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Background: The Stewart model for analyzing acid-base disturbances emphasizes serum albumin levels, which are ignored in the traditional Boston model. We compared data derived using the Stewart model to those using the Boston model in patients with nephrotic syndrome., Methods: Twenty-nine patients with nephrotic syndrome and six patients without urinary protein or acid-base disturbances provided blood and urine samples for analysis that included routine biochemical and arterial blood gas tests, plasma renin activity, and aldosterone. The total concentration of non-volatile weak acids (A TOT ), apparent strong ion difference (SIDa), effective strong ion difference (SIDe), and strong ion gap (SIG) were calculated according to the formulas of Agrafiotis in the Stewart model., Results: According to the Boston model, 25 of 29 patients (90%) had alkalemia. Eighteen patients had respiratory alkalosis, 11 had metabolic alkalosis, and 4 had both conditions. Only three patients had hyperreninemic hyperaldosteronism. The Stewart model demonstrated respiratory alkalosis based on decreased PaCO 2 , metabolic alkalosis based on decreased A TOT , and metabolic acidosis based on decreased SIDa. We could diagnose metabolic alkalosis or acidosis with a normal anion gap after comparing delta A TOT [(14.09 - measured A TOT ) or (11.77 - 2.64 × Alb (g/dL))] and delta SIDa [(42.7 - measured SIDa) or (42.7 - (Na + K - Cl)]). We could also identify metabolic acidosis with an increased anion gap using SIG > 7.0 (SIG = 0.9463 × corrected anion gap-8.1956)., Conclusions: Patients with nephrotic syndrome had primary respiratory alkalosis, decreased A TOT due to hypoalbuminemia (power to metabolic alkalosis), and decreased levels of SIDa (power to metabolic acidosis). We could detect metabolic acidosis with an increased anion gap by calculating SIG. The Stewart model in combination with the Boston model facilitates the analysis of complex acid-base disturbances in nephrotic syndrome.

Background: Phospholipase A 2 receptor (PLA 2 R) is recognized as a target antigen in primary membranous nephropathy (MN); Anti-α-enolase antibody in primary and secondary MN has been proposed, however, little is known about the potential contribution of α-enolase to the pathogenesis of MN., Methods: We evaluated circulating antibodies to α-enolase by a dot blotting system and PLA 2 R by indirect immunofluorescence, and glomerular deposition of these proteins in 25 patients with primary MN, 20 patients with secondary MN, 44 patients with collagen disease or severe infection, 60 patients with nephritis (each ten patients of IgA nephropathy, focal segmental gloemrulosclerosis, minimal change nephrotic syndrome, membranoproliferative glomeurlonephritis, diabetic glomerulosclerosis, and tubulointerstitial nephritis) as disease control, and 20 healthy subjects., Results: In primary MN, 18 of 25 sera (72 %) showed anti-α-enolase antibody (IgG1 and IgG4, 11 pts; IgG4 alone, six pts; IgG1 alone, one pt). In secondary MN, 15 of 20 sera (75 %) contained anti-α-enolase antibody (IgG1 and IgG3, 13 pts; IgG3 alone, two pts). No circulating anti-α-enolase antibody was found in 44 collagen diseases or septic patients, 60 nephritis without MN, and 20 healthy subjects. Twelve of 25 sera (48 %) from patients with primary MN were positive for anti-PLA 2 R antibody, whereas all patients with secondary MN were negative. Eight of the 12 PLA 2 R-positive patients (67 %) with primary MN also had anti α-enolase antibody. Although PLA 2 R antigen was present in a subepithelial pattern in 10 of 19 (52 %) patients with primary MN, α-enolase was never detected in glomerular deposits in 19 and ten patients with primary and secondary MN, respectively., Conclusions: Circulating anti-α-enolase antibodies are highly present in both primary and secondary MN (about 70 %, respectively), while anti-PLA 2 R antibodies are specific for primary MN (48 %) with a prevalence apparently lower in the Japanese population than in Chinese and Caucasian populations. The absence of α-enolase from subepithelial immune deposits suggests that anti-α-enolase antibodies do not contribute directly to immune-deposit formation, although they may have other pathogenic effects., Competing Interests: Conflicts of Interest: None declared.

