Urine heat shock protein 70 levels as a marker of urinary tract infection in children

Background

Heat shock proteins (HSPs) are a multi-family group of proteins which are upregulated by the cell in response to exposure to hazardous (stress) factors, including infectious agents, to prevent changes in protein structure. The aim of our study was to assess whether urine levels of the 70-kDa family of HSPs (HSP70s) increase in children with urinary tract infection (UTI) and to determine the optimal urine (u) HSP70 cut-off level to predict UTI in children.

Methods

Forty patients with symptomatic UTI (UTI group), 30 healthy children (control group), 21 asymptomatic patients with proven bacterial contamination in their urine culture (contamination group) and 30 patients with fever caused by other infections (non-UTI infection group) were enrolled in the study. Random urine samples were obtained for measurement of HSP70 and creatinine (Cr) from all groups. Urine was collected prior to the treatment of UTI at the time of presentation and after treatment. Urine HSP70 levels were measured by enzyme-linked immunosorbent analysis. A dimercaptosuccinic acid (DMSA) scan was performed at 5–7 days after presentation in UTI group to distinguish patients with acute pyelonephritis from those with cystitis; based on this scan, no patients had acute pyelonephritis. Patients were classified with pyelonephritis in the presence of all of the following signs: axillary fever of?≥39 °C, leukocytosis and positivity for C-reactive protein.

Results

The mean urine HSP70:Cr ratio (uHSP70/Cr) prior to treatment was significantly higher in the UTI group (449.86?±?194.33 pg/mg) than in the control, contamination and non-UTI infection groups (39.93?±?47.61, 32.43?±?9.09 and 45.14?±?19.76, respectively; p?=?0.0001). Using a cut-off of 158 pg/mg uHSP70/Cr for the prediction of UTI, the sensitivity and specificity of the assay were 100 and 100 %, respectively (area under the time–concentration curve?=?1). The uHSP70/Cr was highest in the patients with clinical pyelonephritis (p?=?0.001). Mean uHSP70/Cr after treatment decreased to 60.68?±?51.11 pg/mg in UTI group (p?=?0 .0001).

Conclusions

Our findings suggest that elevated uHSP70/Cr may be a useful biomarker for the prediction of UTI in children, with a high sensitivity and specificity, and that they may help to distinguish UTI from other infections as well as bacterial contamination of the urine.

     

Urine tissue-polypeptide-specific antigen (TPS) as a marker for bladder cancer.

OBJECTIVES: To determine the sensitivity and specificity of urine tissue-polypeptide-specific antigen (TPS) for bladder carcinomas and to evaluate whether urine TPS is influenced by tumour size, number, grade and stage. PATIENTS AND METHODS: A total of 260 patients entered the study, one group (n = 151) with known bladder cancer disease (79 with recurrent tumour and 72 with no tumour at cystoscopy). The other group (n = 109) consisted of patients without previously known bladder tumour disease, 55 with newly detected bladder tumour(s) and 54 investigated for microhematuria found to be idiopathic. TPS in urine was measured using an ELISA-kit, a solid phase two-site immunosorbent assay with polyclonal antibodies against cytokeratin 18. RESULTS: Urine TPS was significantly higher in patients with bladder tumours (p < 0.001). There was a significant correlation between TPS and tumour size (p = 0.004), grade (p = 0.001) and stage (p = 0.001). Tumour number was not significantly correlated to urine TPS (p = 0.75). With TPS 42 as a cut-off level, the sensitivity was 73% for newly detected tumours and 50% for recurrences; the specificity was 70% and 63% respectively. With a 95% specificity, the sensitivity for newly detected tumours was 33% and for recurrences 18%. The lower sensitivity and specificity for recurrences was mainly explained by differences in tumour size, grade and stage between the recurrences and the newly detected tumours. CONCLUSIONS: Urine TPS is a marker for bladder carcinoma correlated to size, grade and stage. The sensitivity and specificity for newly detected tumours are quite comparable with other markers. Its clinical usefulness is however not established and it appears less useful in the follow-up of patients with known bladder tumour disease.     

