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PubMed1986

Influence of inflammation on the efficacy of antibiotic treatment of experimental pyelonephritis.

An acute exudative Escherichia coli pyelonephritis rat model was used to study the influence of progressive pyelonephritis on the efficacy of antibiotic treatment. In this model, transient ureteral obstruction after E. coli bladder inoculation induces early bacterial multiplication in the kidney parenchyma, and the bacterial counts peak by 48 h. The inflammatory response (assessed by the increase in kidney weight) is somewhat delayed, starting 36 h after inoculation and peaking by 72 h. Groups of rats received 4 doses over 48 h of saline, ceftriaxone (100 mg/kg), or ceftriaxone (100 mg/kg) plus gentamicin (4 mg/kg). These treatments were initiated 24, 36, 48, or 72 h after bladder inoculation. Antibiotic treatment started at 24 h was significantly more effective in reducing bacterial counts in the kidney parenchyma than at any later therapy onset. Only when started 24 h after inoculation was the synergistic combination of ceftriaxone plus gentamicin more effective in reducing bacterial counts than ceftriaxone alone. Ceftriaxone and ceftriaxone plus gentamicin regimens started at 24 h reduced significantly (by 42 and 55%, respectively) the incidence of acute exudative pyelonephritis when compared with the incidence in saline-treated controls. Early therapy onset (24 h) strikingly reduced the development of the inflammatory response. This reduction was less marked when antibiotic therapy was started at 36 h and no longer apparent when therapy onset was delayed up to 48 or 72 h. In conclusion, the efficacy of antibiotics in eradicating bacteria from the kidney parenchyma and in preventing acute exudative pyelonephritis was markedly hampered by the development of pyelonephritis.

Animals↗

PubMed1991

Attenuation of antibody response to acute pyelonephritis by treatment with antibiotics.

While acute pyelonephritis is known to elicit an antibody response, it is also known that a patient who has had pyelonephritis once is susceptible to recurrent renal infection. Using our experimental model of pyelonephritis in the monkey, we tested whether antibiotic therapy of the acute disease would affect the antibody response. We found that it did, because antibiotic therapy beginning 72 h after bacterial inoculation attenuated the antibody response so that rechallenge 3 months later produced acute pyelonephritis and prolonged bacteriuria. The animals with untreated infection had an antibody response that lasted a sufficient period of time to prevent acute pyelonephritis after renal challenge. We have confirmed that antibody titers against P fimbriae are protective, and to a degree, this protective effect may be abrogated by antibiotic therapy.

Acute Disease↗

PubMed1996

Experimental pyelonephritis in piglets: diagnosis with MR imaging.

PURPOSE: To compare findings at magnetic resonance (MR) imaging with those at histopathologic examination in the detection of experimentally induced pyelonephritis in piglets. MATERIALS AND METHODS: MR imaging was performed in 23 piglets with and nine piglets without experimentally induced pyelonephritis. Escherichia coli were injected into the bladder of the 23 piglets with surgically created vesicoureteral reflux. Imaging was performed with unenhanced and contrast material-enhanced T1-weighted and fast multiplanar inversion-recovery (IR) and fast spinecho T2-weighted sequences. MR images and pathologic findings were reviewed independently by two pediatric radiologists and a pathologist, respectively, in a blinded fashion. RESULTS: Sixty-four kidneys and 192 renal zones were evaluated. Coronal gadolinium-enhanced fast multiplanar IR imaging was the only sequence that was sensitive and specific for the diagnosis of pyelonephritis. For the two reviewers, respectively, sensitivity was 85% (n = 75) and 92% (n = 81) of 88 histopathologically positive zones and specificity was 95% (n = 99) and 94% (n = 98) of 104 pathologically negative zones. Findings at gadolinium-enhanced fast multiplanar IR imaging were not statistically different from findings at histopathologic examination in the detection of pyelonephritis. Interobserver reproducibility for the contrast-enhanced fast multiplanar IR sequence was excellent (kappa statistic = 0.82 and 0.90, respectively, for interpretation of a renal zone and of a kidney). CONCLUSION: Contrast-enhanced fast multiplanar IR imaging is a sensitive and specific test for detection of experimental pyelonephritis in this piglet model.

