Standardization of urinary tract infection diagnosis in the neonatal ICU: Experience at a tertiary care center.

BACKGROUND: Urinary tract infections (UTIs) and antibiotic overexposure are common neonatal problems. Recently, evidence has emerged that a standardized approach to neonatal UTI can reduce unnecessary diagnosis without complications. This quality improvement project aimed to achieve those goals in our neonatal intensive care unit (NICU). METHODS: A UTI diagnosis guideline was adapted from the literature with the goal of maximizing the proportion of diagnosed UTIs that conform to accepted diagnostic criteria: >10,000 CFU/mL of one organism with pyuria, or >50,000 CFU/mL of one organism regardless of pyuria. The guideline was implemented in a level III NICU. Adherence, results, and complications were monitored for 12 months. RESULTS: Guideline adherence after implementation was favorable, as evidenced by increased adoption of urinalysis with microscopy. There was a non-significant increase in diagnostic adherence to criteria, 87% to 93%, and non-significant decrease in the rate of UTI diagnosis, 39% to 36%. Complications were not significantly changed. Most UTIs were due to gram-negative rods, especially E. coli; Enterococcus was a common contaminant. CONCLUSIONS: A guideline for diagnosing UTIs can safely increase uniformity. In contrast to previously published results, no significant changes were seen in the rate of UTI or the proportion of diagnoses conforming to the criteria for UTI. It is likely that guideline effects depend on the established practices of NICU providers. Additionally, a consistent pattern was seen in which organisms were more likely to be judged the source of true UTIs or contaminated cultures, meriting further study.

Clinical Course of Children 1 to 24 Months Old With Positive Urine Cultures Without Pyuria.

OBJECTIVE: To describe the clinical course of children with positive urine cultures without pyuria who were not given antibiotics initially, identify predictors of subsequent antibiotic treatment, and evaluate the association between subsequent treatment and urinary tract infection (UTI) within 30 days. METHODS: We conducted a multicenter retrospective cohort study of children 1 to 24 months old who had positive urine cultures without pyuria and who were not started on antibiotics upon presentation to 3 health care systems from 2010 to 2021. Outcomes included clinical status at the time urine cultures resulted, escalation of care (emergency department visit or hospitalization) and subsequent antibiotic treatment within 7 days, and subsequent UTI within 30 days of presentation. RESULTS: Of 202 included children, 61% were female and median age was 9 months. Of 151 patients with clinical status information when cultures resulted, 107 (70.8%, 95% confidence interval [CI] 62.9-77.9%) were improved. Two of 202 children (1.0%, 95% CI 0.2-4.0%) experienced care escalation. Antibiotics were started in 142 (82.2%) children, and treatment was associated with prior UTI (risk ratio [RR] 1.20, 95% CI 1.15-1.26) and lack of improvement (RR 1.22, 95% CI 1.13-1.33). Subsequent UTI was diagnosed in 2 of 164 (1.2%, 95% CI 0.1-4.3%) treated and 0 of 36 (0%, 95% CI 0-9.7%) untreated children. CONCLUSIONS: Seventy percent of children with positive urine cultures without pyuria improved before starting antibiotics; however, >80% were ultimately treated. Future research should study the impact of diagnostic stewardship interventions and various urine testing strategies to optimize the management of children evaluated for UTI.retain-->.

Kawasaki disease in children with Bacillus Calmette-Guérin scar reactivity: Focus on coronary outcomes.

