Autopsy study examining non-chronic kidney disease versus chronic kidney disease caused by hypertensive-nephrosclerosis in elderly subjects.

BACKGROUND: The aim of this autopsy study was to clarify the differences of renal histopathology between non-chronic kidney disease (CKD) and CKD caused by hypertensive-nephrosclerosis in the elderly and during the aging process. METHODS: We examined autopsy specimens from 105 elderly patients (53 male subjects; mean age, 86.2 years) including 44 patients with CKD as a result of nephrosclerosis. The analysis was divided into two groups depending on whether they had CKD. RESULTS: The incidences of arterial intimal thickening (AIT), obsolescent-type global glomerulosclerosis (OB), and interstitial fibrosis and tubular atrophy (IF/TA) were higher in the CKD group than in the non-CKD group (all p < 0.01). These factors were all correlated with each other (AIT vs. OB, r = 0.43; AIT vs. IF/TA, r = 0.25; OB vs. IF/TA, r = 0.53). IF/TA had the strongest association with hypertension and decreased eGFR. In the non-CKD group, the frequency of OB was more than 20% in subjects aged 90 years or older. However, the individuals in the non-CKD group tended to have compensatory glomerular hypertrophy with increasing age and a retained eGFR, while the CKD group was unable to obtain compensatory hypertrophy and had a lower eGFR. We also found that AIT, OB and IF/TA occurred independently of systemic atherosclerosis. CONCLUSIONS: Non-CKD in the elderly refers to the so-called aging kidney. The progression from aging kidney to CKD caused by nephrosclerosis was influenced by increases in AIT, OB and IF/TA. IF/TA was thought to be the most important downstream factor in the progression of aging kidney to CKD.

The efficacy and safety of mizoribine for maintenance therapy in patients with myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis: the usefulness of serum mizoribine monitoring.

BACKGROUND: The life prognosis of elderly patients with myeloperoxidase-anti-neutrophil cytoplasmic antibodies-associated vasculitis (MPO-AAV) has been improved by reducing the corticosteroid or cyclophosphamide dose to avoid opportunistic infection. However, many elderly MPO-AAV patients experience recurrence and renal death. An effective and safer maintenance treatment method is necessary to improve the renal prognosis of MPO-AAV. METHODS: Patients with MPO-AAV who reached complete or incomplete remission after induction therapy were prospectively and randomly divided into mizoribine (MZR; n = 25) and control (n = 28) groups. The primary endpoint was relapse of MPO-AAV. The patients' serum MZR concentration was measured before (C0) and 3 h after taking the MZR. The maximum drug concentration (Cmax) and the serum MZR concentration curves were determined using population pharmacokinetics parameters. We also assessed the relationship between the MZR concentrations and adverse events. The observation period was 12 months. RESULTS: Fifty-eight MPO-AAV patients from 16 hospitals in Japan were enrolled. Ten patients relapsed (MZR group, n = 6; control group, n = 4; a nonsignificant between-group difference). Changes in the serum MZR concentration could be estimated for 22 of the 25 MZR-treated patients: 2 of the 11 patients who reached a Cmax of 3 µg/mL relapsed, whereas 4 of the 11 patients who did not reach this Cmax relapsed. The treatment of one patient with C0 > 1 µg/mL was discontinued due to adverse events. No serious adverse events occurred. CONCLUSION: There was no significant difference in the recurrence rate of MPO-AAV between treatment with versus without MZR.

Identification of histopathological and clinical spectrum of diabetic kidney disease based on an unsupervised hierarchical clustering analysis of elderly autopsy specimens.

AIM: Diabetic kidney disease (DKD), a chronic kidney disease caused by diabetes and other comorbidities, is the leading cause of end-stage renal disease. The pathogenesis of DKD is diverse and influenced by various causes, some but not all of which cause proteinuria. Some factors such as hypertension can modify DKD. Therefore, the spectrum of DKD is difficult to elucidate and remains unsolved. This study aims to classify and characterize DKD. METHODS: We examined autopsy specimens from type 2 diabetes mellitus (DM) (n = 44) and non-DM (n = 21) groups. RESULTS: The frequency of interstitial fibrosis and tubular atrophy was higher in patients with proteinuric DKD than in those with non-proteinuric DKD. The presence of polar vasculosis was associated with hypertension in DKD. In addition, an unsupervised hierarchical clustering analysis revealed the spectrum of renal histopathology findings for more-proteinuric and less-proteinuric DKD. With changes in the diagnostic criteria for hypertension and advances in antihypertensive drugs, the pathogenesis of DKD may be changing. Furthermore, a decision tree model suggested how diabetes, hypertension, and dyslipidemia interacted in predicting the characteristics of DKD. CONCLUSION: Polar vasculosis is a good indicator of the presence of DM and hypertension. Furthermore, the histopathological and clinical spectrum of DKD were related to the interaction of diabetes, hypertension, and dyslipidemia. These histopathological and clinical results may help to show the range of patient characteristics when conducting clinical trials and could help to determine whether chronic kidney disease is caused by DM or some other cause.

