Lobar nephronia in a transplanted kidney

Acute focal bacterial nephritis is associated with invasive diagnostic procedures - a cohort of 138 cases extracted through a systematic review

BACKGROUND

Acute focal bacterial nephritis (AFBN) is a rare disease currently described only in case reports and small case series. In this study we summarize the clinical features of AFBN as has been documented in the literature and draw recommendations on the proper diagnosis and therapy.

METHODS

A systematic literature review was undertaken in PUBMED, Web of Science and The Cochrane Library online databases for relevant literature on AFBN in adults.

RESULTS

Literature review revealed a total of 38 articles according to our inclusion criteria, of which we could extract data from 138 cases of AFBN. Fever (98%) and flank pain (80%) were most commonly reported symptoms. E. coli was the most frequent pathogen. Diagnosis was set by CT and/or MRI (52%) with or without sonography or by sonography alone (20%) as well as by sonography combined with IVU. In total, sonography was applied in 83% of cases. All but one patient received antibiotic treatment. Kidney lesions were occasionally mistaken for neoplasms or renal abscesses and as a result, cases were subjected to percutaneous puncture (12.3%), surgical exploration (5.1%) and partial or radical nephrectomy (4.4%). Four cases (2.9%) developed a renal abscess.

CONCLUSIONS

The diagnosis of AFBN is set by characteristic clinico-radiological findings. Differential diagnoses of this interstitial bacterial infection include renal abscess and tumor. Correct diagnosis is occasionally impeded by atypical symptoms. Invasive diagnostic and therapeutic procedures should be limited as the majority of cases respond well to conservative treatment.

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.

Acute focal bacterial nephritis due to methicillin-resistant Staphylococcus aureus in an immunocompetent adult

Acute focal bacterial nephritis (AFBN) is a rare, acute focal infection of the renal parenchyma without liquefaction. The pathogenesis is thought to be due to hematogenous infection or ascending infection from the lower urinary tract. Escherichia coli has been the major pathogen isolated in prior cases, but other Gram-negative enteric pathogens and Staphylococcus aureus have been reported as well. It is well described in children and adults with diabetes and organ transplantation, but has not been previously reported in healthy adults. We report a case of an immunocompetent adult female who presented with a methicillin-resistant Staphylococcus aureus bacteremia after a skin and soft tissue infection that resulted in AFBN.

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.

Acute lobar nephronia in a renal allograft: a case report and literature review

We report a diabetic renal transplant recipient who presented with fever and right lower quadrant abdominal pain. Acute appendicitis was considered initially and she underwent emergent appendectomy. However, persistent symptoms postoperatively made us perform an imaging study to identify the problems. Abdominal and pelvic computed tomography disclosed several focal wedge-shaped lesions of low attenuation in the renal allograft. Acute lobar nephronia was successfully managed with parenteral antibiotics. The patient recovered without any sequela. A renal allograft in the right iliac fossa complicates the diagnosis among acute renal infection, malignancy, acute rejection, and even acute appendicitis. Biopsy of the renal allograft is sometimes needed due to clinically ambiguous imaging results. In this report, we not only detail the clinical course of such a rare case, but also review the previous 3 cases of acute lobar nephronia in renal allografts in the literature.