Renal histology in Chinese patients with anti-myeloperoxidase autoantibody-positive Wegener's granulomatosis.

BACKGROUND: Proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) was the serological marker for Wegener's granulomatosis (WG), while myeloperoxidase (MPO)-ANCA was the serological marker for microscopic polyangiitis (MPA). However, our previous study suggested that patients with MPO-ANCA positive WG were common in Chinese. This study aimed to analyse the renal histology of patients with MPO-ANCA positive WG. METHODS: Patients in our centre with WG were selected according to both the Chapel Hill Consensus Conference (CHCC) definition and American College of Rheumatology classification criteria. Patients with MPA were selected according to the CHCC definition. The renal histology was compared between patients with MPO-ANCA positive WG and with PR3-ANCA positive WG as well as patients with MPO-ANCA positive MPA. RESULTS: Sixty-one patients with WG had complete renal histological data, 39/61 with positive MPO-ANCA and 22/61 with positive PR3-ANCA. Among patients with crescents in glomeruli, those with MPO-ANCA had fewer cellular crescents and more fibrous crescents than those with PR3-ANCA (P < 0.01 and P < 0.05, respectively). Interstitial fibrosis and tubular atrophy were more prevalent and severe in patients with MPO-ANCA than in those with PR3-ANCA (P < 0.01 and P < 0.05, respectively). Compared with 44 patients with MPO-ANCA positive MPA, patients with MPO-ANCA positive WG had fewer glomeruli with crescents and more normal glomeruli (P < 0.01 and P < 0.01, respectively). CONCLUSION: Patients with MPO-ANCA positive WG are common in Chinese. In renal histology, chronic lesions were more severe and prevalent in patients with MPO-ANCA positive WG than in patients with PR3-ANCA positive WG. Glomerular lesions were less severe and less prevalent in patients with MPO-ANCA positive WG than in those with MPO-ANCA positive MPA.     

Reversible acute renal failure associated with clomipramine-induced interstitial nephritis

We describe a 41-year old man with obsessive-compulsive neurosis who developed acute renal failure (ARF) due to acute interstitial nephritis (AIN) during 6 weeks of treatment with clomipramine hydrochloride (CPH). He had a slight fever, mild arthralgia, appetite loss, and diarrhea after taking CPH. On admission, he showed serum creatinine (sCr) of 7.31 mg/dl, and creatinine clearance (Ccr) of 2.5 ml/min. He subsequently became anuric and required hemodialysis. Renal biopsy revealed AIN with diffuse mononuclear cell infiltration. After the withdrawal of CPH and treatment with prednisolone (PSL) 0.5 mg/kg per day, his urinary output improved, along with improvement of his renal function; therefore hemodialysis was finally discontinued. To our knowledge, this is the first case report of AIN induced by clomipramine.     

Characteristics of Chinese patients with Wegener's granulomatosis with anti-myeloperoxidase autoantibodies

BACKGROUND: Cytoplasmic antineutrophil cytoplasmic autoantibodies (cANCA)/proteinase-3(PR3)-ANCA was considered the serologic diagnostic marker for Wegener's granulomatosis (WG). However, Chinese patients with MPO-ANCA positive WG were frequently diagnosed. We now analyze the characteristics of patients with MPO-ANCA positive WG and investigate the difference between patients with MPO-ANCA and PR3-ANCA. METHODS: Patients with WG were selected according to both Chapel Hill Consensus Conference definition and American College of Rheumatology (ACR) classification criteria in 500 Chinese patients with ANCA-associated systemic vasculitides. The clinical manifestions were compared between patients with MPO-ANCA and with PR3-ANCA. RESULTS: Eight-nine patients fulfilled the diagnostic criteria of WG: 54/89(60.7%) were MPO-ANCA positive, 34/89(38.2%) were PR3-ANCA positive. Patients with MPO-ANCA were predominantly female compared with patients with PR3-ANCA. Patients with MPO-ANCA also had multisystem involvement. However, the prevalences of arthagia, skin rash, ophthalmic and ear involvement were significantly lower in patients with MPO-ANCA than those in patients with PR3-ANCA (46.3% vs. 70.6%, P < 0.05; 20.4% vs. 44.1%, P < 0.05; 27.8% vs. 58.8%, P < 0.01; 40.7% vs. 67.6%, P < 0.05, respectively). The prevalence of elevated initial serum creatinine was significantly higher in patients with MPO-ANCA than that in patients with PR3-ANCA (81.5% vs. 61.8%, chi(2) = 4.20, P < 0.05). CONCLUSION: Patients with MPO-ANCA positive WG were not rare in Chinese.     

