Rationale and design of the Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study.

INTRODUCTION: Disease subtyping and monitoring are essential for the management of nephrotic syndrome (NS). Although various biomarkers for NS have been reported, their clinical efficacy has not been comprehensively validated in adult Japanese patients. METHODS: The Japanese Biomarkers in Nephrotic Syndrome (J-MARINE) study is a nationwide, multicenter, and prospective cohort study in Japan, enrolling adult (≥18 years) patients with minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), membranoproliferative glomerulonephritis (MPGN), C3 glomerulopathy (C3G), and lupus nephritis (LN). Baseline clinical information and plasma and urine samples will be collected at the time of immunosuppressive therapy initiation or biopsy. Follow-up data and plasma and urine samples will be collected longitudinally based on the designated protocols. Candidate biomarkers will be measured: CD80, cytotoxic T-lymphocyte antigen 4, and soluble urokinase plasminogen activator receptor for MCD and FSGS; anti-phospholipase A2 receptor and thrombospondin type-1 domain-containing protein 7A antibodies for MN; fragment Ba, C3a, factor I, and properdin for MPGN/C3G; and CD11b, CD16b, and CD163 for LN. Outcomes include complete and partial remission, relapse of proteinuria, a 30% reduction in estimated glomerular filtration rate (eGFR), eGFR decline, and initiation of renal replacement therapy. The diagnostic accuracy and predictive ability for clinical outcomes will be assessed for each biomarker. RESULTS: From April 2019 to April 2023, 365 patients were enrolled: 145, 21, 138, 10, and 51 cases of MCD, FSGS, MN, MPGN/C3G, and LN, respectively. CONCLUSION: This study will provide valuable insights into biomarkers for NS and serve as a biorepository for future studies.

Detecting and exploring kidney-derived extracellular vesicles in plasma.

BACKGROUND: Extracellular vesicles (EVs) have received considerable attention as ideal biomarkers for kidney diseases. Most reports have focused on urinary EVs, that are mainly derived from the cells in the urinary tract. However, the detection and the application of kidney-derived EVs in plasma remains uncertain. METHODS: We examined the kidney-derived small EVs (sEVs) in plasma that were supposedly released from renal mesangial and glomerular endothelial cells, using clinical samples from healthy controls and patients with kidney transplants. Plasma from healthy controls underwent ultracentrifugation, followed by on-bead flow cytometry, targeting α8 integrin, an antigen-specific to mesangial cells. To confirm the presence of kidney-derived sEVs in peripheral blood, plasma from ABO-incompatible kidney transplant recipients was ultracentrifuged, followed by western blotting for donor blood type antigens. RESULTS: Immunohistochemistry and immunoelectron microscopy confirmed α8 integrin expression in kidney mesangial cells and their sEVs. The CD9-α8 integrin double-positive sEVs were successfully detected using on-bead flow cytometry. Western blot analysis further revealed transplanted kidney-derived sEVs containing blood type B antigens in non-blood type B recipients, who had received kidneys from blood type B donors. Notably, a patient experiencing graft kidney loss exhibited diminished signals of sEVs containing donor blood type antigens. CONCLUSION: Our findings demonstrate the potential usefulness of kidney-derived sEVs in plasma in future research for kidney diseases.

Application of a scoring system in Japanese patients diagnosed with atypical hemolytic uremic syndrome to assess the relationship between the score and clinical responses to eculizumab.

