Acute lobar nephronia is associated with a high incidence of renal scarring in childhood urinary tract infections

Acute Focal Bacterial Nephritis without Pyuria: A Peculiar Subtype of Urinary Tract Infection

Acute focal bacterial nephritis (AFBN) without pyuria is a subtype of urinary tract infection in children, often leading to diagnostic challenges. The clinical characteristics of 6 children diagnosed with AFBN, who exhibited an absence of pyuria, were retrospectively summarized and compared with the control group consisting of 49 hospitalized AFBN children with pyuria. The cases of AFBN without pyuria presented with more severe inflammatory responses and were predisposed to complications, such as sepsis and neurological abnormalities.

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.

A case of acute focal bacterial nephritis with acute kidney injury presenting as acute abdomen

Acute focal bacterial nephritis (AFBN) refers to the bacterial infection of the renal parenchyma without abscess formation. Although AFBN has mainly been reported in pediatric patients, it may be underdiagnosed in adults as it resembles acute pyelonephritis in its clinical presentation. However, the symptoms suggesting acute abdomen is an important clue to diagnose AFBN, which requires additional imaging studies such as contrast-enhanced computed tomography (CECT). Here, we present the case of a 49-year-old female presenting to our emergency room with acute abdomen as well as acute kidney injury (AKI). CECT was performed to rule out critical etiologies of severe abdominal pain and the results revealed multifocal wedge-shaped shadows in the right kidney and diffuse enlargement of bilateral kidneys. We diagnosed the patient with AFBN and treated her through temporal hemodialysis (two sessions) and antibiotics for 23 days. Although AKI associated with AFBN has rarely been reported, her renal dysfunction and other symptoms were completely improved. In conclusion, clinicians should be aware of AFBN and be cautious to avoid the unnecessary invasive interventions.

Acute Focal Bacterial Nephritis: Two Cases and Review of the Literature

Rationale:

Acute focal bacterial nephritis (AFBN) has mainly been reported in pediatrics. It may be an underdiagnosed condition in adults because it resembles acute pyelonephritis (APN) in its clinical presentation.

Presenting concerns of the patients:

Two young women (25 and 27 years old, respectively) presented with complaints compatible with a diagnosis of APN. However in both, fever was of high grade, persistent for several days in spite of antibiotic administration, and there was demonstrated worsening of the inflammatory biomarkers. A contrast-enhanced computed tomography (CECT) led to the diagnosis in both cases.

Diagnoses:

Contrast-enhanced computed tomography reveals the most sensitive and specific images of AFBN. This includes wedge-shaped lesions with decreased enhancement, which may be focal or multifocal.

Interventions (including prevention and lifestyle):

Antibiotic therapy for at least 3 weeks.

Outcomes:

Resolution of AFBN was obtained after 3 weeks of antibiotics.

Lessons learned:

Our 2 cases illustrate the importance of CECT imaging to confirm the diagnosis of AFBN. Interstitial bacterial inflammation may have a worse prognosis if not diagnosed early and efficiently treated. Unlike APN, the management of AFBN requires at least 3 weeks of antibiotics to prevent the development of renal scarring and renal abscess.

Acute focal bacterial nephritis in a cohort of hospitalized adult patients with acute pyelonephritis. Assessment of risk factors and a predictive model

BACKGROUND

Acute focal bacterial nephritis (AFBN) is a complicated form of acute pyelonephritis (APN) characterized by single or multiple areas of localised infection in the kidney without liquefaction or abscess. Studies investigating AFBN in adults are scarce.

AIM

The present study was aimed at evaluating the prevalence, associated factors, and presence of atypical clinical and radiological manifestations in adult AFBN patients. Also, we developed a clinical prediction model to evaluate the probability of AFBN in patients with APN.

METHODS

The clinical records of 377 patients (mean age 54years, 74.0% females) admitted to a hospital over a 5-year period with APN were reviewed.

RESULTS

A total of 57 cases of AFBN were radiologically identified (prevalence, 15.1%). Patients with AFBN were younger and displayed atypical manifestations more frequently than patients without AFBN; these included both clinical and radiological (pleural effusion, gallbladder wall thickening, fluid around the gallbladder, perirenal fluid, and ascites) manifestations. Patients with AFBN showed lower systolic blood pressure and needed more days of therapy to become afebrile, longer total duration of antibiotic therapy, and longer hospital stay than patients without AFBN. Contraceptive use was more frequent in patients with AFBN. A model based on five clinical variables showed good discrimination performance for the diagnosis of AFBN (Area under the curve, 0.77 (95% CI, 0.69-0.89)).

CONCLUSIONS

Patients with AFBN frequently present with atypical clinical and radiological manifestations. Clinical presentation by means of a predictive model may predict the presence of AFBN. Patients with AFBN need more intensive therapy, which is followed by a favourable outcome.

Role of Renal Ultrasonography in Predicting Vesicoureteral Reflux and Renal Scarring in Children Hospitalized with a First Febrile Urinary Tract Infection

BACKGROUND

This study was designed to examine the capability of renal ultrasonography (US) for predicting vesicoureteral reflux (VUR) and renal scarring (RS), and to assess, using initial US, the significant urologic abnormalities that impact on management of children hospitalized with a first febrile urinary tract infection (UTI).