BACKGROUND: /Purpose: Reactivity at the Bacillus Calmette-Guérin (BCG) scar is a pathognomonic feature of Kawasaki disease (KD). However, its value in predicting KD outcomes has not been emphasized. This study explored the clinical significance of BCG scar redness with respect to coronary artery outcomes. METHODS: This retrospective study collected data on children with KD from 13 hospitals in Taiwan during 2019-2021. Children with KD were categorized into four groups based on the KD type and BCG scar reactivity. Risk factors of coronary artery abnormalities (CAA) were analyzed in all groups. RESULTS: BCG scar redness occurred in 49% of 388 children with KD. BCG scar redness was associated with younger age, early intravenous immunoglobulin (IVIG) treatment, hypoalbuminemia, and CAA at the first echocardiogram (p < 0.01). BCG scar redness (RR 0.56) and pyuria (RR 2.61) were independent predictors of any CAA within 1 month (p < 0.05). Moreover, pyuria (RR 5.85, p < 0.05) in children with complete KD plus BCG scar redness was associated with CAA at 2-3 months; first IVIG resistance (RR 15.2) and neutrophil levels ≥80% (RR 8.37) in children with complete KD plus BCG scar non-redness were associated with CAA at 2-3 months (p < 0.05). We failed to detect any significant risk factors of CAA at 2-3 months in children with incomplete KD. CONCLUSION: BCG scar reactivity contributes to diverse clinical features in KD. It can be effectively applied to determine the risk factors of any CAA within 1 month and CAA at 2-3 months.

A nomogram for predicting the development of serious bacterial infections in febrile term neonates: A single medical center experience in Southern Taiwan.

BACKGROUND: Serious bacterial infections (SBIs) could lead to mortality or severe long-term sequelae in neonates and infants aged <3 months. Accordingly, the aim of this study was to develop a quantitative and accurate assessment tool for predicting the risk of SBIs in febrile neonates. METHODS: This retrospective study enrolled 131 febrile term neonates (aged <30 days) who were hospitalized at Kaohsiung Veterans General Hospital between January 2005 and December 2020. These neonates were classified into SBI and nonbacterial infection (NBI) groups on the basis of microbiological laboratory reports. The clinical characteristics and routine blood tests of both groups at the time of admission were analyzed. Stepwise logistic regression was applied to create and validate the nomogram for SBI prediction. RESULTS: Among the 131 febrile neonates, 38 and 93 developed SBIs and NBIs, respectively. At the time of admission, ill clinical appearance, serum myelocyte/metamyelocyte presence, C-reactive protein (CRP) > 2.5 mg/dL, and pyuria were associated with an increased risk of SBIs. Accordingly, these four factors were used to develop a nomogram for SBI prediction, which exhibited significantly high performance (area under curve = 0.848, p < 0.001) in predicting SBI risk. CONCLUSION: We developed a nomogram combining clinical appearance, serum myelocyte/metamyelocyte presence, CRP, and pyuria for predicting SBI risk in febrile neonates. This tool can assist clinicians in making early diagnoses and delivering the appropriate treatment.

Asymptomatic Pyuria as a Prognostic Biomarker in Autosomal Dominant Polycystic Kidney Disease.

Background: Autosomal dominant polycystic kidney disease (ADPKD) has phenotypic variability only partially explained by established biomarkers that do not readily assess pathologically important factors of inflammation and kidney fibrosis. We evaluated asymptomatic pyuria (AP), a surrogate marker of inflammation, as a biomarker for disease progression. Methods: We performed a retrospective cohort study of adult patients with ADPKD. Patients were divided into AP and no pyuria (NP) groups. We evaluated the effect of pyuria on kidney function and kidney volume. Longitudinal models evaluating kidney function and kidney volume rate of change with respect to incidences of AP were created. Results: There were 687 included patients (347 AP, 340 NP). The AP group had more women (65% versus 49%). Median ages at kidney failure were 86 and 80 years in the NP and AP groups (log rank, P=0.49), respectively, for patients in Mayo Imaging Class (MIC) 1A-1B as compared with 59 and 55 years for patients in MIC 1C-1D-1E (log rank, P=0.02), respectively. Compared with the NP group, the rate of kidney function (ml/min per 1.73 m2 per year) decline shifted significantly after detection of AP in the models, including all patients (-1.48; P<0.001), patients in MIC 1A-1B (-1.79; P<0.001), patients in MIC 1C-1D-1E (-1.18; P<0.001), and patients with PKD1 (-1.04; P<0.001). Models evaluating kidney volume rate of growth showed no change after incidence of AP as compared with the NP group. Conclusions: AP is associated with kidney failure and faster kidney function decline irrespective of the ADPKD gene, cystic burden, and cystic growth. These results support AP as an enriching prognostic biomarker for the rate of disease progression.