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is caused by complement dysregulation and is generally diagnosed by exclusion from other disorders of thrombotic microangiopathy (TMA). Eculizumab, a terminal complement inhibitor, has been approved for aHUS treatment since 2013 in Japan. Recently, a scoring system was published to support diagnosis of aHUS. Herein we modified this scoring system to apply it to patients diagnosed with aHUS and treated with eculizumab, and assessed the association between the score and clinical responses to eculizumab. METHODS: One hundred eighty-eight Japanese patients who were clinically diagnosed with aHUS, treated with eculizumab, and enrolled in post-marketing surveillance (PMS) were included in this analysis. Some of parameters in the original scoring system were replaced with clinically similar parameters collected in the PMS to modify the system, hereafter referred to as the TMA/aHUS score, which ranges from -15 to 20 points. Treatment responses within 90 days after eculizumab initiation were also assessed, and the relationship between treatment response and TMA/aHUS scores calculated at TMA onset was explored. RESULTS: The median (range) TMA/aHUS score was 10 (3-16). Receiver operating characteristic curve analysis showed that the cutoff value of TMA/aHUS score to predict treatment response to eculizumab was estimated as 10, and negative predictive value indicated that ≥ 5 points was appropriate to consider assessing the treatment response to eculizumab; 185 (98%) patients had ≥ 5 points and 3 (2%) had < 5 points. Among the patients with ≥ 5 points, 96.1% showed partial response and 31.1% showed complete response. One of the three patients with < 5 points met partial response criteria. No significant difference in the TMA/aHUS scores was observed between survivors and non-survivors, suggesting that the score was not appropriate to predict the outcome (i.e., survival/death) in patients treated with eculizumab. CONCLUSION: Almost all patients clinically diagnosed with aHUS scored ≥ 5 points and responded to eculizumab. The TMA/aHUS score system could become a supporting tool for the clinical diagnosis of aHUS and probability of response to treatment with a C5 inhibitor. TRIAL REGISTRATION: This study was conducted as per good PMS practice guidelines for drugs (MHLW Ministerial Ordinance No. 171 of 2004).

Basigin is released in extracellular vesicles derived from the renal tubular epithelium in response to albuminuria.

AIM: Irrespective of the cause, albumin/proteinuria induces tubulointerstitial damage and accelerates the progression of kidney diseases. Our series of studies demonstrated that proteinuria, an independent prognostic factor for chronic kidney disease (CKD), is correlated with urinary basigin/CD147 (Bsg) levels. We examined the morphology and origin of Bsg in the tubular lumen through the effects of filtered glucose and protein solutes on the tubules. METHODS: Diabetic kidney disease (DKD) patients (N = 50) were treated with spironolactone 25 mg for 4 weeks or by conservative treatment. The associations between urinary Bsg values and clinical indicators were examined. Primary-cultured proximal tubular epithelial cells (PTECs) from human adult kidneys were exposed to high glucose or bovine serum albumin (BSA). RESULTS: In patients with early phase DKD, urinary Bsg levels were closely correlated with proteinuria but not HbA1c. Full-length Bsg on extracellular vesicles (EVs) was investigated primarily in urine collected from DKD patients. EVs obtained from the urine of DKD patients included Bsg and SGLT2 proteins. Notably, spironolactone treatment concomitantly suppressed the release of Bsg-bearing EVs in correlation with decreased albuminuria. Exposure of PTECs to BSA (but not high glucose) enhanced the storage of supernatant Bsg in EVs despite the absence of exposure-specific changes in Bsg transcription. CONCLUSION: Proteinuria induces the release of Bsg-bearing EVs derived from PTECs into the tubular lumen.

Systematic characterization of seed overlap microRNA cotargeting associated with lupus pathogenesis.

BACKGROUND: Combinatorial gene regulation by multiple microRNAs (miRNAs) is widespread and closely spaced target sites often act cooperatively to achieve stronger repression ("neighborhood" miRNA cotargeting). While miRNA cotarget sites are suggested to be more conserved and implicated in developmental control, the pathological significance of miRNA cotargeting remains elusive. RESULTS: Here, we report the pathogenic impacts of combinatorial miRNA regulation on inflammation in systemic lupus erythematosus (SLE). In the SLE mouse model, we identified the downregulation of two miRNAs, miR-128 and miR-148a, by TLR7 stimulation in plasmacytoid dendritic cells. Functional analyses using human cell lines demonstrated that miR-128 and miR-148a additively target KLF4 via extensively overlapping target sites ("seed overlap" miRNA cotargeting) and suppress the inflammatory responses. At the transcriptome level, "seed overlap" miRNA cotargeting increases susceptibility to downregulation by two miRNAs, consistent with additive but not cooperative recruitment of two miRNAs. Systematic characterization further revealed that extensive "seed overlap" is a prevalent feature among broadly conserved miRNAs. Highly conserved target sites of broadly conserved miRNAs are largely divided into two classes-those conserved among eutherian mammals and from human to Coelacanth, and the latter, including KLF4-cotargeting sites, has a stronger association with both "seed overlap" and "neighborhood" miRNA cotargeting. Furthermore, a deeply conserved miRNA target class has a higher probability of haplo-insufficient genes. CONCLUSIONS: Our study collectively suggests the complexity of distinct modes of miRNA cotargeting and the importance of their perturbations in human diseases.