Background: The aim of this study was to identify risk factors for end-stage renal failure (ESRF) or death in Japanese patients with microscopic polyangiitis (MPA) with renal involvement., Methods: From 54 consecutive patients with systemic vasculitis based on Watt's algorithm, we retrospectively analyzed 39 MPA patients with renal involvement, including 19 (48.7 %) with renal-limited vasculitis., Results: Thirty-three of 39 patients (84.6 %) demonstrated rapidly progressive glomerulonephritis, and 13 (33.3 %) developed ESRF; 8 of 13 required dialysis within 1 week. Thirteen (33.3 %) died during follow-up of more than 12 months, and 7 died during the first 6 months, mainly because of opportunistic infections. Overall survival at 6 and 12 months was 79.5 and 71.1 %, respectively. Serum creatinine levels did not differ significantly between survivors and non-survivors (P = 0.092). The mean Birmingham Vasculitis Activity Score, version 3 (BVAS v.3), was 16.2 ± 6.5, with a renal subscore of over 12 points in 82.1 %, and BVAS v.3 was marginally higher in non-survivors than survivors (P = 0.045). An age- and sex-adjusted Cox proportional hazards analysis demonstrated that neither the serum creatinine level (P = 0.277) nor BVAS v.3 (P = 0.188) at initial diagnosis was a risk factor for overall survival. The baseline serum creatinine cutoff value for discriminating between ESRF and non-ESRF was 4.6 mg/dl, with a sensitivity and specificity of 92.3 and 84.6 %, respectively., Conclusions: Survival rates do not relate to ESRF in MPA patients with mainly renal involvement. Although patients with ESRF required regular hemodialysis, longer survival can be achieved.

We report an unusual pathological finding, a large-sized bubbling appearance of the glomerular basement membrane (GBM), in a patient with pulmonary limited AL amyloidosis and a past history of lupus nephritis. The first renal biopsy specimen from 10 years ago, when systemic lupus erythematosus was diagnosed, demonstrated mild mesangial proliferation and subepithelial deposits (WHO classification: III + V). Light microscopy of the current biopsy using periodic acid methenamine silver (PAMS) stain demonstrated a large-sized bubbling appearance of the GBM; however, very weak immunoglobulin and complement deposition was observed in immunofluorescence studies. Routine electron microscopy demonstrated partial subendothelial expansion with electron-lucent materials, but no electron-dense deposits or amyloid fibrils. Electron microscopy with PAMS stain revealed electron-lucent endothelial scalloping, including some cellular components and microspheres in the GBM; however, it is not clear if these materials are derived from endothelial cells. One possibility is that these unique findings represent a recovery phase of lupus membranous nephritis; another is that these findings correspond to a new disease entity.

A 60-year-old Japanese man exhibited rapidly progressive glomerulonephritis 10 years after receiving prednisolone therapy for clinically amyopathic dermatomyositis (CADM). Upon admission, there were no signs of dermatomyositis. Laboratory analyses revealed the presence of myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA) at 1,280 EU in the absence of anti-glomerular basement membrane antibody and anti-melanoma differentiation-associated gene 5 antibodies, which are typically expressed in CADM. A renal biopsy demonstrated that 14 of 29 glomeruli showed global sclerosis, and the remaining 15 glomeruli exhibited fibrotic and fibrocellular crescent formation without immunoglobulin and complement. Following treatment with 500 mg/day methylprednisolone pulse therapy for 3 days, the patient was started on 30 mg/day of prednisolone orally. On the third day of hospitalization, we began hemodialysis for uremia and anuria with three treatments of plasma exchange starting on the tenth hospital day. Unfortunately, the patient's renal function did not recover, despite decreases in CRP and MPO-ANCA levels to the normal range. This case is the first English language report of MPO-ANCA-related crescentic glomerulonephritis in a patient who had recovered from CADM.