Animals↗

PubMed1998

Childhood pyelonephritis: comparison of gadolinium-enhanced MR imaging and renal cortical scintigraphy for diagnosis.

PURPOSE: To compare gadolinium-enhanced inversion-recovery magnetic resonance (MR) imaging with renal cortical scintigraphy in the diagnosis of childhood pyelonephritis. MATERIALS AND METHODS: Thirty-seven patients with fever-producing urinary tract infection underwent gadolinium-enhanced inversion-recovery MR imaging and technetium-99m renal cortical scintigraphy. Each study was read in double-blind fashion by two radiologists. The kidney was divided into three zones, and each was graded as positive, equivocal, or negative for pyelonephritis. RESULTS: Seventy kidneys (210 zones) were imaged. Twenty-six kidneys (54 zones) had evidence of pyelonephritis at both MR imaging and scintigraphy. Twenty-four kidneys (100 zones) were negative on both studies. Twelve kidneys (42 zones) were positive at MR imaging but negative at scintigraphy, and four kidneys (seven zones) were negative at MR imaging but positive at scintigraphy. The results of MR imaging for pyelonephritis were not equivalent to the results of scintigraphy (P = .001 for renal zones). The proportion of positive agreement between readers for the presence of pyelonephritis was 0.85 and 0.57 for MR imaging and scintigraphy, respectively. The proportion of negative agreement was 0.88 and 0.80 for MR imaging and scintigraphy, respectively. CONCLUSION: Gadolinium-enhanced inversion-recovery MR imaging enabled detection of more pyelonephritic lesions than did renal cortical scintigraphy and had superior interobserver agreement.

Adolescent↗

PubMed2001

Acute pyelonephritis: comparison of diagnosis with 99mTc-DMSA, SPECT, spiral CT, MR imaging, and power Doppler US in an experimental pig model.

PURPOSE: To compare the sensitivity and specificity of technetium-99m dimercaptosuccinic acid (DMSA) single photon emission computed tomography (SPECT), spiral computed tomography (CT), magnetic resonance (MR) imaging, and power Doppler ultrasonography (US) for the detection and localization of acute pyelonephritis by using histopathologic findings as the standard of reference. MATERIALS AND METHODS: Bilateral vesicoureteric reflux was surgically created in 35 piglets (70 kidneys). One week later, a liquid bacterial culture of Escherichia coli was injected into the bladder. Three days after induction of urinary infection, imaging studies were performed, and the kidneys were removed for histopathologic examination. SPECT images were obtained 2-3 hours after injection of 99mTc-DMSA. Transverse and coronal MR images were obtained with gadolinium-enhanced fast inversion recovery. Transverse CT images were obtained before and after injection of contrast agent. Power Doppler US was performed in longitudinal, transverse, and coronal planes. Each kidney was divided into three zones for correlation of findings. RESULTS: Histopathologic examination revealed pyelonephritis in 102 zones in 38 kidneys. Sensitivity and specificity for detecting pyelonephritis in the kidneys were 92.1% and 93.8% for SPECT, 89.5% and 87.5% for MR imaging, 86.8% and 87.5% for CT, and 74.3% and 56.7% for US. Sensitivity and specificity for detecting pyelonephritis in the zones were 94.1% and 95.4% for SPECT, 91.2% and 92.6% for MR imaging, 88.2% and 93.5% for CT, and 56.6% and 81.4% for US. The pairwise comparison of these modalities showed no statistically significant difference among them except for US. CONCLUSION: 99mTc-DMSA SPECT, spiral CT, and MR imaging appear to be equally sensitive and reliable for the detection of acute pyelonephritis; power Doppler US is significantly less accurate.

Acute Disease↗

PubMed1998

Soluble interleukin-6 receptor, interleukin-10 and granulocyte colony-stimulating factor in acute pyelonephritis: relationship to markers of bacterial virulence and renal function.