The increase of antiglomerular basement membrane antibody following pauci-immune-type crescentic glomerulonephritis

A 50-year-old woman was admitted because of high fever and fatigue. Proteinuria, hematuria, and elevated BUN (47.8mg/dl) and creatinine (3.4mg/dl) suggested rapidly progressive glomerulonephritis. The serological study revealed all negative results for rheumatoid factor, antinuclear antibody, serum cryoglobulins, MPO-ANCA, PR3-ANCA, and anti-streptolysin O. Antiglomerular basement membrane (GBM) antibody, as assessed by ELISA, was 11EU (normal, <10). Kidney biopsy on the eighth hospital day demonstrated pauci-immune-type crescentic glomerulonephritis without ANCA. Methylprednisolone pulse therapy (500mg/day, 3 days) and 45mg/day prednisolone orally were started. At 3 weeks after kidney biopsy, the anti-GBM antibody value increased from 11EU/ml to 116EU/ml, and MPO and PR3-ANCA were still negative. HLA type was DR8 and DR 15(2), with a genotype of HLA-DRB1*08021 and HLA-DRB1*15011. The present case suggests that HLA-DR15 plays an important role on antibody production against alpha 3(IV) NC1 autoantigen after severe nephritis or tissue damage.     

抗髓过氧化物酶抗体阳性的韦格纳肉芽肿病的特点

目的 分析抗髓过氧化物酶(MPO)抗体阳性的韦格纳肉芽肿病(WG)患者的临床病理特点及其与传统的抗蛋白酶3(PR3)抗体阳性者之间的差异&#65377;方法 89例WG患者经本院肾内科确诊,分析其临床病理资料并对比抗MPO抗体阳性和抗PR3抗体阳性的两组患者之间的差异&#65377;结果 89例患者中54例抗MPO抗体阳性,34例抗PR3抗体阳性&#65377;抗MPO抗体阳性患者中男性所占的比例显著低于抗PR3抗体阳性者(男:女分别为23:31与24:10, P<0.05)&#65377;抗MPO抗体阳性的WG临床亦呈多器官受累的表现,其中关节痛&#65380;皮疹&#65380;眼&#65380;耳受累的发生率显著低于抗PR3抗体阳性者(分别为46.3%比70.6%,P < 0.05; 20.4%比44.1%,P < 0.05;27.8%比58.8%,P < 0.01和40.7%比67.6%,P < 0.05);伯明翰血管炎活动度积分(BVAS)显著低于抗PR3抗体阳性者(22.2±6.2比24.7±6.9, P < 0.05);而在确诊时Scr增高的发生率则显著高于抗PR3抗体阳性者(81.5%比61.8%, P < 0.05)&#65377;结论 在国人的WG患者中,抗MPO抗体阳性者可能不占少数,它与抗PR3抗体阳性者临床表现有所不同&#65377;     

Clinical characteristics and prognosis of ANCA-associated vasculitis in patients with renal injury

