The spectrum of glomerular and vascular kidney pathology associated with myeloproliferative neoplasms

A high prevalence of chronic kidney disease (CKD) occurs in patients with myeloproliferative neoplasms (MPN). However, MPN-related glomerulopathy (MPN-RG) may not account for the entirety of CKD risk in this population. The systemic vasculopathy encountered in these patients raises the hypothesis that vascular nephrosclerosis may be a common pattern of injury in patients with MPN and with CKD. In an exhaustive, retrospective, multicenter study of MPN kidney biopsies in four different pathology departments, we now describe glomerular and vascular lesions and establish clinicopathologic correlations. Our study encompassed 47 patients with MPN who underwent a kidney biopsy that included 16 patients with chronic myeloid leukemia (CML) and 31 patients with non-CML MPN. Fourteen cases met a proposed definition of MPN-RG based on mesangial sclerosis and hypercellularity, as well as glomerular thrombotic microangiopathy. MPN-RG was significantly associated with both myelofibrosis and poorer kidney survival. Thirty-three patients had moderate-to-severe arteriosclerosis while 39 patients had moderate-to-severe arteriolar hyalinosis. Multivariable models that included 188 adult native kidney biopsies as controls revealed an association between MPN and chronic kidney vascular damage, which was independent of established risk factors such as age, diabetes mellitus and hypertension. Therefore, MPN-RG is associated with myelofibrosis and has a poor kidney prognosis. Thus, our findings suggest that the kidney vasculature is a target during MPN-associated vasculopathy and establish a new link between MPN and CKD. Hence, these results may raise new hypotheses regarding the pathophysiology of vascular nephrosclerosis in the general population.

Short-chain fatty acids inhibit the activation of T lymphocytes and myeloid cells and induce innate immune tolerance

The intestinal microbiota contributes to gut immune homeostasis, where short-chain fatty acids (SCFAs) function as the major mediators. We aimed to elucidate the immunomodulatory effects of acetate, propionate, and butyrate. With that in mind, we sought to characterise the expression of SCFA receptors and transporters as well as SCFAs' impact on the activation of different immune cells. Whereas all three SCFAs decreased tumour necrosis factor (TNF)-α production in activated T cells, only butyrate and propionate inhibited interferon (IFN)-γ, interleukin (IL)-17, IL-13, and IL-10 production. Butyrate and propionate inhibited the expression of the chemokine receptors CCR9 and CCR10 in activated T- and B-cells, respectively. Similarly, butyrate and propionate were effective inhibitors of IL-1β, IL-6, TNF-α, and IL-10 production in myeloid cells upon lipopolysaccharide and R848 stimulation. Acetate was less efficient at inhibiting cytokine production except for IFN-α. Moreover, SCFAs inhibited the production of IL-6 and TNF-α in monocytes, myeloid dendritic cells (mDC), and plasmacytoid dendritic cells (pDC), whereas acetate effects were relatively more prominent in pDCs. In monocytes and mDCs, acetate was a less efficient inhibitor, but it was equally effective in inhibiting pDCs activation. We also studied the ability of SCFAs to induce trained immunity or tolerance. Butyrate and propionate - but not acetate - prevented Toll-like receptor-mediated activation in SCFA-trained cells, as demonstrated by a reduced production of IL-6 and TNF-α. Our findings indicate that butyrate and propionate are equally efficient in inhibiting the adaptive and innate immune response and did not induce trained immunity. The findings may be explained by differential SCFA receptor and transporter expression profiles of the immune cells.

A wave of deep intronic mutations in X-linked Alport Syndrome

X-linked Alport syndrome (XLAS) is an inherited kidney disease caused exclusively by pathogenic variants in the COL4A5 gene. In 10-20% of cases, DNA sequencing of COL4A5 exons or flanking regions cannot identify molecular causes. Here, our objective was to use a transcriptomic approach to identify causative events in a group of 19 patients with XLAS without identified mutation by Alport gene panel sequencing. Bulk RNAseq and/or targeted RNAseq using a capture panel of kidney genes was performed. Alternative splicing events were compared to those of 15 controls by a developed bioinformatic score. When using targeted RNAseq, COL4A5 coverage was found to be 23-fold higher than with bulk RNASeq and revealed 30 significant alternative splicing events in 17 of the 19 patients. After computational scoring, a pathogenic transcript was found in all patients. A causative variant affecting COL4A5 splicing and absent in the general population was identified in all cases. Altogether, we developed a simple and robust method for identification of aberrant transcripts due to pathogenic deep-intronic COL4A5 variants. Thus, these variants, potentially targetable by specific antisense oligonucleotide therapies, were found in a high percentage of patients with XLAS in whom pathogenic variants were missed by conventional DNA sequencing.

Challenging diagnosis of renal failure associated with severe neurological symptoms in a patient with mixed connective tissue disease

We report the case of a patient followed for a mixed connective tissue disease with signs of systemic sclerosis and systemic lupus, who presented an acute renal failure with severe neurological symptoms (confusion, obnubilation) and hypertension. The distinction between scleroderma renal crisis and lupus nephritis was challenging and hence, the decision to use or not high dose of corticosteroids. Kidney biopsy was of major importance for the diagnosis and therapeutic strategy. The diagnosis of neurological symptoms was also made difficult given the clinical presentation and the results of imaging. Neurolupus, malignant hypertension, or posterior reversible encephalopathy syndrome were the evoked diagnosis.

Bi-allelic pathogenic variants in ITGA8 cause slowly progressive renal disease of unknown etiology

Integrin Subunit Alpha 8 gene (ITGA8) encodes an integrin chain that is known to be critical in the early stage of the kidney development. Bi-allelic pathogenic variants in ITGA8 are associated with bilateral renal agenesis, as well as anomalies involving urogenital system. Here, we report two unrelated patients presenting with slowly progressing chronic kidney disease associated with bilateral renal hypodysplasia carrying homozygous loss of function variants in the ITGA8 gene. These results broaden the clinical and genotypic spectrum of ITGA8 defects, revealing the high and unexpected degree of phenotypic heterogeneity of this autosomal recessive disease. Our study emphasizes the usefulness of Next-Generation Sequencing in unraveling the genetic cause of chronic kidney disease of unknown etiology, and raises the question of genetic modifiers involved in the variation of the phenotypes associated with autosomal recessive ITGA8 pathogenic variants.

Multicentric Carpotarsal Osteolysis Syndrome Associated Nephropathy: Novel Variants of MAFB Gene and Literature Review

Multicentric carpo-tarsal osteolysis (MCTO) is a rare osteolysis syndrome mainly involving carpal and tarsal bones usually presenting in early childhood. MCTO has autosomal dominant inheritance with heterozygous mutation in the MAFB gene. The skeletal disorder is often associated with chronic kidney disease. Data on clinical characterization and best treatment option of MCTO-associated nephropathy are scarce and mostly limited to case reports. With the aim to better define the phenotype and long-term outcomes of MCTO-associated nephropathy, we launched an online survey through the Workgroup for hereditary glomerulopathies of the European Rare Kidney Disease Network (ERKNet). Overall, we collected clinical and genetic data of 54 MCTO patients, of which 42 previously described and 12 new patients. We observed a high rate of kidney involvement (70%), early age of kidney disease onset, nephrotic-range proteinuria, and a kidney survival around of 40% at long-term follow-up. Our finding confirmed the heterogeneity of clinical manifestations and widen the spectrum of phenotypes resulting from MCTO-associated nephropathy. Furthermore, we report the first case of complete remission after treatment with cyclosporine A. We demonstrated that multidisciplinary care is essential for MCTO patients and early referral to nephrologists is therefore warranted to facilitate prompt treatment.

Weaning of maintenance immunosuppressive therapy in lupus nephritis (WIN-Lupus): results of a multicentre randomised controlled trial

Objectives

Lupus nephritis (LN) is a frequent complication of systemic lupus erythematosus (SLE). Severe (proliferative) forms of LN are treated with induction immunosuppressive therapy (IST), followed by maintenance IST, to target remission and avoid relapses. The optimal duration of maintenance IST is unknown. The WIN-Lupus trial tested whether IST discontinuation after 2‒3 years was non-inferior to IST continuation for two more years in proliferative LN.

Methods

WIN-Lupus was an investigator-initiated multicentre randomised controlled trial. Patients receiving maintenance IST with azathioprine or mycophenolate mofetil for 2–3 years, and hydroxychloroquine, were randomised (1:1) into two groups: (1) IST continuation and (2) IST discontinuation. The primary endpoint was the relapse rate of proliferative LN at 24 months. Main secondary endpoints were the rate of severe SLE flares, survival without renal relapse or severe flare, adverse events.

