Efficacy and safety of first-line biological DMARDs in rheumatoid arthritis patients with chronic kidney disease.

OBJECTIVE: To evaluate the efficacy and safety of first-line biological disease-modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA) with chronic kidney disease (CKD), including those undergoing haemodialysis (HD). METHODS: This retrospective cohort study included 425 patients with RA prescribed their first bDMARDs at two hospitals from 2004 to 2021. Patients were categorised by kidney function and bDMARD modality (TNFα inhibitors (TNFαis), interleukin-6 inhibitors (IL-6is), cytotoxic T-lymphocyte antigen-4 immunoglobulin (CTLA4-Ig)). The primary outcome was the 36-month drug retention rate, with secondary outcomes including changes in Disease Activity Score 28 (DAS28)-C reactive protein (CRP)/erythrocyte sedimentation rate (ESR), prednisolone dosage and reasons for discontinuation. RESULTS: The 36-month drug retention rates by estimated glomerular filtration rate (eGFR) (≥60, 30-60, <30 mL/min/1.73 m2) were as follows: all bDMARDs (45.2%, 32.0%, 41.4%), TNFαis (45.3%, 28.2%, 34.0%), IL-6is (47.4%, 66.7%, 71.4%) and CTLA-4Ig (50.0%, 31.3%, 33.3%). Even in groups with lower kidney function, the drug retention rate of bDMARDs was generally maintained. However, the retention rate of TNFαis was significantly lower in patients with eGFR <30 mL/min/1.73 m2. IL-6is showed the highest retention rate and the lowest discontinuation rate due to ineffectiveness in this group (HR 0.11, 95% CI 0.02 to 0.85, p=0.03). All bDMARDs improved DAS28-CRP/ESR and reduced prednisolone dosage across all groups. CONCLUSION: bDMARDs demonstrated effective and safe profiles in patients with RA with CKD, even among patients on HD. In particular, IL-6is had a significantly higher drug retention rate in patients with an eGFR of <30 mL/min/1.73 m2 and fewer discontinuations due to ineffectiveness. IL-6is were more efficacious as monotherapy compared with the other bDMARDs.

A Case of Autosomal Dominant Polycystic Kidney Disease With Resolution of Massive Pericardial Effusion After Renal Transcatheter Artery Embolization.

A 68-year-old woman being treated with hemodialysis for autosomal dominant polycystic kidney disease was admitted for progressive dyspnea over 6 months. On chest radiography, her cardiothoracic ratio had increased from 52.2% 6 months prior, to 71%, and echocardiography revealed diffuse pericardial effusion and right ventricular diastolic insufficiency. A resultant pericardial tamponade was thought to be the cause of the patient's dyspnea, and therefore a pericardiocentesis was performed, with a total of 2,000mL of fluid removed. However, 21 days later the same amount of pericardial fluid had reaccumulated. The second pericardiocentesis was performed, followed by transcatheter renal artery embolization (TAE). The kidneys, which were hard on palpation before TAE, softened immediately after TAE. After resolution of the pericardial effusion was confirmed, the patient was discharged after 24 days in hospital. Twelve months later, the patient was asymptomatic, the cardiothoracic ratio decreased to 48% on chest radiography and computed tomography revealed no reaccumulation of pericardial effusion. This case illustrates a potential relationship between enlarged kidneys in autosomal dominant polycystic kidney disease and pericardial effusion.

Protocol for the nationwide registry of patients with polycystic kidney disease: japanese national registry of PKD (JRP).

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are major genetic polycystic kidney diseases that can progress to end-stage kidney disease (ESKD). Longitudinal data on the clinical characteristics associated with clinical outcomes in polycystic kidney disease (PKD), including the development of ESKD and cardiovascular disease (CVD) are lacking in Japan. To address this unmet need the authors are establishing a novel, web-based, Nationwide Cohort Registry Study-the Japanese Registry of PKD (JRP). METHODS: The JRP is a prospective cohort study for ADPKD (aim to recruit n = 1000 patients), and both a retrospective and prospective study for ARPKD (aim to recruit n = 100). In the prospective registry, patients will be followed-up for 10 years every 6 months and 12 months for patients with ADPKD and ARPKD, respectively. Data collection will be recorded on Research Electronic Data Capture (REDCap) starting on April 1, 2024, with recruitment ending on March 31, 2029. (jRCT 1030230618). RESULTS: Data to be collected include: baseline data, demographics, diagnostic and genetic information, radiological and laboratory findings, and therapeutic interventions. During follow-up, clinical events such as development of ESKD, hospitalization, occurrence of extra kidney complications including CVD events, and death will be recorded, as well as patient-reported health-related quality of life for patients with ADPKD. CONCLUSIONS: The JRP is the first nationwide registry study for patients with ADPKD and ARPKD in Japan, providing researchers with opportunities to advance knowledge and treatments for ADPKD and ARPKD, and to inform disease management and future clinical practice.

