Yasushi Higa

Induction of Anti-Carbonic-Anhydrase-II Antibody Causes Renal Tubular Acidosis in a Mouse Model of Sjögren’s Syndrome

Background/Aim: We recently reported that renal tubular acidosis (RTA) in Sjögren’s syndrome (SjS) is associated with high titers of an autoantibody against carbonic anhydrase (CA) II, an important enzyme in renal acid-base regulation. The purpose of this study was to determine whether a CA-II antibody could cause RTA in a mouse model of SjS. Methods: PL/J mice were immunized with human CA II to induce CA II antibody formation, whereas controls were injected with phosphate-buffered saline and adjuvant. After 6 weeks, anti-CA-II antibody titers were measured, then ammonium chloride was administered orally for 1 week to detect any acidification defect. Results: CA-II-immunized mice showed higher anti-CA-II antibody titers than control mice. Pathologically, lymphocytic and plasma cell infiltration was seen in the salivary glands and kidneys of CA-II-immunized mice, but not in controls. On acid loading, blood pH and urine pH decreased in both groups of mice, but the slope of urine pH versus blood pH was less steep in the CA-II-immunized mice, suggesting that these mice had an impaired ability to reduce their urine pH in the face of metabolic acidosis. Conclusion: CA-II-immunized mice had a urinary acidification defect, which may be similar to that seen in patients with SjS.

Infected hepatic and renal cysts: differential impact on outcome in autosomal dominant polycystic kidney disease.

Background: Infected cysts are a frequent and serious complication of autosomal dominant polycystic kidney disease. Such infections are classified into those affecting hepatic cysts and those affecting renal cysts. The purpose of this study was to compare the clinical course of infected hepatic cysts with that of infected renal cysts in patients with autosomal dominant polycystic kidney disease. Methods: We analyzed 43 patients referred to us for additional treatment of severely infected cysts between January 2004 and December 2006. All patients who required further treatment in addition to antibiotic therapy were included. Results: Aspiration was performed in all 28 patients with infected hepatic cysts. As a result, 17 patients were cured, 4 remain under treatment, and 6 died. One patient was cured by partial hepatectomy. Among the 15 patients with renal cysts, aspiration was performed in 4 with identifiable infected cysts, while renal transcatheter arterial embolization after appropriate antibiotic therapy was performed in 11 without identifiable infected cysts. No patient developed recurrence. Conclusion: In patients with infected renal cysts, aspiration or renal transcatheter arterial embolization after appropriate antibiotic therapy was effective. Although aspiration was often effective in patients with infected hepatic cysts, a good outcome was less likely than in those with renal cysts.

Hyporeninemic hypoaldosteronism from secondary amyloidosis

Fumi Takemoto, Yoshifumi Ubara, Shinya Kaname, Hideyuki Katori, Naoki Sawa, Junichi Hoshino, Tatsuya Suwabe, Yasushi Higa, Shohei Nakanishi, Michio Nagata, Kenichi Ohashi and Kenmei Takaichi Kidney Center, Toranomon Hospital, Tokyo, Japan; Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan; Department of Molecular Pathology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan and Department of Pathology, Toranomon Hospital, Tokyo, Japan Correspondence: Fumi Takemoto, Kidney Center, Toranomon Hospital, Toranomon 2-2-2, Minato-ku, Tokyo 105-8470, Japan. E-mail: ftakemoto-ind@umin.ac.jp

Systemic AA-amyloidosis related to MPO-ANCA microscopic polyangiitis: A case report

We report autopsy findings in an 83-year-old woman with myeloperoxidase-type anti-neutrophil cytoplasmic antibody (MPO-ANCA)-positive microscopic polyangiitis and systemic AA amyloidosis. With a diagnosis of MPO-ANCA-related microscopic polyangiitis, the patient was treated with corticosteroids, but she died of intractable enteritis. Autopsy showed inactive vasculitis affecting small arteries in kidney, lung, intestinal tract, and skeletal muscle. Gastrointestinal viscera were thickened, and AA-amyloid was demonstrated in arterioles and surrounding tissues. Amyloidosis also involved heart, kidney, gallbladder, pancreas, salivary gland, and subcutis. ANCA-positive microscopic polyangiitis appears to have been the likely cause of this patients AA-amyloidosis.

Tonsillectomy and Corticosteroid Therapy with Concomitant Methylprednisolone Pulse Therapy for IgA Nephropathy

IgA nephropathy (IgAN) is the most common chronic kidney disease in Japan, but the optimum treatment remains controversial. Our objective was to evaluate the effect of tonsillectomy and corticosteroid therapy combined with methylprednisone pulse therapy in patients at our hospital who had IgAN. Tonsillectomy plus pulse therapy was evaluated in 72 patients (33 men and 39 women) with a diagnosis of IgAN based on renal biopsy who were followed up for more than 1 year. The mean age of the patients was 35.2 +/- 10.9 years (range: 20-58 years) and the mean observation period after tonsillectomy was 20.3 +/- 9.7 months (range: 12-36 months). After tonsillectomy, steroid pulse therapy was administered (methylprednisolone at 500 mg daily for 3 days) 1-3 times and was followed by oral prednisolone from an initial dose of 30 mg on alternate days that was tapered gradually over one year. At 2 years after tonsillectomy, serum creatinine was unchanged or improved in the majority of patients, but worsened in 5 patients. Hematuria (erythrocytes/HPF) improved from Grade 3.76 (11-30/HPF) to Grade 1.94 (1-5/HPF) on average (we defined the grade of hematuria). None of the patients experienced exacerbation of hematuria. Proteinuria decreased from 1.32 g/day to 0.86 g/day (65% of the pretreatment value), and only 4 patients showed an increase of proteinuria. Mean protein loss decreased to less than 0.5 g/day in patients with creatinine clearance > or =90 ml/min and/or patients with initial protein excretion < or =1.0 g/day.