Four- and sixteen-month clinical status of a cohort of patients following hospitalization for COVID-19.

BACKGROUND AND OBJECTIVES: Although many symptoms of post-COVID syndrome have been described, a comprehensive evaluation of their prevalence is lacking. We aimed to describe symptoms at 16 months from hospitalization for COVID-19. METHODS: A telephone assessment was performed one year later in a cohort of COVID-19 survivors hospitalized between March and May 2020 and already evaluated four months after discharge. Patients with relevant symptoms at 16 months, patients who presented symptoms at four months, and all intensive care unit patients were invited for assessment at an outpatient facility. At telephone consultation, respiratory, cognitive, and functional symptoms were assessed. Patients underwent pulmonary function tests, lung CT scans, and psychometric and cognitive tests at the outpatient facility. RESULTS: Among 478 patients evaluated four months after discharge, 317 (67 %) were assessed at telephone consultation and 124 at ambulatory assessment. At telephone assessment, ≥1 new symptom was reported by 216 patients (68 %), mainly fatigue (53 %), dyspnea (37 %), and memory difficulties (24 %). Seventy-nine patients (25 %) were asymptomatic at four months but declared ≥1 symptom one year later. In patients evaluated twice, the prevalence of cognitive impairment was 45 % at four months and 40 % at 16 months. Depression and post-traumatic symptoms prevalence remained stable, and the prevalence of anxiety significantly decreased. Dysfunctional breathing was detected in 32 % of patients. At 16 months after discharge, lung CT-scan exhibited abnormalities in 30/80 patients (38 %), compared to 52/85 patients (61 %) at four months. CONCLUSION: At 16 months after hospitalization for COVID-19, 68 % of patients declared symptoms, including patients whose symptoms appeared between 4 and 16 months. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04704388.

Objectivizing issues in the diagnosis of complex rare diseases: lessons learned from testing existing diagnosis support systems on ciliopathies.

BACKGROUND: There are approximately 8,000 different rare diseases that affect roughly 400 million people worldwide. Many of them suffer from delayed diagnosis. Ciliopathies are rare monogenic disorders characterized by a significant phenotypic and genetic heterogeneity that raises an important challenge for clinical diagnosis. Diagnosis support systems (DSS) applied to electronic health record (EHR) data may help identify undiagnosed patients, which is of paramount importance to improve patients' care. Our objective was to evaluate three online-accessible rare disease DSSs using phenotypes derived from EHRs for the diagnosis of ciliopathies. METHODS: Two datasets of ciliopathy cases, either proven or suspected, and two datasets of controls were used to evaluate the DSSs. Patient phenotypes were automatically extracted from their EHRs and converted to Human Phenotype Ontology terms. We tested the ability of the DSSs to diagnose cases in contrast to controls based on Orphanet ontology. RESULTS: A total of 79 cases and 38 controls were selected. Performances of the DSSs on ciliopathy real world data (best DSS with area under the ROC curve = 0.72) were not as good as published performances on the test set used in the DSS development phase. None of these systems obtained results which could be described as "expert-level". Patients with multisystemic symptoms were generally easier to diagnose than patients with isolated symptoms. Diseases easily confused with ciliopathy generally affected multiple organs and had overlapping phenotypes. Four challenges need to be considered to improve the performances: to make the DSSs interoperable with EHR systems, to validate the performances in real-life settings, to deal with data quality, and to leverage methods and resources for rare and complex diseases. CONCLUSION: Our study provides insights into the complexities of diagnosing highly heterogenous rare diseases and offers lessons derived from evaluation existing DSSs in real-world settings. These insights are not only beneficial for ciliopathy diagnosis but also hold relevance for the enhancement of DSS for various complex rare disorders, by guiding the development of more clinically relevant rare disease DSSs, that could support early diagnosis and finally make more patients eligible for treatment.

Kidney Transplantation in Patients With AA Amyloidosis: Outcomes in a French Multicenter Cohort.

