Atonal BHLH transcription factor 8 (ATOH8) is a basic helix-loop-helix (bHLH) transcription factor; however, its role in glomerular epithelial cells (podocytes) remains unclear. This study aimed to elucidate the function of ATOH8 in podocytes. First, ATOH8 expression in the mouse kidney was confirmed in podocytes by immunofluorescence staining and in situ hybridization. In cultured human podocytes, transforming growth factor-beta (TGF-β) treatment significantly reduced ATOH8 mRNA expression. To examine the functional consequences of ATOH8 downregulation, ATOH8 expression was knocked down with shRNA. Subsequent RNA sequencing analysis of ATOH8-knockdown podocytes revealed increased extracellular matrix gene expression and activation of TGF-β signaling. ATOH8-knockdown podocytes also showed SMAD2/3 nuclear translocation, increased SMAD transcriptional activity, as determined by a luciferase assay, and upregulated TGFB1 mRNA even without TGF-β stimulation, consistent with TGF-β signaling activation. In vivo, C57BL/6 Atoh8-deficient mice showed no renal abnormalities at baseline. However, in an adriamycin (ADR)-induced focal segmental glomerulosclerosis (FSGS) model, Atoh8-deficient mice developed significantly more severe glomerulosclerosis than wild-type mice, with higher renal cortical Tgfb1 and Col4a1 mRNA levels. Reduced ATOH8 expression was also observed in ADR-induced nephropathy in mice and rats and in various human glomerular diseases. These findings suggest that ATOH8 downregulation enhances TGF-β signaling and glomerulosclerosis progression, indicating a protective role for ATOH8 in maintaining podocyte integrity and preventing kidney injury.NEW & NOTEWORTHY This study identifies atonal transcription factor 8 (ATOH8) as a previously unexplored regulator of podocyte function. We demonstrate that ATOH8 knockdown activates TGF-β signaling and increases extracellular matrix gene expression. Notably, ATOH8 deficiency alone does not cause renal injury but exacerbates glomerulosclerosis in an adriamycin-induced nephropathy model, accompanied by increased Tgfb1 mRNA expression in the renal cortex. These findings indicate that ATOH8 plays a protective role in podocyte function and limits glomerulosclerosis during kidney injury.
Relapse is a major concern in patients with antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV). There are several reports on predictors of AAV relapse; however, reports on Japanese patients are limited. This study aimed to identify risk factors for relapse in Japanese patients with AAV. We retrospectively analyzed 200 patients who initiated treatment at our institution and were subsequently managed across affiliated facilities. Clinical and laboratory data were analyzed. The primary outcome was relapse, and Cox proportional hazards models were used to identify associated risk factors. The median age of AAV onset was 69 years (interquartile ranges (IQR), 62–76 years). There were 103 (51
This study by miRNA microarray analysis demonstrated that miR-143-3p expression was upregulated in cultured human podocytes following exposure to transforming growth factor (TGF)-β1. Furthermore, we report that the miR-143/145 cluster contributes to decreased expression of Wilms’ tumor 1, which represents a possible mechanism for podocyte injury induced by TGF-β1. This study is important because it presents a novel mechanism for TGF-β-associated glomerular diseases, including diabetic kidney disease (DKD), and suggests potential therapeutic strategies targeting miR-143-3p/145-5p.
This study aimed to assess the utility of quantitative high-resolution computed tomography (HRCT) for determining the clinical course of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease (MDA5+ ILD). This study retrospectively analyzed the data of 34 patients with MDA5+ ILD to determine the association between the clinical findings and extent of ILD via quantitative CT analysis at baseline and short-term follow-up. Quantified HRCT scores were evaluated as the lung severity score (LSS), percentage of opacity, and percentage of high opacity. Thirty-four patients underwent follow-up CT scans 35 (range: 14–78) days after diagnosis. Patients who died of rapidly progressive ILD had higher LSS (p < 0.01), percentage of opacity (p < 0.01), percentage of high opacity (p = 0.01), total ground-glass opacity score (p = 0.01), serum C-reactive protein (CRP) (p = 0.03), and alveolar–arterial oxygen difference (Aa-DO2) (p = 0.01) at follow-up than those who survived. Quantified HRCT scores correlated with serum CRP and Aa-DO2 levels at follow-up. LSS at follow-up (AUC = 0.844, p < 0.01) was the best predictor of death in MDA5+ ILD patients. Patients with an LSS of > 6.5 at follow-up had higher mortality than those with an LSS of ≤ 6.5, especially when receiving triple therapy. In multivariate analysis, an LSS of > 6.5 at follow-up was significantly associated with a poor outcome. Quantitative CT analysis of MDA5+ ILD is useful for the objective assessment of respiratory status and disease activity. Short-term HRCT evaluation, particularly LSS, is most important in predicting its clinical course during triple therapy.
