A 75-year-old woman, who had been on maintenance hemodialysis (HD) from 2000, was receiving erythro- poiesis stimulating agent (ESA) for renal anemia. In November 2013, although still continuing ESA, she was admitted to our hospital due to worsening anemia. Since blood tests suggested the possibility of hemolytic anemia, we consulted,with hematologists, and she was transferred to another hospital. Differential diagnosis for anemia revealed that she had newly developed Evans syndrome, which is the complication of autoimmune hemolytic ane- mia (AIHA) and idiopathic thrombocytopenic purpura(ITP). She was successfully treated for AIHA with blood transfusion and administration of steroids, and for ITP by eradicating Melicobacter pylort. Anemia is commonly seen in HD patients, and the majority of anemia cases are diagnosed as renal anemia; however, hemolytic anemia should be considered in order to make a differential diagnosis. There are few reports of Evans syndrome in HD, and the pathogenesis of Evans syndrome is largely unknown. Further accumulation of clinical reports is needed to clarify its etiology.
An 18-year-old man was admitted to our hospital due to gross hematuria and proteinuria after a marathon race. Contrast-enhanced CT showed no remarkable findings. His gross hematuria and proteinuria disappeared with- out treatment. One year later, he was admitted to our hospital due to reburrent gross hematuria and anemia (serum hemoglobin level of 8.0 g/dL). Both contrast-enhanced CT and renal arteriography revealed no remarkable find- ings; however, cystoscopy showed that his hematuria came from the left ureteral orifice. Ureteroscopy revealed hemorrhage from a large hemangioma at the left renal papilla of the calix. He presented with intermittent gross hematuria, proteinuria, and hypocomplimentemia, suggesting the possibility of glomerulonephritis. His gross hematuria and proteinuria improved after laser coagulation was performed.
In the past, little attention had been paid to the intestine and its microbial flora as a potential source of systemic inflammation in chronic kidney disease(CKD). Systemic inflammation plays a central role in progression of CKD and its cardiovascular and various other complications. The gastrointestinal tract houses a large community of microbes that have a symbiotic relationship with the host. The normal microbial flora protects the host against pathogenic microorganisms. It also contributes to the energy metabolism, micronutrient homeostasis and nitrogen bal- ance. Recent studies have revealed significant changes in the composition and function of the microbial flora in CKD patients and animals. These changes are driven by altered intestinal bio- chemical environment caused by: I-heavy influx of urea and uric acid from body fluids into the gastrointestinal tract, II- restrictions of potassium-rich food including fruits and vegetables which as the main source of indigestible complex carbohydrates are the essential nutrients for the guts' symbiotic microbial com- munity, and III- various medications such as phosphate binders, antibiotics etc. Together the changes in intestinal milieu and the resultant microbial dysbiosis play a major role in systemic inflammation and uremic toxicity by several mechanisms : I-generation of several microbial derived uremic toxins such as indoxyl sulfate, p-cresol sulfate and trimethylamine-N-oxide etc. II-reduction of microbial derived micronutrients such a short chain fatty acids (SCFA) which are the main source of nutrients for colonocytes. This is caused by diminished substrates (indigestible complex carbohydrates) which leads to depletion of SCFA-making bacteria. In addition, III-Disruption of the intestinal epithelial barrier by ammonia and ammonium hydroxide generated from hydrolysis of urea by urease-possessing microbial species which are common complications of CKD, and bowel ischemia caused by excessive use of diuretics (in CKD patients) and aggressive ultrafiltration by hemodialysis (in ESRD patients) can impair gastrointestinal epithelial barrier. The resulting breakdown of the gut epithelial barrier (tight junction complex) leads to influx of endotoxin, microbial fragments, and other noxious luminal products in the sub-epithelial tissue and systemic circulation leading to local and systemic inflammation and oxidative stress which are the major cause of morbidity and mortality in CKD population. This review is intended to provide an overview of the effects of CKD on the gut microbiome and intestinal epithelial barrier structure and the potential interventions aimed at mitigating these abnormalities.
A 20-year-old woman, who was suffering from appetite loss, weight loss and livedo reticularis for one and half months, was referred to our hospital. On admission, laboratory studies demonstrated proteinuria (1.0 g/g Cr), hematuria (erythrocytes': 50 - 99/HPF), ,.enal dysfunction (Cr : 2.09 mg/dL), elevated C reactive protein (CRP: 10.82 mg/dL), elevated MPO-ANCA titer (11.6 U/mL) and elevated pentraxin3 (PTX3: 24.05 ng/mL). Her kidney and skin biopsy revealed massive crescentic necrotizing glomerulonephritis and leukocytoclastic vasculitis, respectively. She was diagnosed with microscopic polyangiitis (MPA), and treated with 500 mg/day of intravenous methyl-prednisolone (mPSL) for 3 days followed by 40 mg/day of oral PSL, rituximab (375 mg/m² once a week for a month) and plasma exchange. When PSL tapered to 30 mg/day in 4 weeks, her renal function was only partially recovered, while the CRP level had been normalized and the MPO-ANCA titer was almost negative (3.6 IU/mL). To evaluate histological activity, a second renal biopsy was conducted, which showed fibrocellular crescents in 32% of her glomeruli. The PTX3 level remained high (14.82 ng/mL) at that point. Taken together, the vasculitis was considered to be active still. Steroid pulse therapy for 3 days was administered again, followed by oral PSL 30 mg/day. Her renal function completely recovered in 70 days. The PTX3 level also normalized in 161 days. PTX3 is one of the short pentraxins, produced by a variety of cell types in response to pro-inflammatory signals such as IL-1 and TNF-α. It was reported that PTX3 reflects activity of vasculitis independently from CRP. In the presenting case, when the second renal biopsy revealed a histologically active lesion of the vasculitis, PTX3 was elevated independently from CRP and MPO-ANCA, suggesting that PTX3 may be a more sensitive marker of the disease activity than other tests.