RATIONALE & OBJECTIVE: Outcomes of kidney transplantation for patients with renal AA amyloidosis are uncertain, with reports of poor survival and high rates of disease recurrence. However, the data are inconclusive and mostly based on studies from the early 2000s and earlier. STUDY DESIGN: Retrospective multicenter cohort study. SETTING & PARTICIPANTS: We searched the French national transplant database to identify all patients with renal AA amyloidosis who underwent kidney transplantation between 2008 and 2018. EXPOSURES: Age, cause of amyloidosis, use of biotherapies, and C-reactive protein levels. OUTCOMES: Outcomes were all-cause mortality and allograft loss. We also reported amyloidosis allograft recurrence, occurrence of acute rejection episodes, as well as infectious, cardiovascular, and neoplastic disease events. ANALYTICAL APPROACH: Kaplan-Meier estimator for mortality and cumulative incidence function method for allograft loss. Factors associated with patient and allograft survival were investigated using a Cox proportional hazards model and a cause-specific hazards model, respectively. RESULTS: 86 patients who received kidney transplants for AA amyloidosis at 26 French centers were included. The median age was 49.4 years (IQR, 39.7-61.1). The main cause of amyloidosis was familial Mediterranean fever (37 cases; 43%). 16 (18.6%) patients received biotherapy after transplantation. Patient survival rates were 94.0% (95% CI, 89.1-99.2) at 1 year and 85.5% (77.8-94.0) at 5 years after transplantation. Cumulative incidences of allograft loss were 10.5% (4.0-17.0) at 1 year and 13.0% (5.8-20.1) at 5 years after transplantation. Histologically proven AA amyloidosis recurrence occurred in 5 transplants (5.8%). An infection requiring hospitalization developed in 55.8% of cases, and there was a 27.9% incidence of acute allograft rejection. Multivariable analysis showed that C-reactive protein concentration at the time of transplantation was associated with patient survival (HR, 1.01; 95% CI, 1.00-1.02; P=0.01) and allograft survival (HR, 1.68; 95% CI, 1.10-2.57; P=0.02). LIMITATIONS: The study lacked a control group, and the effect of biotherapies on transplantation outcomes could not be explored. CONCLUSIONS: This relatively contemporary cohort of patients who received a kidney transplant for AA amyloidosis experienced favorable rates of survival and lower recurrence rates than previously reported. These data support the practice of treating these patients with kidney transplantation for end-stage kidney disease. PLAIN-LANGUAGE SUMMARY: AA amyloidosis is a severe and rare disease. Kidney involvement is frequent and leads to end-stage kidney disease. Because of the involvement of other organs, these patients are often frail, which has raised concerns about their suitability for kidney transplantation. We reviewed all patients with AA amyloidosis nephropathy who underwent kidney transplantation in France in the recent era (2008-2018) and found that the outcomes after kidney transplantation were favorable, with 85.5% of patients still alive 5 years after transplantation, a survival rate that is comparable to the outcomes of patients receiving a transplant for other forms of kidney diseases. Recurrence of amyloidosis in the transplanted kidney was infrequent (5.8%). These data support the practice of kidney transplantation for patients with AA amyloidosis who experience kidney failure.

COVID-19 Hospitalization in Solid Organ Transplant Recipients on Immunosuppressive Therapy.

Importance: Solid organ transplant recipients are at high risk of severe infection with SARS-CoV-2 compared with the general population. However, factors associated with COVID-19-related severity in this population are still insufficiently explored in the literature. Objective: To examine which health conditions and immunosuppressive drugs for preventing graft rejection are associated with the risk of COVID-19-related hospitalization in solid organ transplant recipients. Design, Setting, and Participants: Using the French National Health Data System, this cohort study assessed patients of any age who received transplants between their date of birth and entry into the cohort on February 15, 2020. The cohort was followed up between February 15, 2020, and July 31, 2022. Exposures: Immunosuppressive drugs, including steroids, and health conditions (age, sex, and comorbidities). Main Outcomes and Measures: The main outcome was hospitalization for COVID-19, defined by main diagnostic International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes. Factors associated with the outcome were identified with a nonconditional logistic regression. Confounding by indication was controlled using a multivariable model with adjustment for individual confounders. Each transplanted organ was examined separately. Results: Overall, 60 456 participants (median [IQR] age, 59 [47-67] years; 63.7% male) were included in the study, of whom 41 463 (68.6%) had kidney transplants, 14 464 (23.9%) had liver transplants, 5327 (8.8%) had heart transplants, and 2823 (4.6%) had lung transplants. Among them, 12.7% of kidney transplant recipients, 6.4% of liver transplant recipients, 12.9% of heart transplant recipients, and 18.0% of lung transplant recipients were hospitalized for COVID-19. In kidney transplant recipients, steroids (adjusted odds ratio [AOR], 1.60; 95% CI, 1.49-1.73) and mycophenolic acid (AOR, 1.37; 95% CI, 1.25-1.51) were associated with a high risk of hospitalization. In liver transplant recipients, tacrolimus (AOR, 0.77; 95% CI, 0.61-0.98) was associated with a decreased risk, and steroids (AOR, 1.60; 95% CI, 1.38-1.86) and mycophenolic acid (AOR, 1.61; 95% CI, 1.37-1.90) were associated with an increased risk of hospitalizations. In heart transplant recipients, cyclosporine (AOR, 0.67; 95% CI, 0.47-0.94) was associated with a decreased risk, and steroids (AOR, 1.42; 95% CI, 1.11-1.82), mycophenolic acid (AOR, 1.29; 95% CI, 1.02-1.64), sirolimus (AOR, 2.71; 95% CI, 1.20-6.09), and everolimus (AOR, 1.24; 95% CI, 1.01-1.51) were associated with an increased risk of hospitalization. Only steroids (AOR, 1.72; 95% CI, 1.19-2.48) were associated with a high risk of COVID-19 hospitalization in lung transplant recipients. Conclusions and Relevance: This study suggests that mycophenolic acid, sirolimus, and steroids are associated with an increased risk of COVID-19-related hospitalization in solid organ transplant recipients. These results should be considered by clinicians treating transplant recipients and may help inform epidemic-related decisions for this population in the future.

