Acute Focal Bacterial Nephritis Research Articles

Diagnosis and treatment of acute focal bacterial nephritis in children

Diagnosis and treatment of acute focal bacterial nephritis in children

Role of Imaging in Renal Infections: A Narrative Review

Urinary tract infections (UTIs) are among the most common bacterial infections in community and hospital settings. Infections of the urinary system can range from pyelonephritis to urethritis. Acute renal infections encompass entities such as acute pyelonephritis, acute focal bacterial nephritis, renal and perinephric abscesses, emphysematous pyelonephritis, and pyonephrosis, while xanthogranulomatous pyelonephritis is a chronic granulomatous inflammatory condition that affects the kidneys.The diagnosis of UTIs predominantly relies on clinical assessment and confirmation through abnormal laboratory results. Routine medical imaging is therefore typically reserved for complicated cases, aiming to identify contributing factors such as renal calculi, determine the type of infection, and evaluate the extent of the infection and its associated complications. Furthermore, imaging has become crucial for radiologists during interventional procedures in treating pyonephrosis and renal abscesses. Traditional imaging tools, like abdominal X-rays, are vital for identifying renal calculi and gas shadows in emphysematous pyelonephritis, while ultrasonography emerges as an excellent modality for assessing urinary infections in emergency scenarios, pregnancy, and paediatric cases. Contrast-enhanced computed tomography (CECT) or non-contrast computed tomography (NCCT) is the imaging method of choice in the most complex situations, allowing for precise assessment of the disease burden. Current magnetic resonance imaging (MRI) sequences yield promising results in specific scenarios such as pregnancy and paediatric subjects where minimising radiation exposure is a concern. This review focuses on elucidating the essential radiological modalities and their distinctive features in the context of renal infections, offering valuable guidance to microbiologists and physicians.

Acute Focal Bacterial Nephritis in a Patient with Solitary Kidney: Case Report.

Acute focal bacterial nephritis is an underdiagnosed condition. It clinically resembles acute pyelonephritis. If unrecognized and undertreated, it may progress into complications (kidney abscess and scars). Contrast-enhanced computed tomography (CT) reveals specific images of the disease and is considered the gold standard to make the diagnosis. A 63-year-old male patient with solitary kidney presented with symptoms compatible with acute pyelonephritis. Kidney ultrasound was not conclusive. Because of persisting high-grade fever not resolving after 48 hours of antibiotics, a contrast-enhanced CT was then performed, and the diagnosis of acute focal bacterial nephritis was made. A repeat CT after three weeks of intravenous (IV) antibiotics showed marked improvement of the intrarenal lesions, and a fourth week of IV antibiotics was dispensed. Diagnosing acute focal bacterial nephritis is important (particularly in a patient with solitary kidney). This will dictate the therapy duration. Unlike acute pyelonephritis, acute focal bacterial nephritis requires at least three weeks duration of antibiotics to avoid progress into further complications.

Two Cases of Acute Focal Bacterial Nephritis With Central Nervous System Manifestations in Children and Literature Review.

Acute focal bacterial nephritis (AFBN) is a kidney disease characterized by a localized bacterial infection that manifests as an inflammatory mass. Most children with AFBN have nonspecific symptoms including fever, vomiting, and abdominal discomfort, and some develop neurological symptoms such as meningeal irritation, unconsciousness, and seizures as their condition worsens. This was 2 cases of AFBN with central nervous system manifestations in children, and we analyzed its possible mechanisms of the clinical and radiographic features. We experience 2 very unusual cases of AFBN which were linked to central nervous system abnormalities. A 6-year-old boy with AFBN and clinically moderate ncephalitis/encephalopathy with a reversible splenial lesion (MERS) presented with neurological symptoms, including unconsciousness and convulsions. The second case involved an 8-year-old child with AFBN-associated acute encephalopathy who exhibited neurological symptoms, including unconsciousness. According to previous research, AFBN is linked to central nervous system impairment. As a result, when a clinician meets a patient with an inexplicable fever caused by a neurological condition, he should pay attention to this diagnosis of AFBN and follow it in the abdominal graph.