Objective To investigate the characteristics and outcome of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in patients with renal injury. Methods AAV patients with renal injury diagnosed in the Department of Nephrology, Renmin Hospital of Wuhan University, from January 2012 to January 2017 were included into this study. Patients were divided into MPO-ANCA positive and PR3-ANCA positive groups for further study. The clinical characteristics, pathological and laboratory indexes, treatment and prognosis were retrospectively analyzed. Results A total of 68 cases were enrolled, among which 52 cases (76.5%) were MPO-ANCA positive and 16 cases (23.5%) were PR3-ANCA positive, and 41 patients (60.3%) were over 65 years old. The incidences of interstitial lung disease, digestive and nervous system damage in PR3-ANCA positive group were significantly higher than those MPO-ANCA positive group (P＜0.05). There were significant differences of hemoglobin, complement C3, complement C1q, IgE, 24 h urinary protein, erythrocyte sedimentation rate, procalcitonin, BVAS score and eGFR in two groups (P＜0.05). 19 cases had done renal biopsy,among them 14 cases were MPO-ANCA positive and 5 cases were PR3-ANCA positive. Incidence of crescentic necrotizing glomerulonephritis in PR3-ANCA positive group was significantly higher than that in MPO-ANCA positive group, and incidence of diffuse global glomerulosclerosis in MPO-ANCA positive group was significantly higher than that in PR3-ANCA positive group (all P＜0.05). At the median follow-up time of 32 months, the relapse rate at 6 month of MPO-ANCA-positive and PR3-ANCA-positive patients were 46.2% and 75.0%, respectively (P＜0.05). Multivariate logistic regression analysis showed that PR3-ANCA positive, age≥65 years old, baseline eGFR＜30 ml?min-1?(1.73 m2)-1, and combined with pulmonary interstitial lesions were all independent risk factors for relapse. And the incidence of ESRD were 42.3% and 75.0% during the follow-up period and 10 patients (14.7%) died. COX regression analysis showed that patients older than 65 years old, BVAS score≥18 points, eGFR＜30 ml?min-1?(1.73 m2)-1 and complicated with pulmonary interstitial disorders at the onset were independent risk factors causing ESRD or death. Conclusion The PR3-ANCA-positive patients had more severe renal injury than those with MPO-ANCA-positive patients, and the injury of extrarenal organs was more serious, recurrence rate was higher, and the prognosis was worse.     

MPO-ANCA-positive IgA nephropathy successfully treated with tonsillectomy

A 20-year-old Japanese woman was admitted to a hospital because of gross hematuria. She was diagnosed with IgA nephropathy with a poor prognosis, based on the formation of many crescents in the glomerulus and monocyte infiltration in the interstitium in a renal biopsy specimen in February 2003. Myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) was not identified at that time. After treatment with high-dose steroid pulse therapy and heparin/warfarin, her urinary protein improved, to 0.5 g/day. However, 1 year after the steroid pulse therapy, urinary protein was increased to 1.2 g/day, associated with repeated episodes of tonsillitis. A second renal biopsy was performed, and showed an improving tendency, compared to the findings of the previous one, although some crescent formation and adhesions of Bowman's capsule remained. Interestingly, MPO-ANCA was positive in the serological examination done at this time. One month and a half after the second renal biopsy, she had a tonsillectomy, followed by a regimen of 5 mg oral prednisolone daily, in order to prevent the progression of IgA nephropathy. After the tonsillectomy, her urinary protein level was markedly improved, at 0.14 g/day. Her creatinine clearance was ameliorated, at 102 ml/min, and in addition, MPO-ANCA had disappeared. This case suggests that an inflammation such as tonsillitis may be associated not only with the activity of IgA nephropathy but also with the production of MPO-ANCA.     

ANCA-associated vasculitis with renal involvement: an outcome analysis.

BACKGROUND: The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are a group of heterogeneous diseases. This study was undertaken to investigate the outcome of Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and renal-limited vasculitis (RLV). Furthermore, we analysed the differences in patients with proteinase 3-ANCA (PR3-ANCA) and those with myeloperoxidase-ANCA (MPO-ANCA), which have not been assessed in a homogeneously treated group of patients with renal involvement. METHODS: In this retrospective analysis, 80 patients with a new diagnosis of WG, MPA or RLV with biopsy-proven renal involvement were followed over a median of 46.7 months (range: 0.8-181.9 months). All patients had induction treatment with cyclophosphamide and oral corticosteroids. RESULTS: At the end of follow-up, 23% were dependent on dialysis. Renal survival was significantly worse in patients with WG compared with patients with MPA or RLV (P = 0.04). A higher rate of end-stage renal disease (ESRD) was noticed in PR3-ANCA- vs MPO-ANCA-positive patients. A total of 21 patients (26%) died. Predictors of patient mortality were development of ESRD, older age and the maximum creatinine in the first month. Mortality was found to be higher in patients with WG and was significantly higher in PR3-ANCA-positive cases (P = 0.02). The relative risk of death was 9.32 times higher in PR3-ANCA- vs MPO-ANCA-positive patients. CONCLUSIONS: Our data underscore the pathogenetic potential of ANCA by demonstrating a more aggressive disease state and a poorer outcome in patients with PR3-ANCA.     