Relationship between MRI findings and renal histopathology in IgG4-related tubulointerstitial nephritis.

BACKGROUND: MRI is expected to be a valuable tool for evaluating disease activity in immunoglobulin G4 (IgG4)-related tubulointerstitial nephritis (IgG4-TIN). However, the correlation between MRI findings and renal histopathological findings remains to be elucidated. PURPOSE: This study aimed to clarify the correlation between MRI findings and renal histopathological findings in IgG4-TIN. METHOD: This retrospective cross-sectional study investigated 26 patients with biopsy-proven IgG4-TIN who underwent simultaneous percutaneous kidney biopsies and abdominal MRI examinations at Toranomon Hospital or Toranomon Hospital Kajigaya between December 2007 and November 2022. We reviewed kidney biopsy specimens and scored the degree of inflammatory cell infiltration and interstitial fibrosis. We assessed abdominal MRI, specifically examining T1WI, T2WI, and DWI, for the presence of abnormal signals in the inferior pole of the kidney on the side where the kidney biopsy was performed. Spearman's correlation coefficient test was conducted to examine the relationship between the images and histological findings. RESULT: For T1WI, eight cases showed a positive low-intensity signal, and 18 cases were negative. For T2WI, 19 cases were positive for a low-intensity signal, and seven cases were negative. In DWI, 23 cases were positive for a high-intensity signal, and one was negative. T1WI low-intensity signal and T2WI low-intensity signal were significantly correlated with interstitial fibrosis score (correlation coefficient 0.52 and 0.64). DWI revealed IgG4-TIN detected IgG4-TIN lesions with the highest sensitivity; however, the correlation with inflammatory cell infiltration score was not significant. CONCLUSION: Low-intensity signal on T2WI is useful for predicting the degree of fibrosis in IgG4-TIN.

Public support for patients with intractable diseases in Japan: impact on clinical indicators from nationwide registries in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Clinical practice guidelines recommend antihypertensive and tolvaptan therapies for patients with autosomal dominant polycystic kidney disease (ADPKD) in Japan. However, tolvaptan therapy may pose an economic burden. The Japanese Ministry of Health, Labour and Welfare supports patients with intractable diseases. This study aimed to confirm the impact of the intractable disease system in Japan on the clinical treatment of ADPKD. METHODS: We analyzed the data of 3768 patients with ADPKD having a medical subsidy certificate from the Japanese Ministry of Health, Labour and Welfare in 2015-2016. The following quality indicators were use: the adherence rate to the 2014 clinical practice guideline for polycystic kidney disease (prescription rates of antihypertensive agents and tolvaptan in this cohort) and the number of Japanese patients with ADPKD nationwide started on renal replacement therapy in 2014 and 2020. RESULTS: Compared with new applications from 2015 to 2016, the prescription rates of antihypertensives and tolvaptan for the indicated patients at the 2017 renewal application increased by 2.0% (odds ratio = 1.41, p = 0.008) and 47.4% (odds ratio = 10.1, p > 0.001), respectively. These quality indicators improved with antihypertensive treatment, especially in patients with chronic kidney disease stages 1-2 (odds ratio = 1.79, p = 0.013) and in those aged < 50 years (odds ratio = 1.70, p = 0.003). The number of patients with ADPKD who were started on renal replacement therapy in Japan decreased from 999 in 2014 to 884 in 2020 in the nationwide database (odds ratio = 0.83, p < 0.001). CONCLUSIONS: The Japanese public intractable disease support system contributes to improvement of ADPKD treatment.

Use of biologic agents and methotrexate improves renal manifestation and outcome in patients with rheumatoid arthritis: a retrospective analysis.

