Transient encephalopathy complicating poststreptococcal glomerulonephritis in an adult with diagnostic findings consistent with cerebral vasculitis

Posterior reversible encephalopathy syndrome and autoimmunity

Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by acute or subacute onset of neurological symptoms (e.g., headache, seizure, confusion, vomiting, and diminished eyesight) and impaired endothelial barrier function of the cerebral circulation that leads to bilateral subcortical vasogenic edema, while exhibiting a "reversible" feature in most cases. Clinically, various predisposing or precipitating conditions have been identified, such as hypertension, autoimmune diseases, renal dysfunction/failure, preeclampsia/eclampsia, post-transplantation conditions, and certain therapeutic agents. Among several putative mechanisms, the immune activation hypothesis prevails, as up to 50% of patients with PRES harbor abnormalities related to autoimmunity, such as concurrent systemic lupus erythematosus. In this Review, we summarize the clinical and laboratory evidence that places PRES in the context of autoimmunity.

Posterior reversible leukoencephalopathy syndrome associated with acute postinfectious glomerulonephritis: systematic review

BACKGROUND

Kidney diseases are a recognized cause of posterior reversible leukoencephalopathy syndrome, usually abbreviated as PRES. The purpose of this review was to systematically address the association between acute postinfectious glomerulonephritis and PRES.

METHODS

We performed a systematic review of the literature on acute postinfectious glomerulonephritis associated with PRES. The principles recommended by the Economic and Social Research Council guidance on the conduct of narrative synthesis and on the Preferred Reporting Items for Systematic Reviews and Meta-analyses were used. Databases searched included Excerpta Medica, US National Library of Medicine, and Web of Science.

RESULTS

For the final analysis, we evaluated 47 reports describing 52 cases (32 males and 20 females). Fifty patients were ≤ 18 years of age. Blood pressure was classified as follows: normal-elevated (n = 3), stage 1 hypertension (n = 3), stage 2 hypertension (n = 5), and severe hypertension (n = 41). Acute kidney injury was classified as stage 1 in 32, stage 2 in 16, and stage 3 in four cases. Neuroimaging studies disclosed a classic posterior PRES pattern in 28 cases, a diffuse PRES pattern in 23 cases, and a brainstem-cerebellum PRES pattern in the remaining case. Antihypertensive drugs were prescribed in all cases and antiepileptic drugs in cases presenting with seizures. A resolution of clinical findings and neuroimaging lesions was documented in all cases with information about follow-up.

CONCLUSIONS

The main factor associated with PRES in acute postinfectious glomerulonephritis is severe hypertension. Prompt clinical suspicion, rapid evaluation, and management of hypertension are crucial. A higher resolution version of the Graphical abstract is available as Supplementary information.

Streptococcal zymogen type B induces angiotensin II in mesangial cells and leukocytes

Previous reports have shown that angiotensin II and oxidative stress may be important features in acute poststreptococcal glomerulonephritis (APSGN) and that streptococcal erythrogenic toxin type B (ETB) and its precursor (ETBP) may have an important role in the pathogenesis of APSGN. The aim of this study was to determine the effect of ETBP on the production of angiotensin II and oxidative stress in rat mesangial cells and human mononuclear leukocytes. Mesangial cells and leukocytes were isolated from digested glomeruli and by histopaque gradient, respectively, while ETBP was isolated from nephritogenic streptococcus cultures using a cation exchange column. Angiotensin II was determined by an enzyme-linked immunosorbent assay and by cytometrics. Superoxide anion, reduced glutathione, nitrites, lipid peroxidation and catalase activity were determined by cytochemical, biochemical and enzymatic assays. Inducible nitric oxide synthase expression was determined by cytometrics. An increased production of angiotensin II was observed in ETBP-treated mesangial cell and leukocyte cultures. The ETBP induced an elevated production of superoxide anions and nitrites in mesangial cells and superoxide anions in leukocytes, while this streptococcal protein decreased the expression of inducible nitric oxide synthase in leukocytes. The ETBP was capable of inducing an increased production of angiotensin II and increased oxidative stress, both of which may be important mediators of inflammatory events in the renal tissue and during APSGN.

Cerebral vasculitis and unilateral sixth-nerve palsy in acute post-streptococcal glomerulonephritis

Cerebral vasculitis associated with acute post-streptococcal glomerulonephritis (APSGN) is rare. A 13-year-old girl presented with severe headache, vomiting, oedema and macroscopic haematuria. There was a history of upper respiratory infection 2 weeks previously. A diagnosis of APSGN was made. On admission, she was normotensive and biochemically well balanced. She experienced a tonic-clonic seizure 2 hours later. An MRI brain scan demonstrated multiple areas of abnormal signal intensity in the cerebral and cerebellar white matter, and subarachnoid haemorrhage consistent with vasculitis was diagnosed. A sixth-nerve palsy developed on the 6th day of admission. An elevated anti-streptolysin titre and low serum C3 complement level together with typical features on renal biopsy supported the diagnosis of APSGN. All clinical and laboratory abnormalities improved with corticosteroid therapy, pulse methyl-prednisolone. APSGN can present with central nervous system abnormalities without hypertension, uraemia and electrolyte disturbance.