Patients with antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis and idiopathic interstitial lung diseases (IIPs) are positive for myeloperoxidase (MPO)–ANCA. MPO–ANCA-positive vasculitis mainly comprises microscopic polyangiitis (MPA) and unclassifiable vasculitis. These diseases are frequently complicated by interstitial lung disease (ILD). Few studies have reported the clinical differences between the subtypes of MPO–ANCA-positive ILD. Therefore, this study aimed to examine the clinical findings and courses of MPO–ANCA-positive ILD. This retrospective study enrolled 100 patients with MPO–ANCA-positive ILD who were categorized into three groups: MPA (n = 44), unclassifiable vasculitis (n = 29), and IIP (n = 27). Our study compared the clinical findings and prognosis of these patients and analyzed the poor prognostic factors. Furthermore, we assessed the association between the patients with and without acute exacerbation of ILD (AE-ILD). Our study found clinical differences in serum markers, clinical symptoms, and treatment regimens among the three groups. ILD complications, as the main cause of death, differed among the three groups (P = 0.04). Patients with unclassifiable vasculitis showed higher survival rates than those with IIP (P = 0.046). Patients with AE-ILD showed fewer general symptoms (P = 0.02) and lower survival rates (P < 0.01) than those without AE-ILD. In multivariate analysis, AE-ILD development was a strong poor prognostic factor for MPO–ANCA-positive ILD. The subtypes of MPO–ANCA-positive ILD have different clinical features and prognoses. Patients who develop AE-ILD require careful evaluation of clinical courses.
A 41-year-old woman with a 14-month history of systemic lupus erythematosus (SLE) presented with headache, aphasia, and agraphia. A laboratory examination revealed mild proteinuria, hypocomplementemia, and elevated anti-double-stranded DNA antibody levels. A cerebrospinal fluid analysis demonstrated elevated protein and interleukin-6 levels. Magnetic resonance imaging (MRI) of the brain identified multiple lesions suggestive of brain edemas and small haemorrhages. She was diagnosed as having neuropsychiatric lupus and lupus nephritis and received remission induction therapy with high-dose corticosteroid and intravenous cyclophosphamide. She achieved a complete remission, and treatment with mycophenolate mofetil (MMF) was initiated 3 months thereafter for remission maintenance. At 13 months after the exacerbation of SLE, she complained of headache and nausea. A gadolinium-enhanced MRI of the brain revealed a low-signal-intensity tumour with marginal ring enhancement of 50 mm in the left frontal lobe. The tumour was excised, and the histological diagnosis was diffuse large B-cell lymphoma with positive Epstein-Barr virus (EBV). MMF was discontinued. Remission induction therapy with rituximab, high-dose methotrexate, procarbazine, and vincristine was administered, and she achieved remission. Previous reports suggest that use of MMF is associated with primary central nervous system (CNS) lymphoma (PCNSL) in patients with lupus nephritis or other autoimmune diseases or in post-transplant patients. Our observation that PCNSL occurred after CNS involvement of SLE suggests that EBV and CNS inflammation arising from SLE might have contributed to the development of PCNSL.
Background: Obesity is a major risk factor for developing various respiratory diseases. Patients with anti-ami-noacyl tRNA synthetase (ARS) antibodies often have interstitial lung disease (ILD). The present study was conducted to evaluate the association between obesity and outcomes of anti-ARS antibody-related ILD (ARS-ILD). Methods: We retrospectively investigated 58 patients with ARS-ILD and compared the clinical characteristics, treatment, and prognoses between obese (body mass index [BMI] >= 25 kg/m(2)) and nonobese (BMI <25 kg/m(2)) patients. Chest fat was quantified via computed tomography (CT). Thoracic subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were measured at diagnosis and first relapse of ILD. Results: Sixteen patients were obese. Obese patients had lower percentages of predicted diffusing capacity of the lungs for carbon monoxide and higher high-resolution CT scores and SAT and VAT indexes than did nonobese patients. The ILD relapse rate was higher in obese patients (P < 0.01), especially among those with high SAT indexes (P < 0.01). The SAT and VAT indexes increased significantly from diagnosis until first relapse. Among clinical parameters at first relapse, SAT and VAT indexes were correlated with serum Krebs von den Lungen-6 levels (r = 0.720, P = 0.008) and total ground-glass attenuation scores (r = 0.620, P = 0.024), respectively. Conclusions: Obesity and high SAT indexes are risk factors for ILD relapse in patients positive for anti-ARS an-tibodies. Evaluating and quantifying patients' chest fat on CT is important for predicting ILD relapse.