BACKGROUND: Cytokines and cytokine receptors are involved in the systemic and local inflammatory response in patients with urinary tract infections. METHODS: We examined urine and serum concentrations of soluble IL-6 receptor (sIL-6R), IL-10 and granulocyte colony-stimulating factor (G-CSF) in 29 women with acute pyelonephritis caused by Escherichia coli 2 weeks after the infection, during the subsequent episode of cystitis or asymptomatic bacteriuria and also later when the same patients were free from bacteriuria. Concentrations of sIL-6R, IL-10 and G-CSF were related to the expression of five virulence markers of E. coli and to glomerular filtration rate (GFR) after pyelonephritis. RESULTS: On admission because of acute pyelonephritis the serum concentration of sIL-6R was similar to that of 12 healthy controls. Two weeks after the infection when all patients had received antibiotic treatment, the serum concentration of sIL-6R was significantly higher compared to that on admission (p < 0.001) and also higher compared to healthy controls (p = 0.001). Patients with increased concentrations of sIL-6R in serum 2 weeks after infection had significantly lower GFR at follow-up (p < 0.05). Patients with acute pyelonephritis had higher concentrations of G-CSF and IL-10 in serum compared to healthy subjects (p < 0.001 and p = 0.06, respectively). G-CSF in serum was higher in patients infected by E. coli producing cytotoxic necrotizing factor (p < 0.05). Patients infected by strains producing hemolysin had lower concentrations of sIL-6R (p < 0.001). Patients with detectable levels of the anti-inflammatory cytokine IL-10 in serum had significantly higher concentrations of IL-6 and the soluble tumor necrosis factor receptors I and II in serum as compared to patients in whom IL-10 was not detectable (p < 0.001, p = 0.001 and p < 0.05, respectively. CONCLUSION: These investigations, together with our previous findings summarized in this paper, contribute to an increased understanding of the local and systemic inflammatory response arising in response to acute pyelonephritis.

Acute Disease↗

PubMed1997

Experimental study of ascending Candida albicans pyelonephritis focusing on the hyphal form and oxidant injury.

To investigate the pathogenicity of the hyphal form of Candida in pyelonephritis a Candida albicans strain, assuming only the yeast form but not the hyphal form when induced by ultraviolet mutagenesis, and a revertant strain from this mutant strain showing bimorphism were compared in a rat experimental model with regard to the incidence of ascending Candida pyelonephritis and the grade of inflammation. To increase the frequency of pyelonephritis unilateral incomplete ureteral stenosis was created. The revertant strain assuming the hyphal form showed a significantly (p < 0.01) higher frequency of pyelonephritis as compared with the mutant strain not assuming this form, and the grade of inflammation was also higher in the revertant strain group. Also, higher renal tissue and serum levels of both lipid peroxide and superoxide dismutase, which are related to marked renal oxidant injury, tended to be correlated with the degree of neutrophil infiltration in the acute phase. These findings suggest that the hyphal form plays an important role in the development of C. albicans pyelonephritis and also that the oxygen radicals from neutrophils appearing at the sites of inflammation play a major part in the further extension of inflammatory lesions.

Animals↗

PubMed1990

Xanthogranulomatous pyelonephritis associated with renal cell carcinoma. Report on two cases and review of the literature.

Xanthogranulomatous pyelonephritis is a rare and particularly aggressive variant of chronic destructive pyelonephritis. Even when all modern diagnostic possibilities are exhausted, it is often not possible to distinguish xanthogranulomatous pyelonephritis from a renal cell carcinoma preoperatively. In clinical practice false diagnoses are therefore frequent. The coexistence of xanthogranulomatous pyelonephritis and renal cell carcinoma is extremely rare. We report 2 such cases. In 1 case surgery was performed on the kidney affected by xanthogranulomatous pyelonephritis using a renal sparing technique.

Aged↗

PubMed1988

Altered clinical and histological features of male MM mouse pyelonephritis associated with a change in its microbiology.