Geriatric assessment of estimated glomerular filtration rate: a cross-sectional study.

BACKGROUND: Estimated glomerular filtration rate (eGFR) is routinely calculated based on the serum creatinine level. However, the validity of such calculation in the geriatric population has not been sufficiently assessed. To examine whether the discrepancies between the eGFR determined based on the serum creatinine (eGFRcr) and that based on the serum cystatin C (eGFRcys) may be influenced to a lesser degree, by factors such as aging and muscle mass. METHODS: We measured the cystatin C and creatinine levels in 19,764 subjects (mean 77.0 years) and the eGFRcys and eGFRcr using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Japanese, and Berlin Invitation Study (BIS) equations were calculated. RESULTS: The mean measured eGFRcys and eGFRcr values by the CKD-EPI equation were 48.2 and 66.6 ml/min/1.73 m2 body surface area, respectively. The correlation between the eGFRcr (x) and eGFRcys (y) was y = 0.728x (r = 0.867; p < 0.001). Analysis of the slope among all ages could be shown by the relation, eGFRcys = (0.43 + 0.33/(1 + 10^((82-age)* - 0.046)))*eGFRcr. The correlation between the eGFRcr and eGFRcys by the Japanese equation were also similar. However, when it was calculated by the BIS equation, no drop of the slope of the linear regression line was observed with age. CONCLUSIONS: The eGFRcr was overestimated irrespective of whether the CKD-EPI or the Japanese equation was used. We could convert eGFRcr into eGFRcys by an equation using age. Estimation of eGFR including serum cystatin C was more accurate in elderly people.

A novel autoantibody against moesin in the serum of patients with MPO-ANCA-associated vasculitis.

BACKGROUND: Antineutrophil cytoplasmic autoantibody (ANCA) directed against myeloperoxidase (MPO), a diagnostic criterion in MPO-ANCA-associated vasculitis (MPO-AAV), does not always correlate with disease activity. Here, we detected autoantibodies against moesin, which was located on the surface of stimulated endothelial cells, in the serum of patients. METHODS: The anti-moesin autoantibody titer was evaluated by ELISA. Seventeen kinds of cytokines/chemokines were measured by a Bio-Plex system. RESULTS: Serum creatinine in the anti-moesin autoantibody-positive group was higher than that in the negative group. Additionally, interferon (IFN)-γ, macrophage chemotactic peptide-1 (MCP-1), interleukin (IL)-2, IL-7, IL-12p70, IL-13, granulocyte/macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor were significantly higher in the positive group. Furthermore, IL-7 and IL-12p70 levels correlated with the anti-moesin autoantibody titer. Based on these findings and the binding of anti-moesin IgG to neutrophils and monocytes, we detected the secretion of cytokines/chemokines such as IFN-γ, MCP-1 and GM-CSF from these cells. CONCLUSIONS: The anti-moesin autoantibody existed in the serum of patients with MPO-AAV and was associated with the production of inflammatory cytokines/chemokines targeting neutrophils with a cytoplasmic profile, which suggests that the anti-moesin autoantibody has the possibility to be a novel autoantibody developing vasculitis via neutrophil and endothelial cell activation.

A functional variant in FCRL3, encoding Fc receptor-like 3, is associated with rheumatoid arthritis and several autoimmunities.