OBJECTIVES:Otitis media with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (OMAAV) is a new category of otitis media in which cases of otitis media due to ANCA-associated vasculitis (AAV) are classified, regardless of ANCA variant or ANCA serotype. We aimed to describe the clinical features and course of patients with OMAAV and identify factors associated with hearing outcomes.METHODS:We retrospectively analysed 30 patients with OMAAV, classified based on the criteria proposed by the Japan Otological Society in 2016.RESULTS:Single-positive myeloperoxidase-ANCA, single-positive proteinase 3-ANCA, double-positive ANCA, and double-negative ANCA were identified in 47%, 33%, 7%, and 13% of the patients, respectively. All patients subjected to audiometry showed hearing impairments, and 85% were affected bilaterally. Mixed- and sensorineural-type hearing impairments were identified in 80% and 20% of impaired ears, respectively. Hypertrophic pachymeningitis (HPM) was identified in 37% of the patients. Immunosuppressive therapy was administered to 93% of patients, and the median air conduction hearing levels at pre- and post-treatment were 66.1 dB and 43.4 dB, respectively, indicating significant hearing improvements. HPM and a long interval between disease onset and treatment initiation were significantly correlated with poor hearing prognosis.CONCLUSIONS:OMAAV develops under any type of ANCA-serology and typically causes mixed or sensorineural bilateral hearing loss. The early initiation of immunosuppressive therapy and the absence of HPM were associated with good hearing outcomes.
Background Pregnancy is an important issue for many women with systemic lupus erythematosus (SLE). This study examined maternal and fetal outcomes among SLE women with or without a history of lupus nephritis (LN). Methods We retrospectively analyzed 98 pregnancies in 57 women previously diagnosed with SLE who gave birth at our hospital. Results There were 44 pregnancies in women with a history of LN and 54 pregnancies in those without. Fetal loss was observed in 16.1% of SLE pregnancies when excluding induced abortion, and preeclampsia and SLE flare were observed in 12.2 and 6.1% of SLE pregnancies, respectively. No significant differences were evident between women with or without LN in rate of fetal loss, preeclampsia or SLE flare. Women with a history of LN exhibited a significantly shorter duration of gestation (37.0 weeks vs. 38.4 weeks, P = 0.006) and lower birth weight (2484 g vs. 2746 g, P = 0.007) than those without LN. Multivariate analysis revealed glucocorticoid dose but not history of LN, as an independent risk factor for preterm delivery and low birth weight. Conclusion This study was unable to conclude that a history of LN predicted pregnancy outcomes among SLE women. Instead, a higher dose of glucocorticoid at conception was unexpectedly associated with preterm delivery and low birth weight. Further studies are awaited to verify the relationship.
Objectives: Anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody-positive and age at onset >= 60 years are poor prognosis factors in polymyositis (PM) and dermatomyositis (DM) associated with interstitial lung disease (ILD) among Japanese patients. However, the influence of age on the clinical features of anti-MDA5 autoantibody-positive patients with DM remains unclear. Methods: We retrospectively examined 40 patients with DM and anti-MDA5 autoantibodies according to age. We compared patients aged <60 and >= 60 years with respect to clinical features including laboratory test findings, high-resolution lung computed tomography data, treatment content, and complications such as infections and prognosis. We also examined clinical features between surviving and deceased patients in the older patient group. Results: Of 40 enrolled patients, 13 were classified as old and 27 as young. Older patients had significantly fewer clinical symptoms including arthralgia/arthritis (p < .01), skin ulceration (p = .02), and higher mortality than younger patients (p = .02) complicated with rapidly progressive ILD (RP-ILD), combination immunosuppressive therapy, and strictly controlled infections. Conclusion: Clinical features and mortality of anti-MDA5 autoantibody-positive DM patients were influenced by age. Patients aged >= 60 years had a worse prognosis, and combination immunosuppressive therapy was often ineffective for RP-ILD in older patients.
Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65–74 years, n = 29; 75–79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan–Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.