[Nephroprotection: General principles and application to the patients with cancers - when nephroprotection is essential for oncological care plan]. / Néphroprotection : principes généraux et application au patient de cancérologie ­ quand la protection du rein est indispensable à la bonne conduite du plan de soin oncologique.

Nephroprotection is a set of recommendations that aim to prevent the risks of acute and/or chronic renal failure and to limit the progression of renal failure towards an end stage. Nephroprotection is not limited to nephrology and applies to all patients at risk of renal failure. Cancer patients are particularly at risk of developing intrinsic and extrinsic renal failure, as well as the toxicity of specific treatments. However, they are poorly included in nephroprotection studies. Thus, current guidelines have not been adapted to these pathologies and oncology-specific comorbidities, such as malnutrition or prognosis, are often not taken into account. In this article, we review the established recommendations by transposing them to the cancer patient as a whole. In addition to the reminder of hygiene and dietary rules to control blood pressure and diabetes, we discuss the importance of therapeutic education, iatrogeny and treatment options to control renal failure in this context. The lack of clearly established data in cancer confirms the needs to strengthen links between oncologists, hematologists and nephrologists and reinforces the emergence of onco-nephrology as a new discipline.

Tracking kidney transplant fitness.

An implantable bioelectronic device detects the early signs of kidney transplant rejection in rats.

Rare Variants in Complement Gene in C3 Glomerulopathy and Immunoglobulin-Mediated Membranoproliferative GN.

BACKGROUND: C3 glomerulopathy and idiopathic immunoglobulin-mediated membranoproliferative GN (Ig-MPGN) are rare complement-mediated kidney diseases. Inherited forms of C3 glomerulopathy/Ig-MPGN are rarely described. METHODS: Three hundred ninety-eight patients with C3 glomerulopathy ( n =296) or Ig-MPGN ( n =102) from a national registry were screened for three complement genes: factor H ( CFH ), factor I ( CFI ), and C3 . Patients with rare variant (minor allele frequency <0.1%) were included. Epidemiologic, clinical, and immunologic data at diagnosis and kidney outcomes of patients were retrospectively collected. RESULTS: Fifty-three different rare variants, including 30 (57%), 13 (24%), and ten (19%) in CFH , CFI , and C3 variants, were identified in 66/398 (17%) patients. Thirty-eight (72%) variants were classified as pathogenic, including 20/30 (66%) and 11/13 (84%) variants in CFH and CFI , respectively, impairing synthesis of factor H or factor I regulators. Fifteen of 53 (27%) variants were of unknown significance. At diagnosis, 69% of patients were adult (median age of 31 years). With the exception of biologic stigma of thrombotic microangiopathy, which was more frequent in patients with CFI variants (5/14 [36%] versus 1/37 [3%] and 0% in the CFH group and C3 group, respectively, P < 0.001), the clinical and histologic features were similar among the three variants groups. The kidney outcome was poor regardless of the age at onset and treatment received. Sixty-five percent (43/66) of patients with rare variant reach kidney failure after a median delay of 41 (19-104) months, compared with 28% (55/195) after a median delay of 34 (12-143) months in the nonvariant group. Among 36 patients who received a kidney transplant, 2-year recurrence was frequent, occurring in 39% (12/31), without difference between variant groups, and led to graft failure in three cases. CONCLUSIONS: In our cohort, 17% of C3 glomerulopathy/Ig-MPGN cases were associated with rare variants in the CFH , CFI , or C3 genes. In most cases, a quantitative deficiency in factor H or factor I was identified. The presence of a rare variant was associated with poor kidney survival. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_11_08_CJN0000000000000252.mp3.