Skin-to-Renal Pelvis Distance Predicts Costovertebral Angle Tenderness in Adult Patients with Acute Focal Bacterial Nephritis

The aim of this study was to examine whether the distance between the skin and the renal pelvis affects the detection of costovertebral angle (CVA) tenderness in patients with acute focal bacterial nephritis (AFBN). We retrospectively reviewed the charts of our patients between April 2013 and June 2019 who were diagnosed as having AFBN. Diagnosis was based on ultrasound or computed tomography with contrast, revealing at least one wedge-shaped area of decreased vascularity and confirmation of fever not attributable to another condition. We extracted 23 cases, all Japanese (mean age 60.0 years old [range 45-81 years], 7 males, 16 females). CVA tenderness was present in 8 of these 23 patients. Receiver operating characteristic curves were drawn to evaluate the ability to differentiate skin-to-renal pelvis distance (SPD), body mass index, and age. Only SPD was a useful predictor of CVA tenderness, and 66 mm was determined as the optimal cutoff point (area under the receiver operating characteristic curve 0.858, 95% confidence interval 0.70-1.00). Logistic regression analysis was performed with CVA tenderness as a dependent variable, and SPD, body mass index, and age as explanatory variables. SPD was an independent predictive variable of CVA tenderness (P = 0.038, odds ratio 0.76, 95% confidence interval 0.590-0.986). CVA tenderness showed low yield in the diagnosis of AFBN in patients with longer SPD. Its use for diagnosis in obese patients may therefore be limited.

Acute focal bacterial nephritis caused by Ralstonia insidiosa in a 9-year-old boy.

Acute focal bacterial nephritis caused by Ralstonia insidiosa in a 9-year-old boy.

Incidence of renal scarring on technetium-99m dimercaptosuccinic acid renal scintigraphy after acute pyelonephritis, acute focal bacterial nephritis, and renal abscess.

To evaluate the association between the incidence of renal scarring on technetium-99m dimercaptosuccinic acid (DMSA) renal scintigraphy and the severity of renal parenchymal infections, such as acute pyelonephritis (APN), acute focal bacterial nephritis (AFBN), and renal abscess, based on computed tomography (CT) diagnosis. Sixty-one children with renal parenchymal infections were included and classified into two groups: those with (renal scarring group) and without renal scarring (non-renal scarring group) on chronic-phase DMSA renal scintigraphy. The severity of renal parenchymal infection was classified into three grades using CT: APN, AFBN, and renal abscess as grades 1, 2, and 3, respectively. The severity of renal parenchymal infection, vesicoureteral reflux (VUR) grade, and intrarenal reflux occurrence during voiding cystourethrography (VCUG) were evaluated between the renal and non-renal scarring groups. Fisher's exact test and Mann-Whitney U test were used for statistical analysis. Renal scars were detected in 28 (45.9%) of the 61 patients. We found that 2/9 (22.2%), 18/41 (43.9%), and 8/11 (72.7%) patients with APN (grade 1), AFBN (grade 2), and renal abscess (grade 3) had renal scarring, respectively. There was a significant difference in the grade of severity of renal parenchymal infection between the renal (median = 2 [interquartile range, 2-3]) and non-renal (median = 2 [interquartile range, 2-2]) scarring groups (p = 0.023). There was a significant difference in the grade of VUR between the renal (median = 3 [interquartile range, 0-4]) and non-renal (median = 0 [interquartile range, 0-2]) scarring groups (p = 0.004). No significant difference in intrarenal reflux occurrence was observed between the renal (present/absent: 3/25) and non-renal (present/absent: 0/29) scarring groups (p = 0.112). Our results showed that pediatric patients with renal scarring on chronic-phase DMSA renal scintigraphy tended to have a more severe renal infection.

A predictive score for detecting vesicoureteral reflux in children with their first Escherichia coli-induced urinary tract infection.