X-chromosome inactivation patterns in females with Fabry disease examined by both ultra-deep RNA sequencing and methylation-dependent assay.

BACKGROUND: Fabry disease is an X-linked inherited lysosomal storage disorder caused by mutations in the gene encoding α-galactosidase A. Males are usually severely affected, while females have a wide range of disease severity. This variability has been assumed to be derived from organ-dependent skewed X-chromosome inactivation (XCI) patterns in each female patient. Previous studies examined this correlation using the classical methylation-dependent method; however, conflicting results were obtained. This study was established to ascertain the existence of skewed XCI in nine females with heterozygous pathogenic variants in the GLA gene and its relationship to the phenotypes. METHODS: We present five female patients from one family and four individual female patients with Fabry disease. In all cases, heterozygous pathogenic variants in the GLA gene were detected. The X-chromosome inactivation patterns in peripheral blood leukocytes and cells of urine sediment were determined by both classical methylation-dependent HUMARA assay and ultra-deep RNA sequencing. Fabry Stabilization Index was used to determine the clinical severity. RESULTS: Skewed XCI resulting in predominant inactivation of the normal allele was observed only in one individual case with low ⍺-galactosidase A activity. In the remaining cases, no skewing was observed, even in the case with the highest total severity score (99.2%). CONCLUSION: We conclude that skewed XCI could not explain the severity of female Fabry disease and is not the main factor in the onset of various clinical symptoms in females with Fabry disease.

CD147/Basigin Deficiency Prevents the Development of Podocyte Injury through FAK Signaling.

Podocytes, which are susceptible to injury by various stimuli and stress, are critical regulators of proteinuric kidney diseases, regardless of the primary disease and pathogenesis. We further confirmed a significant correlation between urinary CD147/basigin (Bsg) levels and proteinuria in patients with focal segmental glomerulosclerosis. However, the molecular mechanism of podocyte injury involving Bsg is not fully understood. Here, the involvement of Bsg in the pathogenesis of podocyte injury was elucidated. Healthy podocytes rarely express Bsg protein. In two independent mouse models, including adriamycin-induced nephropathy and Nω-nitro-l-arginine methyl ester (l-name)-induced endothelial dysfunction, Bsg induction in injured podocytes caused podocyte effacement, which led to development of proteinuria. Bsg silencing in cultured podocytes exposed to transforming growth factor-ß suppressed focal adhesion rearrangement and cellular motility via the activation of ß1 integrin-focal adhesion kinase-matrix metallopeptidase signaling. In addition, induction of vascular endothelial growth factor and endothelin-1, which are implicated in podocyte-to-endothelial cross-communication, was lower in the supernatants of cultured Bsg-silenced podocytes stimulated with transforming growth factor-ß. In this setting, Bsg may be involved in a physiological positive feedback loop that accelerates podocyte cell motility and depolarization. The current study thus suggests that Bsg silencing via suppression of ß1 integrin-focal adhesion kinase-matrix metallopeptidase signaling may be an attractive therapeutic strategy for the maintenance of podocytes in patients with proteinuric kidney diseases.

miR-146a targeted to splenic macrophages prevents sepsis-induced multiple organ injury.