Clinical and Prognostic Factors in Patients with IgG4-Related Kidney Disease.

BACKGROUND: IgG4-related kidney disease is a major manifestation of IgG4-related disease, a systemic fibroinflammatory disorder. However, the clinical and prognostic kidney-related factors in patients with IgG4-related kidney disease are insufficiently defined. METHODS: We conducted an observational cohort study using data from 35 sites in two European countries. Clinical, biologic, imaging, and histopathologic data; treatment modalities; and outcomes were collected from medical records. Logistic regression was performed to identify the possible factors related to an eGFR ≤30 ml/min per 1.73 m 2 at the last follow-up. Cox proportional hazards model was performed to assess the factors associated with the risk of relapse. RESULTS: We studied 101 adult patients with IgG4-related disease with a median follow-up of 24 (11-58) months. Of these, 87 (86%) patients were male, and the median age was 68 (57-76) years. Eighty-three (82%) patients had IgG4-related kidney disease confirmed by kidney biopsy, with all biopsies showing tubulointerstitial involvement and 16 showing glomerular lesions. Ninety (89%) patients were treated with corticosteroids, and 18 (18%) patients received rituximab as first-line therapy. At the last follow-up, the eGFR was below 30 ml/min per 1.73 m 2 in 32% of patients; 34 (34%) patients experienced a relapse, while 12 (13%) patients had died. By Cox survival analysis, the number of organs involved (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.01 to 1.55) and low C3 and C4 concentrations (HR, 2.31; 95% CI, 1.10 to 4.85) were independently associated with a higher risk of relapse, whereas first-line therapy with rituximab was protective (HR, 0.22; 95% CI, 0.06 to 0.78). At their last follow-up, 19 (19%) patients had an eGFR ≤30 ml/min per 1.73 m 2 . Age (odd ratio [OR], 1.11; 95% CI, 1.03 to 1.20), peak serum creatinine (OR, 2.74; 95% CI, 1.71 to 5.47), and serum IgG4 level ≥5 g/L (OR, 4.46; 95% CI, 1.23 to 19.40) were independently predictive for severe CKD. CONCLUSIONS: IgG4-related kidney disease predominantly affected middle-aged men and manifested as tubulointerstitial nephritis with potential glomerular involvement. Complement consumption and the number of organs involved were associated with a higher relapse rate, whereas first-line therapy with rituximab was associated with lower relapse rate. Patients with high serum IgG4 concentrations (≥5 g/L) had more severe kidney disease.

[Electrolyte disorders in oncological patients]. / Principaux troubles hydro-électrolytiques chez le patient de cancérologie.

Electrolyte disorders (ED) are common in patients with cancer and in most cases, the etiologies do not differ from the general population. They may also be induced by the cancer, its therapy or paraneoplastic syndromes. ED are associated with poor outcomes, increased morbidity and mortality in this population. Hyponatremia is the most common disorder, often multifactorial, iatrogenic or secondary to the syndrome of inappropriate antidiuretic hormone secretion, usually due to small cell lung cancer. More rarely, hyponatremia may reveal adrenal insufficiency. Hypokalemia is generally multifactorial and associated with other ED. Cisplatin and ifosfamide induce proximal tubulopathies with hypokalemia and/or hypophosphatemia. Hypomagnesemia is often iatrogenic, related to cisplatin or cetuximab, but can be prevented by supplementation. Hypercalcemia can impair life quality and be life-threatening in the most severe cases. Hypocalcemia is less common and often of iatrogenic origin. Finally, the tumor lysis syndrome is a diagnostic and therapeutic emergency that affects the prognosis of patients. Its incidence tends to increase in solid oncology, related to the improvement of therapies. Prevention and early diagnosis of ED are essential to optimize the overall management of patients with underlying cancer and cancer therapy. The aim of this review is to synthesize most frequent ED and their management.