In children with a first Escherichia coli-induced febrile urinary tract infection (fUTI), routine voiding cytourethrography (VCUG) is not recommended for detecting vesicoureteral reflux (VUR). Meanwhile, the sensitivity of renal and bladder ultrasound (RBUS) for detecting VUR is insufficient. Aiming to implement VCUG properly for children with a first E.coli-induced fUTI, we attempted to construct a predictive scoring system for the early screening of VUR. This study enrolled patients aged <2 years of age hospitalized for their first E.coli-induced fUTI during the period when VCUG was implemented for all patients (2007-14, non-selective group [n = 111]) and only for those with VUR-suspected RBUS findings, bacteremia or acute focal bacterial nephritis (2016-19, selective group [n = 102]). We evaluated the accuracy of the current criteria and the VUR predictive score constructed using data from the non-selective group. In the non-selective group, 32 patients had VUR (29%). In the selective group, 20 of 45 VCUG-tested patients had VUR (44%). Among 57 patients not undergoing VCUG in the selective group, 8 had a recurrence of fUTI, 3 of whom were diagnosed with VUR. In the non-selective group, 9 patients with VUR did not fulfill the current criteria and the VUR predictive score consisting of young age, female sex, prolonged fever, hypoproteinemia, hyponatremia and hyperglycemia, showed higher sensitivity, specificity than the current criteria. The current imaging/bacteriological criteria were ineffective in screening for VUR in patients with their first E.coli-induced fUTI. The VUR predictive score can be an accurate indicator for implementing VCUG.

Mild Encephalopathy with a Reversible Corpus Callosum Splenium Lesion Associated with Acute Focal Bacterial Nephritis in a Boy

Mild Encephalopathy with a Reversible Corpus Callosum Splenium Lesion Associated with Acute Focal Bacterial Nephritis in a Boy

Clinical features of acute focal bacterial nephritis in adults

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidneys presenting as an inflammatory mass that can develop into renal abscess. The current reports on AFBN mostly are among children and rarely described in adults. This study was aimed to analyze the clinical features of AFBN in adults and make a review for the disease to give the clinicians some clues to suspect and recognize it in adults. From January 2014 to December 2019, AFBN was diagnosed by contrast-enhanced computed tomography (CT) in 238 adults at the Department of Nephrology, the Second Hospital of Hebei Medical University, Shijiazhuang, China. We reviewed the clinical records of these patients and asked them about their post-discharge status via telephone follow-up. Of all the patients, 195 were female and 43 were male, the median age were 46.87 years. 86.13% presented with fever, 55.89% presented with lower urinary tract symptoms and 97.9% presented with pyuria. In renal ultrasonography, abdominal findings were seen only 22.69% patients. E.coli accounted for 74.73% of the isolated pathogen. After 4 weeks of treatment, the patients had no recurrence of symptoms. We recommend that when a patient presents clinically with acute pyelonephritis, but the fever persist longer after antimicrobial treatment (≥ 4 days in our study), AFBN should be suspected. For the diagnosis, contrast-enhanced CT is the “gold standard”, magnetic resonance imaging (MRI) may be a good option, but the ultrasonography is probably not satisfied. 3–4 weeks of antibiotic therapy may be appropriate for AFBN in adults.

Increased cytokines/chemokines and hyponatremia as a possible cause of clinically mild encephalitis/encephalopathy with a reversible splenial lesion associated with acute focal bacterial nephritis

ObjectiveClinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), the second most common encephalopathy syndrome in Japan, is most often associated with viral infection. Bacterial MERS has been rarely reported but is mostly associated with acute focal bacterial nephritis (AFBN) for an unknown reason. We examined cytokines and chemokines in four MERS patients with AFBN to determine if they play an important role in the pathogenesis. MethodsWe examined the clinical charts and MRI results in four MERS patients with AFBN, and measured 10 cytokines and chemokines in serum and cerebrospinal fluid in the acute phase. These were analyzed using the Mann-Whitney U test, compared with the control group (cases with a non-inflammatory neurological disease). Longitudinal changes in the serum cytokine and chemokine levels were evaluated in two patients. ResultsHyponatremia was observed in all four patients with MERS associated with AFBN (128–134 mEq/L). CSF analysis revealed increased cytokines/chemokines associated with Th1 (CXCL10, TNF-α, IFN-γ), T reg (IL-10), Th17 (IL-6), and neutrophil (IL-8 and CXCL1). In serum, upregulation was observed in those associated with Th1 (CXCL10, TNF-α, IFN-γ), Th17 (IL-6), and inflammasome (IL-1ß). The increased serum cytokines/chemokines in the acute stage normalized within 2 weeks in patients 1 and 2, so examined, in accordance with their clinical improvement. ConclusionIncreased cytokines/chemokines and hyponatremia may be factors that explain why AFBN is likely to cause MERS.

POS-444 ACUTE FOCAL BACTERIAL NEPHRITIS IN ADULTS: A SINGLE CENTER EXPERIENCE

Acute Focal Bacterial Nephritis (AFBN) resembles clinically acute pyelonephritis (APN) and remains an underdiagnosed condition. Therefore, the condition is managed as APN and the renal lesions insufficiently treated may progress to abscess leading to nephrectomy. Contrast-enhanced computer tomography (CECT) makes the diagnosis by showing wedge-shaped parenchymal areas with decreased enhancement. However CECT is not regularly requested. We report here our experience with the management of 17 consecutive cases admitted with AFBN and look at the clinical features that may help differentiating AFBN from APN.

Acute focal bacterial nephritis with congenital partial renal duplication

A healthy 8-year-old girl presented to our hospital with fever and vomiting for 5 days. She had no complaint of flank pain during this time. On examination, she appeared exhausted,...

Long-Term Durability of Infliximab for Pediatric Ulcerative Colitis: A Retrospective Data Review in a Tertiary Children's Hospital in Japan.

PurposeThe long-term efficacy and safety of infliximab (IFX) in children with ulcerative colitis (UC) have not been well-evaluated. Here, we reviewed the long-term durability and safety of IFX in our single center pediatric cohort with UC.MethodsThis retrospective study included 20 children with UC who were administered IFX.ResultsFor induction, 5 mg/kg IFX was administered at weeks 0, 2, and 6, followed by every 8 weeks for maintenance. The dose and interval of IFX were adjusted depending on clinical decisions. Corticosteroid (CS)-free remission without dose escalation (DE) occurred in 30% and 25% of patients at weeks 30 and 54, respectively. Patients who achieved CS-free remission without DE at week 30 sustained long-term IFX treatment without colectomy. However, one-third of the patients discontinued IFX treatment because of a primary nonresponse, and one-third experienced secondary loss of response (sLOR). IFX durability was higher in patients administered IFX plus azathioprine for >6 months. Four of five patients with very early onset UC had a primary nonresponse. Infusion reactions (IRs) occurred in 10 patients, resulting in discontinuation of IFX in four of these patients. No severe opportunistic infections occurred, except in one patient who developed acute focal bacterial nephritis. Three patients developed psoriasis-like lesions.ConclusionIFX is relatively safe and effective for children with UC. Clinical remission at week 30 was associated with long-term durability of colectomy-free IFX treatment. However, approximately two-thirds of the patients were unable to continue IFX therapy because of primary nonresponse, sLOR, IRs, and other side effects.