Diabetic nephropathy is a leading cause of end-stage renal disease worldwide. The multipronged drug approach targeting blood pressure and serum levels of glucose, insulin, and lipids fails to fully prevent the onset and progression of diabetic nephropathy. Therefore, a new therapeutic target to combat diabetic nephropathy is required. Autophagy is a catabolic process that degrades damaged proteins and organelles in mammalian cells and plays a critical role in maintaining cellular homeostasis. The accumulation of proteins and organelles damaged by hyperglycemia and other diabetes-related metabolic changes is highly associated with the development of diabetic nephropathy. Recent studies have suggested that autophagy activity is altered in both podocytes and proximal tubular cells under diabetic conditions. Autophagy activity is regulated by both nutrient state and intracellular stresses. Under diabetic conditions, an altered nutritional state due to nutrient excess may interfere with the autophagic response stimulated by intracellular stresses, leading to exacerbation of organelle dysfunction and diabetic nephropathy. In this review, we discuss new findings showing the relationships between autophagy and diabetic nephropathy and suggest the therapeutic potential of autophagy in diabetic nephropathy.
A man in his fifties with diabetes had a past history of myocardial infarction and ventricular septal perforation. He underwent hemodialysis about a year ago and was taking amiodarone. He presented with sores and purpura on the lower limbs.-Skin biopsy showed immunofluorescence-negative leukocytoclastic vasculitis. Skin lesions were treated with ointments, which ameliorated the symptoms to some extent, but ulceration relapsed and deteriorated in both number and size. Calciphylaxis was suspected, and a second skin biopsy was performed. No calcium detection,on the arteries was observed, but leukocytoclastic vasculitis was seen. Antineutrophil cytoplasmic antibody-related vasculitis, cryoglobulin vasculitis, or anti-phospholipid syndrome were ruled out by negative findings for autoantibodies. Although he was treated with 30 mg prednisolone, his systemic condition deteriorated, and he died of disseminated intravascular coagulation. Autopsy findings showed no vasculitis in the lung, kidney or intestine, and perimyocardial patch infection was observed.Although calciphylaxis was clinically suspected, his condition was diagnosed finally as cutaneous small-vessel vasculitis.
本邦における糖尿病の総患者数は,厚生労働省の「平成 26年(2014)患者調査の概況」によると,316.6万人と推計さ れている。また,糖尿病性腎症の罹患率は,JDDM(Japan Diabetes Clinical Data Management Study Group)の 2型糖尿 病 3,297例を対象とした検討によると,微量アルブミン尿 を 21.4%,顕性アルブミン尿を 8.9%,60 mL/分/1.73 m未 満の推算糸球体濾過量(glomerular filtration rate:GFR)低下 を 15.3%に認めたことが示されている1)。一方,末期腎不 全患者における糖尿病性腎症の割合は,日本透析医学会の 統計調査によると,1998年末から導入患者の原疾患におい て糖尿病性腎症が第 1位となり,2015年末には 43.7% (16,072人)を占めている。さらに,2011年末から年末患者 の原疾患においても糖尿病性腎症が第 1位となり,2015年 末には 38.4%(120,278人)を占めている。加えて,糖尿病性 腎症を原疾患とする導入患者の平均年齢は 1987年末の 59.0歳が2015年末には67.3歳,年末患者の平均年齢は1987 年末の 58.0歳が 2015年末には 67.5歳へと上昇している。 糖尿病性腎症の確定診断には腎組織所見が一助となる。 日本腎臓学会・腎生検レジストリー(Japan Renal Biopsy Registry:J-RBR)では,2009~2010 年に登録された移植腎 を除く成人腎生検 7,034例の病因分類において糖尿病性腎 症の割合が 5.3%(376例)であったことが示されている2)。 日本透析医学会の統計調査結果との乖離は,日常臨床では 典型的な臨床経過を示す糖尿病性腎症例に腎生検を実施す ることが少なく,網膜症などの糖尿病合併症の有無,尿検 査・腎機能検査所見などから臨床診断されることが多いこ とによるものと考えられる。なお,日本腎臓学会より刊行 された「CKD診療ガイドライン 2013」では,糖尿病による CKDは「糖尿病性腎症」と表記され,糖尿病を有する CKD で糖尿病性腎症かどうかは区別できない場合,あるいは広 く糖尿病に合併した CKDは「糖尿病を伴う CKD」あるいは 「糖尿病合併 CKD」などと表現し,これらの 2つの言葉の意 味を明確に区別して用いている3)。