Results

Between 2011 and 2016, 96 patients (out of 200 planned) were randomised in WIN-Lupus: IST continuation group (n=48), IST discontinuation group (n=48). Relapse of proliferative LN occurred in 5/40 (12.5%) patients with IST continuation and in 12/44 (27.3%) patients with IST discontinuation (difference 14.8% (95% CI −1.9 to 31.5)). Non-inferiority was not demonstrated for relapse rate; time to relapse did not differ between the groups. Severe SLE flares (renal or extrarenal) were less frequent in patients with IST continuation (5/40 vs 14/44 patients; p=0.035). Adverse events did not differ between the groups.

Conclusions

Non-inferiority of maintenance IST discontinuation after 2‒3 years was not demonstrated for renal relapse. IST discontinuation was associated with a higher risk of severe SLE flares.

Trial registration number

NCT01284725.

POS0244 ASSOCIATION OF PROTEINASE 3 GENE (PRTN3) Val119Ile POLYMORPHISM (SNP rs351111) WITH RISK OF RELAPSE AMONG HOMOZYGOUS PATIENTS WITH PR3 ANCA-ASSOCIATED VASCULITIS

Background

The frequency of the proteinase 3 gene (PRTN3) polymorphisms in patients with ANCA-associated vasculitis (AAV) is not well characterized. We hypothesize that PRTN3 gene polymorphisms induce allosteric changes in PR3 conformation which may alter its interaction with ligands and PR3-ANCA during inflammation with potential implications for disease presentation and clinical outcomes.

Objectives

To analyze the association of PRTN3 Val119Ile polymorphism (SNP rs351111) with risk of relapse risk among homozygous patients with PR3 ANCA-associated vasculitis.

Methods

DNA variant calling for SNP rs351111 (chr.19:844020, c.355G>A) in PRTN3 gene assessed the allelic frequency in patients with PR3-AAV included in the Rituximab versus Cyclophosphamide (RAVE) trial. This was followed by RNA-seq variant calling to characterize the mRNA expression. We compared clinical presentation and outcomes between patients homozygous for PR3-Ile119 or PR3-Val119.

Results

Serum samples for DNA calling were available in 188 of the 197 patients with AAV in the RAVE cohort. 75 PR3-AAV patients had the allelic variant: 13 patients were homozygous for PR3-Ile119 and 62 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 29.3 – 55.1% of reads (Figure 1A and 1B). RNA-seq was available for 89 patients and the mRNA corresponding to the allelic variant was found in 35 PR3-AAV patients: 13 patients were homozygous for PR3-Ile119 and 22 patients were heterozygous PR3-Val119Ile with an allele frequency threshold of 11.1 – 62.8% of reads (Figure 1A and 1C). The agreement between the DNA calling results and the mRNA expression of the 86 patients that overlapped was 100%. We found an additional homozygous patient for PR3-Val119 in which blood was not available for DNA calling. We compared the clinical presentation and outcomes of 74 patients with PR3-AAV: 13 homozygous for PR3-Ile119 and 51 homozygous for PR3-Val119 (Table 1). The frequency of severe flares at 18 months in homozygous PR3-Ile119 was ≥ 2x higher when compared with homozygous PR3-Val119 (46.2% vs. 19.6%, p=0.048). We found no differences in clinical presentation.

Figure 1.

RAVE trial population distribution according to the zygosity status for PRTN3 gene (PR3 and MPO-ANCA patients) and DNA or RNA variant calling (panel A). Allelic frequency for rs351111, chr.19:844020 (c.355G>A) in PRTN3 among patients with AAV (PR3 and MPO-ANCA) in the DNA (panel B) and RNA (panel C) variant calling.

Table 1.

Outcomes of patients with PR3-ANCA according with PRTN3 zygosity.

PR3-ANCA (n=64)Homozygous PR3-Val119(n=51)HomozygousPR3-Ile119(n=13)p-value Remission, n (%)45 (88.2)13 (100)0.194 Complete remission, n (%)36 (70.6)10 (76.9)0.650 Any flare 18 months, n (%)30 (58.8)7 (53.8)0.746 Severe Relapse* 18 months, n (%)10 (19.6)6 (46.2)0.048

* Relapse was considered “Severe” if Birmingham Vasculitis Activity Score for Wegener’s Granulomatosis (BVAS/WG) > 3 or one major item as per the RAVE trial definition.

Abbreviations: ANCA - anti-neutrophil cytoplasmic antibody; Ile – isoleucine; n- number; PR3 - proteinase 3; Val - valine.

Conclusion

In patients with PR3-AAV the presence of PRTN3 Val119Ile polymorphism was associated with higher frequency of severe relapse. Further studies are necessary to understand the association of this observation with the risk of severe relapse.

References

[1]Stone JH et al N Engl J Med 2010; 363:221-232

Disclosure of Interests

None declared

OP0280 WEANING OF MAINTENANCE IMMUNOSUPPRESSIVE THERAPY IN LUPUS NEPHRITIS (WIN-Lupus): A MULTICENTER RANDOMIZED CONTROLLED TRIAL

Background

Lupus nephritis (LN) is a frequent complication of systemic lupus erythematosus (SLE). Severe (proliferative) forms of LN are treated with an induction immunosuppressive therapy (IST), followed by a maintenance IST, to target remission and avoid relapses. The optimal duration of maintenance IST for proliferative LN is unknown.

Objectives

The WIN-Lupus trial tested whether IST discontinuation after 2-3 years in proliferative LN was non-inferior to IST continuation for 2 more years.

Methods

WIN-Lupus is an investigator-initiated academic randomized controlled trial, conducted in 28 French centers. Patients on maintenance IST with azathioprine or mycophenolate mofetil for a minimum of 2 years and a maximum of 3 years, and who were taking Hydroxychloroquine, were randomized (1:1) between 2 groups: IST continuation and IST discontinuation. The primary endpoint was the relapse rate of proliferative LN at 24 months. Secondary endpoints were the rate of severe SLE flares, survival without renal relapse or severe flare, adverse events, kidney function, disease activity, corticosteroid exposure, patient-reported outcome and medico-economic impact.

Results

Between 2011 and 2016, 125 patients were screened and 96 were randomized in the trial: 48 in the IST continuation group, 48 in the IST discontinuation group. In the per-protocol population, a relapse of proliferative LN occurred in 5/40 (10.4%) patients with IST continuation, and in 12/44 (25%) patients with IST discontinuation (difference 14.8%, 95%CI [-1.9; 31.5]). Non-inferiority was not demonstrated for relapse rate. Time to renal relapse did not differ between groups (p=0.092). Severe SLE flares (renal or extra-renal) were less frequent in patients with IST continuation compared to IST discontinuation (5/40 vs 14/44 patients, p=0.035). IST discontinuation was associated with lower health-related costs. Adverse events did not differ between groups.

Conclusion

Non-inferiority of maintenance IST discontinuation after 2 to 3 years was not demonstrated for renal relapse. IST discontinuation was associated with a higher risk of severe SLE flare.

References

[1]Moroni G et al. When and how is it possible to stop therapy in patients with lupus nephritis? Clin J Am Soc Nephrol. 2021. CJN.04830421. doi: 10.2215/CJN.04830421.

[2]Fanouriakis A et al. 2019 Update of the Joint European League Against Rheumatism and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of lupus nephritis. Ann Rheum Dis. 2020;79(6):713-723.

[3]Jourde-Chiche N et al. Proliferative lupus nephritis treatment: practice survey in nephrology and internal medicine in France. Nephrol Ther. 2014;10(3):170-6.

[4]Zen M et al. Immunosuppressive therapy withdrawal after remission achievement in patients with lupus nephritis. Rheumatology (Oxford). 2021;keab373. doi: 10.1093/rheumatology/keab373.

[5]Malvar A et al. Kidney biopsy-based management of maintenance immunosuppression is safe and may ameliorate flare rate in lupus nephritis. Kidney Int. 2020;97(1):156-162.