Incidence of urinary tract infection following initiation of intermittent catheterization among patients with recent spinal cord injury in Germany and the Netherlands.

Objective: To assess incidence of urinary tract infection (UTI) among patients with recent spinal cord injury (SCI) who initiated intermittent catheterization (IC).Design: Retrospective chart review.Setting: Two European SCI rehabilitation centers.Participants: Seventy-three consecutive patients with recent SCI who initiated IC.Outcome measures: Incidence of UTI, using six different definitions, each based on microbiology ± symptomatology ± mention of UTI . Rates were expressed in terms of numbers of UTIs per 100 patient-months (PMs). Attention was focused on first-noted UTI during the three-month follow-up, as assessed with each of the six definitions.Results: Fifty-eight percent of patients (n = 33) met ≥1 definitions for UTI during follow-up (rate: 31.5 UTIs per 100 PMs), ranging from 14% (5.3 per 100 PMs; definition requiring bacteriuria, pyuria, and presence of symptoms) to 45% (22.7 per 100 PMs; definition requiring "mention of UTI"). Ten cases were identified using the definition that required bacteriuria, pyuria, and symptoms, whereas definitions that required bacteriuria and either pyuria or symptoms resulted in the identification of 20-25 cases. Median time to UTI ranged from 42 days ("mention of UTI") to 81 days (definition requiring bacteriuria and ≥100 leukocytes/mm3).Conclusion: Depending on definition, 14% to 45% of patients with recent SCI experience UTI within three months of initiating IC. Definitions requiring bacteriuria and either pyuria or symptoms consistently identified about twice as many cases as those that required all three conditions. Standardizing definitions may help improve detection, treatment, and prevention of UTI within this vulnerable population.

[CLINICAL AND IMAGING FINDINGS OF ACUTE EPIDIDYMITIS IN CHILDREN].

(Objective) The etiology of acute epididymitis in children remains poorly understood. Several studies have demonstrated that urine tests are negative in the majority of children with acute epididymitis, and the condition is self-limiting. The need for radiological evaluation of the urinary tract in children with acute epididymitis is still debatable. The aim of this study was to describe clinical and imaging findings in children with acute epididymitis. (Methods) We identified 47 children with acute epididymitis at our institute between 2017 and 2021.We retrospectively reviewed their clinical features and radiological and laboratory data. All children underwent ultrasonography of the kidney and urinary tract. (Results) Median patient age was 9 years (range, 6 months-16 years) and 60% of the cases occurred between the ages of 7 and 12 years. Thirteen children (28%) had a past history of genitourinary malformations. The common malformations were hypospadias in eight children and bladder dysfunction in three. Ultrasound revealed no new urinary tract abnormalities in the remaining 34 children. Urinalysis were performed in 27 children, nine of whom (33%) had pyuria. Urine culture was positive in two children. Of the nine children with genitourinary malformations, eight had pyuria. All 18 children without genitourinary malformations had a negative urinalysis except for one patient (p< 0.0001). (Conclusions) Acute epididymitis is a common cause of acute scrotum in pediatric patients. In this study, one-third of acute epididymitis cases presented pyuria, and about 30% had a past history of genitourinary malformations. The presence of pyuria was associated with a past history of genitourinary malformations. For children with no previous genitourinary malformations, routine use of ultrasound for the detection of urinary tract abnormalities is questionable due to the low yield.

Risk factors of febrile urinary tract infections following retrograde intrarenal surgery for renal stones.