Development of a novel agent against life-threatening sepsis requires the in-depth understanding of the relevant pathophysiology and therapeutic targets. Given the function of microRNAs (miRNAs) as potent oligonucleotide therapeutics, here we investigated the pathophysiological role of exogenously applied miRNA in sepsis-induced multiple organ injury. In vitro, miR-16, miR-126, miR-146a, and miR-200b suppressed the production of pro-inflammatory cytokines in RAW264.7 macrophage cells after lipopolysaccharide (LPS) stimulation. Of these, miR-146a displayed the most highly suppressive effect, wherein the transcriptional activity of nuclear factor kappa B (NF-κB) was decreased via targeting of interleukin 1 receptor-associated kinase 1 and tumor necrosis receptor-associated factor 6. Sepsis was induced in mice via cecal ligation and puncture (CLP) and an intravenous injection of a complex of miR-146a-expressing plasmid and polyethyleneimine. Treatment with this complex significantly decreased the level of serum inflammatory cytokines, attenuated organ injury including kidney injury, and led to increased survival from polymicrobial sepsis induced by CLP. miR-146a-expressing plasmid was abundantly distributed in splenic macrophages, but not in renal parenchymal cells. CLP mice treated with miR-146a displayed significantly decreased NF-κB activation and splenocyte apoptosis. Splenectomy diminished the anti-inflammatory effects of miR-146a. The collective results support the conclusion that the induction of miR-146a expression in splenic macrophages prevents excessive inflammation and sepsis-induced multiple organ injury. This study establishes a novel and critical pathophysiological role for splenic macrophage interference in sepsis-related organ injury.

Therapeutic efficacy of rituximab for the management of adult-onset steroid-dependent nephrotic syndrome: a retrospective study.

BACKGROUND: Recent reports have described the efficacy of rituximab in treating steroid-dependent nephrotic syndrome (SDNS) in pediatric patients. However, few reports describe data regarding adult-onset SDNS. We investigated the efficacy of rituximab for the management of adult-onset SDNS. METHODS: We performed a retrospective cohort study investigating eight patients with adult-onset SDNS who were treated with rituximab. Clinical data were obtained at the initiation of rituximab therapy. The primary outcomes evaluated were successful suppression of relapses and CD19+ cells after rituximab treatment. The corticosteroid- and immunosuppressant-sparing effect and adverse events were additionally evaluated. RESULTS: All eight patients were diagnosed with minimal change nephrotic syndrome and received immunosuppressants in addition to corticosteroid. Total number of relapses was 10.5 times as a median value. Rituximab administration was repeated in two patients, whereas six received single-dose rituximab. Three of eight (37.5%) patients showed relapse after rituximab therapy. A rituximab-induced depletion in CD19+ cells noted initially was followed by their reappearance in all patients. There were cases with no relapse after the reappearance of CD19+ cells. The median relapse time pre- and post-rituximab therapy showed a decrease from 1 time/year (interquartile range [IQR] 1-3 times/year) to 0 time/year (IQR 0-1 time/year). Rituximab treatment induced a significant reduction in the required doses of corticosteroid and cyclosporine (P < 0.01). No serious adverse events were observed. CONCLUSION: Rituximab treatment was effective not only in childhood-onset but also in adult-onset SDNS. Further studies are needed to establish optimal treatment regimens.

Growth Factor Midkine Promotes T-Cell Activation through Nuclear Factor of Activated T Cells Signaling and Th1 Cell Differentiation in Lupus Nephritis.

Activated T cells play crucial roles in the pathogenesis of autoimmune diseases, including lupus nephritis (LN). The activation of calcineurin/nuclear factor of activated T cells (NFAT) and STAT4 signaling is essential for T cells to perform various effector functions. Here, we identified the growth factor midkine (MK; gene name, Mdk) as a novel regulator in the pathogenesis of 2,6,10,14-tetramethylpentadecane-induced LN via activation of NFAT and IL-12/STAT4 signaling. Wild-type (Mdk+/+) mice showed more severe glomerular injury than MK-deficient (Mdk-/-) mice, as demonstrated by mesangial hypercellularity and matrix expansion, and glomerular capillary loops with immune-complex deposition. Compared with Mdk-/- mice, the frequency of splenic CD69+ T cells and T helper (Th) 1 cells, but not of regulatory T cells, was augmented in Mdk+/+ mice in proportion to LN disease activity, and was accompanied by skewed cytokine production. MK expression was also enhanced in activated CD4+ T cells in vivo and in vitro. MK induced activated CD4+ T cells expressing CD69 through nuclear activation of NFAT transcription and selectively increased in vitro differentiation of naive CD4+ T cells into Th1 cells by promoting IL-12/STAT4 signaling. These results suggest that MK serves an indispensable role in the NFAT-regulated activation of CD4+ T cells and Th1 cell differentiation, eventually leading to the exacerbation of LN.