Two autopsy cases of ANCA-associated glomerulonephritis manifested after contrast medium use

[Case 1]: An 81-year old man was referred to our hospital with dyspnea and bloody sputum. Computed tomography with contrast medium for the evaluation of metastasis of urinary bladder carcinoma had been performed 4 months previously. On admission, his serum creatinine and potassium were 15.3 mg/dl and 6.9 mEq/l, respectively. His chest X ray revealed cardiomegaly, butterfly shadow and interstitial change, indicating congestive heart failure and interstitial pneumonia. His electrocardiogram showed that he was on the brink of cardiac arrest due to hyperkalemia. Mechanical ventilation and hemodialysis were initiated. Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) was highly positive(321 EU), leading to the diagnosis of MPO-ANCA-associated rapidly progressive glomerulonephritis (RPGN) with interstitial pneumonia. Treatment with pulse methylprednisolone was not effective and he died. Autopsy findings showed crescentic glomerulonephritis, alveolar hemorrhage and interstitial pneumonia with honeycomb formation. [Case 2]: A 73-year old man was referred to our hospital with rapid deterioration of his renal function. He had received a cardiac catheter examination 3 weeks previously. On admission, his serum creatinine was 4.5 mg/dl. His chest X ray showed cardiomegaly and interstitial change. Renal biopsy findings showed crescentic formation in the glomeruli. Moreover, MPO-ANCA was 494 EU, leading to the diagnosis of MPO-ANCA-associated RPGN with interstitial pneumonia. Treatment with pulse methylprednisolone and cyclophosphamide was not effective and he died. Autopsy findings revealed crescentic glomerulonephritis and interstitial pneumonia with honeycomb formation. Here we described two cases of ANCA-associated RPGN complicated by microscopic polyantitis and interstitial pneumonia after the use of contrast medium. The relation between ANCA-associated RPGN and the contrast medium was unclear. However, in the case of rapid deterioration of renal function, MPO-ANCA should be measured even after the use of contrast medium. The complication of lung diseases, especially interstitial pneumonia, should be investigated simultaneously.     

Re-biopsy in a patient with IgA nephropathy showing success of treatment with cyclosporin A and angiotensin-II receptor blocker

We report a patient with IgA nephropathy (IgAN) showing reduction of proteinuria and histological improvement of renal injury with cyclosporin A (CsA) and angiotensin-II receptor blocker (ARB) therapy. The amount of urinary protein was reduced from 4.4 to 1.8 g/24 h after 2 months of CsA (150 mg/day) therapy, and further, to 0.4 g/24 h after 1 month of the combination therapy with ARB (candesartan, 4 mg/day). A renal re-biopsy, after treatment with CsA for 3 months and ARB for 1 month, demonstrated a reduction of IgA deposits, disappearance of crescents, re-separation of foot process fusion and decrease of interstitial cellular infiltration. After CsA therapy for 20 months and ARB for 18 months, the patient currently remains stable without deterioration of serum creatinine (1.7 mg/dl) and urinary protein excretion (0.5 g/day). These findings seem to indicate that combination therapy with CsA and ARB is effective for achieving histological improvement and protecting against deteriorated renal function, in addition to reducing proteinuria, in IgAN. Received: October 1, 2001 / Accepted: April 10, 2002     

Renal expression of ICAM-1 and VCAM-1 in ANCA-associated glomerulonephritis--are there differences among serologic subgroups?

