Estimating baseline creatinine levels based on the kidney parenchymal volume.

BACKGROUND: Acute kidney injury (AKI) diagnosis often lacks a baseline serum creatinine (Cr) value. Our study aimed to create a regression equation linking kidney morphology to function in kidney donors and chronic kidney disease patients. We also sought to estimate baseline Cr in minimal change disease (MCD) patients, a common AKI-predisposing condition. METHODS: We analyzed 119 participants (mean age 60 years, 50% male, 40% donors) with CT scans, dividing them into derivation and validation groups. An equation based on kidney parenchymal volume (PV) was developed in the derivation group and validated in the validation group. We estimated baseline Cr in 43 MCD patients (mean age 45 years, 61% male) using the PV-based equation and compared with their 6 month post-MCD onset Cr values. RESULTS: In the derivation group, the equation for the estimated glomerular filtration rate (eGFR) was: eGFR (mL/min/1.73m2) = 0.375 × PV (cm3) + (- 0.395) × age (years) + (- 2.93) × male sex + (- 13.3) × hypertension + (- 14.0) × diabetes + (- 0.210) × height (cm) + 82.0 (intercept). In the validation group, the eGFR and estimated Cr values correlated well with the measured values (r = 0.46, p = 0.01; r = 0.51, p = 0.004, respectively). In the MCD group, the baseline Cr values were significantly correlated with the estimated baseline Cr values (r = 0.52, p < 0.001), effectively diagnosing AKI (kappa = 0.76, p < 0.001). CONCLUSIONS: The PV-based regression equation established in this study holds promise for estimating baseline Cr values and diagnosing AKI in patients with MCD. Further validation in diverse AKI populations is warranted.

Associations between nephron number and podometrics in human kidneys.

Podocyte loss and resultant nephron loss are common processes in the development of glomerulosclerosis and chronic kidney disease. While the cortical distribution of glomerulosclerosis is known to be non-uniform, the relationship between the numbers of non-sclerotic glomeruli (NSG), podometrics and zonal differences in podometrics remain incompletely understood. To help define this, we studied autopsy kidneys from 50 adults with median age 68 years and median eGFR 73.5 mL/min/1.73m2 without apparent glomerular disease in a cross-sectional analysis. The number of NSG per kidney was estimated using the physical dissector/fractionator combination, while podometrics were estimated using model-based stereology. The number of NSG per kidney was directly correlated with podocyte number per tuft and podocyte density. Each additional 100,000 NSG per kidney was associated with 26 more podocytes per glomerulus and 16 podocytes per 106 µm3 increase in podocyte density. These associations were independent of clinical factors and cortical zone. While podocyte number per glomerulus was similar in the three zones, superficial glomeruli were the smallest and had the highest podocyte density but smallest podocytes. Increasing age and hypertension were associated with lower podocyte number, with age mostly affecting superficial glomeruli, and hypertension mostly affecting juxtamedullary glomeruli. Thus, in this first study to report a direct correlation between the number of NSG and podometrics, we suggest that podocyte number is decreasing in NSG of individuals losing nephrons. However, another possible interpretation may be that more nephrons might protect against further podocyte loss.

Tubulointerstitial nephritis: a biopsy case series of 139 Japanese patients.

BACKGROUND: Tubulointerstitial nephritis (TIN) is an important cause of acute kidney injury (AKI) and advanced CKD. Only a limited number of studies have reported etiology-based differences in the clinical and/or histopathological properties and kidney outcomes of the biopsy-proven TIN. METHODS: Patients with biopsy-proven TIN identified from 2005 to 2016 in five hospitals were categorized based on the etiologies and were retrospectively analyzed in relation to the clinicopathological findings and kidney outcomes. RESULTS: Among 4815 biopsy cases screened, 153 Japanese TIN patients were identified, of whom 139 patients with ≥ 6 months of follow-up data (median 58 years old, 45.3% female, median 31.5 months follow-up) were further analyzed. TIN was drug-induced in 32.4%, autoimmune-related in 24.5%, of unknown etiology in 27.3% and other disease-related in 15.8%. Non-steroidal anti-inflammatory drugs and antibiotics were major causative drugs in drug-induced TIN, and IgG4-related disease, Sjögren's syndrome and sarcoidosis were common in autoimmune-related TIN. Among etiology groups, drug-induced TIN showed advanced AKI with elevated serum creatinine (sCr) and increased C-reactive protein levels at the diagnosis. TIN patients with autoimmune diseases showed less-severe AKI, but were more frequently treated with corticosteroids than others. Tubulointerstitial injury expansion in biopsy specimens was comparable among the groups. Complete or partial kidney function recovery at 6 months was more frequent in drug-induced and autoimmune-related TIN than in others. sCr levels at 6 months were similar among the groups. CONCLUSIONS: This largest case series study of the biopsy-proven TIN in Japan provides detailed information regarding both etiology-based clinicopathological properties and kidney outcomes.