Investigation on the benefits of mycophenolate mofetil and therapeutic drug monitoring in the treatment of Japanese patients with lupus nephritis.

BACKGROUND: Mycophenolate mofetil (MMF) is recommended as a first-line immunosuppressant to treat lupus nephritis (LN). Prognosis and therapeutic response in LN are known to vary depending on race. We investigated the benefits of MMF and therapeutic drug monitoring (TDM) in the treatment of Japanese LN patients. METHODS: In this retrospective cohort study, a total of 20 patients with LN who started MMF treatment were included. Clinical data were collected regularly after MMF administration. We evaluated complete remission (CR) rate as the primary outcome. Predictors of CR were identified using univariate and multivariate analyses. In the research of TDM, the correlation with the area under the curve (AUC) was analyzed at MMF dose, single-point value, treatment response, and adverse events. RESULTS: Overall, 70% of cases showed CR; both flare-ups and refractory cases had favorable results. Cases of LN with nephrotic syndrome (NS) or class III/IV + V showed a significantly lower CR rate (p < 0.005). The ratio of maintaining CR after MMF therapy was as high as 85.7%. In multivariate analysis, NS was an independent negative predictor of CR (HR 0.09, 95% confidence interval 0.01-0.81; p = 0.03). The relationship between AUC and MMF dose was low, and AUC correlated with trough level (r = 0.73). AUC tended to be high in the treatment responder (p = 0.09), but did not correlate with adverse events of infection (p = 0.92). CONCLUSION: MMF is a beneficial treatment option for Japanese LN patients, and further investigation on TDM-based therapy is needed.

The clinical relevance of plasma CD147/basigin in biopsy-proven kidney diseases.

BACKGROUND: Precise understanding of kidney disease activity is needed to design therapeutic strategies. CD147/basigin is involved in the pathogenesis of acute kidney injury and renal fibrosis through inflammatory cell infiltration. The present study examined the clinical relevance of CD147 in biopsy-proven kidney diseases that lead to the progression of chronic kidney disease. METHODS: Kidney biopsy specimens and plasma and urine samples were obtained from patients with kidney diseases, including IgA nephropathy (IgAN), Henoch-Schönlein purpura nephritis (HSPN), diabetic kidney disease (DKD), focal segmental glomerulosclerosis (FSGS), and membranous nephropathy (MN), who underwent renal biopsy between 2011 and 2014. Plasma and urinary CD147 levels were measured and evaluated for their ability to reflect histological features. Disease activity of IgAN tissues was evaluated according to the Oxford classification and the Japanese histological grading system. RESULTS: In biopsy tissues, CD147 induction was detected in injured lesions representing renal inflammation. Plasma CD147 values correlated with eGFR in patients with inflammation-related kidney diseases such as IgAN, HSPN, and DKD. Particularly in IgAN patients, plasma CD147 levels were correlated with injured regions comprising more than 50% of glomeruli or with tubular atrophy/interstitial injury in biopsy tissues. Proteinuria showed a closer correlation with urinary values of CD147 and L-FABP. Of note, plasma and urinary CD147 levels showed a strong correlation with eGFR or proteinuria, respectively, only in DKD patients. CONCLUSION: Evaluation of plasma and urinary CD147 levels might provide key insights for the understanding of the activity of various kidney diseases.

The efficacy of tolvaptan as a diuretic for chronic kidney disease patients.