BACKGROUND: Antineutrophil cytoplasmic autoantibodies (ANCA) play a role in the expression of adhesion molecules. Differences in ANCA test results in ANCA-associated vasculitis may provide differences in their renal expression. PATIENTS AND METHODS: We assessed the renal expression of ICAM-1 and VCAM-1 with monoclonal antibodies in 19 patients with ANCA-vasculitis: 7 microscopic polyangiitis, 5 Wegener's granulomatosis, 4 renal-limited vasculitis and 3 Churg-Strauss disease. Immunofluorescence and ELISA for myeloperoxidase (MPO) and proteinase 3 (PR3) were performed for ANCA-testing. 10 normal renal tissues were used as controls. RESULTS: The ANCA staining pattern was perinuclear in 14 patients, with MPO-ANCA 31 - 220 EU/ml, and cytoplasmic in 5, with PR3-ANCA 37 - 144 EU/ml. Abnormal tubular expression of ICAM-1 and VCAM-1 was seen in more than 80% of biopsies and abnormal expression of VCAM-1 in glomerular tuft was seen in 60%. Glomerular tuft stains of ++ or +++ for VCAM-1 were observed in 10% of renal biopsies from MPO-ANCA-GN patients, but in 60% of biopsies from PR3-ANCA-GN patients (Fi = 8.538, p = 0.03). IN CONCLUSION: De novo expression of VCAM-1 on glomerular tuft suggests that the endothelial cells play a role in ANCA-GN. De novo glomerular expression of VCAM-1 is associated more with ANCA directed against PR3 than with ANCA directed against MPO. Upregulated glomerular expression of VCAM-1 may reflect a higher histological activity in patients with PR3-ANCA, and supports the existence of specific immune activation mechanisms in the different serologic subgroups in ANCA-GN. The de novo tubular expression of ICAM-1 and VCAM-1 suggests that the epithelial cells may participate in adhesive interactions in ANCA-GN.     

ANCA相关性血管炎肾损害临床特征及早期诊治探讨

目的 分析抗中性粒细胞胞浆抗体(ANCA)相关性血管炎的临床表现和肾脏病理特征,探讨早期诊断和治疗对预后的影响.方法选取本院2000年1月至2009年8月明确诊断的ANCA相关性血管炎共21例,18例行肾活检.总结患者的临床病理资科.分析不同治疗时机对肾功能转归的影响.结果本组21例ANCA相关性血管炎平均年龄(52.5±11.5)岁,显微镜下多血管炎(MPA)16例,韦格纳肉芽肿(WG)3例,变应性肉芽肿性血管炎(CSS)2例.肾外表现主要为发烧17例(80.1%)、下呼吸道症状18例(85.7%)、肺影像学改变21例(100%)、贫血16例(76.2%)、眼耳鼻受累8例(38.1%);肾脏表现血尿21例(100%),蛋白尿19例(90.1%),血肌酐正常6例(28.5%),升高15例(71.4%),8例需透析替代.ANCA检测pANCA和MPO-ANCA阳性16例,cANCA和PR3-ANCA阳性3例.pANCA/MPO-ANCA和cANCA/PR3-ANCA均阳性1例,全阴性1例.肾活检可见节段性小血管壁纤维素样坏死,新月体多见.免疫荧光无或微量免疫复合物沉积.治疗采用糖皮质激素联合环磷酰胺,重症加用血浆置换.7例血肌酐异常但不需透析者5例治疗后血肌酐恢复正常;8例需透析者2例治疗后血肌酐恢复正常,2例脱离透析但血肌酐异常,4例未能脱离透析.结论ANCA相关性小血管炎临床表现多样,肺、肾是最常见的受累器官.ANCA检测和肾活检有助于早期诊断,尽早积极治疗有助于肾功能的恢复.     