Acknowledgements

Groupe Coopératif sur le Lupus Rénal (GCLR)

Disclosure of Interests

Noemie JOURDE-CHICHE Speakers bureau: Vifor Pharma, Grant/research support from: Fresenius Medical Care: grant paid to my institution (AP-HM) for the CINEVAS study in ANCA-associated vasculitis, Nathalie Costedoat-Chalumeau Grant/research support from: AP-HP received a research support from ROCHE for the OBILUP trial, Karine Baumstarck: None declared, LAURENCE BOUILLET Speakers bureau: GSK, novartis, biocryst, takeda, behring, Paid instructor for: takeda, novartis, Consultant of: GSK, novartis, biocryst, takeda, behring, blueprint, Grant/research support from: takeda, gsk, sanofi, biocryst, novartis, Stéphane Burtey: None declared, Valerie Caudwell: None declared, Laurent Chiche Speakers bureau: BMS, Paid instructor for: BMS, Lionel Couzi Speakers bureau: Astellas, Chiesi, Novartis, Sandoz, Ostuka, GSK, Biotest, Consultant of: Biotest, Hansa, Novartis, Grant/research support from: Novartis, Astellas, Christophe DELIGNY: None declared, Bertrand Dussol Speakers bureau: Genzyme, Novonordisk, Grant/research support from: Shire, Stanislas Faguer Speakers bureau: Asahi, Vifor Pharma, Sanofi, Consultant of: Abyonyx Pharma, Pierre Gobert: None declared, Guillaume Gondran Speakers bureau: Pfizer, Novartis, Consultant of: Genzyme, Antoine Huart Speakers bureau: Janssen, Paid instructor for: Pfizer, Aurélie Hummel: None declared, Emilie Kalbacher: None declared, Alexandre Karras Speakers bureau: Vifor, GSK, Astra-Zeneca, Roche, Paid instructor for: Vifor, Sanofi, Alexion, Consultant of: Novartis, GSK, Bohringer-Ingelheim, Marc Lambert Speakers bureau: CHUGAI-ROCHE, BAYER, PFIZER, LEOPHARMA, Paid instructor for: CHUGAI-ROCHE, Consultant of: CHUGAI-ROCHE, BAYER, PFIZER, LEOPHARMA, Grant/research support from: CHUGAI-ROCHE, Véronique LE GUERN: None declared, Sandrine Loubiere: None declared, Helene Maillard: None declared, Francois Maurier: None declared, Micheline Pha: None declared, Viviane Queyrel Paid instructor for: GSK, Consultant of: Boehringer Ingelheim, Francoise Sarrot-Reynauld: None declared, David Verhelst: None declared, Eric Hachulla Speakers bureau: Johnson & Johnson, GSK, Roche-Chugai, Consultant of: Johnson & Johnson, Boehringer Ingelheim, Bayer, GSK, Roche-Chugai, Sanofi-Genzyme, Grant/research support from: CSL Behring, GSK, Roche-Chugai and Johnson & Johnson, Zahir Amoura Speakers bureau: GSK, CSL Behring, Consultant of: GSK, Grant/research support from: GSK, Eric Daugas Speakers bureau: GSK, Amgen, Paid instructor for: GSK, Astra Zeneca, Consultant of: GSK, Astra Zeneca, Amgen, Grant/research support from: ROCHE for the OBILUP trial (AP-HP)

Idiopathic nephrotic syndrome relapse following SARS-CoV-2 vaccination: a series of 25 cases

Background

Several cases of idiopathic nephrotic syndrome (INS) relapse following the administration of coronavirus disease 2019 (COVID-19) vaccines have recently been reported, raising questions about the potential relationship between the immune response to COVID-19 vaccination and INS pathogenesis.

Methods

We performed a retrospective multicentre survey describing the clinical and biological characteristics of patients presenting a relapse of INS after COVID-19 vaccination, with an assessment of outcome under treatment.

Results

We identified 25 patients (16 men and 9 women) presenting a relapse within 1 month of a COVID-19 vaccine injection. The glomerular disease was of childhood onset in half of the patients and most patients (21/25) had received at least one immunosuppressive drug in addition to steroids for frequently relapsing or steroid-dependent nephrotic syndrome (NS). All patients were in a stable condition at the time of injection and 11 had no specific treatment. In five patients, the last relapse was reported >5 years before vaccine injection. The Pfizer-BioNTech (BNT162b2) vaccine was used in 80% of the patients. In 18 cases, INS relapse occurred after the first injection, a mean of 17.5 days after vaccination. A second injection was nevertheless administered in 14 of these patients. Five relapses occurred after administration of the second dose and two relapses after the administration of the third dose. All but one of the patients received steroids as first-line treatment, with an additional immunosuppressive agent in nine cases. During follow-up, complete remission was achieved in 21 patients, within 1 month in 17 cases. Only one patient had not achieved at least partial remission after 3 months of follow-up.

Conclusions

This case series suggests that, in rare patients, COVID-19 vaccination may trigger INS relapse that is generally easy to control. These findings should encourage physicians to persuade their patients to complete the COVID-19 vaccination schedule.

FC067: Long-Term Outcome of Childhood Onset Idiopathic Nephrotic Syndrome

BACKGROUND AND AIMS

Little is known about the long-term outcome during adulthood of childhood onset idiopathic nephrotic syndrome (INS). We aimed to determine which patients require long-term follow up after transition, to identify risk factors of relapse and to analyze treatment strategies.

METHOD

In this monocentric retrospective study, we included all patients admitted in our adult nephrology department with INS diagnosed during childhood. Patients who reached kidney failure during childhood were excluded. Data regarding the outcome at adult age were obtained through clinical database and medical charts.

RESULTS

Eighty-two patients (male/female = 2/1) were included, with a median age at diagnosis of 3.9 years (1.2–16.5). Sixty-eight patients had steroid-sensitive INS, including 52 with steroid-dependent nephrotic syndrome or frequently relapsing nephrotic syndrome. Fourteen patients had steroid-resistant nephrotic syndrome. A total of 89% of patients received corticosteroid sparing treatment during childhood. Median follow-up during adulthood was 6.2 (0.3–25) years. A total of 71% of patients experienced at least one relapse during adulthood. The total number of relapses during childhood and the number of relapses per year during childhood, reflecting disease activity, were significantly higher in patients who experienced relapses during adulthood than in patients who did not (Figure 1). The risk of relapse during adulthood was also significantly associated with the need for immunosuppressive regimen at the time of the transition visit (P = 0.002). To promote the successful transition of young people, we propose to organize a transition visit where the adolescent/young adult is seen jointly by pediatric and adult nephrologists, as it was done for 68% of patients in this study. The relapse rate was significantly lower (50%) in the subgroup of patients who had such a transition visit. We also found that relapse during the first two-years of adulthood follow-up was significantly associated with the risk of further relapse, highlighting the need for a close follow-up during the transition period. A total of 45% of patients received corticosteroid sparing treatment during adulthood, mainly mycophenolate mofetil (N = 23), calcineurin inhibitors (N = 21) and rituximab (N = 12). The main complications were high blood pressure (20/82, 26%) and osteopenia (19/26, 73% when bone densitometry was performed). Only one thrombo-embolic event and three severe infections were reported. At last follow-up, median eGFR was 87.1 (23.4–150.8) mL/min/1.73 m².

CONCLUSION

The incidence of relapses in adulthood is high in patients with active disease during childhood. A long-term follow-up is mandatory in these patients. Whereas renal function remained normal in most patients, high blood pressure and osteopenia were frequent and should be carefully monitored during adulthood. Transition visit should be carefully coordinated to prevent the risk of nonadherence.

FC053: Weaning of Maintenance Immunosuppressive Therapy in Lupus Nephritis (Win-Lupus): A multicenter randomized controlled trial

BACKGROUND AND AIMS

Lupus nephritis (LN) is a frequent complication of systemic lupus erythematosus (SLE). Severe (proliferative) forms of LN are treated with an induction immunosuppressive therapy (IST), followed by a maintenance IST, to target remission and avoid relapses. The optimal duration of maintenance IST for proliferative LN is unknown. The WIN-Lupus trial tested whether IST discontinuation after 2–3 years in proliferative LN was non-inferior to IST continuation for 2 more years.

METHOD

WIN-Lupus is an investigator-initiated academic randomized controlled trial, conducted in 28 French centres. Patients on maintenance IST with azathioprine

or mycophenolate mofetil for a minimum of 2 years and a maximum of 3 years, and those who were taking hydroxychloroquine were randomized (1:1) between two groups: IST continuation and IST discontinuation. The primary endpoint was the relapse rate of proliferative LN at 24 months. Secondary endpoints were the rate of severe SLE flares, survival without renal relapse or severe flare, adverse events, kidney function, disease activity, corticosteroid exposure, patient-reported outcome and medico-economic impact.

RESULTS

Between 2011 and 2016, 125 patients were screened and 96 were randomized in the trial: 48 in the IST continuation group and 48 in the IST discontinuation group. In the per-protocol population, a relapse of proliferative LN occurred in 5/40 (10.4%) patients with IST continuation, and in 12/44 (25%) patients with IST discontinuation (difference 14.8%, 95% CI [−1.9; 31.5]). Noninferiority was not demonstrated for relapse rate. Time to renal relapse did not differ between groups (P = 0.092). Severe SLE flares (renal or extrarenal) were less frequent in patients with IST continuation compared to IST discontinuation (5/40 versus 14/44 patients; P = 0.035). IST discontinuation was associated with lower health-related costs. Adverse events did not differ between groups.

CONCLUSION

Noninferiority of maintenance IST discontinuation after 2 to 3 years was not demonstrated for renal relapse. IST discontinuation was associated with a higher risk of severe SLE flare.

Kidney Histopathology Can Predict Kidney Function in ANCA-Associated Vasculitides with Acute Kidney Injury Treated with Plasma Exchanges

BACKGROUND

Data from the PEXIVAS trial challenged the role of plasma exchange (PLEX) in ANCA-associated vasculitides (AAV). We aimed to describe kidney biopsy from patients with AAV treated with PLEX, evaluate whether histopathologic findings could predict kidney function, and identify which patients would most benefit from PLEX.