BACKGROUND AND PURPOSE: We examined whether advances in treatment strategies from older disease-modifying antirheumatic drugs (DMARDs) to new biologic agents and methotrexate improved renal complications and outcome in patients with rheumatoid arthritis (RA). METHODS: We reviewed records of 156 patients with RA who underwent kidney biopsy at our institute between January 1990 and December 2019. All patients were assigned to one of three periods: period 1, 1990-1999 (n = 48); period 2, 2000-2009(n = 57); period 3, 2010-2019 (n = 51). RESULTS: Membranous nephropathy, nephrosclerosis, AA-amyloidosis, and IgA nephropathy were the four major renal manifestations of RA. AA-amyloidosis was diagnosed by kidney biopsy in 21 patients: period 1, 7 patients (15%); period 2, 10 patients (18%); and period 3, 4 patients (8%). The 4 patients in period 3 were in the years 2010-2014, and no new case of AA-amyloidosis was recorded from 2015 to 2019. In all 21 of the patients with AA-amyloidosis, neither a biologic agent nor methotrexate was administered. Fifteen of the 21 patients required dialysis, and 13 died in periods 1-3 because of amyloid-related cardiac dysfunction less than 2 years after the initiation of dialysis. Two of them are doing well using biologic agent despite dialysis. The remaining three patients who received a biologic agent or methotrexate does not progress to end-stage renal failure. In addition, the other renal complications showing progression to dialysis also decreased over time. CONCLUSION: Advances in treatment strategies have improved renal outcome and reduced mortality in patients with RA.

Correcting anemia and native vitamin D supplementation in kidney transplant recipients: a multicenter, 2 × 2 factorial, open-label, randomized clinical trial.

Anemia and vitamin D deficiency are associated with allograft failure, and hence, are potential therapeutic targets among kidney transplant recipients (KTRs). We conducted a multicenter, two-by-two factorial, open-label, randomized clinical trial to examine the effects of anemia correction and vitamin D supplementation on 2-year change in eGFR among KTRs (CANDLE-KIT). We enrolled 153 patients with anemia and >1-year history of transplantation across 23 facilities in Japan, and randomly assigned them to either a high or low hemoglobin target (>12.5 vs. <10.5 g/dl) and to either cholecalciferol 1000 IU/day or control. This trial was terminated early based on the planned interim intention-to-treat analyses (α = 0.034). Among 125 patients who completed the study, 2-year decline in eGFR was smaller in the high vs. low hemoglobin group (i.e., -1.6 ± 4.5 vs. -4.0 ± 6.9 ml/min/1.73 m2 ; P = 0.021), but did not differ between the cholecalciferol and control groups. These findings were supported by the fully adjusted mixed effects model evaluating the rate of eGFR decline among all 153 participants. There were no significant between-group differences in all-cause death or the renal composite outcome in either arm. In conclusion, aggressive anemia correction showed a potential to preserve allograft kidney function.

A case of thrombotic microangiopathy associated with polymyositis.

A 60-year-old Japanese woman with polymyositis (PM) developed hemolytic anemia (hemoglobin of 7.3 g/dL), thrombocytopenia (platelet of 9.1×104/µL), and acute kidney injury (Cre of 4.7 mg/dL) at 14 days after starting steroid therapy. Renal biopsy revealed glomerular endothelial swelling with fibrin thrombi and fragmented erythrocytes in the capillary lumens. Hemolytic uremic syndrome (HUS) with thrombotic microangiopathy (TMA) was diagnosed. Hemodialysis and plasma exchange/plasma transfusion were initiated, but HUS did not subside. After 45 days, the patient died of hemorrhagic respiratory failure. Autopsy showed fibrin thrombi filling the glomerular vascular pole and the small arteries in most glomeruli, resulting in glomerular collapse and glomerular basement membrane (GBM) duplication. Although renal involvement by PM is rare, HUS/TMA should be remembered as one of the serious renal complications of PM.

Factors predicting decline in renal function and kidney volume growth in autosomal dominant polycystic kidney disease: a prospective cohort study (Japanese Polycystic Kidney Disease registry: J-PKD).