Antineutrophil cytoplasmic antibodies (ANCA) in Chinese patients with anti-GBM crescentic glomerulonephritis

OBJECTIVE: To study the prevalence of ANCA and their target antigen in Chinese patients with anti-GBM crescentic glomerulonephritis (CGN), and to evaluate the possible role of ANCA in Chinese anti-GBM CGN patients with coexisting serum ANCA by studying clinicopathologic features of this disease. MATERIAL AND METHODS: Twenty-three sera were collected from 23 renal biopsy-proven anti-GBM CGN patients. According to the standardized procedures, all of the sera were determined by both, indirect immunofluorescence (IIF) ANCA, and enzyme-linked immunosorbent assay (ELISA) MPO-ANCA, PR3-ANCA and BPI-ANCA. The patients were divided into two groups according to serum ANCA positivity (Group A) or negativity (Group B). Thirty-three ANCA-associated pauci-immune CGN patients were regarded as control group (Group C). Their clinicopathologic features were compared to reveal whether ANCA correlated with disease activity. RESULTS: There were 11 (47.8%) cases with positive serum ANCA in 23 anti-GBM glomerulonephritis patients. There were 4/11 MPO-ANCA (one with positive PR3-ANCA and C-ANCA, three with negative IIF-ANCA), 1/11 PR3-ANCA (with positive MPO-ANCA and C-ANCA), 3/11 P-ANCA (with negative ELISA-ANCA) and 5/11 C-ANCA (one with positive PR3-ANCA and MPO-ANCA, and the other four with negative ELISA-ANCA). No BPI-ANCA was detected. No different clinicopathologic features were found between Groups A and B. Both were different from Group C in age, sex ratio, frequence of anuria and ESRD, variety of crescents, glomerular sclerosis, vessel lesion and prognosis. CONCLUSION: Our data demonstrate that ANCA in Chinese patients with anti-GBM CGN is not rare. The major target antigen of ANCA is MPO. ANCA seems not to be correlated with disease activity.     

Successful treatment of severe ANCA-associated RPGN with high-dose IVIg therapy

We report a case of anti-neutrophil cytoplasmic antibody(ANCA)-associated rapid progressive glomerulonephritis (RPGN) that was treated with intravenous immunoglobulin (IVIg) therapy. A 37-year-old woman was admitted to our hospital because of a low-grade fever, general malaise, and a poor appetite. At the time of admission, her renal function had severely deteriorated (serum creatinine level 9.5 mg/dl; mean Ccr 3.3 ml/min) and she had severe anemia (Hb 6.6 g/dl). An immunological examination revealed the presence of ANCA-associated RPGN. A biopsy confirmed a diagnosis of pauci-immune-type necrotizing crescentic glomerulonephritis. After initial treatment with steroid pulse therapy (methylprednisolone, 1,000 mg/day x 3 days), her general condition deteriorated and two sessions of hemodialysis were required. On the 10th hospital day, a high dose of immunoglobulin was administered intravenously (IVIg 400 mg/kg/day x 5 days). This therapy immediately improved her general condition and lowered her serum titer of MPO-ANCA and her serum creatinine level. After two IVIg treatments, her MPO-ANCA titer returned to a normal level and her serum creatinine level improved from 9.5 mg/dl to 3.3 mg/dl. A second biopsy confirmed clinical improvement. These findings suggest that IVIg therapy is effective for cases of ANCA-associated glomerulonephritis that are difficult to treat using conventional immunosuppressive therapy.     

Case of scleroderma with rapid progressive glomerulonephritis associated with both MPO-ANCA and anti-GBM antibodies

A 66-year-old male with scleroderma developed rapidly progressive glomerulonephritis (RPGN). Renal pathology revealed crescentic glomerulonephritis with interstitial inflammation and fibrosis. Immunofluorescent micrography showed linear deposition of IgG along the glomerular capillary wall. Both anti-glomerular basement membrane antibody (anti-GBM Ab), and myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) were detected by an enzyme-linked immunosorbent assay (ELISA). These findings were compatible with ANCA-related vasculitis and anti-GBM Ab nephritis. Laboratory findings showed rapid elevation of the serum creatinine level (5.9 mg/dL), and a high titer of MPO-ANCA (530 EU) and anti-GBM Ab (21 EU). He was started on methylprednisolone pulse therapy and temporary hemodialysis. Since the immunosuppressive therapy lowered both antibody titers steadily and improved renal function, hemodialysis was discontinued 4 weeks after the therapy. It has been reported that some scleroderma patients developed rapid progressive glomerulonephritis due to ANCA-associated vasculitis in addition to the typical scleroderma renal crisis. There have been few reports of a scleroderma patient associated with RPGN, in whom both MPO-ANCA and anti GBM antibodies were detected.     

