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The rate of pregnancy-associated acute kidney injury (P-AKI) has dwindled in high income countries mainly following the legalization of abortion in the seventies and early eighties and the general improvement in obstetrical care. P-AKI has not however disappeared from high income countries and several reports indicate that its frequency has even increased during the last decade. The reasons for such evolution are probably an improved surveillance and reporting of P-AKI and a more aggressive approach to the treatment of pregnancy complications, with unintended renal side effects. The characteristics of pregnant women in high-income countries have also changed as the number of women with medical conditions, including diabetes and chronic kidney disease, has tended to increase. P-AKI in high income countries is still a matter of concern for nephrologists who have in mind that any rate, however low, of P-AKI remains unacceptable.

Data regarding the incidence and outcome of renal involvement in patients with inflammatory myopathies (IM) remain scarce. We assessed the incidence and causes of acute kidney injury (AKI) and chronic kidney disease (CKD) in 150 patients with dermatomyositis, polymyositis, and antisynthetase syndrome followed in 3 French referral centers. Renal involvement occurred in 35 (23.3%) patients: AKI in 16 (10.7%), and CKD in 31 (20.7%) patients. The main cause of AKI was drug or myoglobinuria-induced acute tubular necrosis. Male sex, cardiovascular risk factors, cardiac involvement, and initial proteinuria >0.3 g/d were associated with the occurrence of AKI. The outcome of patients with AKI was poor: 13 (81%) progressed to CKD and 2 (12.5%) reached end-stage renal disease. In multivariate survival analysis, age at IM onset, male sex, a history of cardiovascular events, and a previous episode of AKI were associated with the risk of CKD. We also identified 14 IM patients who underwent a kidney biopsy in 10 nephrology centers. Renal pathology disclosed a wide range of renal disorders, mainly immune-complex glomerulonephritis. We identified in 5 patients a peculiar pattern of severe acute renal vascular damage consisting mainly of edematous thickening of the intima of arterioles. We found that AKI and CKD are frequent in patients with IM. Prevention of AKI is crucial in these patients, as AKI is a major contributor to their relatively high risk of CKD. A peculiar pattern of acute vascular damage is part of the spectrum of renal diseases associated with IM.

Background: Atypical hemolytic uremic syndrome (aHUS) is a devastating form of renal thrombotic microangiopathy. Despite plasma exchange, the standard treatment of aHUS for decades, the renal prognosis for patients with aHUS has remained poor. We assessed the off-trial use of eculizumab in adult patients with aHUS affecting the native kidneys., Study Design: A retrospective study was conducted. aHUS was defined as the presence of 3 or more of the following: acute kidney injury (serum creatinine >1.4 mg/dL [120 μmol/L]), mechanical hemolytic anemia, thrombocytopenia, and the presence of thrombotic microangiopathy features in a kidney biopsy specimen. Patients who had received 4 or more weekly 900-mg infusions of eculizumab were included., Setting & Participants: 19 patients were identified through a query sent to all French nephrology centers., Outcomes & Measurements: Evolution of kidney function, hemolysis, and thrombocytopenia after the initiation of eculizumab therapy., Results: All patients had acute kidney injury (serum creatinine range, 2.2-17.0 mg/dL) and 12 required hemodialysis. Thirteen patients carried a mutation in 1 complement gene and 1 had anti-factor H antibodies. For first-line therapy, 16 patients underwent plasma exchange and 3 patients received eculizumab. Median time between aHUS onset and eculizumab therapy initiation was 6 (range, 1-60) days and median time to platelet count normalization after eculizumab therapy initiation was 6 (range, 2-42) days. At the 3-month follow-up, 4 patients still required dialysis, 8 had non-dialysis-dependent chronic kidney disease, and 7 had normalized kidney function. At last follow-up (range, 4-22 months), 3 patients remained dialysis dependent, 7 had non-dialysis-dependent chronic kidney disease (estimated glomerular filtration rate, 17-55 mL/min/1.73 m(2)), and 9 had normal kidney function. Risks of reaching end-stage renal disease within 3 months and 1 year of aHUS onset were reduced by half in eculizumab-treated patients compared with recent historical controls., Limitations: Retrospective study and use of historical controls., Conclusions: Our data indicate that eculizumab improves kidney disease outcome in patients with aHUS., (Copyright © 2013 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