Radical changes in the clinical, microbiological and histological features of spontaneous pyelonephritis in MM male mice occurred when they were transferred to a new environment after Caesarean derivation. Although the incidence of pyelonephritis remained the same, the survival age was increased. The renal histology indicated a shift to a more chronic form of pyelonephritis with renal amyloidosis as a common feature. At autopsy much more renal scarring was seen, resulting in the 'shrunken' kidney typical of chronic pyelonephritis. Renal lymphocytic accumulations were commonly found in MM mice, but they were also seen frequently in C57BL mice and in germfree stocks of both strains: no association was found between these lesions and pyelonephritis.

Amyloidosis↗

PubMed1975

The relation between experimentally induced pyelonephritis and hypertension.

Hypertension resulting from chronic pyelonephritis has been shown in clinical as well as experimental cases, although some authors deny that there is a pathogenic relationship between the two. To throw light on this problem the present authors conducted a series of experiments with mongrel dogs, in which chronic pyelonephritis was induced and postoperative changes in blood pressure and plasma renin activity were observed over a period of 3 months. The pyelonephritis infection was brought about by a method involving vesicoureteral reflux and ureteral dysfunction, as described in a previous paper. Preoperative and postoperative levels of systolic pressure wer compared, but no definit trends were found for the first 3 weeks after operation. At 30, 60 and 90 days the pressures were found to have risen by 21.2 plus or minus 11.2 mmHg, 21.7 plus or minus 14.6 mmHg and 17.1 plus or minus 16.7 mmHg, respectively. Thus there was a significant elevation (p smaller than 0.01). No appreciable change in the plasma renin activity was found, however, at any stage. From these results it was concluded that experimentally induced chronic pyelonephritis in dogs caused a rise in blood pressure. No connection between the pyelonephritis and the renin angiotensin system was found.

Animals↗

PubMed1978

Elevated plasma renin activity in patients with acute pyelonephritis.

Thirty-three patients with acute pyelonephritis were studied with regard to the changes in plasma renin activity (PRA) along the clinical course of the disease. 1) Abnormally high PRA was found in 64% of patients in the active stage of acute pyelonephritis; they showed a decrease in urinary output of sodium, a reduction in creatinine clearance, and high indices of inflammatory activity. 2) The changes of PRA in the course of acute pyelonephritis were negatively correlated to the urinary sodium excretion and creatinine clearance, but positively to the activity of inflammation, serum sodium concentration and the number of E. coli in the urine. PRA returned to normal with the improvement of pyelonephritis. 3) Concerning the mechanism of hyperreninemia in the active stage of the disease, the following three factors may be considered; renal ischemia, negative sodium balance in the body, and inflammation. Of these, the negative sodium balance seems to be the most important. The patients could not take enough foods to maintain their energy and sodium balance because of fever and pain. 4) The significance of resting PRA in acute pyelonephritis might be to reflect the sodium status in the body, but not to be related to hypertension.

Acute Disease↗

PubMed1991

Diagnosis of acute pyelonephritis in children: comparison of sonography and 99mTc-DMSA scintigraphy.

Ninety-one children 1 week to 10 years old with culture-documented febrile urinary tract infection were evaluated with renal sonography and renal cortical scintigraphy by using 99mTc-labeled dimercaptosuccinic acid (DMSA). On the basis of previous experimental studies, DMSA scintigraphy was used as the standard of reference for the diagnosis of acute pyelonephritis. The DMSA scans showed changes consistent with acute pyelonephritis in 63% (57/91) of the patients. Sonograms showed changes consistent with acute pyelonephritis in 24% (22/91) of the whole group and in only 39% (22/57) of the patients with scintigraphically documented acute pyelonephritis. Pertinent sonographic findings were areas of increased cortical echogenicity in 14 patients and decreased echogenicity in eight, including three patients with renal abscesses. Dilatation of the renal collecting system was noted in nine patients and renal enlargement was noted in three. We conclude that renal sonography is a relatively insensitive test for the detection of acute inflammatory changes of renal cortex. Therefore, it should not be used as the primary imaging technique for the diagnosis of acute pyelonephritis. However, sonography is a useful technique in evaluating the nature of the defects seen on the DMSA scan and in detecting obstructive uropathies that may be associated with urinary tract infections.