BACKGROUND: Tolvaptan selectively binds to the vasopressin V2 receptor and inhibits reabsorption of free water. Although its efficacy for heart failure has been proven, its efficacy for chronic kidney disease (CKD) patients has not been assessed in detail. METHODS: We examined 20 CKD patients (13 men and 7 women) who presented with volume overload and who were administered tolvaptan. We assessed urine volume (UV) and blood biochemistry before administration (dO), 1 day after administration (d1), and 7 to 14 days after administration (d7-14). RESULTS: The mean age was 74.0 +/- 13.1 years. Besides CKD, there were 9, 8, and 5 patients with heart failure, liver failure or liver cirrhosis, andsevere oedema, respectively. UV significantly increased from 959.0 +/- 503.8 mL/day at d0 to 1605.4 +/- 964.0 mL/day at d7-14 (P<0.01). Serum creatinine levels were not exacerbated (3.89 +/- 3.43 mg/dL at d0 and 3.66 +/- 3.02 mg/dL at d7-14). Serum albumin (ALB) levels and urinary protein creatinine ratio (uPCR) did not correlate with UV change. Estimated glomerular filtration rate (eGFR) correlated with UV change from d0 to d1 (r=0.6619, P<0.01). Serum sodium elevation correlated with increased UV (r=0.4951, P<0.05). CONCLUSION: Tolvaptan is useful to reduce volume overload without exacerbation of the renal function; its effect does not depend on ALB or uPCR. the eGFR correlated with the efficacy of tolvaptan. If UV increases drastically after tolvaptan administration, serum Na levels should be carefully monitored.

Deficiency of growth factor midkine exacerbates necrotizing glomerular injuries in progressive glomerulonephritis.

Inflammatory cell infiltration and fibrin deposition play important roles in the development of crescentic glomerulonephritis (GN). In particular, activation of coagulation is an indispensable factor in crescent formation. However, the mechanisms underlying the pathogenesis of crescent formation have not been completely elucidated. We identified the growth factor midkine (MK) as a novel key molecule in the progression of crescentic GN induced by anti-glomerular basement membrane antibody. Despite the lack of significant differences in autologous and heterologous reactions, MK-deficient (Mdk(-/-)) mice unexpectedly showed a greater number of necrotizing glomerular injuries than wild-type (Mdk(+/+)) mice. Likewise, more tubulointerstitial damage was observed in Mdk(-/-) mice, and this damage positively correlated with glomerular injury. Plasminogen activator inhibitor (PAI)-1 was strongly induced in the injured glomerulus of Mdk(-/-) mice, particularly in crescents and endothelial cells. This enhanced PAI-1 production was associated with an increase in inflammatory cell infiltration and matrix deposition in the glomerulus and the interstitium of Mdk(-/-) mice. In line with these in vivo data, primary cultured endothelial cells derived from Mdk(-/-) mice exhibited higher PAI-1 mRNA expression on fibrin challenge and less fibrinolysis than Mdk(+/+) mice. In contrast, the expression of plasminogen activators was not affected. Our combined data suggest that MK leads to a blockade of PAI-1, which is closely associated with the suppression of crescentic GN.

CD147/basigin reflects renal dysfunction in patients with acute kidney injury.

BACKGROUND: Acute tubular necrosis (ATN) describes a form of intrinsic acute kidney injury (AKI) that results from persistent hypoperfusion and subsequent activation of the immune system. A glycosylated transmembrane protein, CD147/basigin, is involved in the pathogenesis of renal ischemia and fibrosis. The present study investigated whether CD147 can reflect pathological features and renal dysfunction in patients with AKI. METHODS: Plasma and spot urine samples were collected from 24 patients (12 controls and 12 with ATN) who underwent renal biopsy between 2008 and 2012. In another study, patients undergoing open surgery to treat abdominal aortic aneurysms (AAAs) were enrolled in 2004. We collected urine and plasma samples from seven patients with AKI and 33 patients without AKI, respectively. In these experiments, plasma and urinary CD147, and urinary L-fatty acid-binding protein (L-FABP) levels were measured, and the former expression in kidneys was examined by immunostaining. RESULTS: In biopsy tissues of ATN with severe histological features, CD147 induction was strikingly present in inflammatory cells such as macrophages and lymphocytes in the injured interstitium, but not in damaged tubules representing atrophy. Both plasma and urinary CD147 levels were strikingly increased in ATN patients; both values showed greater correlations with renal dysfunction compared to urinary L-FABP. In patients who had undergone open AAA surgery, urinary and plasma CD147 values in AKI patients were significantly higher than in non-AKI patients at post-operative day 1, similar to the profile of urinary L-FABP. CONCLUSION: CD147 was prominent in its ability to detect AKI and may allow the start of preemptive medication.