METHODS

We performed a multicenter, retrospective study on 188 patients with AAV and AKI treated with PLEX and 237 not treated with PLEX. The primary outcome was mortality or KRT at 12 months (M12).

RESULTS

No significant benefit of PLEX for the primary outcome was found. To identify patients benefitting from PLEX, we developed a model predicting the average treatment effect of PLEX for an individual depending on covariables. Using the prediction model, 223 patients had a better predicted outcome with PLEX than without PLEX, and 177 of them had >5% increased predicted probability with PLEX compared with without PLEX of being alive and free from KRT at M12, which defined the PLEX-recommended group. Risk difference for death or KRT at M12 was significantly lower with PLEX in the PLEX-recommended group (-15.9%; 95% CI, -29.4 to -2.5) compared with the PLEX not recommended group (-4.8%; 95% CI, 14.9 to 5.3). Microscopic polyangiitis, MPO-ANCA, higher serum creatinine, crescentic and sclerotic classes, and higher Brix score were more frequent in the PLEX-recommended group. An easy to use score identified patients who would benefit from PLEX. The average treatment effect of PLEX for those with recommended treatment corresponded to an absolute risk reduction for death or KRT at M12 of 24.6%.

CONCLUSIONS

PLEX was not associated with a better primary outcome in the whole study population, but we identified a subset of patients who could benefit from PLEX. However, these findings must be validated before utilized in clinical decision making.

OUP accepted manuscript

Background

Patients on maintenance hemodialysis have an increased risk of severe COVID-19 and a reduced response to vaccines. Data are needed to identify immune correlates of protection in this population.

Methods

Following a COVID-19 outbreak among vaccinated patients in a hemodialysis unit, clinical data and serological response to BNT162b2 vaccine were retrospectively recorded.

Results

Among fifty-three patients present in the dialysis room, fourteen were infected by SARS-CoV-2 alpha variant (COVID_Pos) and 39 were not. In comparison to uninfected patients, COVID_Pos patients more frequently had additional causes of immunosuppression (50% vs 21%, p = 0.046), and were more often scheduled on the Monday-Wednesday-Friday (MWF) shift (86% vs 39%, p = 0.002). Moreover, COVID_pos had lower anti-Spike IgG titers than uninfected patients (24 BAU/ml [3–1163] vs 435 BAU/mL [99–2555], p = 0.001) and lower neutralization titers (108 [17–224] vs 2483 [481–43 908], p = 0.007). Anti-Spike and neutralization antibody titers are correlated (r = 0.92, p < 0.001). In multivariable analysis, MWF schedule (OR = 10.74 (1.9–93.5), p = 0.014) and anti-spike IgG titers one month before the outbreak (<205 BAU/ml: OR = 0.046 (0.002–0.29), p = 0.006) were independently associated with COVID-19 infection. None of the patients with anti-Spike IgG above 284 BAU/mL got infected. Ten out of fourteen COVID_Pos patients were treated with Casirivimab and Imdevimab. No patient developed severe disease.

Conclusions

Anti-spike IgG titer measured prior to exposure correlates to protection from SARS-CoV-2 infection in hemodialysis patients. BNT162b2 vaccination alone or in combination with monoclonal antibodies prevented severe COVID-19.

Erythrocytosis associated with IgA nephropathy

Background

Erythrocytosis is a hematological disorder usually related to hematopoietic stem cell somatic mutations. However, unexplained erythrocytosis remains frequent. In this study, we evaluated the involvement of IgA1, a regulator of erythropoiesis also implicated in IgA nephropathy (IgAN) pathophysiology, in unexplained polycythemia/erythrocytosis (PE) of IgAN patients.

Methods

IgAN-PE patients’ serum was collected, analyzed and used to study IgA1 effect on proliferation and differentiation of erythroid progenitors. Hematological parameters of transgenic mice for human alpha1 heavy chain were studied. Multicentric observational cohorts of chronic kidney disease (CKD) patients, including both native kidney diseases and renal transplants, were studied to analyze patient hemoglobin levels.

Findings

We retrospectively identified 6 patients with IgAN and unexplained PE. In large CKD cohorts, IgAN was associated with PE in 3.5% of patients (p<0.001 compared to other nephropathies). IgAN was an independent factor associated with higher hemoglobin levels (13.1g/dL vs 12.2 g/dL, p=0.01). During post-transplant anemia, anemia recovery was faster in IgAN patients. Elevated polymeric/monomeric IgA1 ratio as well as high Gd-IgA1 rate were observed in circulating IgA1 of the 6 IgAN-PE patients as compared with control or IgAN patients without PE. IgA1 from these patients increased the sensitivity of erythroid progenitors to Epo. In mice, we also observed an elevation of hematocrit in alpha1 knock-in mice compared to wild type controls.

Interpretation

These data identify a new etiology of erythrocytosis and demonstrate the role of pIgA1 in human erythropoiesis. This syndrome of IgA-related erythrocytosis should be investigated in case of unexplained erythrocytosis and renal disease.

Funding

This work was supported by INSERM (French national institute for health and medical research), Labex GRex and Imagine Institute (Paris, France)

Reappraisal of Renal Arteritis in ANCA-associated Vasculitis: Clinical Characteristics, Pathology, and Outcome

BACKGROUND

Renal involvement in ANCA-associated vasculitis (AAV) is associated with poor outcomes. The clinical significance of arteritis of the small kidney arteries has not been evaluated in detail.

METHODS

In a multicenter cohort of patients with AAV and renal involvement, we sought to describe the clinicopathologic characteristics of patients with AAV who had renal arteritis at diagnosis, and to retrospectively analyze their prognostic value.

RESULTS

We included 251 patients diagnosed with AAV and renal involvement between 2000 and 2019, including 34 patients (13.5%) with arteritis. Patients with AAV-associated arteritis were older, and had a more pronounced inflammatory syndrome compared with patients without arteritis; they also had significantly lower renal survival (P=0.01). In multivariable analysis, the ANCA renal risk score, age at diagnosis, history of diabetes mellitus, and arteritis on index kidney biopsy were independently associated with ESKD. The addition of the arteritis status significantly improved the discrimination of the ANCA renal risk score, with a concordance index (C-index) of 0.77 for the ANCA renal risk score alone, versus a C-index of 0.80 for the ANCA renal risk score plus arteritis status (P=0.008); ESKD-free survival was significantly worse for patients with an arteritis involving small arteries who were classified as having low or moderate risk, according to the ANCA renal risk score. In two external validation cohorts, we confirmed the incidence and phenotype of this AAV subtype.

CONCLUSIONS

Our findings suggest AAV with renal arteritis represents a different subtype of AAV with specific clinical and histologic characteristics. The prognostic contribution of the arteritis status remains to be prospectively confirmed.

Long-term health-related quality of life outcomes of adults with pediatric onset of frequently relapsing or steroid-dependent nephrotic syndrome

BACKGROUND

Long-term psychosocial outcomes and health-related quality of life (HRQOL) in adults with pediatric onset of frequently relapsing or steroid-dependent idiopathic nephrotic syndrome (FRNS or SDNS) remain to be determined.

METHODS

In this prospective cohort study, 59 adults with pediatric onset of FRNS/SDNS and persistent active glomerular disease in adulthood completed the GEDEPAC-2 questionnaire exploring 11 well-being domains. Data were compared to the French general population (FGP) with standardized incidence ratio ([SIR]; adjusted for period, age, gender). Regression models were performed to identify predictive factors of psychosocial well-being.

RESULTS

In 82% of cases, the questionnaire was completed while the participants (n = 59; 47 men; median age = 32 years; median number of relapses = 13) were in complete remission (under specific therapy in 76% of cases). Participants had higher educational degree than in the FGP (SIR = 6.3; p < 0.01) and more frequently a managerial occupation (SIR = 3.1; p < 0.01). Social integration was acceptable with regard to marital status and experience of sexual intercourse, but experiences of discrimination were far more frequent (SIR = 12.5; p < 0.01). The SF-12 mental component summary (MCS) score was altered (Z-score = - 0.6; p < 0.01) and mean multidimensional fatigue inventory (MFI-20) global fatigue score appeared high (12). Transfer from pediatric to adult healthcare was followed by a period of discontinued care for 33% of participants. Multivariate analysis revealed a close relationship between MFI-20, physical health, and MCS.

CONCLUSIONS

This study shows that pediatric onset FRNS and SDNS may have a long-term negative impact on mental HRQOL and highlights the impact of fatigue, which is often not adequately considered in routine care.

Apheresis in Adult With Refractory Idiopathic Nephrotic Syndrome on Native Kidneys

Background

Apheresis is the gold standard for idiopathic nephrotic syndrome (INS) relapse after transplantation, but it remains unknown whether such treatment is useful for adults with refractory INS on native kidneys.