Rheumatoid arthritis is a common autoimmune disease with a complex genetic etiology. Here we identify a SNP in the promoter region of FCRL3, a member of the Fc receptor-like family, that is associated with susceptibility to rheumatoid arthritis (odds ratio = 2.15, P = 0.00000085). This polymorphism alters the binding affinity of nuclear factor-kappaB and regulates FCRL3 expression. We observed high FCRL3 expression on B cells and augmented autoantibody production in individuals with the disease-susceptible genotype. We also found associations between the SNP and susceptibility to autoimmune thyroid disease and systemic lupus erythematosus. FCRL3 may therefore have a pivotal role in autoimmunity.

Assessment of the Birmingham vasculitis activity score in patients with MPO-ANCA-associated vasculitis: sub-analysis from a study by the Japanese Study Group for MPO-ANCA-associated vasculitis.

OBJECTIVES: In the study cohort enrolled in a prospective open-label, multicenter trial conducted by the Japanese Study Group for MPO-ANCA-associated vasculitis (JMAAV), we conducted this sub-analysis to establish the validity of the Birminghan vasculitis activity score (BVAS) for Japanese patients with MPO-ANCA-associated vasculitis. METHODS: We recorded the BVAS at the time of diagnosis, at 6 weeks after the diagnosis, and at 3, 6, 9, 12, 15 and 18 months after the diagnosis in this study. RESULTS: The most frequently involved organs in the patients were the lungs, kidneys and the nervous system. The kidney (BVAS; new/worse 69.2 %, persistent 40.4 %), general (BVAS; new/worse 67.3 %, persistent 53.8 %), chest (BVAS; new/worse 36.5 %, persistent 46.2 %) and nervous system (BVAS; new/worse 38.5 %, persistent 25.0 %) were the organ systems most frequently involved by the disease at the baseline. The BVAS for new/worse disease decreased immediately after induction therapy, while improvement of the BVAS for persistent disease after therapy differed among the organ systems. CONCLUSIONS: BVAS was demonstrated to be a valuable guide for selection of the optimal treatment. Thus, BVAS was also found to be a useful tool in Japanese patients for the assessment of disease activity and degree of organ damage in patients with MPO-ANCA-associated vasculitis.

Correlation of interleukin-6 and monocyte chemotactic protein-1 concentrations with crescent formation and myeloperoxidase-specific anti-neutrophil cytoplasmic antibody titer in SCG/Kj mice by treatment with anti-interleukin-6 receptor antibody or mizoribine.

Myeloperoxidase-specific anti-neutrophil cytoplasmic antibody (MPO-ANCA) is associated with rapidly progressive glomerulonephritis (RPGN) and glomerular crescent formation. Pathogenic factors in RPGN were analyzed by using SCG/Kj mice, which spontaneously develop MPO-ANCA-associated RPGN. The serum concentration of soluble IL-6R was determined by using ELISA and those of another 23 cytokines and chemokines by Bio-Plex analysis. Sections of frozen kidney tissue were examined by fluorescence microscopy and the CD3(+) B220(+) T cell subset in the spleen determined by a flow cytometry. Concentrations of IL-6 and monocyte chemotactic protein-1 were significantly correlated with the percentages of crescent formation. Anti-IL-6R antibody, which has been effective in patients with rheumatoid arthritis, was administered to SCG/Kj mice to elucidate the role of IL-6 in the development of RPGN. MPO-ANCA titers decreased after administration of anti-IL-6R antibody, but not titers of mizoribine, which is effective in Kawasaki disease model mice. These results suggest that IL-6-mediated signaling is involved in the production of MPO-ANCA.

Patients with adult minimal change nephrotic syndrome treated with long-term cyclosporine did not experience a reduction in their eGFR.

BACKGROUND: The long-term efficacy and safety of cyclosporine (CyA) in the treatment of adult minimal change nephrotic syndrome (MCNS) was examined. METHODS: The medical record of 15 patients diagnosed with MCNS by renal biopsy and treated with CyA for at least 2 years were reviewed. RESULTS: The mean administration period of CyA was 78.3 months. The mean CyA dose for the induction period was 2.1 ± 0.9 mg/kg and 1.7 ± 1.0 mg/kg for the maintenance period. The mean dose of prednisolone used during the induction period was 20.3 mg and 2.7 mg during the maintenance. The frequency of MCNS relapse was decreased to 0.5 times/year in patients treated with CyA, compared to treatment without CyA (2.4 times/y). Two cases of mild liver damage and 3 cases of elevated blood pressure were observed during the administration of CyA. These adverse effects improved after reducing the CyA dose or treatment with an antihypertensive agent. A decrease in the estimated glomerular filtraion rate (eGFR) was not associated with long-term CyA use. CONCLUSION: At our institution, patients who were treated for MCNS with CyA for at least 2 years experienced no deterioration in renal function.