Urine cytology as a screening method for polyoma virus active infection

Polyoma virus nephropathy (PVN) occurs in 3% to 4% of renal transplants, causing graft loss in about 50% of cases. The presence of viral cytopathic changes in graft epithelial cells is the only diagnostic tool for PVN. However, identification of cells with viral inclusions (decoy cells) in urine can be used as a screening tool for viral replication of or for active infection with PV. The aim of the present study was to identify the occurrence of PV active infection in renal transplant recipients. Two hundred forty urine cytology samples, collected from 80 transplant patients with stable renal function, were collected on a monthly basis and stained with the Pap smear for decoy cells. Active infection with polyoma virus was confirmed by urine immunostaining. All samples were analyzed blindly and classified as negative or positive (>1 decoy cell/sample). Among 240 urine cytologies collected from 48 men and 32 women, decoy cells were identified in 37.5%. No differences were observed in serum creatinine or immunosuppressive regimen between patients with positive versus negative cytology. No graft losses occurred secondary to PVN in the present study setting. The incidence of decoy cells in this series (37.5%) was consistent with previous reports (20% to 40%), suggesting that active infection may be confirmed by PV immunohistochemistry. The absence of PVN in this group may be attributed to the low doses of immunosuppressive drugs in the late posttransplant transplant period, but also to the unknown incidence of polyoma virus infection in Brazil.     

Urine Cell-Free DNA integrity as a marker for early bladder cancer diagnosis: Preliminary data

ObjectivesUrine cell-free (UCF) DNA has recently been proposed as a potential marker for early bladder cancer diagnosis. It is known that normal apoptotic cells produce highly fragmented DNA while cancer cells release longer DNA. Therefore, we verified the potential role of UCF DNA integrity in early bladder cancer diagnosis.Materials and methodsUCF DNA was isolated from 51 bladder cancer patients, 46 symptomatic patients, and 32 healthy volunteers. To verify UCF DNA integrity, sequences longer than 250 bp, c-Myc, BCAS1, and HER2, were quantified by real time PCR.ResultsAt the best cutoff value of 0.1 ng/μl, UCF DNA integrity analysis showed a sensitivity of 0.73 (95% CI 0.61–0.85), and a specificity of 0.84 (95% CI 0.71–0.97) in healthy individuals and 0.83 (95% CI 0.72–0.94) in symptomatic patients. Receiver operating characteristic (ROC) curve analysis revealed an area under the curve of 0.834 (95% CI 0.739–0.930) for healthy individuals and 0.796 (95% CI 0.707–0.885) for symptomatic patients.ConclusionsThese preliminary data suggest that UCF DNA integrity is a potentially good marker for early noninvasive diagnosis of bladder cancer. Its diagnostic performance does not seem to vary significantly, even in an “at risk” population of symptomatic individuals.     

Procalcitonin as a predictive marker for surgical site infection in elective colorectal cancer surgery

Purpose

Surgical site infection (SSI) is a frequent complication of elective surgery for colorectal cancer. The classical clinical markers of infection—elevations in white blood cell count, C-reactive protein (CRP) level, and body temperature—do not precisely predict SSI after elective colorectal resection. The objective of this study was to evaluate the efficacy of procalcitonin (PCT) as a tool for diagnosis of SSI in elective surgery for colorectal cancer.

Methods

A total of 114 consecutive patients undergoing elective colorectal resection for cancer were evaluated. Routine blood samples, for determining PCT level, CRP plasma concentration, and white blood cell count, were obtained on postoperative days (POD) 1 and 3. Predictive values for each of the laboratory markers were examined.

Results

SSI was diagnosed in 18 (15.7 %) of 114 patients. Patients with SSI exhibited significantly higher PCT levels (on PODs 1 and 3) and CRP levels (on POD 3) than did patients without SSI. According to receiver operating characteristic analysis, PCT showed the highest area under the curve (AUC) for predicting SSI on both PODs 1 and 3 (AUC, 0.76 and 0.77, respectively). Multivariate logistic regression analysis showed that PCT (on PODs 1 and 3) was an independent predictor for SSI (odds ratio?=?14.41 and 9.79, respectively).