Methods

This retrospective study included patients older than 16 years with biopsy-proven refractory (persistent nephrotic syndrome on corticosteroids plus at least 1 immunosuppressive drug) INS treated by apheresis and followed for at least 3 months.

Results

Between September 1997 and January 2020, 21 patients (focal segmental glomerulosclerosis: 12, minimal change nephrotic syndrome: 9, men: 67%, median age: 34 years) were identified. At last follow-up (12 months), 7 of 21 patients were in complete or partial remission. Remission was associated with older age (51 vs. 30 years, P = 0.05), lower proteinuria (3.9 vs. 7.3 g/d, P = 0.03), and lower estimated glomerular filtration rate (eGFR) (28.0 vs. 48.5 ml/min per 1.73 m², P = 0.05) at apheresis. The need for dialysis before apheresis (odds ratio [OR] 22.0 [1.00–524], P = 0.026), age ≥50 years (OR: 22.6 [1.00–524], P = 0.006), a marked (>4.5 g/d) decrease in proteinuria (OR: 9.17 [1.15–73.2], P = 0.041), and a short (<12 months) time between diagnosis and apheresis (OR: 10.8 [1–117], P = 0.043) were significantly associated with remission. Three of 7 patients in remission who were initially on dialysis became dialysis-free; by contrast, none of the 14 patients without remission was initially on dialysis, but 5 of 14 had become dialysis-dependent (P = 0.01).

Conclusion

Apheresis may result in remission in adult patients with refractory INS, particularly in those at risk of renal failure, with limited sensitivity to medical treatments, if apheresis is initiated within a year of diagnosis.

Characteristics and risk factors for poor outcome in patients with systemic vasculitis involving the gastrointestinal tract

BACKGROUND

Gastrointestinal (GI) involvement was described to be a poor prognostic factor in systemic necrotizing vasculitis. Its prognostic significance may vary according to clinical presentation and vasculitis subtype.

AIMS

This study investigated risk-factors associated to poor outcome in GI-involvement of vasculitis.

METHODS

Patients with systemic vasculitis as defined by the 2012 Chapel Hill Consensus Conference and presenting with GI involvement were retrospectively included. Baseline characteristics, treatments and outcome were recorded. Primary endpoint was a composite of admission to intensive care unit (ICU), emergency surgical procedure, or death.

RESULTS

Two hundred and thirteen patients were included. Vasculitis were distributed as follows: 41% IgA vasculitis, 27% ANCA-associated vasculitis, 17% polyarteritis nodosa (PAN), and 15% other vasculitis. Eighty-three (39%) patients fulfilled the composite primary endpoint within 6 months. Predictive factors associated with the primary endpoint included PAN subtype (OR 3.08, 95% CI 1.29-7.34), performance status (OR 1.40, 1.05-1.87), use of morphine (OR 2.51, 0.87-7.24), abdominal guarding (OR 3.08, 1.01-9.37), ileus (OR 2.29, 0.98-5.32), melena (OR 2.74, 1.17-6.42), increased leukocytes (per G/L, OR 1.05, 1.00-1.10), low hemoglobin (per g/dL, OR 0.80, 0.71-0.91) and increased CRP (log mg/L, OR 1.21, 0.94-1.56). A risk prediction model for the achievement of primary endpoint had a very good performance [C-statistics 0.853 (0.810 to 0.895], and for overall survival as well.

CONCLUSIONS

Vasculitis presenting with GI involvement have a poor outcome in more than one third of cases. An easy-to-use risk prediction model had a very good performance to predict the admission to ICU, emergency surgical procedure, or death.

Molecular Signatures of Kidney Antibody-Secreting Cells in Lupus Patients With Active Nephritis Upon Immunosuppressive Therapy

OBJECTIVE

This study was undertaken to characterize kidney and urine antibody-secreting cells (ASCs) from patients with active lupus nephritis, before and after induction therapy.

METHODS

We included patients with biopsy-proven active lupus nephritis and performed anti-CD138 staining of kidney biopsy samples to visualize ASCs. We performed single-cell gene expression profiling on sorted ASCs from fresh biopsy samples using multiplex reverse transcriptase-polymerase chain reaction. We used a gene set that allowed for the study of ASC maturation from plasmablasts to long-lived plasma cells. We quantified urine ASCs from untreated patients with lupus nephritis at diagnosis and after 6 months of prospective follow-up during induction therapy.

RESULTS

The number of kidney CD138+ ASCs in 46 untreated patients with lupus nephritis was correlated with a low estimated glomerular filtration rate and with tubulointerstitial damage. Most kidney ASCs from 3 untreated patients had a plasmablast molecular signature; in contrast, in 4 patients with refractory lupus nephritis, the kidney ASCs were mainly long-lived plasma cells, representing an ASC transcriptional profile similar to that in the bone marrow of 2 healthy donors. Some urine ASCs with a plasmablast signature were detected in patients with untreated active lupus nephritis. The presence of urine ASCs at 6 months was associated with treatment failure.

CONCLUSION

Our results suggest potential for ASC-directed therapy in refractory lupus nephritis.

IgA nephropathy in association with inflammatory bowel diseases: results from a national study and systematic literature review

BACKGROUND

Little is known about clinical characteristics and kidney outcome in patients with biopsy-proven immunoglobulin A nephropathy (IgAN) in a context of inflammatory bowel disease (IBD).

METHODS

We conducted a retrospective multicenter study with centralized histological review, to analyze the presentation, therapeutic management and outcome of 24 patients suffering from IBD associated IgAN relative to a cohort of 134 patients with primary IgAN without IBD.

RESULTS

Crohn's disease and ulcerative colitis accounted for 75% and 25% of IBD-associated IgAN cases, respectively. IBD was diagnosed before IgAN in 23 cases (a mean of 9 years previously) and was considered active at IgAN onset in 23.6% of patients. Hypertension was present in 41.7% of patients. Urinary protein-to-creatinine ratio exceeded 100 mg/mmol in 70.8% of patients (mean: 254 mg/mmol). Estimated glomerular filtration rate (eGFR) exceeded 60 ml/min/1.73m2 in 13/24 patients and only one patient required dialysis. In the Oxford MEST-C classification of renal biopsies, 57% were M1, 48% E1, 76% S1, 57% T1+T2 and 38% C1+C2. Steroids were administered in 50% of cases. After a mean follow-up of 7.2 years, four patients (16.7%) had a poor kidney outcome: end-stage renal disease (n = 3) or a > 50% decrease in eGFR from initial values (n = 1). A similar evolution was observed in patients with primitive IgAN.

CONCLUSIONS

This first case series suggests that IBD-associated IgAN have frequent inflammatory lesions at onset and variable long-term outcome.

Impact of aging on phenotype and prognosis in IgA vasculitis

OBJECTIVES

Immunoglobulin A vasculitis (IgAV) is a small-vessel vasculitis most frequently benign in children while the disease is more severe in adults. We aimed to study the impact of age on presentation and outcome of adult IgAV.

METHODS

We conducted a nationwide retrospective study including 260 IgAV patients. Patients were divided into four quartiles according to the age at IgAV diagnosis: <36; 36≤age < 52; 52≤age < 63 and ≥63 years. Comparison of presentation and outcome were performed according to age of disease onset.

RESULTS

Mean age at diagnosis was 50.1 ± 18 years and 63% were male. IgAV diagnosed in the lowest quartile of age was associated with more frequent joint (p< 0.0001) and gastrointestinal involvement (p= 0.001). In contrast, the oldest patients had more severe purpura with necrotic lesions (p= 0.001) and more frequent renal involvement (p< 0.0001), with more frequent hematuria, renal failure, higher urine protein excretion and more frequent tubulointerstitial lesions. Patients were treated similarly in all groups of age, and clinical response and relapse rates were similar between groups. In the 127 treated patients with follow-up data for >6 months, clinical response and relapse rates were similar between the four groups. Median follow-up was of 17.2 months (9.1-38.3 months). Renal failure at the end of follow-up was significantly more frequent in the highest quartile of age (p= 0.02), but the occurrence of end-stage renal disease was similar in all groups. Last, overall and IgAV-related deaths were associated with increase age.

CONCLUSION

Aging negatively impacts the severity and outcome of IgAV in adults. Younger patients have more frequent joint and gastrointestinal involvement, while old patients display more frequent severe purpura and glomerulonephritis.

Treatment and long-term outcome in primary nephrogenic diabetes insipidus

BACKGROUND

Primary nephrogenic diabetes insipidus (NDI) is a rare disorder and little is known about treatment practices and long-term outcome.

METHODS

Paediatric and adult nephrologists contacted through European professional organizations entered data in an online form.