A case of ANCA-associated glomerulonephritis without extrarenal symptoms with disease flare after starting dialysis

A Japanese girl aged 13 years with myeloperoxidase anti-neutrophil cytoplasmic antibodies(MPO-ANCA)-associated glomerulonephritis(GN) progressed to end-stage renal failure after 7 years' clinical observation. She had been suffering from recurrent disease flare associated with serum MPO-ANCA elevation(i.e. 153 EU/ml, 208 EU/ml and 358 EU/ml, maximum at each of the episodes, normal < 10 EU/ml). Each flare was treated successfully with prednisolone combined with cyclophosphamide and azathioprine. However, her renal function gradually deteriorated, and peritoneal dialysis(PD) was initiated 7 years after the onset of the disease. During the clinical course, no extrarenal manifestations were observed. Due to subsidence of the serum MPO-ANCA titer(10 EU/ml) after starting PD, prednisolone and azathioprine were tapered thereafter. Her daily urine volume was preserved at approximately 600 ml at that time. She suddenly developed fatigue with severe anemia, oliguria and hypertension 4 months after discontinuation of immunosuppressive therapy. The serum titer of MPO-ANCA increased to 100 EU/ml. These clinical observation suggests that disease flare may occur in selected patients with MPO-ANCA-associated GN, who develop end-stage renal failure requiring PD. Although recurrent flare associated with an increased serological activity in a proportion of patients with lupus nephritis who have received dialysis has been reported to date, to our knowledge, a similar clinical observation in the MPO-ANCA-associated GN has not been reported. Selected patients with the disease should be followed with close observation after undergoing dialysis.     

Carbonic-adsorbent AST-120 reduces overload of indoxyl sulfate and the plasma level of TGF-β1 in patients with chronic renal failure

Background We previously reported a significant increase in plasma TGF-β1 in patients with chronic renal failure (CRF). Progression of CRF may be caused by persistent renal production of TGF-β1. In CRF rat models, an oral carbonic absorbent (AST-120) reduces the expression of the TGF-β1 gene in the kidney, and delays the progression of CRF, in part by alleviating the overload of indoxyl sulfate. The aim of this study was to evaluate the effect of AST-120 on plasma levels of indoxyl sulfate and TGF-β1 in CRF patients. Methods Ten CRF patients (aged 59.3 ± 9.5 years, 5 men, serum creatinine 4.37 ± 1.72 mg/dl) were enrolled in this study. All patients maintained a regular dietary therapy and the same medication throughout the study. AST-120 was added at a dose of 6 g/day. Parameters including the slope of the reciprocal of the serum creatinine – time plot, plasma indoxyl sulfate level, and plasma and urinary levels of TGF-β1 were compared before and after the treatment with AST-120. The mean observation periods before and after the treatment were 9.7 ± 2.8 and 6.5 ± 2.9 months, respectively. Results Administration of AST-120 significantly reduced the plasma levels of indoxyl sulfate (1.42 ± 1.50 vs. 1.26 ± 1.40 mg/dl, P < 0.05) and TGF-β1 (17.9 ± 7.2 vs. 10.6 ± 4.7 ng/ml, P < 0.05) and improved the slope of the reciprocal of serum creatinine (−0.061 ± 0.041 vs. −0.032 ± 0.055 dl/mg/year, P < 0.05). Conclusions These results support the notion that indoxyl sulfate and TGF-β1 may be involved in the progression of CRF, and that the oral adsorbent AST-120 may suppress the progression, at least in part, by reducing overproduction of TGF-β1.     