Predictive markers of acute focal bacterial nephritis. A multicentre case-control study

Acute focal bacterial nephritis is an interstitial bacterial infection, localised in the renal parenchyma, which can be more serious than acute pyelonephritis. The aim of this study is the analysis of predictive factors that may lead to its early diagnosis, which is essential for an adequate therapeutic approach. A retrospective, multicentre case and control study. The participant centres were hospitals in Castellon and Valencia. The study period was 2010-2018, with the cases being patients with focal bacterial nephritis and the patients with pyelonephritis as controls. A total of 158 (1:1) patients were included. The median age of the cases was 2 years and there were 75% females. There were no differences in the clinical presentation. In the univariate analysis, focal nephritis was associated with malformations of the urinary tract, bacteraemia, the neutrophil count, and procalcitonin, as well as febrile convulsions of borderline significance. Procalcitonin values ≥2 ng/ml had an OR of 4.9 (95%CI; 1.77-13.85) of presenting with focal nephritis. In the multivariate analysis, the urological malformations still maintained statistical significance and borderline significance for procalcitonin. The urinary tract malformations predispose the development of focal bacterial nephritis. In patients with a urinary tract infection and predictive factors of acute focal bacterial nephritis it would be worthwhile performing a renal Doppler ultrasound in the acute phase for its appropriate diagnosis and treatment.

Predictive markers of acute focal bacterial nephritis. A multicentre case-control study

IntroductionAcute focal bacterial nephritis is an interstitial bacterial infection, localised in the renal parenchyma, which can be more serious than acute pyelonephritis. The aim of this study is the analysis of predictive factors that may lead to its early diagnosis, which is essential for an adequate therapeutic approach. Patients and methodsA retrospective, multicentre case and control study. The participant centres were hospitals in Castellon and Valencia. The study period was 2010–2018, with the cases being patients with focal bacterial nephritis and the patients with pyelonephritis as controls. ResultsA total of 158 (1:1) patients were included. The median age of the cases was 2 years and there were 75% females. There were no differences in the clinical presentation. In the univariate analysis, focal nephritis was associated with malformations of the urinary tract, bacteraemia, the neutrophil count, and procalcitonin, as well as febrile convulsions of borderline significance. Procalcitonin values ≥2 ng/mL had an OR of 4.9 (95% CI; 1.77–13.85) of presenting with focal nephritis. In the multivariate analysis, the urological malformations still maintained statistical significance and borderline significance for procalcitonin. ConclusionsThe urinary tract malformations predispose the development of focal bacterial nephritis. In patients with a urinary tract infection and predictive factors of acute focal bacterial nephritis it would be worthwhile performing a renal Doppler ultrasound in the acute phase for its appropriate diagnosis and treatment.

Acute bacterial nephritis. A descriptive study of an underdiagnosed entity

Background: Acute bacterial nephritis is an infectious process diagnosed through imaging studies. The clinical course of the disease has been shown to be more aggressive than acute pyelonephritis. It continues to be underdiagnosed, thus there are few studies on the entity in the literature.&#x0D; Objective: To describe the clinical characteristics and imaging features of acute bacterial nephritis, as well as its clinical course.&#x0D; Design: A descriptive, retrospective case series was conducted.&#x0D; Materials and methods: Thirty-two cases of acute bacterial nephritis in patients admitted to the hospital within the time frame of 2009 to 2016 were reviewed. The patients’ clinical characteristics upon admission were registered, as well as inpatient clinical progression, culture results, and antibiotic therapy response. The imaging studies were re-evaluated and the diagnostic consistency with either the focal or multifocal disease presentation was confirmed.&#x0D; Results: Cases predominated in women (n=29, 90.62%) and the most frequently associated comorbidities were diabetes (n=16, 50%) and obesity (n=9, 28.25%). The most important clinical findings upon admission were fever (n=15, 46.87%) and leukocytosis (n=27, 84.38%). Escherichia coli was the most commonly isolated bacterium (63.63%). Both acute focal bacterial nephritis and acute multifocal bacterial nephritis were observed in 46.87% (n=15) and 53.13% (n=17) of the patients, respectively. Imaging studies were required for all diagnoses.&#x0D; Conclusion: Fever and leukocytosis are the main findings in acute bacterial nephritis. Imaging studies are necessary for making the diagnosis, given that acute pyelonephritis and acute bacterial nephritis cannot be clinically differentiated.