RESULTS

Data were collected on 315 patients (22 countries, male 84%, adults 35%). Mutation testing had been performed in 270 (86%); pathogenic variants were identified in 258 (96%). The median (range) age at diagnosis was 0.6 (0.0-60) years and at last follow-up 14.0 (0.1-70) years. In adults, height was normal with a mean (standard deviation) score of -0.39 (±1.0), yet there was increased prevalence of obesity (body mass index >30 kg/m2; 41% versus 16% European average; P < 0.001). There was also increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (32%) and adults (48%). Evidence of flow uropathy was present in 38%. A higher proportion of children than adults (85% versus 54%; P < 0.001) received medications to reduce urine output. Patients ≥25 years were less likely to have a university degree than the European average (21% versus 35%; P = 0.003) but full-time employment was similar. Mental health problems, predominantly attention-deficit hyperactivity disorder (16%), were reported in 36% of patients.

CONCLUSION

This large NDI cohort shows an overall favourable outcome with normal adult height and only mild to moderate CKD in most. Yet, while full-time employment was similar to the European average, educational achievement was lower, and more than half had urological and/or mental health problems.

THU0040 PROTEINASE 3-REACTIVE B CELL RECONSTITUTION AFTER TREATMENT WITH RITUXIMAB FOR ANCA-ASSOCIATED VASCULITIS

Background:

Proteinase 3 (PR3)-reactive B cells are present in PR3-ANCA-associated vasculitis (AAV) at levels higher than healthy controls.

Objectives:

To evaluate the dynamics of the PR3-reactive B cell repopulation in patients with PR3-AAV after treatment with rituximab, and to analyze possible associations between these immunological changes and long-lasting remissions.

Methods:

We analyzed all available frozen peripheral blood mononuclear cells (n=148) from 23 randomly-selected PR3-AAV patients who participated in the RAVE trial and achieved complete remission (BVAS=0, prednisone=0) after treatment with rituximab.

We measured PR3-reactive B cells and the relative subsets by a multi-color flow cytometry panel including CD19, IgD, CD27, CD38, CD24, and a biotinylated PR3 revealed by fluorescent streptavidin. The clinical data of the trial were correlated with flow-cytometry data.

Results:

10/23 (43%) patients relapsed during the follow up, 8/10 relapses were severe. At baseline, clinical features, PR3-ANCA levels, % of total PR3-reactive B cells and PR3-reactive B cell subsets were similar between relapsers and non-relapsers. All patients were followed until the end of the trial, for a mean of 44 months (25-75%IQR 31-54), without difference in follow-up time between relapsers and non-relapsers (p=0.98).

The majority of patients had B cell repopulation at 12 (range 12-24) months after rituximab. At the time of B cell repopulation, transitional (CD19+CD24+CD38+) and naïve (CD19+CD27+IgD-) B cells were higher compared to baseline, while total plasmablasts (PB) were unchanged, and mature B cells significantly decreased in both relapsers and non relapsers. PR3-reactive B cells reappeared in all the patients, and the % of PR3-reactive of B cells were higher at the B cell repopulation visit compared to baseline (5.82% vs 4.25%, p<0.05), while total B cells were lower (66/μL vs 151/μL, p<0.01), regardless of future relapse.

Within PR3-reactive B cells, only the % of PB (CD19+CD27+CD38+PR3+) were higher in relapsers vs. non-relapsers (median [25-75%IQR]; 1.95% [1.315-3.845] vs 0.84% [0.05-1.66], p=0.022) and severe relapsers vs non-severe relapsers (2.165% [1.66-4.315] vs 0.84% [0.1-1.74], p=0.015). Time-to-relapse and time-to severe-relapse were significantly shorter in patients with circulating PR3-PB higher than the median value of the cohort (1.6%) during B cell reconstitution (Figure 1A-B).

Conclusion:

In PR3-AAV, during B cell reconstitution after rituximab, the total fraction of PR3-B cells increases, due to the expansion of the transitional and naïve B cell compartments. Circulating PR3-PB within PR3-B cells are enriched in the peripheral blood of relapsing and severely relapsing patients compared to non-relapsing patients. Higher levels of PR3-PB after rituximab during B cell reappearance significantly increased the risk of subsequent relapse and severe relapse.

References:

[1]Cornec D, Berti A, Hummel A, et al. J Autoimmun. 2017

Disclosure of Interests:

Alvise Berti: None declared, Sophie Hillion: None declared, Amber Hummel: None declared, Eva Carmona: None declared, Tobias Peikert: None declared, Carol Langford: None declared, Peter A. Merkel: None declared, Paul Monach: None declared, Philip Seo: None declared, Robert Spiera Grant/research support from: Roche-Genetech, GSK, Boehringer Ingelheim, Chemocentryx, Corbus, Forbius, Sanofi, Inflarx, Consultant of: Roche-Genetech, GSK, CSL Behring, Sanofi, Janssen, Chemocentryx, Forbius, Mistubishi Tanabe, E. William St. Clair: None declared, Fernando Fervenza: None declared, Kristina Harris: None declared, John H. Stone Grant/research support from: Roche, Consultant of: Roche, Jacques-Olivier Pers: None declared, Ulrich Specks: None declared, Divi Cornec: None declared

P0238LONG-TERM OUTCOME OF CHILDHOOD IDIOPATHIC NEPHROTIC SYNDROME

Background and Aims

Little is known about the long-term outcome of childhood idiopathic nephrotic syndrome (INS), in particular long-term complications, rate of relapses, frequency of prolonged steroid (S) and immunosuppressive treatment (IS). The choice of immunosuppressive drug remains discussed. Our aim was to study the long-term outcome in adulthood of patients with INS diagnosed during childhood.

Method

In this monocentric retrospective study, we included all adult patients (&gt;18 years) admitted in our nephrology department between 2013 and 2019 with INS diagnosed during childhood. Patients who reached ESRD during childhood were excluded. Data regarding the outcome in adulthood were obtained through clinical database and medical charts.

Results

Eighty-two patients (M/F = 2/1) were included. Sixty-height patients had steroid-sensitive nephrotic syndrome (SSNS), including 52 with steroid-dependant nephrotic syndrome (SDNS). The other 14 patients had steroid-resistant nephrotic syndrome (SRNS). The median age at diagnosis was 3.9 years (1.2-16.5). The median number of relapses during childhood was 12 (0-52), 0.9/patient/year. 89% of patients received IS therapy in addition to S during childhood: median number of successive therapeutic lines was 3 (0-10) per child.

Median follow-up during adulthood was 4.6 (0.1-25) years. 67% of patients experienced at least one relapse during adulthood, with a median number of relapses of 0.53 (0-3.7)/patient/year. Risk of relapse during adulthood was significantly associated with the total number of relapses during childhood (p=0.015) and with the number of relapses per year during childhood (p=0.007). 45% of patients received IS in addition to S during adulthood, mainly mycophenolate mofetil (23/82), calcineurin inhibitors (21/82) and rituximab (12/82). High blood pressure was observed in 22% of patients.

At last follow-up, median eGFR was 90 (64-117) mL/min/1.73m in SSNS patients, 86 (57-126) mL/min/1.73m in SDNS patients and 70 (23-113) mL/min/1.73m in SRNS patients. Only 4/82 patients presented with eGFR lower than 60 mL/min/1.73m. Among them, 3 had SRNS. Only 1 thrombo-embolic event and 3 severe infections were reported.

Bone densitometry was performed in 26 adult patients and osteopenia was found in 19 of them (73%).

Conclusion

The incidence of relapses in adulthood was relatively high in our study. However bias related to inclusion criteria could play a role. Whereas renal function remained normal in most patients, high blood pressure and osteopenia were frequent but major complications were rarely reported.

Clinicopathologic features of infection-related glomerulonephritis with IgA deposits: a French Nationwide study

Background

Infection-related glomerulonephritis with IgA deposits (IRGN-IgA) is a rare disease but it is increasingly reported in the literature. Data regarding epidemiology and outcome are lacking, especially in Europe. We aimed to assess the clinical, pathologic and outcome data of IRGN-IgA.

Methods

Clinical and outcome data from patients from 11 French centers over the 2007–2017 period were collected retrospectively. We reviewed pathologic patterns and immunofluorescence of renal biopsies and evaluated C4d expression in IRGN-IgA. We analyzed the correlation between histological presentation and outcome.

Results

Twenty-seven patients (23 men, mean age: 62 ± 15 years) were included. Twenty-one (78%) had Staphylococcus aureus infection and twelve (44%) were diabetic. At the time of biopsy, 95.2% had haematuria, 48.1% had a serum creatinine level of > 4 mg/dL, and 16% had hypocomplementemia. The most common pathologic presentation included mesangial (88.9%) and endocapillary proliferative glomerulonephritis (88.9%) with interstitial fibrosis and tubular atrophy (IF/TA) (85.1%). Diffuse and global glomerular C4d expression was found in 17.8%, mostly in biopsies with acute or subacute patterns, and was associated with a short delay between infection and renal biopsy compared to segmental and focal staining. After median follow-up of 13.2 months, 23.1% died, 46.2% had persistent renal dysfunction and 15.4% reached end-stage renal disease. Renal outcome was correlated to IF/TA severity.