METHODS

Hospitalized children aged ≤ 2 years with a first febrile UTI were prospectively evaluated using imaging studies, including (99m)Tc dimercaptosuccinic acid (DMSA) scan, US, and voiding cystourethrography.

RESULTS

Of the 310 children analyzed (195 boys and 115 girls), 105 (33.9%) had abnormal US. Acute DMSA scans were abnormal in 194 children (62.6%), including 89 (45.9%) with concomitant abnormal US. There was VUR in 107 children (34.5%), including 79 (25.5%) with Grades III-V VUR. The sensitivity and negative predictive values of US were 52.3% and 75.1%, respectively, for Grades I-V VUR and 68.4% and 87.8%, respectively, for Grades III-V VUR. Eighty-five children (27.4%) had RS, including 55 (64.7%) with abnormal US. Of the 105 children with abnormal US, 33 (31.4%) needed subsequent management (surgical intervention, parental counseling, or follow up of renal function). Nephromegaly on initial US and Grades III-V VUR were risk factors of RS.

CONCLUSION

Abnormal US may carry a higher probability of Grades III-V VUR and RS, and can affect subsequent management in a significant number of children. Nephromegaly on initial US and Grades III-V VUR are strongly associated with an increased risk for RS. Thus, US should be performed on children after a first febrile UTI and children with normal US may not require voiding cystourethrography.

Acute focal bacterial nephritis, pyonephrosis and renal abscess in children

BACKGROUND-AIM

Acute focal bacterial nephritis (AFBN), renal abscess and pyonephrosis are uncommon and not fully addressed forms of urinary tract infection (UTI) which may be underdiagnosed without the appropriate imaging studies. Here, we review the characteristics and outcome of these renal entities in children managed at a single medial centre.

PATIENTS AND METHODS

The medical files of all children hospitalized for episodes of AFBN, renal abscess and pyonephrosis during a 10-year period (2003-2012) were reviewed.

RESULTS

Among the 602 children hospitalized for UTI, 21 presented with AFBN, one with abscess and three with pyonephrosis. All 25 children (13 girls), ranging in age from 0.06 to 13.4 years, were admitted with fever and an impaired clinical condition, and 18 had urological abnormalities. More than one lesion, often of different types, were identified in 11 episodes. Urine cultures from 13 episodes grew non-Escherichia coli pathogens and those from two episodes were negative. Antibiotics were administered for 14-60 days, and emergency surgery was required in three cases. During follow-up, 13 patients underwent corrective surgery. Permanent renal lesions were identified in 16 patients.

CONCLUSIONS

AFBN, renal abscess and pyonephrosis should be suspected in children with severe presentation and urological history. Appropriate imaging is crucial for management planning. Prognosis is often guarded despite appropriate treatment. Based on the results of this study we propose a management algorithm.

Comparison of acute lobar nephronia and acute pyelonephritis in children: a single-center clinical analysis in southern taiwan

BACKGROUND

Patients with acute lobar nephronia (ALN) require a longer duration of antimicrobial treatment than those with acute pyelonephritis (APN), and ALN is associated with renal scarring. The aim of this study was to provide an understanding of ALN by comparing the clinical features of pediatric patients with ALN and APN.

METHODS

We enrolled all of the patients with ALN (confirmed by computed tomography) admitted to our hospital from 1999 to 2012 in the ALN group. In addition, each patient diagnosed with APN who was matched for sex, age, and admission date to each ALN patient was enrolled in the APN group. The medical charts of patients in these two groups were retrospectively reviewed and analyzed for comparison.

RESULTS

The fever duration after hospitalization in the ALN group and the APN group were 4.85 ± 2.33 days and 2.30 ± 1.47 days respectively. The microbiological distributions and the majority of susceptibilities were similar in the ALN and APN groups. The majority of clinical manifestations are nonspecific and unreliable for the differentiation of ALN and APN. The patients with ALN were febrile for longer after antimicrobial treatment, had more nausea/vomiting symptoms, higher neutrophil count, bandemia, and C-reactive protein (CRP) levels, and lower platelet count (all p < 0.05). In multivariate analysis, initial CRP levels, nausea/vomiting symptoms, and fever duration after admission were independent variables with statistical significance to predict ALN. Severe nephromegaly occurred significantly more in the ALN group than in the APN group (p = 0.022).

CONCLUSION

The majority of clinical manifestations, laboratory findings, and microbiological features are similar between patients with ALN and APN. Clinicians should keep a high index of suspicion regarding ALN, particularly for those with ultrasonographic nephromegaly, initial higher CRP, nausea/vomiting, and fever for > 5 days after antimicrobial treatment.

Antibiotics for acute pyelonephritis in children

BACKGROUND

Urinary tract infection (UTI) is one of the most common bacterial infections in infants. The most severe form of UTI is acute pyelonephritis, which results in significant acute morbidity and may cause permanent kidney damage. There remains uncertainty regarding the optimum antibiotic regimen, route of administration and duration of treatment. This is an update of a review that was first published in 2003 and updated in 2005 and 2007.