ABSTRACT: We aimed to evaluate the risk factors of febrile urinary tract infection (UTI) following retrograde intrarenal surgery (RIRS) for treating renal stones.We retrospectively reviewed the data of patients with 10 - 30 mm kidney stones who underwent RIRS from January 2014 to July 2017. Evaluation included age, gender, body mass index, stone size, stone location, and operative time. All surgeries were performed by a single surgeon and ureteral stenting was not done prior surgery. The risk factors of febrile UTI after RIRS were assessed by univariate and multivariate logistic regression analysis.A total of 150 patients were included in the present study, and 17 patients (11.3%) had febrile UTI after RIRS. Mean patient age was 56.64 ±â€Š13.91 years, and both genders were evenly distributed. Mean stone size was 14.16 ±â€Š5.89 mm. and mean operation time was 74.50 ±â€Š42.56 minutes. According to univariate analysis, preoperative pyuria was associated with postoperative febrile UTI. Multivariate logistic regression analysis showed that preoperative pyuria was the only independent risk factor of infectious complications after RIRS (odds ratios 8.311, 95% confidence intervals 1.759 - 39.275, P = .008). Age, gender, body mass index, comorbidity, preoperative bacteriuria, presence of hydronephrosis, renal stone characteristics, and operative time were not associated with febrile UTI after RIRS.Preoperative pyuria was the only risk factor of infectious complications following RIRS. Therefore, careful management after RIRS is necessary especially when preoperative urinalysis shows pyuria.

Frequency and clinical significance of prostatic involvement in men with febrile urinary tract infection: a prospective observational study.

Background: Frequent asymptomatic involvement of the prostate has been demonstrated in men with febrile urinary tract infection (fUTI). In view of this, men with fUTI are often given a longer duration of antibiotic treatment; however, evidence to support this is limited. Methods: We prospectively studied adult men with fUTI admitted under the Department of Medicine in a tertiary care hospital in southern India.  fUTI was defined as fever of ≥38°C with at least one symptom/sign of UTI and pyuria, requiring hospitalization. We estimated serum total prostate-specific antigen (PSA) levels at enrollment, one month and three months after treatment completion. We assessed prostatic volume by transrectal ultrasonography (TRUS) and estimated the serum high sensitivity C-reactive protein (hs-CRP) levels at baseline and after three months. Results: We enrolled 64 men (median [IQR] age 53 [45-60] years); 50 patients completed follow-up. At baseline, the median (IQR) serum PSA level was 2.15 (1.18-3.02) ng/mL and median (IQR) serum hs-CRP level was 2.43 (2.28-2.58) mg/L. At three months, serum PSA levels decreased by ≥25% in 47 (94%) of 50 patients. The median (IQR) of prostatic volume was 25.4 (18.9-34) mL at baseline, and ≥10% decrease in prostatic volume was observed in 24 (48%) of 50 patients at three months. The change in the serum PSA levels did not correlate with clinical findings like prostatic tenderness or with prostatic volume changes. Further, serum PSA levels did not correlate with hs-CRP levels. On follow-up, seven patients had lower urinary tract symptoms; only one of them had recurrent fUTI.   Conclusions: Asymptomatic prostatic involvement, although common in men with fUTI, does not seem to influence the treatment outcomes.

Pyuria, urinary tract infection and renal outcome in patients with chronic kidney disease stage 3-5.