Conclusions

Infection-related glomerulonephritis with IgA deposits is usually associated with Staphylococcus infections and mainly affects adult men. This entity has a poor prognosis which is correlated to interstitial fibrosis and tubular atrophy severity.

Central nervous system complications in adult cystinosis patients

Little is known about the long-term progression of adult nephropathic cystinosis patients. Our objective was to study central nervous system complications in cystinosis patients in the era of early cysteamine treatment, using advanced neuroimaging techniques. Neurological examination and multimodal brain 3 Tesla MRI were performed in 21 adult cystinosis patients, including 18 infantile cystinosis patients, 20 controls matched for age and renal function, and 12 healthy controls. Differences in gray matter volume and rest cerebral blood flow (CBF) using arterial spin labeling sequence were investigated using whole-brain voxel-based approach. Median age was 33.8 years (18.7-65.8). Seven patients (38.9%) presented with at least one central nervous system clinical abnormality: two (11.1%) with seizures, three (16.7%) with memory defects, five (27.8%) with cognitive defect, and one (5.5%) with stroke-like episode. These patients had a worse compliance to treatment (compliance score 2 vs 1, P = .03) and received a lower median cysteamine dose (0.9 g/day vs 2.1 g/day, P = .02). Among patients with infantile cystinosis, 13 (72.2%) showed cortical atrophy, which was absent in controls, but it was not correlated with symptoms. Cystinosis patients showed a significant gray matter decrease in the middle frontal gyrus compared with healthy controls and a significant negative correlation between the cystine blood level and rest CBF was observed in the right superior frontal gyrus, a region associated with executive function. Compliance to cysteamine treatment is a major concern in these adult patients and could have an impact on the development of neurological and cognitive complications.

Identification of genetic causes for sporadic steroid-resistant nephrotic syndrome in adults

Monogenic forms of Steroid-Resistant Nephrotic Syndrome (SRNS) have been widely characterized, but genetic screening paradigms preferentially address congenital, infantile onset, and familial cases. Our aim was to characterize the distribution of disease-causing gene mutations in adults with sporadic SRNS or focal segmental glomerulosclerosis (FSGS). We selected adult patients with non-syndromic, biopsy-proven FSGS or SRNS in the absence of known family history. Strict clinical criteria included lack of response to glucocorticoids and cyclosporine, and no recurrence after kidney transplantation. Mutations in SRNS genes were detected using a targeted gene panel. Sixteen of 135 tested participants (11.8%) carried pathogenic mutations in monogenic SRNS genes, and 14 others (10.4%) carried two APOL1 high-risk alleles. Autosomal recessive disease was diagnosed in 5 participants, autosomal dominant disease in 9, and X-linked disease in 2. Four participants carried a de novo heterozygous mutation. Among the 16 participants with identified mutations in monogenic SNRS genes, 7 (43.7%) had type IV collagen mutations. Mutations in monogenic SNRS genes were identified primarily in participants with proteinuria onset before 25 years of age, while the age at disease onset was variable in those with APOL1 high-risk genotype. Mean age at diagnosis was lower and renal survival was worse in participants with identified mutations in SNRS genes than in those without mutations. We found a significant rate of pathogenic mutations in adults with SRNS, with Type IV collagen mutations being the most frequent. These findings may have immediate impact on clinical practice.

Outcomes of Older Patients (≥60 years) with New-Onset Idiopathic Nephrotic Syndrome Receiving Immunosuppressive Regimen: A Multicentre Study of 116 Patients

Because of its rarity, renal presentation and outcomes of idiopathic nephrotic syndrome (INS; minimal changes disease or focal and segmental glomerulosclerosis) has poorly been described in elderly patients, precluding an individualized therapy procedure. Whether immunosuppressive regimens formerly designed in children and young adults are safe and efficient in elderly remains elusive. In a large multicentric retrospective study that included 116 patients with INS and onset ≥ 60 years of age, we showed that cumulative incidence of renal response was 95% after frontline therapy, with an age-dependent median time-to-response (60 days before 70 years of age at the onset vs. 120 days after; p = 0.03). Cumulative incidence of relapse was 90% at 7 years, with relapse occurring continuously over time. After a median follow-up of 34 months (IQR (12; 57)), 7 patients had died (6%) and 5 reached end-stage renal disease. Complications were highly prevalent: diabetes mellitus (23.3%), hypertension (24.1%), infection requiring hospitalization (21.6%) and acute kidney injury (9.5%). Thus, in older patients with INS and receiving steroids, renal response is delayed and relapse is the rule. Alternative immunosuppressive regimens, including B-cells depleting agents as frontline therapy, should be tested in this subset of patients to improve the mid- to long-term outcomes.

Whole exome sequencing resolves complex phenotype and identifies CC2D2A mutations underlying non-syndromic rod-cone dystrophy

Genetic investigations were performed in three brothers from a consanguineous union, the two oldest diagnosed with rod-cone dystrophy (RCD), the youngest with early-onset cone-rod dystrophy and the two youngest with nephrotic-range proteinuria. Targeted next-generation sequencing did not identify homozygous pathogenic variant in the oldest brother. Whole exome sequencing (WES) applied to the family identified compound heterozygous variants in CC2D2A (c.2774G>C p.(Arg925Pro); c.4730_4731delinsTGTATA p.(Ala1577Valfs*5)) in the three brothers with a homozygous deletion in CNGA3 (c.1235_1236del p.(Glu412Valfs*6)) in the youngest correcting his diagnosis to achromatopsia plus RCD. None of the three subjects had cerebral abnormalities or learning disabilities inconsistent with Meckel-Gruber and Joubert syndromes, usually associated with CC2D2A mutations. Interestingly, an African woman with RCD shared the CC2D2A missense variant (c.2774G>C p.(Arg925Pro); with c.3182+355_3825del p.(?)). The two youngest also carried compound heterozygous variants in CUBN (c.7906C>T rs137998687 p.(Arg2636*); c.10344C>G p.(Cys3448Trp)) that may explain their nephrotic-range proteinuria. Our study identifies for the first time CC2D2A mutations in isolated RCD and underlines the power of WES to decipher complex phenotypes.

Preoperative platelet transfusions to reverse antiplatelet therapy for urgent non-cardiac surgery: an observational cohort study

Essentials An increasing number of patients requiring surgery receive antiplatelet therapy (APT). We analyzed 181 patients receiving presurgery platelet transfusions to reverse APT. No coronary thrombosis occurred after platelet transfusion. This justifies a prospective trial to test preoperative platelet transfusions to reverse APT.

SUMMARY

Background Patients receiving antiplatelet therapy (APT) have an increased risk of perioperative bleeding and cardiac adverse events (CAE). Preoperative platelet transfusions may reduce the bleeding risk but may also increase the risk of CAE, particularly coronary thrombosis in patients after recent stent implantation. Objectives To analyze the incidence of perioperative CAE and bleeding in patients undergoing non-cardiac surgery using a standardized management of transfusing two platelet concentrates preoperatively and restart of APT within 24-72 h after surgery. Methods A cohort of consecutive patients on APT treated with two platelet concentrates before non-cardiac surgery between January 2012 and December 2014 was retrospectively identified. Patients were stratified by the risk of major adverse cardiac and cerebrovascular events (MACCE). The primary objective was the incidence of CAE (myocardial infarction, acute heart failure and cardiac troponine T increase). Secondary objectives were incidences of other thromboembolic events, bleedings, transfusions and mortality. Results Among 181 patients, 88 received aspirin, 21 clopidogrel and 72 dual APT. MACCE risk was high in 63, moderate in 103 and low in 15 patients; 67 had cardiac stents. Ten patients (5.5%; 95% CI, 3.0-9.9%) developed a CAE (three myocardial infarctions, four cardiac failures and three troponin T increases). None was caused by coronary thrombosis. Surgery-related bleeding occurred in 22 patients (12.2%; 95% CI, 8.2-17.7%), making 12 re-interventions necessary (6.6%; 95% CI, 3.8-11.2%). Conclusion Preoperative platelet transfusions and early restart of APT allowed urgent surgery and did not cause coronary thromboses, but non-thrombotic CAEs and re-bleeding occurred. Randomized trials are warranted to test platelet transfusion against other management strategies.

Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome

BACKGROUND

Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease.

METHODS

Clinical data were analyzed in 59 SSNS families. EMP2 gene was sequenced in families with a potential autosomal recessive (AR) inheritance. Exome sequencing was performed in a subset of 13 families with potential AR inheritance. Two variations in HLA-DQA1 were genotyped in the whole cohort.