Podometrics in Japanese Living Donor Kidneys: Associations with Nephron Number, Age, and Hypertension.

BACKGROUND: Podocyte depletion, low nephron number, aging, and hypertension are associated with glomerulosclerosis and CKD. However, the relationship between podometrics and nephron number has not previously been examined. METHODS: To investigate podometrics and nephron number in healthy Japanese individuals, a population characterized by a relatively low nephron number, we immunostained single paraffin sections from 30 Japanese living-kidney donors (median age, 57 years) with podocyte-specific markers and analyzed images obtained with confocal microscopy. We used model-based stereology to estimate podometrics, and a combined enhanced-computed tomography/biopsy-specimen stereology method to estimate nephron number. RESULTS: The median number of nonsclerotic nephrons per kidney was 659,000 (interquartile range [IQR], 564,000-825,000). The median podocyte number and podocyte density were 518 (IQR, 428-601) per tuft and 219 (IQR, 180-253) per 106µm3, respectively; these values are similar to those previously reported for other races. Total podocyte number per kidney (obtained by multiplying the individual number of nonsclerotic glomeruli by podocyte number per glomerulus) was 376 million (IQR, 259-449 million) and ranged 7.4-fold between donors. On average, these healthy kidneys lost 5.63 million podocytes per kidney per year, with most of this loss associated with glomerular loss resulting from global glomerulosclerosis, rather than podocyte loss from healthy glomeruli. Hypertension was associated with lower podocyte density and larger podocyte volume, independent of age. CONCLUSIONS: Estimation of the number of nephrons, podocytes, and other podometric parameters in individual kidneys provides new insights into the relationships between these parameters, age, and hypertension in the kidney. This approach might be of considerable value in evaluating the kidney in health and disease.

Podocyte endowment and the impact of adult body size on kidney health.

Low birth weight is a risk factor for chronic kidney disease, whereas adult podocyte depletion is a key event in the pathogenesis of glomerulosclerosis. However, whether low birth weight due to poor maternal nutrition is associated with low podocyte endowment and glomerulosclerosis in later life is not known. Female Sprague-Dawley rats were fed a normal-protein diet (NPD; 20%) or low-protein diet (LPD; 8%), to induce low birth weight, from 3 wk before mating until postnatal day 21 (PN21), when kidneys from some male offspring were taken for quantitation of podocyte number and density in whole glomeruli using immunolabeling, tissue clearing, and confocal microscopy. The remaining offspring were fed a normal- or high-fat diet until 6 mo to induce catch-up growth and excessive weight gain, respectively. At PN21, podocyte number per glomerulus was 15% lower in low birth weight (LPD) than normal birth weight (NPD) offspring, with this deficit greater in outer glomeruli. Surprisingly, podocyte number in LPD offspring increased in outer glomeruli between PN21 and 6 mo, although an overall 9% podocyte deficit persisted. Postnatal fat feeding to LPD offspring did not alter podometric indexes or result in glomerular pathology at 6 mo, whereas fat feeding in NPD offspring was associated with far greater body and fat mass as well as podocyte loss, reduced podocyte density, albuminuria, and glomerulosclerosis. This is the first report that maternal diet can influence podocyte endowment. Our findings provide new insights into the impact of low birth weight, podocyte endowment, and postnatal weight on podometrics and kidney health in adulthood.NEW & NOTEWORTHY The present study shows, for the first time, that low birth weight as a result of maternal nutrition is associated with low podocyte endowment. However, a mild podocyte deficit at birth did not result in glomerular pathology in adulthood. In contrast, postnatal podocyte loss in combination with excessive body weight led to albuminuria and glomerulosclerosis. Taken together, these findings provide new insights into the associations between birth weight, podocyte indexes, postnatal weight, and glomerular pathology.

Remission of proteinuria under therapeutic intervention and the renal outcomes in Japanese patients with lupus nephritis class III and IV.