Conclusion

Serum PCT is more reliable laboratory marker for the early diagnosis of SSI after elective colorectal cancer surgery, compared with conventional inflammatory indicators. PCT could serve as an additional diagnostic tool for the early identification of SSI to improve clinical decision making.     

Urine transparency as an index of absence of infection.

A visual assessment of the clarity of urine was used as an exclusion test to indicate the absence of infection; verified by dipslide culture, it was applied to 363 urine samples collected from patients attending 2 adult nephrology clinics over a period of 6 months. The crimped aluminium bowl used for collection of samples assisted the assessment of clarity. The sensitivity of the method compared with dipslide culture was 73%, with specificity and efficiecy both 58%. The predictive value of a negative test (clarity) was 97% with a false negative rate of 3%, enabling this simple examination to be used as an exclusion test for further testing. In simple terms, a clear urine is unlikely to be infected. It is also an advantage to have an immediate indicator of the absence of infection available at the clinic. Analysis of only those urines assessed as cloudy could result in financial savings and, from the clinics, a 56% reduction in workload.     

Upregulation of chemokines in bronchoalveolar lavage fluid as a predictive marker of post-transplant airway obliteration.

BACKGROUND: The early stage of post-transplant obliterative bronchiolitis (OB) is characterized by an influx of inflammatory cells to the lung, among which neutrophils may play a role in key events. The potential for chemokines to induce leukocyte accumulation in the alveolar space was investigated. We assessed whether changes in the chemotactic expression profile could be used as sensitive markers of the onset of OB. METHODS: Serial bronchoalveolar lavage (BAL) fluids from 13 stable healthy recipients and 8 patients who developed bronchiolitis obliterans syndrome (BOS) were analyzed longitudinally for concentrations of interleukin-8 (IL-8), chemokines regulated-upon-activation and normal T-cell expressed and secreted (RANTES) and monocyte chemoattractant protein-1 (MCP-1), soluble intracellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). These were assessed by enzyme-linked immunosorbent assay (ELISA). RESULTS: Significantly elevated percentages of BAL neutrophils and IL-8 levels were found at the pre-clinical stage of BOS, on average 151 +/- 164 days and 307 +/- 266 days, respectively, before diagnosis of BOS. There was also early upregulation of RANTES and MCP-1 in the BOS group (mean 253 +/- 323 and 152 +/- 80 days, respectively, before diagnosis of BOS). The level of MCP-1 was consistently higher than that of RANTES until airway obliteration. BAL sICAM-1 and sVCAM-1 levels were not statistically different between the groups. CONCLUSIONS: These data support the belief that RANTES, IL-8 and MCP-1 play a crucial role in the pathogenesis of OB. The results show that relevant increased levels of such chemokines may predict BOS, and suggest that there is potential for some of these markers to be used as early and sensitive markers of the onset of BOS. Longitudinal monitoring of these chemokine signals may contribute to better management of patients at risk for developing OB, at a stage when remodeling can either be reversed or altered.     

Urine sodium to urine creatinine ratio as a marker of total body sodium in infants with intestinal failure

PurposeUrine sodium (UNa) is a measure of total body sodium in infants with intestinal failure (IF) but can be misleading as it does not reflect volume status. Urine sodium to urine creatinine ratio (UNa:UCr) may offer a more accurate measure, but is not routinely used. This study compares UNa:UCr to UNa as a maker of sodium status in infants with IF.MethodsA retrospective review of infants with IF, from a single center, from 2018 to 2020 was conducted (REB H20–00,816). IF etiology, intestinal anatomy, nutritional intake, urine electrolytes and anthropometrics were collected. Linear mixed effects models adjusting for repeated measures were used to associate UNa and UNa:UCr with weight gain and sodium intake.ResultsTwenty-two infants with a median gestational age of 31 weeks were included. IF etiology included gastroschisis (41%), necrotizing enterocolitis (23%), and intestinal perforation (14%). Infants had an average of 3 paired UNa and UNa:UCr measures for a total of 74 paired measurements. UNa:UCr more strongly correlated with sodium intake compared to UNa (R = 0.25, p = 0.032 vs. R = 0.10, p = 0.38). Overall, neither UNa (p = 0.21) nor UNa:UCr (p = 0.16) were significantly correlated with weight gain. However, for infants receiving ≤50% nutrition enterally, weight gain correlated with UNa (p = 0.01) and UNa:UCr (p = 0.01). UNa:UCr >35 predicted adequate growth regardless of enteral intake (92% sensitivity, 59% specificity).ConclusionUNa:UCr is a measure of total body sodium that correlates with sodium intake in infants with IF. Our study indicates UNa:UCr >35 is associated with adequate growth and can be used to guide further validation studies.     