RESULTS

Transmission was compatible with an AR (n = 33) or autosomal dominant (AD, n = 26) inheritance, assuming that familial SSNS is a monogenic trait. Clinical features did not differ between AR and AD groups. All patients, including primary (n = 7) and secondary steroid resistant nephrotic syndrone (SRNS), (n = 13) were sensitive to additional immunosuppressive therapy. Both HLA-DQA1 variations were found to be highly linked to the disease (OR = 4.34 and OR = 4.89; p < 0.001). Exome sequencing did not reveal any pathogenic mutation, neither did EMP2 sequencing.

CONCLUSIONS

Taken together, these results highlight the clinical and genetic heterogeneity in familial SSNS. Clinical findings sustain an immune origin in all patients, whatever the initial steroid-sensitivity. The absence of a variant shared by two families and the HLA-DQA1 variation enrichments suggest a complex mode of inheritance.

Proliferative lupus nephritis in the absence of overt systemic lupus erythematosus: A historical study of 12 adult patients

Severe lupus nephritis in the absence of systemic lupus erythematosus (SLE) is a rare condition with an unclear clinical presentation and outcome.We conducted a historical observational study of 12 adult (age >18 years) patients with biopsy-proven severe lupus nephritis or lupus-like nephritis without SLE immunological markers at diagnosis or during follow-up. Excluded were patients with chronic infections with HIV or hepatitis B or C; patients with a bacterial infectious disease; and patients with pure membranous nephropathy. Electron microscopy was retrospectively performed when the material was available. End points were the proportion of patients with a complete response (urine protein to creatinine ratio <0.5 g/day and a normal or near-normal eGFR), partial response (≥50% reduction in proteinuria to subnephrotic levels and a normal or near-normal eGFR), or nonresponse at 12 months or later after the initiation of the treatment.The study included 12 patients (66% female) with a median age of 36.5 years. At diagnosis, median creatinine and proteinuria levels were 1.21 mg/dL (range 0.5-11.6) and 7.5 g/day (1.4-26.7), respectively. Six patients had nephrotic syndrome and acute kidney injury. Renal biopsy examinations revealed class III or class IV A/C lupus nephritis in all cases. Electron microscopy was performed on samples from 5 patients. The results showed mesangial and subendothelial dense deposits consistent with LN in 4 cases, and a retrospective diagnosis of pseudo-amyloid fibrillary glomerulonephritis was made in 1 patient.Patients received immunosuppressive therapy consisting of induction therapy followed by maintenance therapy, similar to treatment for severe lupus nephritis. Remission was recorded in 10 patients at 12 months after the initiation of treatment. One patient reached end-stage renal disease. After a median follow-up of 24 months, 2 patients relapsed.Lupus nephritis in the absence of overt SLE is a nosological entity requiring careful etiological investigation, including systematic electron microscopy examination of renal biopsies to rule out fibrillary glomerulonephritis. In this series, most patients presented with severe glomerulonephritis, which was highly similar to lupus nephritis at presentation and in terms of response to immunosuppressive therapy.

A multicentre study of 95 biopsy-proven cases of renal disease in primary Sjögren's syndrome

Objective.

Renal involvement is a rare event during primary SS (pSS). We aimed to describe the clinico-biological and histopathological characteristics of pSS-related nephropathy and its response to treatment.

Methods.

We conducted a French nationwide, retrospective, multicentre study including pSS patients fulfilling American-European Consensus Group criteria or enlarged American-European Consensus Group criteria, and with biopsy-proven renal involvement.

Results.

A total of 95 patients were included (median age 49 years). An estimated glomerular filtration rate (eGFR) of <60 ml/min was found in 82/95 patients (86.3%). Renal biopsy demonstrated tubulointerstitial nephritis (TIN) in 93 patients (97.9%), and frequent (75%) plasma cell infiltrates. Glomerular lesions were found in 22 patients (23.2%), mainly related to cryoglobulin. The presence of anti-SSA (76.8%) and anti-SSB (53.8%) antibodies was particularly frequent among patients with TIN and was associated with a worse renal prognosis. Eighty-one patients (85.3%) were treated, with CSs in 80 (98.8%) and immunosuppressive agents (mostly rituximab) in 21 cases (25.9%). Despite marked interstitial fibrosis at initial biopsy, kidney function improved significantly during the 12-month period following diagnosis (final eGFR 49.9 vs 39.8 ml/min/1.73 m 2 at baseline, P < 0.001). No proven benefit of immunosuppressive agents over steroid therapy alone was found in this study.

Conclusion.

Renal involvement of pSS is mostly due to TIN with marked T, B and especially plasma cell infiltration. Renal dysfunction is usually isolated but can be severe. Use of CSs can improve the eGFR, but further studies are needed to define the best therapeutic strategy in this disease.

Renal involvement in lysinuric protein intolerance: contribution of pathology to assessment of heterogeneity of renal lesions

Lysinuric protein intolerance (LPI) is a rare autosomal recessive disease caused by mutations in the SLC7A7 gene encoding the light subunit of a cationic amino acid transporter. Symptoms mimic primary urea cycle defects but dysimmune symptoms are also described. Renal involvement in LPI was first described in the 1980s. In 2007, it appeared that it could concern as much as 75% of LPI patients and could lead to end-stage renal disease. The most common feature is proximal tubular dysfunction and nephrocalcinosis but glomerular lesions are also reported. However, very little is known regarding histological lesions associated with LPI. We gathered every kidney biopsy of LPI-proven patients in our highly specialized pediatric and adult institution. Clinical, biological, and histological information was analyzed. Five LPI patients underwent kidney biopsy in our institution between 1986 and 2015. Clinically, 4/5 presented with proximal tubular dysfunction and 3/5 with nephrotic range proteinuria. Histology showed unspecific tubulointerstitial lesions and nephrocalcinosis in 3/5 biopsies and marked peritubular capillaritis in one child. Glomerular lesions were heterogeneous: lupus-like-full house membranoproliferative glomerulonephritis (MPGN) in one child evolved towards monotypic IgG1κ MPGN sensitive to immunomodulators. One patient presented with glomerular non-AA non-AL amyloidosis. Renal biopsy is particularly relevant in LPI presenting with glomerular symptoms for which variable histological lesions can be responsible, implying specific treatment and follow-up.

Case report and literature review: Glomerular and neurologic thrombotic microangiopathy as a primary manifestation of multicentric castleman disease

INTRODUCTION

We report the case of a multicentric Castleman disease (MCD) with initial renal involvement. Although the renal involvement in this case was typical of MCD, it constitutes a rare presentation of the disease, and in our case the renal manifestations led to the haematological diagnosis.

CLINICAL FINDINGS/PATIENT CONCERNS

The patient was admitted for fever, diarrhea, anasarca, lymphadenopathies and acute renal failure. Despite intravenous rehydration using saline and albumin, renal function worsened and the patient required dialysis. While diagnostic investigations were performed, right hemiplegia occurred. There was no anemia or thrombocytopenia.

DIAGNOSES

Kidney biopsy was consistent with glomerular thrombotic microangiopathy (TMA). Lymph node histology was consistent with hyalin-vascular variant of Castleman disease.

OUTCOMES

Given the renal and neurological manifestations of this MCD-associated TMA, the patient was treated with plasma exchange during one month, and six courses of rituximab, cyclophosphamide and dexamethasone. The evolution was favorable.

CONCLUSION

Although rare, this diagnosis is worth knowing, as specific treatment has to be started as soon as possible and proved to be efficient in our case as well as in other reports in the literature.

Atypical haemolytic uraemic syndrome and pregnancy: outcome with ongoing eculizumab

BACKGROUND

A therapeutic strategy based on complement blockade by eculizumab is widely used to treat atypical haemolytic uraemic syndrome (aHUS). Recent data are available on the administration of eculizumab during pregnancy in patients treated for paroxysmal nocturnal haemoglobinuria but there are very few data for aHUS patients.

METHODS

We analysed the use of eculizumab for the treatment of aHUS during five pregnancies in three patients and studied an additional pregnancy without eculizumab. Obstetrical data and maternal and foetal complications during pregnancy, at delivery, and during the post-partum period were recorded.

RESULTS

The mean age at pregnancy was 28.5 (range 25-33) years. The mean serum creatinine before pregnancy was 189 (range 130-300) µmol/L and the mean eGFR was 32 (range 18-45) mL/min/1.73 m². One patient who stopped eculizumab 3 weeks after conception had a termination due to a relapse of HUS at 12 weeks of gestation (WG) during a first pregnancy and an intrauterine death at 24 WG despite continuous eculizumab treatment during a second pregnancy. In the other four pregnancies, treatment stabilized clinical and laboratory markers until 29-34 WG, but did not prevent hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome in one patient or pre-eclampsia in two other patients. All babies were born preterm and two presented with growth retardation. The mean body weight was 1632.5 (range 1070-2500) g. The dose of eculizumab had to be increased during all pregnancies due to incomplete complement blockade.

CONCLUSIONS

Eculizumab therapy during pregnancy displayed no overt safety issues but did not appear to prevent HELLP syndrome or pre-eclampsia in these high-risk chronic kidney disease patients.