The genetic landscape and clinical spectrum of nephronophthisis and related ciliopathies.

Nephronophthisis (NPH) is an autosomal-recessive ciliopathy representing one of the most frequent causes of kidney failure in childhood characterized by a broad clinical and genetic heterogeneity. Applied to one of the worldwide largest cohorts of patients with NPH, genetic analysis encompassing targeted and whole exome sequencing identified disease-causing variants in 600 patients from 496 families with a detection rate of 71%. Of 788 pathogenic variants, 40 known ciliopathy genes were identified. However, the majority of patients (53%) bore biallelic pathogenic variants in NPHP1. NPH-causing gene alterations affected all ciliary modules defined by structural and/or functional subdomains. Seventy six percent of these patients had progressed to kidney failure, of which 18% had an infantile form (under five years) and harbored variants affecting the Inversin compartment or intraflagellar transport complex A. Forty eight percent of patients showed a juvenile (5-15 years) and 34% a late-onset disease (over 15 years), the latter mostly carrying variants belonging to the Transition Zone module. Furthermore, while more than 85% of patients with an infantile form presented with extra-kidney manifestations, it only concerned half of juvenile and late onset cases. Eye involvement represented a predominant feature, followed by cerebellar hypoplasia and other brain abnormalities, liver and skeletal defects. The phenotypic variability was in a large part associated with mutation types, genes and corresponding ciliary modules with hypomorphic variants in ciliary genes playing a role in early steps of ciliogenesis associated with juvenile-to-late onset NPH forms. Thus, our data confirm a considerable proportion of late-onset NPH suggesting an underdiagnosis in adult chronic kidney disease.

Invasive bacillary angiomatosis in a kidney transplant recipient: A challenging case on belatacept immunosuppression.

Bacillary angiomatosis is a disseminated vascular proliferative disease caused by aerobic gram-negative bacilli Bartonella henselae or Bartonella quintana. Bacillary angiomatosis is mostly described in immunosuppressed patients with HIV infection and organ transplant recipients. We describe the case of a female aged 75 years who is a kidney transplant recipient who was admitted for a 3-month history of intermittent fever, chills, vomiting, and a 12-kg weight loss. The maintenance immunosuppression was based on prednisone, mycophenolate, and monthly infusions of belatacept. Physical examination was unremarkable. Laboratory investigations revealed elevated blood acute phase proteins but all blood cultures were negative. Serological tests for Bartonella were negative. Thoracoabdominal computed tomography scan and transesophageal echocardiography were normal. A Positron Emission Tomography scan showed a hypermetabolic mass in the duodenopancreatic region, with multiple hepatic and splenic lesions. Histological findings of spleen and pancreatic biopsies were not conclusive. The histopathological examination of a celiac lymph node biopsy finally demonstrated bacillary angiomatosis. The diagnosis of bacillary angiomatosis in immunocompromised patients is most often delayed in the absence of skin involvement. A high index of clinical suspicion is needed when interpreting negative results.

Pathological spectrum of hereditary transthyretin renal amyloidosis and clinicopathologic correlation: a French observational study.

BACKGROUND: Cardiac and neurological involvements are the main clinical features of hereditary transthyretin (ATTRv) amyloidosis. Few data are available about ATTRv amyloid nephropathy (ATTRvN). METHODS: We retrospectively included 30 patients with biopsy-proven ATTRvN [V30M (26/30) including two domino liver recipients, S77Y (2/30), V122I (1/30) and S50R (1/30) variants] from two French reference centers. We described the pathological features by comparing amyloid deposits distribution to patients with AL or AA amyloidosis, and sought to determine clinicopathological correlation with known disease-modifying factors such as TTR variant, gender and age at diagnosis. RESULTS: In comparison with AL and AA amyloidosis, ATTRv patients had similar glomerular, arteriolar and arterial amyloid deposits, but more cortical and medullary tubulointerstitial (33%, 44%, 77%, P = .03) involvement. While the presence of glomerular deposits is associated with the range of proteinuria, some patients with abundant glomerular ATTRv amyloidosis had no significant proteinuria. V30M patients had more glomerular (100% and 25%, odds ratio = 114, 95% confidence interval 3.85-3395.00, P = .001) deposits, and higher estimated glomerular filtration rate [50 (interquartile range 44-82) and 27 (interquartile range 6-31) mL/min/1.73 m², P = .004] than non-V30M patients. We did not find difference in amyloid deposition according to gender or age at diagnosis. CONCLUSION: ATTRvN affects all kidney compartments, but compared with AL/AA amyloidosis, ATTRvN seems to involve more frequently tubulointerstitial areas. V30M patients represents the dominant face of the disease with a higher risk of glomerular/arteriolar involvement. ATTRvN should thus be considered in patients, and potential relatives, with ATTRv amyloidosis and kidney dysfunction, regardless of proteinuria level.