Evaluation of the newly proposed simplified histological classification in Japanese cohorts of myeloperoxidase-anti-neutrophil cytoplasmic antibody-associated glomerulonephritis in comparison with other Asian and European cohorts.

The prognostic value of renal biopsy in anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis is widely recognized; however, there is no consensus regarding its pathological classification. Berden et al. proposed a new classification of glomerulonephritis in ANCA-associated vasculitis (AAV) categorized into focal, crescentic, mixed, and sclerotic classes and showed its prognostic value in 100 international multicenter cohorts for 1- and 5-year renal outcomes. In order to evaluate whether this new classification has predictive value and reproducibility in Japanese AAV cases, 87 cohorts with only microscopic polyangiitis in 3 limited centers in Japan were analyzed. In addition, those from Japan, Europe (Berden's cohorts) and China were compared in a recent report.

A case of IgG4-related tubulointerstitial nephritis with left hydronephrosis after a remission of urinary tract tuberculosis.

IgG4-related systemic disease encompasses multi-organ disorders, including tubulointerstitial nephritis. This disease is accompanied by a high serum IgG4 concentration and IgG4-positive plasma cell infiltration. We herein describe a 63-year-old woman with renal failure and dryness of the eyes and mouth, who had been treated with antituberculosis agents for urinary tract tuberculosis. She had a negative finding for a PCR analysis for Mycobacterium tuberculosis, a positive QuantiFERON-TB test, high serum IgG4 concentrations (2,660 mg/dl), and low serum IgM and IgA concentrations (34 and 82 mg/dl, respectively). Imaging tests revealed swelling in the submandibular glands, pancreas, and right kidney. A renal biopsy showed IgG4-positive plasma cell infiltration in the interstitium and tubular atrophy. This case was diagnosed as IgG4-related systemic disease. Corticosteroid therapy improved renal failure and swelling in the submandibular glands, pancreas, and right kidney. The case suggests that an abnormal reaction to tuberculosis may be associated with a predominance of type-2 helper T-cell immunity, thus resulting in IgG4-related systemic disease.

Assessment of the Birmingham vasculitis activity score in patients with MPO-ANCA-associated vasculitis: sub-analysis from a study by the Japanese Study Group for MPO-ANCA-associated vasculitis.

OBJECTIVES: In the study cohort enrolled in a prospective open-label, multicenter trial conducted by the Japanese Study Group for MPO-ANCA-associated vasculitis (JMAAV), we conducted this sub-analysis to establish the validity of the Birminghan vasculitis activity score (BVAS) for Japanese patients with MPO-ANCA-associated vasculitis. METHODS: We recorded the BVAS at the time of diagnosis, at 6 weeks after the diagnosis, and at 3, 6, 9, 12, 15 and 18 months after the diagnosis in this study. RESULTS: The most frequently involved organs in the patients were the lungs, kidneys and the nervous system. The kidney (BVAS; new/worse 69.2 %, persistent 40.4 %), general (BVAS; new/worse 67.3 %, persistent 53.8 %), chest (BVAS; new/worse 36.5 %, persistent 46.2 %) and nervous system (BVAS; new/worse 38.5 %, persistent 25.0 %) were the organ systems most frequently involved by the disease at the baseline. The BVAS for new/worse disease decreased immediately after induction therapy, while improvement of the BVAS for persistent disease after therapy differed among the organ systems. CONCLUSIONS: BVAS was demonstrated to be a valuable guide for selection of the optimal treatment. Thus, BVAS was also found to be a useful tool in Japanese patients for the assessment of disease activity and degree of organ damage in patients with MPO-ANCA-associated vasculitis.

Anti-glomerular basement membrane disease developing 3 years after the development of Sweet syndrome and 1 year after the development of anti-neutrophil cytoplasmic antibody-associated vasculitis: a case report.