BACKGROUND: Factors affecting decline in renal function and cyst growth in patients with autosomal polycystic kidney disease (ADPKD) are not fully described, particularly in Japan. METHODS: This was the first multi-facility, prospective, observational cohort study conducted in ADPKD patients at 14 centers in Japan. Patients in the J-PKD registry were assessed from December 2009 to June 2012 (follow-up until June 2017). Patients' data including estimated glomerular filtration rate (eGFR) and total kidney volume (TKV) were assessed initially and a maximum of five times annually. Contributing factors to eGFR decline and TKV growth were identified using multiple linear regression analysis. RESULTS: Of the 340 patients in the J-PKD registry, data analysis was performed for 192 patients in whom serial changes for both eGFR and TKV were obtained. eGFR slope, eGFR change, and TKV change values were as follows: - 2.7 (- 4.2 to - 1.5) (ml/min/1.73 m2/year), - 5.0 (- 9.6 to - 2.3) (%/year), and 4.78 (0.86-8.22) (%/year), respectively. Lower high-density lipoprotein (HDL) cholesterol was an independent predictor of eGFR decline, using both eGFR slope and change (P = 0.04, P = 0.02, respectively), whereas lower hemoglobin and higher uric acid were significantly associated with greater eGFR change only (P = 0.02, P = 0.002, respectively). Younger age and higher fasting blood sugar were independent predictors of greater TKV change (P = 0.01, P = 0.02, respectively). CONCLUSIONS: This real-world study in Japan identified risk factors for renal function decline in ADPKD patients. These included lower HDL cholesterol, lower hemoglobin and higher uric acid for eGFR decline, and youth and higher blood sugar levels for TKV growth.

Genetics May Predict Effectiveness of Tolvaptan in Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Tolvaptan is the only therapeutic drug for autosomal dominant polycystic kidney disease (ADPKD). The influence of mutations in polycystic kidney disease 1 and 2 genes (PKD1 and PKD2) on the treatment effects of tolvaptan is not well documented in the literature. METHODS: We retrospectively evaluated the relationship between genotype and the efficacy of tolvaptan in 18 patients with ADPKD who had been treated at Toranomon Hospital and undergone genetic testing between April 2016 and February 2020. RESULTS: The annual change in estimated glomerular filtration rate (ΔeGFR/y) from before to after tolvaptan was from a median of -5.5 to -2.5 mL/min/1.73 m2 in the PKD1 truncating group, -3.3 to -2.4 mL/min/1.73 m2 in the PKD1 non-truncating group, -3.1 to -1.6 mL/min/1.73 m2 in the PKD2 group, and -1.9 to -2.6 mL/min/1.73 m2 in the group with no PKD1/2 mutation. The median degrees of improvement of ΔeGFR/y were 2.5 (45%), 0.4 (10%), 0.6 (28%), and -0.7 (-37%) mL/min/1.73 m2, respectively. Compared with the group of patients with any PKD1/2 mutation, the group with no PKD1/2 mutation showed significantly less improvement in ΔeGFR/y with tolvaptan (0.6 vs. -0.7 mL/min/1.73 m2, respectively; p = 0.01) and significantly less improvement in the annual rate of increase in total kidney volume (TKV) with tolvaptan (-6.7 vs. -1.1%, respectively; p = 0.02). CONCLUSION: Patients with ADPKD and no PKD1/2 mutation showed less improvement in ΔeGFR/y and the annual rate of increase in TKV with tolvaptan. Detecting PKD1/2 mutations may be useful for predicting the effectiveness of tolvaptan.

Genotype-Clinical Correlations in Polycystic Kidney Disease with No Apparent Family History.