Immune-related generalised oedema - A new category of adverse events with immune checkpoint inhibitors.

BACKGROUND: Generalised oedema was occasionally reported associated with immune checkpoint inhibitors (ICPIs). The purpose of this study is to investigate immune-related generalised oedema (ir-GE) drug related to ICPI, through frequency, clinical and pathological characteristics, and patient's outcome. PATIENTS AND METHODS: Objectives of the study were to report on ir-GE associated with ICPI to define frequency, associated signs and symptoms, pathological characteristics, severity, and response to corticosteroids. To be included in the study, adult patients had to have ir-GE related to ICPI with certain or likely link, without any other known causes of generalised oedema. The study design was observational, over the period 2014-2020, from pharmacovigilance databases in France, including the prospective Registre des Effets Indésirables Sévères des Anticorps Monoclonaux Immunomodulateurs en Cancérologie (REISAMIC) registry. Calculation of the frequency of ir-GE was restricted to the prospective REISAMIC registry. RESULTS: Over 6633 screened patients, 20 had ir-GE confirmed drug related to ICPI. Based on the prospective REISAMIC registry, the frequency of ir-GE was 0.19% of ICPI-treated patients (3 cases out of 1598 screened patients). The 20 patients with ir-GE had a median (range) age of 62 (26-81) years, most frequent tumour types were melanoma (n = 9; 45%) and lung cancer (n = 6; 30%). The most frequent localisations of oedema were peripheral (n = 17; 85%), pleural (n = 13; 65%), and peritoneal (n = 10; 50%). Polyserositis was observed in 11 (55%) patients. The median (range) weight gain per patient was 9 (2-30) kg. Associated signs and symptoms met criteria for capillary leak syndrome (n = 4; 20%), sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) (n = 3; 15%), or subcutaneous autoimmune syndrome (n = 2; 10%). Corticosteroids were administered to 15 patients; of them, 10 (67%) improved clinically after corticosteroids. Based on CTCAEV5.0, the highest severity of ir-GE was grade ≥4 in 11 (55%) patients and four (20%) patients died due to ir-GE. CONCLUSIONS: Generalised immune system-related oedema is a new category of adverse event with immune checkpoint inhibitors and is often associated with a life-threatening condition. The pathophysiology may in some cases be related to endothelial dysfunctions, such as SOS/VOD or capillary leak syndrome.

Pathological characteristics of light chain crystalline podocytopathy.

Monoclonal immunoglobulin light chain (LC) crystalline inclusions within podocytes are rare, poorly characterized entities. To provide more insight, we now present the first clinicopathologic series of LC crystalline podocytopathy (LCCP) encompassing 25 patients (68% male, median age 56 years). Most (80%) patients presented with proteinuria and chronic kidney disease, with nephrotic syndrome in 28%. Crystalline keratopathy and Fanconi syndrome were present in 22% and 10%, respectively. The hematologic condition was monoclonal gammopathy of renal significance (MGRS) in 55% and multiple myeloma in 45%. The serum monoclonal immunoglobulin was IgG κappa in 86%. Histologically, 60% exhibited focal segmental glomerulosclerosis (FSGS), often collapsing. Ultrastructurally, podocyte LC crystals were numerous with variable effacement of foot processes. Crystals were also present in proximal tubular cells as light chain proximal tubulopathy (LCPT) in 80% and in interstitial histiocytes in 36%. Significantly, frozen-section immunofluorescence failed to reveal the LC composition of crystals in 88%, requiring paraffin-immunofluorescence or immunohistochemistry, with identification of kappa LC in 87%. The LC variable region gene segment, determined by mass spectrometry of glomeruli or bone marrow plasma cell sequencing, was IGKV1-33 in four and IGKV3-20 in one. Among 21 patients who received anti-plasma cell-directed chemotherapy, 50% achieved a kidney response, which depended on a deep hematologic response. After a median follow-up of 36 months, 26% progressed to kidney failure and 17% died. The mean kidney failure-free survival was 57.6 months and was worse in those with FSGS. In sum, LCCP is rare, mostly associates with IgG κappa MGRS, and frequently has concurrent LCPT, although Fanconi syndrome is uncommon. Paraffin-immunofluorescence and electron microscopy are essential to prevent misdiagnosis as primary FSGS since kidney survival depends on early diagnosis and subsequent clone-directed therapy.