Anti‐transcription intermediary factor 1γ (anti‐TIF1γ) antibody (Ab) is significantly associated with internal malignancies in adult patients with dermatomyositis (DM). Although pathogenesis of cancer‐associated DM is unknown, TIF1γ overexpression in tumors has been considered to be critical for the development of DM. The objective of this study was to investigate clinical characteristics of patients with anti‐TIF1γ Ab‐positive DM and elucidate risk factors that are potentially associated with internal malignancy. In addition, we compared the expression of TIF1γ in tumor tissues of patients with anti‐TIF1γ Ab‐positive DM, anti‐TIF1γ Ab‐negative DM and without DM in order to investigate the pathogenesis of cancer‐associated DM. We analyzed 77 Japanese patients with DM, and found 19 patients to be positive for anti‐TIF1γ Ab. Patients with anti‐TIF1γ Ab‐positive DM were older and presented heliotrope rash and flagellate erythema more frequently than patients without anti‐TIF1γ Ab (P < 0.05). Interstitial lung disease (ILD) and rapidly progressive ILD, as well as palmar violaceous erythema, were less frequent in patients with anti‐TIF1γ Ab than in patients without. Furthermore, internal malignancy and dysphagia were significantly more frequent in the anti‐TIF1γ Ab‐positive group (P < 0.01). Male sex and dysphagia were significantly associated with internal malignancy in patients with anti‐TIF1γ Ab‐positive DM (P < 0.01 and <0.05, respectively). Using immunohistochemistry, we examined the TIF1γ expression in tumors of 11 patients with cancer‐associated DM (anti‐TIF1γ Ab‐positive, nine; anti‐TIF1γ Ab‐negative, two) and 25 patients without DM. TIF1γ was highly expressed in all tumors, and there was no significant difference in TIF1γ expression between patients with and without DM. Furthermore, TIF1γ expressions in tumors were similar irrespective of the presence of anti‐TIF1γ Ab. These results suggest that anti‐TIF1γ antibody may not be simply induced by overexpression of TIF1γ in tumors in patients with DM, but that other mechanisms may exist.
Background Anti-melanoma differentiation-associated gene 5 (MDA5) antibody has been recognized to be significantly associated with a subset of dermatomyositis patients with rapidly progressive interstitial lung disease (RP-ILD). Objectives To elucidate the clinical characteristics and poor prognostic factors in Japanese dermatomyositis patients with anti-MDA5 antibody. Materials and methods Clinical features of anti-MDA5 antibody-positive dermatomyositis patients and risk factors, potentially associated with a poor prognosis, were retrospectively analysed. Results A total of 37.3% (28/75) dermatomyositis patients were positive for anti-MDA5 antibody. The frequency of Gottron’s papules, palmar violaceous macules, antihelix/helix violaceous macules, and clinically amyopathic dermatomyositis (CADM) was significantly higher in patients with anti-MDA5 antibody. Of anti-MDA5 antibody-positive dermatomyositis patients, 57.1% developed RP-ILD, and in those with RP-ILD, serum ferritin level was markedly high and partial pressure of arterial oxygen (PaO 2 ) was significantly low at first visit. Among patients with anti-MDA5 antibody with RP-ILD, non-survivors were older and revealed lower PaO 2 at first visit relative to survivors. Furthermore, patients who did not take triple therapy (prednisolone, calcineurin inhibitor and cyclophosphamide) as initial treatment resulted in poor outcome. Conclusion Anti-MDA5 antibody may be associated with CADM, the progression to RP-ILD, high serum ferritin level, and characteristic skin manifestations. High serum ferritin level in patients with anti-MDA5 antibody may be associated with the development of RP-ILD and poor prognosis. Early treatment with triple therapy, including intravenous cyclophosphamide, may improve the prognosis of RP-ILD.
Tissue resident mononuclear phagocytes (Mophs), comprising monocytes, macrophages, and dendritic cells (DCs), play important roles under physiological and pathological conditions. The presence of these cells in the kidney has been known for decades, and studies of renal Mophs (rMophs) are currently underway. Since no unified procedure has been identified to isolate rMophs, results of flow cytometric analysis of rMophs have been inconsistent among studies. We therefore first evaluated a preparative method for rMophs using collagenous digestion. The yield of rMophs greatly increased after the collagenase digestion. In particular, F4/80(high) rMophs, which were positive for CD11c, a specific marker of DCs, dramatically increased. In addition, since neutrophils are sometimes mixed among rMophs in the analysis of flow cytometry, we established a gating strategy for eliminating neutrophils. To determine the contribution of rMophs to the development of autoimmune nephritis, we analyzed an experimental model of autoimmune nephritis that was applied to Shp1 conditional knockout mice (Shp1 CKO). This knockout strain is generated by crossing a mouse line carrying floxed Shp1 allele to mice expressing Cre recombinase under the control of the CD11c promoter. Shp1 CKO therefore specifically lack Shp1 in cells expressing CD11c. As a result, Shp1 CKO were susceptible to that experimental glomerulonephritis and F4/80(high) rMophs of Shp1 CKO increased dramatically. In conclusion, our preparative methods for collagenase digestion and gating strategy for neutrophils are necessary for the analysis of rMophs, and Shp1 suppresses the development of autoimmune nephritis through the control of rMophs.