Pyuria is common in chronic kidney disease (CKD), which could be due to either urinary tract infection (UTI) or renal parenchymal inflammation. Only little is known regarding the association of pyuria or UTI with renal outcomes. We investigated 3226 patients with stage 3-5 CKD. Pyuria was defined as ≥ 50 WBC per high-power field (hpf) and was correlated to old age, female, diabetes, hypoalbuminemia, lower eGFR, and higher inflammation status. In Cox regression, patients with more than one episode of pyuria in the first year (11.8%) had increased risks for end-stage renal disease (ESRD) [hazard ratio (95% CI): 1.90 (1.58-2.28); p < 0.001], rapid renal function progression [odds ratio (95% CI): 1.49 (1.13-1.95); p = 0.001], and all-cause mortality [hazard ratio: 1.63 (1.29-2.05); p < 0.001], compared to those without pyuria. In a subgroup analysis, the risk of pyuria for ESRD was modified by CKD stages. We investigated the effects of UTI (urinary symptoms and treated by antibiotics) and pyuria without UTI (urine WBC < 50 to ≥ 10/hpf without any episodes of ≥ 50 WBC/hpf or UTI), while both groups were associated with clinical outcomes. In conclusion, CKD stage 3-5 patients with frequent pyuria or UTI episodes have increased risks of renal outcomes.

Prevalence and Clinical Characteristics of Asymptomatic Pyuria in Chronic Kidney Disease.

BACKGROUND: Pyuria seems to be common in chronic kidney disease (CKD), irrespective of urinary tract infection (UTI). It has been hypothesized that sterile pyuria occurs in CKD because of chronic renal parenchymal inflammation. However, there are limited data on whether CKD increases the rate of pyuria or how pyuria in CKD should be interpreted. We investigated the prevalence and characteristics of asymptomatic pyuria (ASP) in CKD via urinary white blood cell (WBC) analysis. METHODS: Urine examination was performed for all stable hemodialysis (HD) and non-dialysis CKD patients of the outpatient clinic (total N=298). Patients with infection symptoms or recent history of antibiotic use were excluded. Urine culture and WBC analysis were performed when urinalysis revealed pyuria. RESULTS: The prevalence of ASP was 30.5% (24.1% in non-dialysis CKD and 51.4% in HD patients). Over 70% of the pyuria cases were sterile. The majority of urinary WBCs were neutrophils, even in sterile pyuria. However, the percentage of neutrophils was significantly lower in sterile pyuria. In multivariate logistic regression analysis, the degree of pyuria, percentage of neutrophils, and presence of urinary nitrites remained independently associated with sterile pyuria. CONCLUSIONS: The prevalence of ASP was higher in CKD patients and increased according to CKD stage. Most ASP in CKD was sterile. Ascertaining the number and distribution of urinary WBCs may be helpful for interpreting ASP in CKD.

Role of sterile pyuria in association to elevated PSA values in the diagnosis of non-palpable prostate cancer?

OBJECTIVES: Although cancer is believed to develop and progress with the involvement of inflammation, it is still unclear what the correlation between inflammation and prostate cancer is. This study based on results of transrectal ultrasound-guided prostate biopsies aimed to determine whether C-reactive protein (CRP) and sterile pyuria were clinically useful in the evaluation of patients with suspect of prostate cancer. MATERIALS AND METHODS: This study is a cross-sectional prospective study of patients without clinical prostatitis symptoms. Characteristics of the 200 consecutive patients recruited were 3-20 ng/mL value of serum prostate-specific antigen (PSA), normal digital rectal examination finding, and sterile urine culture result. All patients underwent 12-core prostatic biopsy. 163 of the 200 patients had benign prostatic hyperplasia confirmed through histology, while the residual 37 patients had prostate cancer. Patients with pre-treatment urinary leukocyte count ≤ 3/high power field were categorized as non-pyuria, whilst those with pre-treatment urinary leukocyte count > 3/high power field were categorized as pyuria. The serum CRP level was also used to differentiate patients before the biopsy. Subgroups were compared regarding a number of clinical variables. RESULTS: Histology revealed that 70% of pyuria patients and 38.5% of non-pyuria patients presented inflammation (p = 0.001). The pyuria group exhibited significantly higher total PSA compared to the non-pyuria group (p = 0.044). The two groups did not differ significantly regarding cancer detection rate (p = 0.752). CRP groups were similar regarding cancer detection and histologically-detected inflammation rates. CONCLUSION: In patients with no evidence of clinical prostatitis, sterile pyuria should be considered as a cause of increased PSA. Although sterile pyuria cannot predict non-palpable prostate cancer, it should be taken into account in urological evaluation in order to demonstrate minute prostatic inflammation due to its simplicity, convenience and non-invasiveness.