AbstractsBackground: Recent studies have identified the significance of proteinuria levels after initial induction therapies on the renal outcomes in patients with proliferative lupus nephritis, but the issue has not been evaluated in Japanese patients.Methods: Based on the ISN/RPS classification, only patients diagnosed with lupus nephritis class III or IV were included. The remission of proteinuria 12 months after diagnosis, as well as the clinicopathological features at diagnosis, on renal outcomes was examined retrospectively. Renal progression was defined as a 50% decrease in the estimated glomerular filtration rate or the development of end-stage renal disease.Results: This study included 82 Japanese patients with a median follow-up period of seven years. Although all patients received intensive induction therapy, 15 patients (18%) showed progression. Proteinuric remission 12 months after diagnosis predicted a good renal outcome by multivariate analysis. A receiver-operating characteristic analysis of 38 patients whose quantitative urinary protein excretion levels at 12 months were available for analysis showed that a cut-off value of 0.8 g/day predicted renal progression most effectively. Neither the renal function nor proteinuria level at diagnosis were associated with the renal outcomes.Conclusion: In Japanese patients with lupus nephritis class III or IV, proteinuria levels after 12 months under intensive therapy predicted renal outcomes more accurately than did factors identified at diagnosis.

Group 1 innate lymphoid cells are involved in the progression of experimental anti-glomerular basement membrane glomerulonephritis and are regulated by peroxisome proliferator-activated receptor α.

Innate lymphoid cells play an important role in the early effector cytokine-mediated response. In Wistar Kyoto rats, CD8+ non-T lymphocytes (CD8+Lym) infiltrate into glomeruli during the development of anti-glomerular basement membrane (anti-GBM) glomerulonephritis. Here, we examined the profiles and roles of CD8+Lym in anti-GBM glomerulonephritis. The regulation of CD8+Lym by peroxisome proliferator-activated receptor (PPAR)-α in anti-GBM glomerulonephritis was also evaluated. Glomerular infiltrating CD8+Lym were lineage-negative cells that showed markedly high expression of IFN-γ and T-bet mRNAs but not Eomes, indicating these cells are group 1 innate lymphoid cells. In anti-GBM glomerulonephritis, the glomerular mRNAs of innate lymphoid cell-related cytokines (IFN-γ and TNF-α) and chemokines (CXCL9, CXCL10, and CXCL11) are significantly increased. Treatment with a PPARα agonist ameliorated renal injury, with reduced expression of these mRNAs. In vitro, enhanced IFN-γ production from innate lymphoid cells upon IL-12 and IL-18 stimulation was reduced by the PPARα agonist. Moreover, CXCL9 mRNA in glomerular endothelial cells and CXCL9, CXCL10, and CXCL11 mRNAs in podocytes and macrophages were upregulated by IFN-γ, whereas the PPARα agonist downregulated their expression. We also detected the infiltration of innate lymphoid cells into glomeruli in human anti-GBM glomerulonephritis. Thus, innate lymphoid cells are involved in the progression of anti-GBM glomerulonephritis and regulated directly or indirectly by PPARα. Our findings suggest that innate lymphoid cells could serve as novel therapeutic targets for anti-GBM glomerulonephritis.

Synthesis and characterization of bent fluorine-containing donor-π-acceptor molecules as intense luminophores with large Stokes shifts.

Herein, we prepared novel bent fluorine-containing donor-π-acceptor (D-π-A) molecules from commercially available octafluorocyclopentene using a facile two-step procedure, revealing that the above molecules absorb UV-light and exhibit yellow photoluminescence (PL) with high PL efficiencies (ΦPL) in solution. The corresponding Stokes shifts exceeded 10 000 cm-1, and the maximum PL wavelength (λPL) strongly depended on solvent polarity or intermolecular interactions in the solid state. On the basis of a Lippert-Mataga plot, PL was confidently assigned to radiative relaxation from an intramolecular charge-transfer excited state. Moreover, the synthesized luminophores showed intense PL even in the crystalline state and exhibited alkoxy chain length-dependent PL behavior (e.g., high ΦPL, λPL = 486-540 nm).

Biopsy-based estimation of total nephron number in Japanese living kidney donors.