TGF-ß1-containing exosomes from injured epithelial cells activate fibroblasts to initiate tissue regenerative responses and fibrosis.

Hypoxia is associated with tissue injury and fibrosis but its functional role in fibroblast activation and tissue repair/regeneration is unknown. Using kidney injury as a model system, we demonstrate that injured epithelial cells produce an increased number of exosomes with defined genetic information to activate fibroblasts. Exosomes released by injured epithelial cells promote proliferation, α-smooth muscle actin expression, F-actin expression, and type I collagen production in fibroblasts. Fibroblast activation is dependent on exosomes delivering TGF-ß1 mRNA among other yet to be identified moieties. This study suggests that TGF-ß1 mRNA transported by exosomes constitutes a rapid response to initiate tissue repair/regenerative responses and activation of fibroblasts when resident parenchyma is injured. The results also inform potential utility of exosome-targeted therapies to control tissue fibrosis.

Clinical characteristics of anti-GBM disease with thrombotic microangiopathy: a case report and literature review.

The coexistence of anti-glomerular basement membrane (anti-GBM) disease with thrombotic microangiopathy (TMA) is rarely encountered, and the clinical characteristics of this phenomenon are not well known.A 76-year-old Japanese woman with a history of idiopathic pulmonary disease was diagnosed with anti-GBM disease due to rapidly progressive glomerulonephritis and a positive anti-GBM antibody test result. We treated the patient with hemodialysis, glucocorticoids, and plasmapheresis. During treatment, the patient suddenly became comatose. TMA was then diagnosed because of thrombocytopenia and microangiopathic hemolytic anemia. The activity of a disintegrin-like and metalloproteinase with thrombospondin type 1 motif 13 (ADAMTS-13) was retained at 48%. Although we continued the treatment, the patient died of respiratory failure. An autopsy revealed the cause of respiratory failure to be an acute exacerbation of interstitial pneumonia. The clinical findings of the renal specimen indicated anti-GBM disease; however, there were no lesions suggestive of TMA. A genetic test did not reveal an apparent genetic mutation of the atypical hemolytic uremic syndrome.We conducted a literature review of past case reports of anti-GBM disease with TMA. The following clinical characteristics were obtained. First, 75% of the cases were reported in Asia. Second, TMA tended to appear during the treatment course for anti-GBM disease and usually resolved within 12 weeks. Third, ADAMTS-13 activity was retained above 10% in 90% of the cases. Fourth, central nervous system manifestations occurred in more than half of the patients. Fifth, the renal outcome was very poor. Further studies are required to understand the pathophysiology of this phenomenon.

Association of calciprotein particles with serum phosphorus among patients undergoing conventional and extended-hours haemodialysis.