BACKGROUND: Genetic characteristics of polycystic kidney disease (PKD) patients without apparent family history were reported to be different from those with a positive family history. However, the clinical course of PKD patients with no apparent family history is not well documented in the literature. METHODS: We evaluated the relationship between genotype and the clinical course of 62 PKD patients with no apparent family history. RESULTS: The annual decline of renal function was faster in the patients with PKD1/PKD2 mutation (PKD1 truncating [-3.08; 95% CI -5.30 to -0.87, p = 0.007], PKD1 nontruncating [-2.10; -3.82 to -0.38, p = 0.02], and PKD2 [-2.31; -4.40 to -0.23, p = 0.03]) than in the other patients without PKD1/PKD2 mutation. Similar results were obtained after adjustment for gender, age, estimated glomerular filtration rate (eGFR), height-adjusted total kidney volume (TKV), and mean arterial pressure (MAP). There was no significant difference in the annual decline of renal function among the different PKD1/PKD2 groups, but Kaplan-Meier analysis showed that progression to eGFR < 15 mL/min/1.73 m2 was significantly faster in PKD1 truncating group (p = 0.05). The annual rate of TKV increase was larger in the patients with PKD1/PKD2 mutation (PKD1 truncating [4.63; 95% CI 0.62-8.64, p = 0.03], PKD1 nontruncating [3.79; 0.55-7.03, p = 0.02], and PKD2 [2.11; -1.90 to 6.12, p = 0.29]) than in the other patients without PKD1/PKD2 mutation. Similar results were obtained after adjustment for gender, age, eGFR, and MAP. CONCLUSION: Detection of PKD1/PKD2 mutation, especially PKD1 truncating, is useful for predicting the renal outcome and rate of TKV increase in PKD patients with no apparent family history.

Significance of urinary albumin excretion in patients with cast nephropathy
.

BACKGROUND: This study was performed to determine whether the urinary albumin excretion rate (%UAE) could distinguish myeloma cast nephropathy (MCN) without glomerular amyloid deposition from MCN with glomerular amyloid deposition. MATERIALS AND METHODS: We retrospectively reviewed clinicopathological data on 16 patients with MCN diagnosed by renal biopsy at Toranomon Hospital from 2004 to 2014. RESULTS: A total of 10 patients had pure MCN without glomerular amyloid deposition (group 1), and 6 patients had MCN with glomerular amyloid deposition (group 2). In all 10 patients from group 1, the underlying disease was multiple myeloma (MM), while 4 patients had MM, and 2 patients had lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (LPL/WM) in group 2. Total protein did not show a significant difference between the two groups, but serum albumin was significantly higher in group 1 than group 2 (p = 0.0101). Serum-adjusted calcium did not show a significant difference between the groups, while serum creatinine (Cre) was significantly higher in group 1 than group 2 (p = 0.0343). Although urinary protein excretion did not differ significantly between the groups, the %UAE was significantly lower in group 1 than group 2 (p = 0.00198). In group 2, 3 of the 4 patients with MM died within 15 months of diagnosis, but the 2 patients with LPL/WM are alive after 32 months. In group 1, only 1 patient died (of unknown causes) within 15 months after diagnosis. CONCLUSION: In patients with MCN, %UAE may be a useful marker for the detection of coexistence of glomerular lesions, such as amyloidosis, which are associated with a poor outcome.

Immunoglobulin G subclass 3 in ISN/RPL lupus nephritis classification
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OBJECTIVES: In lupus nephritis, the immune complex plays a very important role in kidney disease progression, and immunoglobulin G subclass 3 (IgG3) may play an important role in endothelial damage as lupus nephropathy progresses. We evaluated the association between IgG3 positivity and lupus nephritis activity. MATERIALS AND METHODS: We identified 71 biopsies taken from 57 patients who had lupus nephritis with enough tissue to allow light and immunofluorescence microscopy. We compared the intensity of IgG subclass staining (on a scale of 0 - 3+) with IgG subclass dominance among lupus nephritis classes as defined by the ISN/RPS 2003 classification. RESULTS: The proportion of IgG3-positive patients with capillary loop lesion was significantly higher in the class IV group compared with other groups (p < 0.01). Interestingly, in most patients IgG1 was the strongest subclass; in class IV groups, IgG3 was the strongest in 21% of the biopsies. IgG3 deposition in capillary loops was significantly associated with C1q deposition in those loops. According to Kaplan-Meier analysis, renal survival rates in the patients with IgG3 deposition was lower (82.2%) than in patients without IgG3 deposition (93.3%), but the difference was not significant. CONCLUSION: Our results suggest that capillary loop deposition of IgG3 is associated with disease activity in lupus nephritis.
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Long-term outcome of biopsy-proven cholesterol crystal embolism.