Acute Disease↗

PubMedDate not supplied

Autoimmune responses to Tamm-Horsfall protein in the pathogenesis of chronic pyelonephritis.

Although the role of bacterial infection as the major determinant in the development of acute pyelonephritis has been well documented for years, the nature of the renal scarring typical of chronic "atrophic" pyelonephritis has been a matter of controversy for at least three decades. In the past, recurrent bacterial infection of the kidney was thought to be responsible for the pathologic entity of "chronic pyelonephritis." However, more recent studies suggest that recurrent bacteriuria, in the absence of some form of obstructive uropathy, rarely produces chronic pyelonephritis. The close association between vesicoureteral reflex and chronic pyelonephritis has also been firmly established and has been observed to occur frequently in the absence of urinary tract infection. However, the mechanism by which vesicoureteral reflux injures the kidney has not been firmly established. A number of observations have suggested that some normal component of urine, particularly Tamm-Horsfall protein, might serve as an antigenic determinant involved in the immunopathogenesis of renal scarring in vesicoureteral reflux. The present studies were designed to investigate the immunopathogenic role of Tamm-Horsfall protein in a rabbit model of tubulointerstitial nephritis, and in a swine model of reflux nephropathy. The immune responses to Tamm-Horsfall protein in patients with recurrent nephrolithiasis were also examined, as were the antigenic similarities between Tamm-Horsfall protein and protein-containing components of uropathic bacteria. The results of these studies indicate that autoimmune responses to Tamm-Horsfall protein may occur after exposure to Tamm-Horsfall protein by intravenous challenge in rabbits, and by urinary reflux in pigs, as well as in recurrent nephrolithiasis in man.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Tc-99m dimercaptosuccinic acid(DMSA) renal scintigraphy in patients with acute pyelonephritis.

OBJECTIVES: Recently, several authors reported that Tc-99m DMSA renal scan frequently showed cortical defects of the involved kidneys even in the patients with acute pyelonephritis who did not show abnormal findings in the ultrasonography and intravenous pyelography (IVP). METHODS: In order to evaluate the utilities of Tc-99m DMSA renal scan and the clinical meaning of cortical defects in the Tc-99m DMSA renal scan of the patients with acute pyelonephritis, ninety two patients with acute pyelonephritis, from March 1991 to February 1994 in Chungnam National University Hospital(CNUH), were included in this study. Patients were subdivided as Group A:Patients showing normal Tc-99m DMSA renal scan (n = 42) and Group B:Patients with definite cortical defects on the Tc-99m DMSA renal scan (n = 50). We compared clinical characteristics such as age and sex, recurrency, duration of fever, bacterial culture study, incidence of renal insufficiency and the results of renal ultrasonography and intravenous pyelography between the two groups. RESULTS: Fifty four percents of 92 patients with acute pyelonephritis showed a significantly longer febrile period after admission, higher positive rates on the urine and blood culture studies and higher incidence of renal insufficiency than those of the Group A patients. Sixty nine percents of Group B patients showed normal results in ultrasonography or IVP study. CONCLUSIONS: Tc-99m DMSA renal scan was a more sensitive imaging test than ultrasonography in kidneys and IVP to detect pyelonephritis lesions and may be useful to predict the patient group with a severe disease course. These patients may need more careful management and further studies to evaluate the possibility of complications.

Acute Disease↗

PubMed1996

Power Doppler sonographic evaluation of acute pyelonephritis in children.

Twelve children admitted to the hospital with a clinical diagnosis of acute pyelonephritis were studied with power Doppler sonography and either renal cortical scintigraphy or contrast-enhanced CT. Imaging studies were normal in four patients. A single focus of pyelonephritis was seen by cortical scintigraphy in five children, with a matching defect observed on power Doppler sonography in four patients and a small focus of infection not detected on power Doppler sonography in one child. Multifocal pyelonephritis was identified correctly by power Doppler sonography in two children, although this imaging modality underestimated the extent of involvement in one of the children. One child with diffuse pyelonephritis had a normal power Doppler sonogram. In this study, power Doppler sonography had an overall sensitivity of 75% and specificity of 100% in the evaluation of children with acute pyelonephritis.