Microbiology and outcomes of polymicrobial peritonitis associated with peritoneal dialysis: a register-based cohort study from the French Language Peritoneal Dialysis Registry.

BACKGROUND: Previous studies have reported that polymicrobial peritonitis in peritoneal dialysis (PD) is associated with poor outcomes, but recent data from European cohorts are scarce. METHODS: We included from the French Language Peritoneal Dialysis Registry all patients ≥18 years of age who started PD between January 2014 and November 2020. We compared microbiology and patient characteristics associated with mono- and polymicrobial peritonitis. We assessed patient outcomes after a first polymicrobial peritonitis using survival analysis with competing events. We differentiated microorganisms isolated from dialysis effluent as enteric or non-enteric pathogens. RESULTS: A total of 8848 patients contributed 13 023 patient-years of follow-up and 3348 culture-positive peritonitis episodes, including 251 polymicrobial ones. This corresponded to rates of 0.32 and 0.02 episodes/patient-year, respectively. For most patients (72%) who experienced polymicrobial peritonitis, this was their first peritonitis episode. Enteric pathogens were more frequently isolated in polymicrobial than in monomicrobial peritonitis (57 versus 44%; P < .001). In both cases of peritonitis with and without enteric pathogens, the polymicrobial versus monomicrobial character of the peritonitis was not associated with mortality in patients who did not switch to haemodialysis {adjusted cause-specific hazard ratio [acsHR] 1.2 [95% confidence interval (CI) 0.3-5.0], P = .78 and 1.1 [95% CI 0.7-1.8], P = .73, respectively}. However, the risks of death and switch to haemodialysis were higher for monomicrobial peritonitis with enteric pathogens compared with those without [acsHR 1.3 (95% CI 1.1-1.7), P = .02 and 1.9 (95% CI 1.5-2.4), P < .0001, respectively]. CONCLUSION: Isolation of enteric pathogens, rather than the polymicrobial character of the peritonitis, is associated with poorer outcomes.

Impact of sleeve gastrectomy on renal function in patients with morbid obesity: a 1-year prospective cohort study.

PURPOSE: Obesity is an independent risk factor for renal injury. A more favorable metabolic environment following weight loss may theoretically lead to improved renal function. We aimed to evaluate the evolution of renal function one year after sleeve gastrectomy in a large prospective cohort of patients with morbid obesity and assess the influence of fat-free mass (FFM) changes. METHODS: We prospectively included obese patients admitted for sleeve gastrectomy between February 2014 and November 2016. We also included a historical observational cohort of patients undergoing sleeve gastrectomy between January 2013 and January 2014 who had FFM evaluation. Patients were systematically evaluated 1 year after surgery. The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The FFM was estimated by analyzing computerized tomography (CT) scan sections from CT systematically performed 2 days and 1 year after sleeve gastrectomy to detect surgery complications. RESULTS: Five hundred sixty-three patients fulfilled the inclusion criteria. The mean age was 41.2 ± 0.5 years. The mean body mass index was 43.5 ± 0.3 kg/m2 and 20.4, 30.5, and 30.7% of the included patients had type 2 diabetes, hypertension, and dyslipidemia, respectively. One hundred fifteen patients were excluded and four hundred forty-eight patients were finally included in the analysis. The eGFR was significantly higher 1 year after sleeve gastrectomy than before surgery (87.8 ± 0.9 versus 86.1 ± 0.9, p < 0.01). There was no difference in terms of post-surgery FFM loss between patients with an improved eGFR and those without (6.7 ± 0.3 kg versus 6.8 ± 0.5 kg, p = 0.9). Furthermore, post-surgery changes in the eGFR did not correlate with the amount of FFM loss (r = 0.1, p = 0.18). CONCLUSION: Renal function assessed by eGFR is significantly improved at 1-year post-sleeve gastrectomy, independent of changes in skeletal muscle mass.

Renal involvement of lymphomas proven by kidney biopsy: report of 10 cases from a tertiary care center and comparison with the literature.