BACKGROUND: Cholesterol crystal embolism (CCE) causes renal damage, and there is an extremely high risk of end-stage renal disease. However, the time course of CCE-related renal deterioration varies and little is known about the subsequent risk of dialysis among patients with biopsy-proven CCE. METHODS: We performed a retrospective cohort study of 38 Japanese patients in whom a histological diagnosis of CCE was made from September 1992 to July 2005. Competing risk regression analysis was used to investigate the association between declining renal function ( ≥ 1.5 elevation of serum creatinine within 26 weeks after CCE) or its subtypes (acute [ < 1 week after CCE], subacute [1 to < 6 weeks], and chronic [6 to < 26 weeks]) and the risk of dialysis, with adjustment for age, baseline serum creatinine, and the precipitating event (iatrogenic or spontaneous). RESULTS: During a median follow-up period of 25.9 weeks, 14 patients (35.9%) started dialysis. Multivariable analysis showed that patients with declining renal function had a higher risk of commencing dialysis than those without declining function (subdistribution hazard ratio [SHR] 9.47; 95% confidence interval [CI] 1.34-66.8). Patients with different renal presentations had a similarly increased risk of commencing dialysis, with the risk being significantly higher for the subacute and chronic patterns of declining renal function (adjusted SHR [95% CI] for acute, subacute, and chronic declining renal function[vs. no decline]: 7.36 [0.85-63.6], 11.9 [1.36-101], and 10.7 [1.49-77.0], respectively). CONCLUSION: Declining renal function after CCE, even later than 6 weeks, was significantly associated with the subsequent risk of dialysis.

Increase of 1,25 dihydroxyvitamin D in sarcoidosis patients with renal dysfunction.

INTRODUCTION: In sarcoidosis, renal involvement includes hypercalcemia-related nephrocalcinosis and granulomatous tubulointerstitial nephritis. Hypercalcemia is thought to be due to increased production of 1,25 dihydroxyvitamin D (1-25D), but 1-25D levels have not been evaluated in sarcoidosis patients with renal dysfunction. MATERIALS AND METHODS: We enrolled 9 sarcoidosis patients who underwent renal biopsy, and compared the serum 1-25D concentration and eGFR with those in 428 non-sarcoidosis patients who had renal dysfunction (stage 2 or higher CKD with an estimated glomerular filtration rate < 90). RESULTS: Serum calcium and 1-25D levels were significantly higher in the sarcoidosis patients than in the non-sarcoidosis patients (p < 0.01 and p = 0.01, respectively). There was a positive correlation between 1-25D and eGFR in the patients without sarcoidosis (r = 0.693; p < 0.01). As the renal function of sarcoidosis patients was improved by steroid therapy, the serum 1-25D and adjusted serum calcium levels decreased to near the median values in non-sarcoidosis patients. On renal biopsy, CD68 staining was positive for tissue macrophages in all 8 patients who had tubulointerstitial nephritis (with or without typical granulomas), while Von Kossa staining showed calcification of tubules near or inside granulomas in 6 of these 8 patients. CONCLUSION: While tissue macrophages promote development of tubulointerstitial nephritis and 1-25D overproduction in renal sarcoidosis, hypercalcemia secondary to elevation of 1-25D may be related to renal calcification and granuloma formation.

PKD1-associated autosomal dominant polycystic kidney disease with glomerular cysts presenting with nephrotic syndrome caused by focal segmental glomerulosclerosis.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) may manifest non-nephrotic range proteinuria, but is rarely complicated with nephrotic syndrome. Limited number of reports describe the histology of ADPKD with nephrotic syndrome in detail. CASE PRESENTATION: We encountered a 23-year-old man with polycystic kidney disease (PKD) with small kidney volume and nephrotic syndrome, which eventually progressed to end-stage renal disease. Renal histology showed typical focal segmental glomerulosclerosis and remarkable glomerular cyst formation, but did not reveal tubular cysts. PKD1 mutation was detected in him and his father, who also had PKD with small kidney volume. CONCLUSIONS: In contrast to tubular cysts which develop along ADPKD progression, glomerular cysts may likely be associated with ADPKD with slower volume progression manifesting small kidney volume. Although previous investigations report that ADPKD with smaller kidney volume is attributed to slower decline in renal function, coexistence of nephrotic-range proteinuria implies complication of other glomerular diseases and needs histological evaluation since it may lead to poor renal outcome.