AKI in pregnancy remains a cause of significant fetomaternal mortality and morbidity, particularly in developing countries. Hypertensive complications of pregnancy (preeclampsia/eclampsia or hemolysis, elevated liver enzymes, and low platelets count syndrome) are the leading cause of AKI in pregnancy worldwide. Thrombotic microangiopathy is another peculiar and devastating cause of AKI in pregnancy. During the last decade, our understanding, and in some cases, our management, of these causes of AKI in pregnancy has dramatically improved. For instance, convincing data have linked pre-eclampsia/eclampsia to an increase in circulating antiangiogenic factors soluble Flt 1 and endoglin, which induce endothelial cell dysfunction, hypertension, and proteinuria. Several distinct pathogenic mechanisms underlying thrombotic microangiopathy, including thrombotic microangiopathy occurring during pregnancy, have been established. Thrombotic microangiopathy, which can present as hemolytic uremic syndrome or thrombotic thrombocytopenic purpura, can be reclassified in four potentially overlapping subtypes: disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 deficiency-related thrombotic microangiopathy, complement alternative pathway dysregulation-related thrombotic microangiopathy, secondary thrombotic microangiopathy (verotoxin and antiangiogenic drugs), and thrombotic microangiopathy of undetermined mechanism. In most cases, pregnancy is only a precipitating factor for thrombotic microangiopathy. Treatment of thrombotic microangiopathy occurring during pregnancy should be tailored to the underlying pathogenic mechanism: (1) restoration of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 serum activity in the setting of thrombotic thrombocytopenic purpura through plasma exchanges and in some cases, B cell-depleting therapy and (2) inhibition of complement alternative pathway activation in atypical hemolytic uremic syndrome using antiC5 blocking antibody (eculizumab).

The objective of the study was to investigate the role of endothelin-1 in the pathogenesis of scleroderma renal crisis in patients with systemic sclerosis. We used immunohistochemical analysis with anti-endothelin-1 and anti-von Willebrand factor antibodies in comparing kidney biopsies from patients with systemic sclerosis and scleroderma renal crisis (n = 14); from normal kidneys (n = 5); and from patients with typical hemolytic uremic syndrome and thrombotic microangiopathy (n = 5), antiphospholipid syndrome (n = 6), diabetic nephropathy (n = 5), minimal change disease with cyclosporine toxicity (n = 5), or nephroangiosclerosis (n = 5). Kidney biopsies from all systemic sclerosis patients presented specific lesions: glomerular lesions with thickened capillary walls (n = 6, 42.8%), mesangiolysis (n = 3, 21.4%), fibrin thrombi (n = 3, 21.4%), hypertrophy of juxtaglomerular apparatus (n = 5, 35.7%), arteriolar lesions showing mucinous intimal thickening and lumen mucoid occlusions (n = 13, 92.8%), proliferation of intimal cells (ie, "onion-skin" lesions; n = 13, 92.8%), fibrinoid necrosis (n = 3, 21.4%), and fibrin thrombosis (n = 4, 28.6%). Chronic lesions in large arteries showed modifications such as fibrous intimal thickening (n = 13, 92.8%). The pattern of endothelial staining for endothelin-1 in both glomeruli and arteriolar lesions appears to be specific for scleroderma renal crisis. Glomerular endothelin-1 staining without arteriolar staining was seen in hemolytic uremic syndrome; and isolated arteriolar staining (without glomerular staining) was seen in a number of conditions including antiphospholipid nephropathy, cyclosporine toxicity, and diabetic nephropathy. Endothelin-1 is overexpressed in glomeruli and arterioles of patients with scleroderma renal crisis, which suggests that endothelin-1 might be a therapeutic target in this condition., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Acute renal failure (ARF) is a rare complication of acute pyelonephritis in adult immunocompetent patients. Recovery of renal function usually occurs if antibiotics are promptly initiated. However, long-term consequences of renal scarring due to acute pyelonephritis are probably underestimated, and some patients present with prolonged renal failure despite adequate antibiotic therapy. We report two cases of severe ARF complicating bacterial pyelonephritis successfully treated with corticosteroids in association with conventional antibiotics.

Acute renal failure is frequent in HIV-infected patients and may be related to HIV-associated nephropathy, drugs, or opportunistic infections. We report a peculiar case of disseminated cryptococcosis complicated by acute renal failure associated with obstruction of intrarenal capillaries by Cryptococus neoformans dead bodies and successfully treated with plasma exchanges.

Acute renal failure (ARF) is a rare complication of the use of intravenous immunoglobulins (IVIg) with an estimated incidence lower than 1 %. It is related to acute tubulo-interstitial nephropathy due to to the occurrence of osmotic nephrosis mainly in the proximal tubule. The recovery of renal function usually occurs within ten days. The risk factors for the occurrence of ARF during the use of IVIg are: age > 65 years, preexisting renal failure (creatinine clearance < 60 ml/min), diabetes, dose, hypovolemia, the concomitant use of other nephro-toxic agents (contrast media agents, etc.). IVIg related ARF has been reported mainly with saccharose-containing IVIg but also with maltose and glucose-containing IVIg. However, no definite conclusion can be drawn concerning the role of the stabilising agent in the genesis of ARF due to the larger use of saccharose-containing IVIG compared to other IVIG and the absence of controlled trials comparing various types of IVIg. Clinicians must be aware that ARF may occur with all types of IVIg. In patients with at least one risk factor for ARF, diuretics should be discontinued, an hydration using saline solutions should be started and the concomitant administration of other nephrotoxic drugs be avoided. Clinicians should use the minimal required dose of IVIg and slow the flow of perfusion (1-2 ml/kg/h).