Lymphomas localized in the kidney are a rare entity that may be challenging to diagnose. We analyzed data from 10 patients with renal involvement of lymphoma diagnosed between 2009 and 2019 on fine needle biopsy from our tertiary center, and compared these with findings of 160 cases reported in the literature. Diffuse large B-cell lymphoma was the main histology subtype (40 and 38% in our sample and in the literature, respectively), followed by low-grade B-cell lymphomas, mostly from the marginal zone (MZ). Altogether, 106 patients had urological inaugural symptoms and 64 had general symptoms. Patients with urological presentation more often had renal masses than diffuse infiltration (p < 0.001), unilateral tumors (p = 0.0036) and low-grade B-cell lymphomas (17 vs 6%, p = 0.043). In both groups, nearly one-fourth of patients had diffuse (stage IV) lymphomas. Overall survival did not differ by the presence of urological/systemic symptoms, stage or aggressive lymphoma status. Notably, 3 of 10 patients from our series had MZ lymphomas associated with primary Sjögren syndrome revealed by acute kidney injury, including one where the autoimmune disease was detected. Lymphoproliferative disorders localized in the kidney are a challenging condition that can lead to detection of aggressive or diffuse lymphomas.

Results from a nationwide retrospective cohort measure the impact of C3 and soluble C5b-9 levels on kidney outcomes in C3 glomerulopathy.

C3 glomerulopathy (C3G) is a rare complement-mediated disease. Specific treatments are not yet available and factors predictive of kidney survival such as age, kidney function and proteinuria are not specific to C3G. The prognostic value of biomarkers of complement activation, which are pathognomonic of the diseases, remains unknown. In a large cohort of 165 patients from the French National registry, we retrospectively assess the prognostic value of C3, soluble C5b-9 (sC5b-9), C3 nephritic factor, and rare disease-predicting variants in complement genes in predicting clinical outcome of patients. By multivariate analysis age (adult onset), reduced kidney function (defined by estimated glomerular filtration rate under 60ml/min) and presence of rare disease-predicting variants in complement genes predicted risk of progression to kidney failure. Moreover, by multivariate analysis, normal C3/high sC5b-9 levels or low C3/normal sC5b-9 levels remained independently associated with a worse kidney prognosis, with the relative risk 3.7- and 8-times higher, respectively. Subgroup analysis indicated that the complement biomarker profiles independently correlated to kidney prognosis in patients with adult but not pediatric onset. In this subgroup, we showed that profiles of biomarkers C3 and/or sC5b-9 correlated with intra glomerular inflammation and may explain kidney outcomes. In children, only the presence of rare disease-predicting variants correlated with kidney survival. Thus, in an adult population, we propose a three-point C3G prognostic score based on biomarker profiles at risk, estimated glomerular filtration rate at presentation and genetic findings, which may help stratify adult patients into subgroups that require close monitoring and more aggressive therapy.

Patient-Patient Similarity-Based Screening of a Clinical Data Warehouse to Support Ciliopathy Diagnosis.

A timely diagnosis is a key challenge for many rare diseases. As an expanding group of rare and severe monogenic disorders with a broad spectrum of clinical manifestations, ciliopathies, notably renal ciliopathies, suffer from important underdiagnosis issues. Our objective is to develop an approach for screening large-scale clinical data warehouses and detecting patients with similar clinical manifestations to those from diagnosed ciliopathy patients. We expect that the top-ranked similar patients will benefit from genetic testing for an early diagnosis. The dependence and relatedness between phenotypes were taken into account in our similarity model through medical concept embedding. The relevance of each phenotype to each patient was also considered by adjusted aggregation of phenotype similarity into patient similarity. A ranking model based on the best-subtype-average similarity was proposed to address the phenotypic overlapping and heterogeneity of ciliopathies. Our results showed that using less than one-tenth of learning sources, our language and center specific embedding provided comparable or better performances than other existing medical concept embeddings. Combined with the best-subtype-average ranking model, our patient-patient similarity-based screening approach was demonstrated effective in two large scale unbalanced datasets containing approximately 10,000 and 60,000 controls with kidney manifestations in the clinical data warehouse (about 2 and 0.4% of prevalence, respectively). Our approach will offer the opportunity to identify candidate patients who could go through genetic testing for ciliopathy. Earlier diagnosis, before irreversible end-stage kidney disease, will enable these patients to benefit from appropriate follow-up and novel treatments that could alleviate kidney dysfunction.