BACKGROUND: Increasing evidence suggests that individuals with low nephron number have an increased lifetime risk of renal insufficiency, thereby emphasizing the importance of evaluating total nephron number in each individual. In recent years, new methods have been described for estimating human total nephron number using a combination of image analysis and renal biopsy, though the reproducibility and accuracy of these methods remain uncertain. This study estimated total nephron number in healthy Japanese subjects using such a method. METHODS: Implantation biopsies from 44 living kidney donors were analyzed. Using pre-donation contrast CT angiograms, transplantation donor kidneys were three-dimensionally reconstructed, and total renal cortical volume was estimated. Total nephron number was estimated based on glomerular density in biopsy specimens and total renal cortical volume. The obtained results were analyzed in relation to clinical variables and compared with those of a previously reported Japanese autopsy study. RESULTS: The estimated non-sclerotic and total numbers of glomeruli in this cohort were 650,000 ± 220,000 and 710,000 ± 220,000 (mean ± SD) per kidney. Non-sclerotic glomerular number ranged from 280,000 to 1,220,000 per kidney (4.4-fold) and correlated directly with eGFR (r = 0.328, p = 0.030) and inversely with age (r = - 0.355, p = 0.018). CONCLUSION: The estimated total nephron number obtained in the present study was 25% less than that reported in American living kidney donors obtained using the same procedure and similar to that obtained in a previous Japanese autopsy study using the disector/fractionator method. These results confirm the feasibility of a combined CT angiography and biopsy-based method to estimate total nephron number in humans.

Synthesis and Photochemical Properties of Axially Chiral Bis(dinaphthofuran).

Both enantiomers of axially chiral bis(dinaphthofuran) were prepared in only two steps from 1'-hydroxy-4'-methoxy-2,2'-binaphthalenyl-1,4-dione, followed by optical resolution via high-performance liquid chromatography (HPLC) using a chiral stationary phase (CSP). The absolute configurations were determined by comparison of experimental and calculated vibrational circular dichroism (VCD) spectra. Synthetic bis(dinaphthofuran) exhibited a broad and unstructured emission derived from an intramolecular excimer in both solution and solid state. The methylene bridge brings both chromophores close to each other and induces significant changes in the photophysical behavior. Chiral bis(dinaphthofuran) displayed a bathochromic shift in emission, as compared to the racemic mixture in the solid state. Furthermore, the compounds showed high circularly polarized luminescence (CPL) with a dissymmetry factor ( glum) of 10-3 at 405 nm upon excitation at 265 nm in a methanol solution. This compound serves as a model for the design and synthesis of organic materials having CPL activity.

Successful treatment of recurrent immunoglobulin a nephropathy using steroid pulse therapy plus tonsillectomy 10 years after kidney transplantation: a case presentation.

BACKGROUND: Both prevention and treatment of recurrent immunoglobulin A nephropathy (IgAN) in kidney transplant recipients are important since recurrent IgAN seems to affect long-term graft survival. We present here a case of recurrent IgAN that was successfully treated using steroid pulse therapy plus tonsillectomy 10 years after kidney transplantation. CASE PRESENTATION: A 46-year-old male was admitted for an episode biopsy with a serum creatinine level of 1.8 mg/dl and proteinuria (0.7 g/day). Histological features showed recurrent IgAN (only focal segmental mesangial proliferation) and severe arteriolar hyalinosis partly associated with calcineurin inhibitor toxicity, with limited interstitial fibrosis and tubular atrophy (5%) (IF/TA) 8 years after transplantation. Sodium restriction and conversion from cyclosporine to tacrolimus successfully reduced his proteinuria to the level of 0.15 g/day. However, 2 years later, his proteinuria increased again (1.0 g/day) and a second episode biopsy showed global mesangial proliferation with glomerular endocapillary and extracapillary proliferation accompanied by progressive IF/TA (20%). The steroid pulse therapy plus tonsillectomy successfully decreased his proteinuria and he achieved clinical remission 3 years after this treatment. CONCLUSION: This case, presented with a review of relevant literature, demonstrates the difficulty and importance of the treatment of recurrent IgAN and calcineurin inhibitor arteriolopathy, especially in long-term kidney allograft management.

Circadian blood pressure abnormalities in patients with primary nephrotic syndrome.