Cross-over data supporting long-term antibiotic treatment in patients with painful lower urinary tract symptoms, pyuria and negative urinalysis.

PURPOSE: To measure the effects of an unplanned, sudden cessation of treatment in an unselected group of patients with chronic painful LUTS managed with protracted antimicrobial treatment and to report these observational data collected from a cross-over process. MATERIALS AND METHODS: The imposition of a guideline resulted in the immediate cessation of antibiotic treatment in a cohort of patients with chronic painful LUTS and microscopic pyuria. Patients were assessed before treatment withdrawal, whilst off treatment, and following reinstatement. Outcome measures included a validated symptom score, microscopic enumeration of urinary white cells and uroepithelial cells, and routine urine culture. RESULTS: These patients had reported treatment-resistant, painful LUTS for a mean of 6.5 years before treatment at this centre. Treatment was stopped in 221 patients (female = 210; male = 11; mean age = 56 years; SD = 17.81). Sixty-six per cent of women were post-menopausal. After unplanned treatment cessation, 199 patients (90%; female = 188; male = 9) reported deterioration. Eleven patients required hospital care in association with disease recurrence, including acute urinary tract infection (UTI) and urosepsis. Symptom scores increased after cessation and recovered on reinitiating treatment (F = 33; df = 2; p < 0.001). Urinary leucocyte (F = 3.7; df = 2; p = 0.026) and urothelial cells counts mirrored symptomatic changes (F = 6.0; df = 2; p = 0.003). Routine urine culture results did not reflect changes in disease status. CONCLUSION: These data support the hypothesis that treating painful LUTS associated with pyuria with long-term antimicrobial courses, despite negative urine culture, is effective. The microscopy of fresh unspun, unstained urine to count white cells and epithelial cells offers a valid method of monitoring disease. An unplanned cessation of antibiotic therapy produced a resurgence of symptoms and lower urinary tract inflammation in patients with chronic LUTS, supporting an infective aetiology below the level of routine detection.

Effect of Preoperative Bacteriuria and Pyuria on Intravesical Recurrence in Patients with Upper Tract Urothelial Carcinoma Undergoing Radical Nephroureterectomy.

BACKGROUND/AIM: We investigated the effect of bacteriuria and pyuria on intravesical recurrence (IVR) in patients with upper tract urothelial carcinoma (UTUC) undergoing radical nephroureterectomy (RNU). PATIENTS AND METHODS: Preoperative bacteriuria and pyuria were defined as urine containing ≥5 bacteria/high-power field (HPF) and >5 white blood cells/HPF, respectively. Their associations with IVR were evaluated in 97 patients with UTUC undergoing RNU. RESULTS: Preoperative bacteriuria [n=15 (15%)] was significantly associated with preoperative pyuria [n=42 (43%), p<0.001]. During follow-up (median of 19 months), 45 (46%) patients developed IVR (median IVR-free survival=38 months). On multivariate analysis, preoperative bacteriuria was an independent predictor for reduced risk of IVR (hazard ratio=0.23, p=0.010). The 2-year IVR-free survival of patients with preoperative bacteriuria and pyuria was significantly longer than that of patients without preoperative bacteriuria (83% vs. 54%, p=0.028) and pyuria (69% vs. 50%, p=0.024), respectively. CONCLUSION: Bacteriuria and pyuria may reduce the risk of IVR in patients with UTUC undergoing RNU.

Preoperative Pyuria Is a Poor Prognostic Factor in Patients With Urothelial Carcinoma of the Upper Urinary Tract After Surgery.