MPO-ANCA-positive anti-glomerular basement membrane antibody disease successfully treated by plasma exchange and immunosuppressive therapy

Anti-glomerular basement membrane (GBM) antibody disease is clinically manifested as rapidly progressive glomerulonephritis (RPGN) with crescentic changes. The renal prognosis is poor. We report here the case of a 61-year-old woman with myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-positive anti-GBM antibody disease. This patient was referred to our hospital because of RPGN. Anti-GBM antibody was positive with a titer of 38 EU. The MPO-ANCA titer was 65 EU. Chest imaging examination revealed pulmonary multiple nodules. ANCA-associated vasculitis was suspected. Renal pathology revealed cellular crescents in 13 out of 17 glomeruli. Immunofluorescence with anti-IgG antibody, anti-C3 antibody, and anti-fibrin antibody showed linear staining along the glomerular capillary walls. Based on these findings, the patient was diagnosed with anti-GBM antibody disease. Hemodialysis was started because of uremic syndrome with elevated serum creatinine (6.84 mg/dL). In addition, treatment with plasma exchange using 3.6 L (90 mL/kg) of fresh frozen plasma combined with an oral dose of 40 mg of prednisolone was initiated. Within 3 weeks, both types of autoantibodies became undetectable. Subsequently, this patient achieved dialysis independence and remission of glomerulonephritis. No adverse effects were observed. In patients with MPO-ANCA-positive anti-GBM antibody disease, intensive therapy predominantly with plasma exchange might be operative, even though renal function is less likely to recover.     

Determination of reference values for plasma cystatin C and comparison with creatinine in premature infants

Cystatin C (CysC) is a low-molecular-mass protein (13,343 dalton, 120 amino acids) belonging to the cystatin superfamily of reversible inhibitors of cysteine proteases. CysC appears to be eliminated from the circulation almost exclusively by glomerular filtration, which makes it a promising endogenous marker of renal function. CysC has been demonstrated to reflect glomerular filtration rate better than other low-molecular-weight proteins, including creatinine (Cr). We established reference values for serum CysC and compared them with Cr in 108 preterm infants by particle-enhanced nephelometric immunoassay. On the first day, serum CysC values ranged from 1.25 to 2.84 mg/L, significantly decreasing after 3 days of life. Cr levels determined simultaneously on the first day ranged from 0.05 to 1.12 mg/dl and were also significantly different from day 3 levels. Both CysC and Cr levels were independent of gender, birth weight, hemoglobin levels, and hydration state. Cr correlated negatively with gestational age (r = −0.25, p = 0.009), but not CysC. A significant correlation was found between CysC and Cr on day 1 (r = 0.21, p = 0.031), but no correlation was found according to day 3 blood samples (r = 0.19, p = 0.053). CysC is regarded as an alternative for assessing renal function in preterm neonates, but its advantages over Cr are not yet proven.     

Lupus nephritis associated with positive MPO-ANCA in a patient with underlying autoimmune hemolytic anemia

A 19-year-old female was admitted with general malaise and systemic edema. She had been diagnosed as having autoimmune hemolytic anemia (AIHA) eight years earlier and was successfully managed with oral prednisolone. During the current admission, she was diagnosed as having systemic lupus erythematosus (SLE) based on the presence of renal involvement, hematological abnormalities, and antinuclear and anti-double-stranded DNA antibodies, along with a recurrence of AIHA; her serology revealed a high myeloperoxydase-antineutrophil cytoplasmic antibody (MPO-ANCA) titer. She was treated with prednisolone (50 mg day⁻¹), but her renal function started to deteriorate. She responded to treatment with hemodialysis, plasmapheresis, and methylprednisolone pulse therapy; her MPO-ANCA titer and renal function improved. Treatment with intravenous cyclophosphamide gradually suppressed her AIHA and SLE activity. A renal biopsy revealed a diffuse proliferative lupus nephritis (class IV-G (A)) with necrotizing crescentic glomerulonephritis that was presumed to be associated with MPO-ANCA. The association of MPO-ANCA with SLE in this refractory case is discussed.