BACKGROUND: Only a few studies have evaluated the abnormalities of ambulatory blood pressure (ABP) in patients with nephrotic syndrome (NS). METHODS: The 24-h ABPs were measured in primary NS patients with acute onset of disease and analyzed in relation to the clinical variables. RESULTS: Our subjects comprised 21 patients: 17 with minimal change disease and 4 with focal segmental glomerulosclerosis. Of these patients, 8 (38%) had daytime hypertension, 13 (62%) had nighttime hypertension, and 13 (62%) were non-dippers (nighttime-to-daytime ratio of ABP: NDR > 0.9). The serum sodium level was correlated with the average 24-h ABP and NDR, after adjustment for other clinical variables, such as the increase in body weight, serum albumin level, and urinary protein excretion. The data from repeated ABP measurements, before and after the achievement of remission, showed a marked decrease in the average 24-h ABP after remission. Furthermore, change in the serum sodium level was significantly correlated with the change in NDR. CONCLUSION: These results suggest that alteration in renal handling of sodium and water, which might be reflected in serum sodium level, is involved in the abnormality of circadian blood pressure in primary NS patients.

Reduction of proteinuria by therapeutic intervention improves the renal outcome of elderly patients with IgA nephropathy.

BACKGROUND: The number of elderly patients with IgA nephropathy (IgAN) is increasing in parallel with the increased longevity in the general population. However, information is limited regarding the characteristics of such patients. METHODS: IgAN patients who were ≥60 years of age at diagnosis were retrospectively analyzed. The clinicopathological features at biopsy, therapies during the follow-up period, renal outcomes and extrarenal complications were evaluated. RESULTS: The characteristics of a total of 87 patients were as follows (mean values): 65 years of age, an eGFR of 47 mL/min/1.73 m2, and urinary protein excretion (UPE) of 1.9 g/day. In the initial 1-year follow-up period, UPE decreased from 2.4 to 0.4 g/day in patients treated with corticosteroids and 1.4 to 0.8 g/day in patients treated with conservative therapies, including renin-angiotensin system blockade. During the observation period, 26 % of the patients who received corticosteroids and 38 % of the patients treated with conservative therapies showed a ≥30 % decrease in their eGFR or reached end-stage renal disease. In the analysis of all patients, UPE at 1 year after the diagnosis was identified to be an independent predictor of the subsequent loss of renal function. However, neither corticosteroid therapy nor conservative therapies was identified to be an independent valuable. There was no significant difference in the incidence of the extrarenal complications between patients treated with corticosteroids and those with conservative therapies. CONCLUSION: In elderly IgAN patients, the reduction of proteinuria by therapeutic interventions may lead to better renal outcomes without causing severe extrarenal complications.

Successful treatment of recurrent Henoch-Schönlein purpura nephritis in a renal allograft with tonsillectomy and steroid pulse therapy.

We report a case of recurrent Henoch-Schönlein purpura nephritis (HSPN) treated successfully with a tonsillectomy and steroid pulse therapy in a kidney transplant patient. A 29-year-old woman was admitted to our hospital for an episode biopsy; she had a serum creatinine (S-Cr) of 1.0 mg/dL and 1.34 g/day proteinuria 26 months after kidney transplantation. Histological examination revealed increased amounts of mesangial matrix and mesangial hypercellularity with IgA deposition. Of note, one glomerulus showed focal endocapillary proliferation and tuft necrosis. We diagnosed active recurrent HSPN. Considering both the histological findings and refractory clinical course of the native kidney, she was treated for 3 consecutive days with steroid pulse therapy and a tonsillectomy. The patient's proteinuria decreased gradually to less than 150 mg/day 6 months later. A second biopsy 6 years after kidney transplantation showed an excellent response to treatment and revealed a marked reduction in both the mesangial matrix and mesangial hypercellularity, with trace IgA deposition. We conclude that a tonsillectomy and steroid pulse therapy appeared to be useful in this patient with active recurrent HSPN. This paper is the first to report a tonsillectomy and steroid pulse therapy as a therapeutic option for active recurrent HSPN. Further studies are needed to elucidate the efficacy and mechanisms of tonsillectomy with recurrent HSPN in kidney transplant patients.

Subclinical antibody-mediated rejection due to anti-human-leukocyte-antigen-DR53 antibody accompanied by plasma cell-rich acute rejection in a patient with cadaveric kidney transplantation.