Background and hypothesis: Extended-hours haemodialysis (HD) is associated with better clinical outcomes than conventional HD. We investigated whether extended-hours HD and conventional HD have varying effects on blood levels of calciprotein particles (CPPs) and phosphorus, which have been identified as major pathogenic molecules for vascular calcification. Methods: Patients who underwent conventional or extended in-centre daytime HD between January and March 2020 were included. Plasma CPP levels, representing only secondary CPPs (CPP-II), were measured in pre-dialysis samples. Linear and non-linear associations between CPPs and serum phosphorus levels were examined across dialysis modalities. Results: A total of 382 participants (185 undergoing extended-hours HD and 197 undergoing conventional HD) were included in the analysis. The median age of participants was 71 years, 65% of the patients were men and the mean phosphorus level was 5.4 mg/dl. Plasma CPP (CPP-II) levels were lower in the extended-hours HD group than in the conventional HD group [40 018 (arbitrary units) AU versus 75 728 AU; P < .01]. Multivariable linear regression analysis showed that extended-hours HD was associated with lower natural logarithmic plasma CPP (CPP-II) levels: -0.64 (95% confidence interval -0.74 to -0.55). A restricted cubic spline function indicated that extended-hours HD was associated with lower plasma CPP (CPP-II) levels across levels of serum phosphorus, with significant differences observed between groups, especially in hyperphosphataemic conditions (P for interaction <.01). Conclusions: The extended-hours HD group had lower CPP levels than the conventional HD group despite no significant differences in serum phosphorus levels, which may contribute to better clinical outcomes in patients on extended-hours HD.

Eculizumab for adult patients with atypical haemolytic-uraemic syndrome: full dataset analysis of Japanese post-marketing surveillance.

BACKGROUND: Eculizumab has been approved for atypical haemolytic-uraemic syndrome (aHUS) in Japan since 2013. Post-marketing surveillance enrolled patients with aHUS who received ≥ 1 dose of eculizumab to assess eculizumab safety and effectiveness. METHODS: We evaluated serious adverse events and effectiveness endpoints, i.e., haematologic normalization, a decrease of ≥ 25% in serum creatinine (sCr) levels, and complete thrombotic microangiopathy (TMA) response in adult patients with aHUS without other underlying diseases. In addition, the difference of baseline characteristics between patients who did and did not meet effectiveness endpoints was examined. RESULTS: In this safety and effectiveness analysis, 79 adult patients were included; median age was 54.0 years, median treatment duration was 30 weeks. Total exposure time of eculizumab was 75.51 patient-years, and 94 serious adverse events were reported in 39 patients. No unexpected safety signals were identified in this population. Mean platelet count, lactate dehydrogenase and estimated glomerular filtration rate significantly improved after 7 days of treatment. Complete TMA response, haematologic normalization and the improvement of sCr levels were met by 35.3%, 40.4% and 51.3% of patients, respectively. Median treatment duration was shorter in patients who did not achieve complete TMA response (6 weeks) than in patients who did (114 weeks). Multivariate analysis suggested that the time from the most recent TMA episode to start of eculizumab treatment was negatively associated with kidney function improvement. CONCLUSIONS: No unexpected safety signals of eculizumab were identified in Japanese patients with aHUS in a real-world setting. Renal outcomes were negatively associated with the time from the most recent TMA episode to the initiation of eculizumab treatment.

Case report: A family of atypical hemolytic uremic syndrome involving a CFH::CFHR1 fusion gene and CFHR3-1-4-2 gene duplication.

Mutations in the complement factor H (CFH) gene are associated with complement dysregulation and the development of atypical hemolytic uremic syndrome (aHUS). Several fusion genes that result from genomic structural variation in the CFH and complement factor H-related (CFHR) gene regions have been identified in aHUS. However, one allele has both CFHR gene duplication and CFH::CFHR1 fusion gene have not been reported. An 8-month-old girl (proband) presented with aHUS and was treated with ravulizumab. Her paternal grandfather developed aHUS previously and her paternal great grandmother presented with anti-neutrophil cytoplasmic antibody-associated vasculitis and thrombotic microangiopathy (TMA). However, the proband's parents have no history of TMA. A genetic analysis revealed the presence of CFH::CFHR1 fusion gene and a CFHR3-1-4-2 gene duplication in the patient, her father, and her paternal grandfather. Although several fusion genes resulting from structural variations of the CFH-CFHR genes region have been identified, this is the first report of the combination of a CFH::CFHR1 fusion gene with CFHR gene duplication. Because the CFH-CFHR region is highly homologous, we hypothesized that CFHR gene duplication occurred. These findings indicate a novel pathogenic genomic structural variation associated with the development of aHUS.