A 52-year-old woman was diagnosed with chronic myeloid leukemia. Treatment with dasatinib, a second-generation Bcr–Abl tyrosine kinase inhibitor, was initiated, and complete cytogenetic remission was achieved. Two years later, proteinuria occurred, and the urinary protein level increased gradually in the next 3 years. Moreover, the serum creatinine level increased mildly during this period. The urinary protein level reached 2.18 g/gCr; hence, a renal biopsy was conducted. Light microscopy revealed mild proliferation of mesangial cells, and immunofluorescence analysis revealed IgG and C3 depositions in the mesangial area. Electron microscopy revealed electron-dense deposition in the paramesangial area, partial podocyte foot process effacement, and segmental endothelial cell swelling with a slight expansion of the subendothelial space. Dasatinib was discontinued, and within 3 weeks, the proteinuria disappeared, with improvements in her renal function. After switching to bosutinib, a new second-generation of tyrosine kinase inhibitor, the proteinuria remained negative. The rapid cessation of proteinuria following dasatinib discontinuation indicated that proteinuria was induced by the long-term administration of dasatinib. Proteinuria and renal function should be regularly monitored during dasatinib therapy.
The N-type Ca2+ channel (Cav2.2) is distributed in sympathetic nerves that innervate the tubules, the vessels, and the juxtaglomerular granular cells of the kidney. However, the role of N-type Ca2+ channels in renal disease remains unknown. To address this issue, Cav2.2 knockout mice were utilized. Immunoreactive Cav2.2 was undetectable in normal kidneys of C57BL/6N mice, but it became positive in the interstitial S100-positive nerve fibers after unilateral ureteral obstruction (UUO). There were no significant differences in mean blood pressure, heart rate, and renal function between wild-type littermates and Cav2.2-knockout mice at baseline, as well as after UUO. Cav2.2 deficiency significantly reduced the EVG-positive fibrotic area, alpha-SMA expression, the production of type I collagen, and the hypoxic area in the obstructed kidneys. The expression of tyrosine hydroxylase, a marker for sympathetic neurons, was significantly increased in the obstructed kidneys of wild-type mice, but not in Cav2.2-knockout mice. These data suggest that increased Cav2.2 is implicated in renal nerve activation leading to the progression of renal fibrosis. Blockade of Cav2.2 might be a novel therapeutic approach for preventing renal fibrosis.
Activin A, a member of the transforming growth factor-beta superfamily, is a critical modulator of inflammation and plays a key role in controlling the cytokine cascade that drives the inflammatory response. However, the role of activin A in inflammatory kidney diseases remains unknown. To address this issue, we examined here whether activin A can be detected in the kidney and/or urine from patients with antineutrophil cytoplasmic antibody (ANCA) -associated vasculitis (AAV). Fifty-one patients who had been diagnosed with AAV and were treated in our department between November 2011 to March 2018 were included in this study. Forty-one patients had renal complications (renal AAV). Serum and urinary activin A levels were measured by enzyme-linked immunosorbent assay. Correlation of urinary activin A concentration with clinical parameters was analyzed. Urinary activin A was undetectable in healthy volunteers. In contrast, urinary activin A concentration was significantly increased in patients with renal AAV but not in those with non-renal AAV. Urinary activin A concentration decreased rapidly after immunosuppressive treatment. There was a significant correlation of urinary activin A level with urinary protein, L-FABP, and NAG. Histologic evaluation revealed that urinary activin A levels were significantly higher in patients with cellular crescentic glomeruli than in those lacking this damage. In situ hybridization demonstrated that the mRNA encoding the activin A βA subunit was undetectable in normal kidneys but accumulated in the proximal tubules and crescentic glomeruli of the kidneys of patients with renal AAV. Immunostaining showed that activin A protein also was present in the proximal tubules, crescentic glomeruli, and macrophages infiltrating into the interstitium in the kidneys of patients with renal AAV. These data suggested that urinary activin A concentration reflects renal inflammation and tubular damage in AAV and may be a useful biomarker for monitoring renal AAV.