A 73-year-old Japanese woman, with a history of Sweet syndrome diagnosed 3 years earlier and anti-myeloperoxidase (MPO) antibody anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis diagnosed 1 year earlier, presented with an episode of rapidly progressive glomerulonephritis (RPGN) with anti-glomerular basement membrane (GBM) disease. At the time of diagnosis of the ANCA-associated vasculitis 1 year earlier, serological testing yielded a negative result for anti-GBM antibody. However, at the present visit, serology for anti-MPO antibody was negative, while that for anti-GBM antibody was positive. This is the first report of anti-GBM disease developing sequentially after Sweet syndrome and ANCA-associated vasculitis. This case may provide clues to the potential immunological links among these three distinct conditions.

Accelerated recovery from nephrotic syndrome with acute renal failure by double filtration plasmapheresis in a patient with lupus podocytopathy.

We describe a case of an adult female who presented with nephrotic syndrome. She was diagnosed with systemic lupus erythematosus with serum antinuclear antibodies, leucopenia with lymphopenia, butterfly erythema, and nephrotic syndrome. Renal biopsy revealed normal glomeruli with diffuse effacement of the foot processes, consistent with lupus podocytopathy. Although human albumin replacement was performed initially, acute renal failure developed rapidly. Therefore, she was treated with double filtration plasmapheresis (DFPP) in addition to oral steroid. After steroid therapy combined with DFPP, the renal function and proteinuria improved rapidly. Although the impact of DFPP on the treatment of lupus nephritis remains to be delineated, our observations suggest that DFPP in lupus podocytopathy played a pivotal role in facilitating the early recovery from renal injuries. Because of the rapid improvement of renal function without any change in body weight by DFPP, acute renal failure in the setting of lupus podocytopathy might contribute to an alternative pathophysiological factor for the diminished glomerular filtration rate, similar to that observed in the setting of idiopathic minimal change glomerulopathy.

Improvement in health-related quality of life in MPO-ANCA-associated vasculitis patients treated with cyclophosphamide plus prednisolone: an analysis of 18 months of follow-up data from the JMAAV study.

OBJECTIVES: To examine the improvement in health-related quality of life (HRQOL) in association with disease activity in myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis patients treated with cyclophosphamide plus prednisolone. METHODS: According to the Japanese Patients with MPO-ANCA-Associated Vasculitis (JMAAV) study protocol, a total of 48 patients with newly diagnosed MPO-ANCA-associated vasculitis received a standardized cyclophosphamide plus prednisolone regimen, and their clinical courses were followed for 18 months following their entry into the study. Disease activity was assessed using the Birmingham Vasculitis Activity Score (BVAS) 2003. HRQOL was assessed using MOS Short-Form 36 (SF-36) v2. BVAS new/worse, BVAS persistent, and SF-36 domain scores (norm-based) were calculated for the 32 eligible patients. RESULTS: The mean SF-36 domain scores were significantly lower than the Japanese general population norm. Stepwise multiple linear regression analysis showed that the presence of new or worsening features of the nervous system was significantly associated with a deterioration in physical function. During the 18 months of follow-up, there were significant improvements in BVAS new/worse and all SF-36 domains except for general health and role emotional. CONCLUSION: MPO-ANCA-associated vasculitis patients experienced a considerable deterioration in HRQOL. The standardized cyclophosphamide plus prednisolone regimen of the JMAAV study induced remission in the majority of patients, and the induction of remission accompanied a recovery in HRQOL.

Severity-based treatment for Japanese patients with MPO-ANCA-associated vasculitis: the JMAAV study.

We (JMAAV [Japanese patients with MPO-ANCA-associated vasculitis] Study Group) performed a prospective, open-label, multi-center trial to evaluate the usefulness of severity-based treatment in Japanese patients with myeloperoxidase-anti-neutrophil cytoplasmic antibodies (MPO-ANCA)-associated vasculitis. Patients with MPO-ANCA-associated vasculitis received a severity-based regimen according to the appropriate protocol: low-dose corticosteroid and, if necessary, cyclophosphamide or azathioprine in patients with mild form; high-dose corticosteroid and cyclophosphamide in those with severe form; and the severe-form regimen plus plasmapheresis in those with the most severe form. We followed up the patients for 18 months. The primary end points were the induction of remission, death, and end-stage renal disease (ESRD). Fifty-two patients were registered, and 48 patients were enrolled in this study (mild form, n = 23; severe form, n = 23; most severe form, n = 2). Among the 47 patients who received the predefined therapies, 42 achieved remission within 6 months, 5 died, and 1 developed ESRD. Disease flared up in 8 of the 42 patients with remission during the 18-month follow-up period. The JMAAV trial is the first prospective trial for MPO-ANCA-associated vasculitis to be performed in Japan. The remission and death rates were comparable to those in several previous clinical trials performed in western counties. The regimen employed in this trial was tailor-made based on patients' disease severity and disease type, and it seems that standardization can be consistent with treatment choices made according to severity.

Accelerated recovery from Candida peritonitis of enteric origin by early surgical drainage in a peritoneal dialysis patient.

A 62-year-old man on continuous ambulatory peritoneal dialysis was transferred to our hospital with recurrent abdominal pain and a cloudy peritoneal effluent. Three weeks before the transfer, his symptoms were successfully treated with broad-spectrum antibiotics. However, their effectiveness was lost for his recurrent symptoms. Fungal peritonitis was diagnosed because of an increased white blood cell count in the peritoneal fluid on admission and isolation of Candida albicans from a peritoneal fluid culture. Intravenous fos-fluconazole was immediately started, although it was ineffective for his deteriorating symptoms. The concomitant isolation of Candida albicans in a stool culture suggested that fungal peritonitis had an enteric origin. An emergency laparotomy revealed multiple diverticulosis and sigmoid colon diverticulitis. A surgical drainage was performed in addition to peritoneal catheter removal. Postoperatively, the patient's symptoms improved rapidly and there were no signs of recurrence with continuous administration of fos-fluconazole. Surgical drainage accelerated the recovery from fungal peritonitis. This patient is the first case showing the usefulness of stool culture in the diagnosis of fungal peritonitis secondary to prior bacterial peritonitis. This case also demonstrated the importance of laparotomy to confirm the enteric origin of the fungus, and the efficacy of early surgical drainage for the treatment.

Nephrotic syndrome and renal failure in a patient with metastatic breast cancer.

This report presents a case of nephrotic syndrome and renal failure that developed in a 53-year-old female with metastatic breast carcinoma. She was diagnosed to have osteolytic bone metastases 5 years prior to admission, and had been administered pamidronate with a total dose of approximately 6800 mg. A renal biopsy revealed tubulointerstitial damage and marked wrinkling and retraction of the glomerular basement membrane with hypertrophy and hyperplasia of the epithelial cells, compatible with the collapsing form of focal segmental glomerulosclerosis (FSGS). Despite the discontinuation of pamidronate after admission, her renal function gradually decreased. She was finally managed with continuous palliative care for advanced malignancy through a shared effort, and died 96 days after undergoing the renal biopsy. Although the clinical impact of the pamidronate-associated kidney injury on the longitudinal changes in renal function remains to be delineated, it is therefore reasonable to consider that the collapsing FSGS associated with tubulointerstitial damage may have resulted in the irreversible renal injuries that were observed in the current case. Further studies and accumulated experience with renal biopsy are required to better determine the relationship between pathological alterations and prognostic characteristics among patients with pamidronate-associated renal impairments.

Renal failure caused by plasma cell infiltration in multiple myeloma.

We report on a case of severe renal failure in a 61-year-old female with multiple myeloma (MM). Two months prior to admission, the patient was diagnosed to have anemia and progressive renal failure associated with urinary Bence Jones protein and was referred to our hospital. A bone marrow biopsy revealed 40% plasma cells with κ light chain restriction. Thus, she was considered to have MM. A renal biopsy revealed neoplastic plasma cell infiltration within the kidney, moderate interstitial fibrosis, tubular atrophy, and punctate, electron-dense material along the peripheral capillary walls, tubular basement membrane, and in the interstitium of the kidney. This suggested that a combination of compression of the tubules and the microvasculature by the infiltrative process, and local light chain deposition-mediated tissue damage might be implicated in the development of renal failure in this patient. Despite a remission of bone marrow plasmacytosis with a bortezomib-based regimen, her renal function gradually deteriorated and a periodic hemodialysis program was finally required. Although the clinical impact of the direct kidney infiltration of neoplastic plasma cells on the longitudinal changes in renal function remains to be delineated, it is reasonable to consider that the infiltration of neoplastic plasma cells associated with local light chain depositions may result in irreversible renal injuries. Obviously, further studies and accumulation of additional experience with renal biopsy are required to better determine the precise and prognostic relationship between renal outcome and morphological alterations among MM patients with varying degrees of renal impairment.