Clinical and histological features of antineutrophil cytoplasmic antibody-associated vasculitis related to antithyroid drugs
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BACKGROUND: Antithyroid drugs such as propylthiouracil and methimazole have been reported to cause antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but little is known about long-term outcomes. MATERIALS AND METHODS: We identified AAV patients who underwent renal biopsy and retrospectively assessed their clinical and histological findings. Patients with AAV who had received propylthiouracil or methimazole were defined as having antithyroid drug-associated AAV (ATD-AAV), and the other patients were defined as having primary AAV. RESULTS: Seven patients with ATD-AAV and 83 patients with primary AAV were identified. Compared with the primary AAV group, the patients with ATD-AAV were significantly younger (mean ± standard deviation; 45.4 ± 21.4 years vs. 65.9 ± 13.8 years, p < 0.01), and had lower serum creatinine (median [interquartile range]; 0.7 mg/dL [0.6 - 1.5] vs. 2.3 mg/dL [1.0 - 4.0], p = 0.02), as well as a higher frequency of positivity for MPO--ANCA/PR3-ANCA (42.9 vs. 4.8%, p < 0.01). While glomerular crescents varied, interstitial fibrosis and tubular atrophy were milder in ATD-AAV patients. Kaplan-Meier analysis showed a significantly higher kidney survival rate in patients with ATD-AAV than in those with primary AAV (p = 0.05). CONCLUSION: Patients with ATD-AAV were younger and had milder kidney involvement, resulting in a better long-term outcome compared with primary AAV.
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Renal histology and MRI in a 25-year-old Japanese man with nephronophthisis 4
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We investigated a 25-year-old Japanese man who had polycystic kidneys and end-stage renal failure without a positive family history. Ultrasonography revealed enlarged kidneys with increased echogenicity and multiple cystic lesions. MRI showed replacement of both kidneys by cystic lesions without definite walls. Renal biopsy demonstrated interstitial fibrosis, especially at the corticomedullary junction. The residual tubular system showed starfish-like disruption. Tubules with cystic dilation were mainly the distal loop of Henle and the distal tubules since immunohistochemical staining was positive for cytokeratin 7 (the distal loop of Henle and the distal tubule) and Tamm-Horsfall protein (the distal loop of Henle), while being negative for aquaporin 3 (the collecting duct) and CD10 (proximal tubule). Comprehensive genetic analysis identified compound heterozygous missense mutations of NPHP4 with autosomal recessive inheritance since his asymptomatic parents each had a single heterozygous missense mutation of NPHP4. In conclusion, MRI and immunohistochemical analysis of renal biopsy specimens may be useful for evaluation of this disease.
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Risk factors of ceftriaxone-associated biliary pseudolithiasis in adults: influence of renal dysfunction.

BACKGROUND: Ceftriaxone (CTRX) is a known cause of biliary pseudolithiasis (BPL) mainly in children. Biliary elimination of CTRX increases in patients with renal dysfunction. However, the influence of renal dysfunction on the incidence of CTRX-associated BPL has not been well investigated. The aim of this study was to investigate the cumulative incidence of CTRX-associated BPL in adults and to assess if renal dysfunction is a risk factor. METHODS: We retrospectively analyzed the medical records of 478 patients treated with CTRX to assess the incidence and risk factors of CTRX-associated BPL. We examined age, sex, body weight, dosage, and duration of CTRX therapy, and the concentrations of serum creatinine, estimated glomerular filtration rate (eGFR), albumin, and serum calcium in all the patients. The cumulative incidence of BPL was calculated using a competing risk model. The multivariate analysis of each variable for the development of BPL was assessed by a Cox proportional hazards model. RESULTS: A total of 362 patients (75.7%) had renal dysfunction (eGFR: < 60 mL/min). The cumulative incidence of BPL in patients with renal dysfunction was significantly higher than that in patients with normal kidney function (4.1 vs. 0.6%, p = 0.017). Renal dysfunction (Hazard ratio (HR) 8.14, 95% CI 1.05-63.0, p = 0.045) and female sex (HR 5.35, 95% CI 1.17-24.5, p = 0.031) were independent risk factors of CTRX-associated BPL, which was confirmed using multivariate analysis (renal dysfunction: HR 7.93, 95% CI 1.04-60.5, p = 0.046) (female sex HR 4.65, 95% CI 1.03-21.1, p = 0.046). CONCLUSIONS: Renal dysfunction is an independent risk factor of CTRX-associated BPL in adults.