. Specific MRI protocols have been shown to provide a reliable estimation of tissue iron content in non-renal patient populations but have not been validated in dialysis patients. Such validation studies require liver biopsy for histological comparison, but this invasive and risky procedure raises ethical concerns, especially regarding frail patients with end-stage renal disease. MATERIALS AND METHODS: We compared in a pilot study Scheuer's histological classification and Deugnier and Turlin's histological classification of iron overload (Perls staining) with signal-intensity-ratio MRI values obtained with the Rennes University algorithm in 11 hemodialysis patients in whom liver biopsy was formally indicated for their medical follow-up. RESULTS: For Scheuer's histological classification, the Wilcoxon non-parametric matched-pairs test showed no significant difference in the ranking of iron overload by the two methods eg histology and MRI (sum of ranks = 1.5; p = 1). The MRI and Scheuer's histological classifications were tightly correlated (rho = 0.866, p = 0.0035, Spearman's coefficient), as were the absolute liver iron concentrations (LIC) at MRI (rho = 0.860, p = 0.0013, Spearman's coefficient). The absolute liver iron concentrations at MRI were also highly correlated with Deugnier and Turlin's histological scoring (rho = 0.841, p = 0.0033, Spearman's coefficient). CONCLUSIONS: This pilot study shows that liver iron determination based on signal-intensity-ratio MRI (Rennes University algorithm) very accurately identifies iron load in hemodialysis patients, by comparison with liver histology.

MicroRNA-146a in Human and Experimental Ischemic AKI: CXCL8-Dependent Mechanism of Action.

AKI leads to tubular injury and interstitial inflammation that must be controlled to avoid the development of fibrosis. We hypothesized that microRNAs are involved in the regulation of the balance between lesion formation and adaptive repair. We found that, under proinflammatory conditions, microRNA-146a (miR-146a) is transcriptionally upregulated by ligands of IL-1 receptor/Toll-like receptor family members via the activation of NF-κB in cultured renal proximal tubular cells. In vivo, more severe renal ischemia-reperfusion injury (IRI) associated with increased expression of miR-146a in both allografts and urine of human kidney transplant recipients, and unilateral IRI in mice induced miR-146a expression in injured kidneys. After unilateral IRI, miR-146a-/- mice exhibited more extensive tubular injury, inflammatory infiltrates, and fibrosis than wild-type mice. In vitro, overexpression or downregulation of miR-146a diminished or enhanced, respectively, IL-1 receptor-associated kinase 1 expression and induced similar effects on C-X-C motif ligand 8 (CXCL8)/CXCL1 expression by injured tubular cells. Moreover, inhibition of CXCL8/CXCL1 signaling prevented the development of inflammation and fibrosis after IRI in miR-146a-/- mice. In conclusion, these results indicate that miR-146a is a key mediator of the renal tubular response to IRI that limits the consequences of inflammation, a key process in the development of AKI and CKD.

[Current aspects of acute humoral rejection]. / Aspects actuels des rejets aigus humoraux.

Acute clinical antibody-mediated rejection is currently defined by (1), an acute renal failure occurring during the first months following transplantation, (2), at least a microcirculation inflammation (glomerulitis and peritubular capillaritis) on kidney biopsy and (3), the presence in peripheral blood of donor specific antibodies, mostly anti-human leukocyte antigen (HLA) antibodies. The prognosis of this rejection is scored using the severity of vascular lesions and the positivity of C4d on peritubular capillaries. Recently, a subclinical variety of antibody-mediated rejection was recognized as an entity because, as the clinical rejection, it leads to chronic antibody-mediated rejection, currently the most frequent cause of graft loss. The description of these various aspects of antibody-mediated rejection allowed a better understanding of its pathophyiology that may lead in a near future to a more specific treatment.

Pleural ultrasound compared with chest radiographic detection of pneumothorax resolution after drainage.

BACKGROUND: Pleural ultrasonography (PU) is more sensitive than chest radiograph (CXR) for diagnosing pneumothorax and could be useful for detecting resolution of pneumothorax after drainage. The aim of this prospective double-blind observational study was to assess PU accuracy during pneumothorax follow-up after drainage. METHODS: All patients hospitalized with pneumothorax requiring drainage were eligible. After drainage, residual pneumothorax was assessed by CXR and PU (1) 24 h after bubbling in the aspiration device had stopped, (2) 6 h after clamping the pleural catheter, and (3) 6 h after removing the pleural catheter. Pneumothorax indicated by PU but not CXR was confirmed by CT scan or by aspiration of > 10 mL of air. RESULTS: Forty-four unilateral pneumothoraces were studied (primary spontaneous: 70.5%), and 162 pairs of examinations (CXR and PU) were performed. Twenty residual pneumothoraces were detected by both CXR and PU. Furthermore, PU suspected 14 pneumothoraces that were not identified by CXR; 13 were confirmed. All of these pneumothoraces resulted in therapeutic intervention. Thus, 39% (13/33) of the confirmed residual pneumothoraces were missed by CXR. In patients with primary spontaneous pneumothorax, the positive predictive value of PU for residual pneumothorax diagnosis was 100%; for other pneumothoraces, this value ranged from 90% in the absence of a lung point to 100% when a lung point was observed. PU results were obtained faster than results from CXR (35 +/- 34 min vs 71 +/- 56 min, P < .0001). CONCLUSIONS: The accuracy of PU is excellent for detecting residual pneumothorax during pneumothorax follow-up after drainage.