Acute Disease↗

PubMed2001

Detection of parenchymal abnormalities in acute pyelonephritis by pulse inversion harmonic imaging with or without microbubble ultrasonographic contrast agent: correlation with computed tomography.

The purpose of this study was to evaluate the ability of pulse inversion harmonic imaging with or without microbubble ultrasonographic contrast agent in depicting renal parenchymal changes in acute pyelonephritis. The study population included 30 patients with acute pyelonephritis and 10 healthy volunteers. Pulse inversion harmonic imaging with or without contrast agent was compared with conventional ultrasonography and tissue harmonic imaging in terms of detection and conspicuity of renal abnormalities. The detection and conspicuity of renal parenchymal abnormalities in acute pyelonephritis on tissue harmonic imaging, pulse inversion harmonic imaging, and contrast-enhanced pulse inversion harmonic imaging were significantly better than those on conventional ultrasonography. In 2 of 10 healthy volunteers all 4 techniques yielded false-positive diagnoses of parenchymal abnormalities. In conclusion, tissue harmonic imaging and pulse inversion harmonic imaging are sensitive techniques for depicting renal parenchymal lesions in acute pyelonephritis. Despite relatively lower specificities and negative predictive values, these techniques are thought to be useful for the depiction of subtle parenchymal changes in acute pyelonephritis.

Acute Disease↗

PubMed1999

Ibuprofen combined with antibiotics suppresses renal scarring due to ascending pyelonephritis in rats.

PURPOSE: In acute pyelonephritis renal scarring may be decreased by immediate antibiotic therapy. Unfortunately in children there is often a delay in starting treatment, which increases the likelihood of renal scarring. In rodents immediate antibiotic therapy is effective for preventing renal scar formation resulting from experimentally induced pyelonephritis. However, the same treatment beginning 72 hours after infection does not prevent renal scarring in this paradigm. We examined whether delayed administration of the nonsteroidal anti-inflammatory agent ibuprofen only or combined with antibiotics suppresses renal scarring in a model of ascending pyelonephritis in rats. MATERIALS AND METHODS: An inoculum of 5x10(9) organisms per ml. of Escherichia coli strain BH-5 was instilled into the bladder of rats and the urethra was occluded for 4 hours. Groups of animals were and were not treated with 15 mg./kg. cefadroxil or 10 mg./kg. ibuprofen given twice daily for 5 days, or the 2 drugs combined. Treatment began 72 hours after inoculation. In an additional group of rats sterile phosphate buffered saline was instilled into the bladder. In each rat the kidneys were examined grossly and microscopically 6 weeks later. RESULTS: Combined antibiotics and ibuprofen significantly inhibited gross renal scarring compared with no treatment or antibiotics only (p<0.05). No difference in renal scarring was detected in animals that received no treatment versus those that received antibiotics or ibuprofen only (p>0.05). CONCLUSIONS: Renal scarring resulting from acute pyelonephritis in this rat model is not decreased by delayed treatment with antibiotics only. The addition of ibuprofen to antibiotic therapy is effective for decreasing renal scarring due to acute pyelonephritis even when treatment is delayed for 72 hours.

Animals↗

PubMedDate not supplied

[Activity of proteolytic enzymes and trypsin inhibitor in blood serum and kidney in pyelonephritis].

In 116 patients with acute and chronic pyelonephritis and in 66 healthy persons the total proteolytic, trypsin-like, catheptic, BAEE-esterase activities and the content of trypsin inhibitor were determined in blood serum and kidney tissue. The total proteolytic and catheptic activities were distinctly increased in blood serum and, especially, in kidney tissue under acute pyelonephritis. In chronic pyelonephritis the activity of cathepsins was decreased in blood serum. The trypsin-like activity tended to decrease both in blood serum and kidney. The BAEE-esterase activity was increased in kidney, particularly in acute pyelonephritis, but in blood serum it was decreased. The inhibitor of trypsin was not found in kidney; in blood serum its content was slightly increased in acute pyelonephritis but there were only slight alterations in the chronic disease.

Acute Disease↗