OBJECTIVES

To evaluate the benefits and harms of antibiotics used to treat children with acute pyelonephritis. The aspects of therapy considered were 1) different antibiotics, 2) different dosing regimens of the same antibiotic, 3) different duration of treatment, and 4) different routes of administration.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register, CENTRAL, MEDLINE, EMBASE, reference lists of articles and conference proceedings without language restriction to 10 April 2014.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing different antibiotic agents, routes, frequencies or durations of therapy in children aged 0 to 18 years with proven UTI and acute pyelonephritis were selected.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study quality and extracted data. Statistical analyses were performed using the random-effects model and the results expressed as risk ratio (RR) for dichotomous outcomes or mean difference (MD) for continuous data with 95% confidence intervals (CI).

MAIN RESULTS

This updated review included 27 studies (4452 children). This update included evidence from three new studies, and following re-evaluation, a previously excluded study was included because it now met our inclusion criteria.Risk of bias was assessed as low for sequence generation (12 studies), allocation concealment (six studies), blinding of outcome assessors (17 studies), incomplete outcome reporting (19 studies) and selective outcome reporting (13 studies). No study was blinded for participants or investigators. The 27 included studies evaluated 12 different comparisons. No significant differences were found in duration of fever (2 studies, 808 children: MD 2.05 hours, 95% CI -0.84 to 4.94), persistent UTI at 72 hours after commencing therapy (2 studies, 542 children: RR 1.10, 95% CI 0.07 to 17.41) or persistent kidney damage at six to 12 months (4 studies, 943 children: RR 0.82, 95% CI 0.59 to 1.12) between oral antibiotic therapy (10 to 14 days) and intravenous (IV) therapy (3 days) followed by oral therapy (10 days). Similarly, no significant differences in persistent bacteriuria at the end of treatment (4 studies, 305 children: RR 0.78, 95% CI 0.24 to 2.55) or persistent kidney damage (4 studies, 726 children: RR 1.01, 95% CI 0.80 to 1.29) were found between IV therapy (three to four days) followed by oral therapy and IV therapy (seven to 14 days). No significant differences in efficacy were found between daily and thrice daily administration of aminoglycosides (1 study, 179 children, persistent clinical symptoms at three days: RR 1.98, 95% CI 0.37 to 10.53). Adverse events were mild and uncommon and rarely resulted in discontinuation of treatment.

AUTHORS' CONCLUSIONS

This updated review increases the body of evidence that oral antibiotics alone are as effective as a short course (three to four days) of IV antibiotics followed by oral therapy for a total treatment duration of 10 to 14 days for the treatment of acute pyelonephritis in children. When IV antibiotics are given, a short course (two to four days) of IV therapy followed by oral therapy is as effective as a longer course (seven to 10 days) of IV therapy. If IV therapy with aminoglycosides is chosen, single daily dosing is safe and effective. Insufficient data are available to extrapolate these findings to children aged less than one month of age or to children with dilating vesicoureteric reflux (grades III-V). Further studies are required to determine the optimal total duration of antibiotic therapy required for acute pyelonephritis.

A rare and unusual presentation of urological infection on a patient on steroids

We report the rare case of adult lobar nephronia in a 49-year-old female, on long-term steroids with no prior urological or transplant history. More frequently reported in paediatric literature, adult lobar nephronia (focal pyelonephritis) is an unusual radiological finding sometimes preceding the development of renal abscess. We advocate that treatment should be a prolonged course of antibiotics and close follow-up.

Nephromegaly is a significant risk factor for renal scarring in children with first febrile urinary tract infections

PURPOSE

We determined whether nephromegaly on ultrasound can be used to identify patients with urinary tract infection at increased risk for renal scarring, and we investigated the effect of vesicoureteral reflux on renal scarring.

MATERIALS AND METHODS

We enrolled hospitalized patients with a first febrile urinary tract infection. All patients underwent renal ultrasound and most patients underwent voiding cystourethrography. Renal scarring was assessed using (99m)technetium dimercapto-succinic acid renal scintigraphy at least 6 months after treatment. Children with recurrent urinary tract infections before scintigraphy were excluded from the study.

RESULTS

A total of 545 children (80 with and 465 without nephromegaly) were enrolled. Infection was more severe in patients with than without nephromegaly. The incidence of renal scarring was significantly higher in patients with nephromegaly (90% vs 32%, p <0.001), in kidneys with nephromegaly (80.5% vs 18.7%, p <0.001) and in kidneys with vesicoureteral reflux (41.5% vs 22.2%, p <0.001). Kidneys with nephromegaly had a greater incidence of reflux. The finding of nephromegaly is associated with a greatly increased likelihood of renal scarring in patients with vesicoureteral reflux.

CONCLUSIONS

Our results indicate that ultrasound diagnosis of nephromegaly at onset is associated with a high incidence of renal scarring, and identification of nephromegaly at onset and vesicoureteral reflux are significant risk factors for renal scarring in children with a first febrile urinary tract infection. Nephromegaly is associated with an increased frequency of vesicoureteral reflux and increased likelihood of renal scarring in patients with reflux.