A 56-year-old man who had undergone cadaveric kidney transplantation 21 months earlier was admitted to our hospital for a protocol biopsy; he had a serum creatinine level of 1.2 mg/dL and no proteinuria. Histological features showed two distinct entities: (i) inflammatory cell infiltration, in the glomerular and peritubular capillaries and (ii) focal, aggressive tubulointerstitial inflammatory cell infiltration, predominantly plasma cells, with mild tubulitis (Banff 13 classification: i2, t1, g2, ptc2, v0, ci1, ct1, cg0, cv0). Immunohistological studies showed mildly positive C4d immunoreactivity in the peritubular capillaries. The patient had donor specific antibody to human-leucocyte-antigen-DR53. We diagnosed him with subclinical antibody-mediated rejection accompanied by plasma cell-rich acute rejection. Both antibody-mediated rejection due to anti- human-leucocyte-antigen -DR53 antibodies and plasma cell-rich acute rejection are known to be refractory and have a poor prognosis. Thus, we started plasma exchange with intravenous immunoglobulin and rituximab for the former and 3 days of consecutive steroid pulse therapy for the latter. Three months after treatment, a follow-up allograft biopsy showed excellent responses to treatment for both histological features. This case report considers the importance of an early diagnosis and appropriate intervention for subclinical antibody-mediated rejection due to donor specific antibody to human-leucocyte-antigen-DR53 and plasma cell-rich acute rejection.

Rare case of nephrocalcinosis in the distal tubules caused by hereditary renal hypouricaemia 3 months after kidney transplantation.

We report a rare case of nephrocalcinosis caused by hereditary renal hypouricaemia 3 months after kidney transplantation. A 41-year-old man who underwent living-related kidney transplantation from his father was admitted to our hospital for a protocol biopsy; he had a serum creatinine (S-Cr) of 1.37 mg/dL and no proteinuria. Histologically, there was no evidence of rejection or calcineurin inhibitor toxicity, although scattered nephrocalcinosis was observed in the distal tubules. Perioperatively, the patient had a serum uric acid (S-UA) of 1.9 mg/dL with a fractional excretion of uric acid (FEUA) of 29% (normal, <10%) and UA clearance of 26.8 mL/min (normal, 7.3-14.7 mL/min) 3 days after kidney transplantation. The donor also had a relatively low S-UA of 2.4 mg/dL and high FEUA of 10.3%. Subsequent DNA direct sequencing followed by restriction fragment length polymorphism revealed that both the recipient's and donor's urate transporter 1 (URAT1) gene had a heterozygous nonsense mutation in exon 5 (C889T). Further, the immunoreactivity of antibodies for the C terminus of URAT1 revealed a partial deletion. De Galantha and von Kossa staining revealed that the nephrocalcinosis was due to urate crystals and calcium stones. Therefore, we diagnosed hereditary renal hypouricaemia. We directed the patient to avoid hard exercise, drink plenty of water, and alkalize the urine. The 1-year follow-up allograft biopsy showed no evidence of nephrocalcinosis in the distal tubules. This is the first report of nephrocalcinosis in the distal tubules as a diagnostic clue to hereditary renal hypouricaemia. We also review the related literature.

Fractional excretion of total protein predicts renal prognosis in Japanese patients with primary membranous nephropathy.

Background: Primary membranous nephropathy (pMN) is one of the most common types of glomerulonephritis, with a third of patients progressing to renal insufficiency. Various prognostic factors have been reported, of which urinary protein and renal function are the most critical parameters. Fractional excretion of total protein (FETP) indicates protein leakage that accounts for creatinine kinetics and serum protein levels. In this study, we investigated the association between FETP and renal prognosis in pMN. Methods: We retrospectively identified 150 patients with pMN. FETP was calculated as follows: (serum creatinine × urine protein)/(serum protein × urine creatinine) %. We divided the patients into three groups according to FETP values and compared the clinicopathological findings. The primary outcome was an estimated glomerular filtration rate (eGFR) decrease of ≥30% from the baseline level. Results: FETP was associated with urinary protein and renal function, Ehrenreich and Churg stage, and global glomerulosclerosis. The primary outcome was observed in 38 patients (25.3%), and the frequency of the primary outcome was higher in the high FETP group (P = .001). FETP is higher than protein-creatinine ratio (PCR) in the area under the curve. In the multivariate analysis adjusted for age, eGFR, PCR and treatment, FETP was significantly associated with primary outcome (adjusted hazard ratio, 8.19; P = .019). Conclusions: FETP is a valuable indicator that can reflect the pathophysiology and is more useful than PCR as a predictor of renal prognosis in patients with Japanese pMN.