Evaluation of a newly proposed renal risk score for Japanese patients with ANCA-associated glomerulonephritis.

BACKGROUND: We determined the usefulness and prognostic ability of the renal risk score (RRS), proposed in Europe, for Japanese patients with antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN) and high myeloperoxidase (MPO)-ANCA positivity; these aspects remain to be verified. METHODS: This retrospective study was conducted on 86 Japanese patients with new, biopsy-confirmed AAGN. We calculated the RRS and analyzed the relationship between this classification, and clinicopathological features and prognosis. We also compared the predictive values between RRS for endpoints including renal death and conventional prognostic tools for patients with AAGN. RESULTS: There were 33, 37, and 16 patients in the low-, medium-, and high-risk groups, respectively. All patients were MPO-ANCA positive. The median follow-up period was 33 months; 16 (18.6%) patients progressed to end-stage renal disease (ESRD). In the high-risk group, 9/16 (56.3%) patients progressed to ESRD, and renal prognosis was significantly poorer than that in other groups (low-risk group, P < 0.001; medium-risk group, P = 0.004). In Cox multivariate regression analysis, RRS was an independent, poor renal prognostic factor (hazard ratio 5.22; 95% confidence interval 2.20-12.40; P < 0.001). The receiver-operating characteristic curves of the RRS for each endpoint were comparable with those of the 2010 histological classification and those of the severity classification of Japanese rapidly progressive glomerulonephritis. CONCLUSIONS: This is the first study to report the usefulness of the RRS for predicting renal outcomes among Japanese patients with AAGN. Our predictive value of the RRS was comparable with that of conventional prognostic tools.

VEGF-VEGFR2 inhibitor-associated hyaline occlusive glomerular microangiopathy: a Japanese single-center experience.

BACKGROUND: Inhibitors of vascular endothelial growth factor (VEGF)-VEGF receptor 2 (VEGFR2) signaling, such as bevacizumab (Bmab), are used for the treatment of various advanced cancers. However, these inhibitors induce renal thrombotic microangiopathy (TMA). Recently, two European cohort studies showed a distinctive histopathological pseudothrombotic pattern different from TMA in Bmab-treated patients. METHODS: We analyzed 9 renal biopsies from proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors in our Japanese cohort. Clinical and laboratory features were also assessed in these patients. RESULTS: All 9 patients had moderate to heavy proteinuria with normal or slightly elevated serum creatinine levels. On light microscopy, a patchy pattern of hemispherical/spherical lesions along glomerular capillary walls was a characteristic finding. On immunofluorescence microscopy, staining for immunoglobulins (IgM dominant) at varying intensities was observed mainly along glomerular capillary walls. Especially, hemispherical/spherical positive staining for immunoglobulins was a characteristic pattern. Immunohistochemical studies showed positive staining for immunoglobulins and negative staining for CD61-positive platelets in capillary hemispherical/spherical lesions and positive VEGF staining in podocytes. On electron microscopy, variably electron-dense material in dilated glomerular capillaries and partial effacement of podocyte foot processes were observed. After the withdrawal of VEGF-VEGFR2 inhibitors, proteinuria improved without any specific treatment in 8 patients. CONCLUSIONS: Histopathological findings in our patients treated with VEGF-VEGFR2 inhibitors were consistent with those observed in the recently described new form of Bmab-associated hyaline occlusive glomerular microangiopathy. This form should be considered in proteinuric cancer patients treated with VEGF-VEGFR2 inhibitors. Discontinuing VEGF-VEGFR2 inhibitors may lead to improvement of glomerular microangiopathy induced by these drugs.

Long-term prognosis of AL and AA renal amyloidosis: a Japanese single-center experience.

BACKGROUND: Few studies have been conducted on the long-term prognosis of patients with amyloid light chain (AL) and amyloid A (AA) renal amyloidosis in the same cohort. METHODS: We retrospectively examined 68 patients with biopsy-proven renal amyloidosis (38 AL and 30 AA). Clinicopathological findings at the diagnosis and follow-up data were evaluated in each patient. We analyzed the relationship between clinicopathological parameters and survival data. RESULTS: Significant differences were observed in several clinicopathological features, such as proteinuria levels, between the AL and AA groups. Among all patients, 84.2 % of the AL group and 93.3 % of the AA group received treatments for the underlying diseases of amyloidosis. During the follow-up period (median 18 months in AL and 61 months in AA), 36.8 % of the AL group and 36.7 % of the AA group developed end-stage renal failure requiring dialysis, while 71.1 % of the AL group and 56.7 % of the AA group died. Patient and renal survivals were significantly longer in the AA group than in the AL group. eGFR of >60 mL/min/1.73 m2 at biopsy and an early histological stage of glomerular amyloid deposition were identified as low-risk factors. A multivariate analysis showed that cardiac amyloidosis and steroid therapy significantly influenced patient and renal survivals. CONCLUSIONS: Our results showed that heart involvement was the major predictor of poor outcomes in renal amyloidosis, and that the prognosis of AA renal amyloidosis was markedly better than that in previously reported cohorts. Therapeutic advances in inflammatory diseases are expected to improve the prognosis of AA amyloidosis.

Progressive glomerulopathy with unusual deposits of striated structures: a new disease entity?

A 68-year-old man developed proteinuria and renal insufficiency. A renal biopsy showed mesangial proliferation and double contour in almost all glomeruli. Congo red staining for amyloid was negative. Immunofluorescence microscopy revealed no deposition of immunoglobulins. Electron microscopy showed unusual deposits of striated structures mainly in the subendothelial space and the mesangium. These deposits contained regularly stacked straight electron-dense bands. Microfilament-like deposits were also observed. The patient did not respond to steroid therapy and developed end-stage renal disease. All known disease entities with non-amyloid non-immunoglobulin-derived organized glomerular deposits were excluded. Progressive glomerulopathy in our patient might be a new disease entity.

Successful autologous peripheral blood stem cell transplantation using thiotepa in a patient with systemic sclerosis and cardiac involvement.

A 19-year-old man with systemic sclerosis (SSc) was hospitalized for autologous peripheral blood stem cell transplantation (auto-PBSCT) due to progressive scleroderma and cardiac involvement despite conventional treatment. During the administration of cyclophosphamide (60 mg/kg/day for 2 days) for mobilization and collection of CD34+ selected peripheral blood stem cells, he developed congestive heart failure. Echocardiogram showed hypokinetic asynergy from the septum to posterior wall, which might indicate underlying cardiac damage. We were also concerned about the risk of high-dose cyclophosphamide-induced cardiotoxicity. Since the dose-limiting toxicity of thiotepa, an alkylating agent, is myelosuppression, and cardiac toxicity due to thiotepa is less common, we used a conditioning regimen consisting of thiotepa (10 mg/kg/day, day -5) and low-dose cyclophosphamide (50 mg/kg/day, days -3 and -2), instead of the conventional high-dose cyclophosphamide (50 mg/kg/day x 4 days/course). The post-transplant course was uneventful, and the modified Rodnan skin thickness score improved from 32 to 15. The present case report demonstrates that thiotepa can be employed as a conditioning regimen for auto-PBSCT in SSc patients with cardiac involvement in order to reduce cyclophosphamide-induced cardiotoxicity.