INTRODUCTION: The purpose of this study was to determine the prognostic significance of preoperative pyuria in patients with upper urinary tract urothelial carcinoma after surgery. PATIENTS AND METHODS: We retrospectively evaluated data on 157 patients with nonmetastatic upper urinary tract urothelial carcinoma who had undergone surgery at our institution. The associations between clinical features and advanced pathological findings were evaluated using a logistic regression model. Recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) were assessed with the Kaplan-Meier method and Cox regression analysis. The influence of pyuria on the predictive accuracy of the multivariate model was assessed using the concordance index. RESULTS: The median postoperative follow-up among patients who survived was 48.1 months. Preoperative pyuria was significantly correlated with worse RFS, CSS, and OS (P < .001 each). Pyuria was also associated with significantly increased risk of a high pathological T stage (≥ pT3; odds ratio, 2.99; P = .003), high tumor Grade (G3; odds ratio, 2.25; P = .038), and lymphovascular invasion (odds ratio, 2.25; P = .008). Moreover, multivariate Cox regression analyses showed that pyuria was an independent prognostic factor for RFS (hazard ratio, 3.02; P < .001), CSS (hazard ratio, 2.15; P = .043), and OS (hazard ratio, 2.10; P = .019). For CSS, the addition of pyuria to the multivariate model increased its predictive accuracy from 0.87 to 0.90. CONCLUSION: Preoperative pyuria is significantly associated with CSS, OS, and increased risk of locally advanced disease and subsequent disease recurrence in patients with upper urinary tract urothelial carcinoma who undergo surgery.

Altered urothelial ATP signaling in a major subset of human overactive bladder patients with pyuria.

Overactive Bladder (OAB) is an idiopathic condition, characterized by urgency, urinary frequency, and urgency incontinence, in the absence of routinely traceable urinary infection. We have described microscopic pyuria (≥10 wbc/µl) in patients suffering from the worst symptoms. It is established that inflammation is associated with increased ATP release from epithelial cells, and extracellular ATP originating from the urothelium following increased hydrostatic pressure is a mediator of bladder sensation. Here, using bladder biopsy samples, we have investigated urothelial ATP signaling in OAB patients with microscopic pyuria. Basal, but not stretch-evoked, release of ATP was significantly greater from the urothelium of OAB patients with pyuria than from non-OAB patients or OAB patients without pyuria (<10 wbc/µl). Basal ATP release from the urothelium of OAB patients with pyuria was inhibited by the P2 receptor antagonist suramin and abolished by the hemichannel blocker carbenoxolone, which differed from stretch-activated ATP release. Altered P2 receptor expression was evident in the urothelium from pyuric OAB patients. Furthermore, intracellular bacteria were visualized in shed urothelial cells from ∼80% of OAB patients with pyuria. These data suggest that increased ATP release from the urothelium, involving bacterial colonization, may play a role in the heightened symptoms associated with pyuric OAB patients.

Can absence of pyuria exclude urinary tract infection in febrile infants? About 2011 AAP guidelines on UTI.

BACKGROUND: The aim of this study was to describe clinical and laboratory characteristics of urinary tract infection (UTI) without significant pyuria in young children aged 2-24 months. METHODS: The subjects consisted of infants and young children with febrile UTI treated at Pusan National University Children's Hospital, Korea. Group A included 283 patients with definite UTI who fulfilled the revised American Academy of Pediatrics diagnostic criteria, and group B included 19 patients with presumed UTI who had significant culture of uropathogens without pyuria, bacteriuria or other focus of infection. RESULTS: Duration of fever before hospital visit in group B was significantly shorter than in group A (17.7 ± 14.0 vs 34.5 ± 30.7 h). Most patients in group B (17/19, 89.5%) came to the hospital within 24 h of onset of fever. Acute scintigraphic lesions were found in 47.8% of patients in group A and 50% in group B. Underlying urological abnormalities such as vesicoureteral reflux and obstructive uropathy were found in 24.5% of patients in group A and in 33.3% of patients in group B (P = 0.74). CONCLUSIONS: Clinicians cannot exclude UTI on the absence of pyuria in young children aged 2-24 months.