Acute bacterial nephritis. A descriptive study of an underdiagnosed entity

Background: Acute bacterial nephritis is an infectious process diagnosed through imaging studies. The clinical course of the disease has been shown to be more aggressive than acute pyelonephritis. It continues to be underdiagnosed, thus there are few studies on the entity in the literature.&#x0D; Objective: To describe the clinical characteristics and imaging features of acute bacterial nephritis, as well as its clinical course.&#x0D; Design: A descriptive, retrospective case series was conducted.&#x0D; Materials and methods: Thirty-two cases of acute bacterial nephritis in patients admitted to the hospital within the time frame of 2009 to 2016 were reviewed. The patients’ clinical characteristics upon admission were registered, as well as inpatient clinical progression, culture results, and antibiotic therapy response. The imaging studies were re-evaluated and the diagnostic consistency with either the focal or multifocal disease presentation was confirmed.&#x0D; Results: Cases predominated in women (n=29, 90.62%) and the most frequently associated comorbidities were diabetes (n=16, 50%) and obesity (n=9, 28.25%). The most important clinical findings upon admission were fever (n=15, 46.87%) and leukocytosis (n=27, 84.38%). Escherichia coli was the most commonly isolated bacterium (63.63%). Both acute focal bacterial nephritis and acute multifocal bacterial nephritis were observed in 46.87% (n=15) and 53.13% (n=17) of the patients, respectively. Imaging studies were required for all diagnoses.&#x0D; Conclusion: Fever and leukocytosis are the main findings in acute bacterial nephritis. Imaging studies are necessary for making the diagnosis, given that acute pyelonephritis and acute bacterial nephritis cannot be clinically differentiated.

Acute focal bacterial nephritis

A description of 13 clinical cases of acute focal bacterial nephritis in children aged from 1 year to 4 years and 8 months (2.6±1.1 years), made up 1,61% from hospitalized for acute urinary tract infections in accordance with existing ideas about this pathology, is presented.Acute focal bacterial nephritis is a rare variant of acute pyelonephritis that can transform into a purulent process, accompanied by nonspecific signs of acute urinary infection with persistent fever and signs of a systemic inflammatory response, which is recognized by visualization technologies. Ultrasound investigation in the case of acute focal bacterial nephritis usually reveals focuses of hyper-echogenicity of one of the kidneys and/ or signs of nephromegaly. The reserve method for diagnosing pathology is the computerized tomography. Adequate treatment of acute focal bacterial nephritis must include mandatory intravenous administration of antibiotics for at least 3 weeks , which allows for a favorable outcome of the disease.

Acute Focal Bacterial Nephritis Associated With Reversible Splenial Corpus Callosum Lesion

Acute focal bacterial nephritis (AFBN) is a localized bacterial infection of the kidney, which presents as an inflammatory mass without formation of a frank abscess. Rare cases of AFBN are accompanied by neurological symptoms such as meningeal irritation, unconsciousness, and seizures. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is characterized by transient high signal intensity splenial lesions on diffusion-weighted magnetic resonance imaging. MERS can be divided into two types: type 1 with an isolated splenium of the corpus callosum and type 2 with extensive white matter and/or entire callosal lesions. We experienced three rare cases of pediatric AFBN associated with neurological symptoms, including unconsciousness and reversible splenial corpus callosum lesion. The first case was an 8-year-old girl who had neurological symptoms, including unconsciousness, and AFBN was associated with MERS type 2. The second (5-year-old boy) and third (5-year-old girl) cases had neurological symptoms, including unconsciousness and AFBN with MERS type 1. Two of the three cases had AFBN caused by Escherichia coli . All three cases showed high levels of urinary beta 2 -microglobulin (B2MG). AFBN should be suspected in children with fever, rapid clinical deterioration, neurological symptoms including unconsciousness, and high urinary B2MG level. We recommend that abdominal enhanced computed tomography should be performed for the diagnosis of AFBN. Int J Clin Pediatr. 2020;9(3):82-86 doi: https://doi.org/10.14740/ijcp395