The role of procalcitonin as a marker of diabetic foot ulcer infection

Foot ulcers are frequent in diabetic patients and are responsible for 85% of amputations, especially in the presence of infection. The diagnosis of diabetic foot ulcer infection is essentially based on clinical evaluation, but laboratory parameters such as erythrocyte sedimentation rate (ESR), white blood count (WBC), C‐reactive protein (CRP) and, more recently, procalcitonin (PCT) could aid the diagnosis, especially when clinical signs are misleading. Fifteen diabetic patients with infected foot ulcers were admitted to our department and were compared with an additional group of patients with non‐infected diabetic foot ulcers (NIDFUs). Blood samples were collected from all patients in order to evaluate laboratory markers. In the current study, the diagnostic accuracy of PCT serum levels was evaluated in comparison with other inflammatory markers such as CRP, ESR and WBC as an indicator to make the distinction between infected diabetic foot ulcers (IDFUs) and NIDFUs. CRP, WBC, ESR and especially PCT measurements represent effective biomarkers in the diagnosis of foot infections in diabetic patients particularly when clinical signs are misleading.     

Alpha-fetoprotein as a marker for hepatic regeneration in the dog

A radioimmunoassay for human α-fetoprotein (AFP) was utilized to quantitate AFP following partial liver resection in the dog. Nine dogs were studied; seven underwent 70% hepatectomy and two received sham operations. Serum AFP, alkaline phosphatase, glutamic-oxaloacetic transaminase (SGOT), glutamic-pyruvate transaminase (SGPT), total bilirubin, and galactose elimination capacity (GEC), a quantitative index of hepatic function, were measured preoperatively and at regular intervals postoperatively. Following 70% hepatectomy, AFP was first noted to be increased from the preoperative level (94 ± 7 SEM ng AFP activity/ml) on the fourth postoperative day (556 ± 75; P < 0.05) with a peak value being reached between Days 8 and 12 (1008 ± 111; P < 0.025). AFP then gradually decreased, returning to normal by Day 24 (116 ± 12; P > 0.5). These changes in AFP concentration parallel, in a slightly delayed fashion, hepatic proliferative activity as measured by DNA synthesis following hepatic resection in the dog. No alteration in AFP concentration was seen in the control animals. Elevations in SGOT, SGPT, and alkaline phosphatase were observed in all dogs following liver resection from Day 2 through 26. In contrast to AFP, changes in the serum concentrations of these enzymes were highly variable in both magnitude and duration. GEC was not significantly altered following liver resection in any dog. The results indicate that AFP is superior to liver enzymes and GEC as a marker for hepatic regeneration in the dog.     

Lipopolysaccharide-binding protein as a new and reliable infection marker after kidney transplantation

The early and reliable differentiation of rejections, viral infections and bacterial infections is one of the main problems after organ transplantation. One promising solution to this problem is the lipopolysaccharide-binding protein (LBP), which is regulated upwards in gram-negative sepsis and related conditions. Therefore, the aim of our study was to explore the diagnostic potential of LBP serum levels in well-defined, non-infectious and infectious events after kidney transplantation (KTx). In a retrospective study the LBP serum levels were measured in a total of 686 serum samples from 52 kidney graft recipients. In all pre-KTx sera tested, the mean LBP level was 8.8+/-3.5 microg/ml (reference range: 2.0-15.2 microg/ml). In 7 of 52 recipients without intraoperative T-cell depletion, the mean LBP level was significantly ( P<0.01) increased (13.0+/-1.5 microg/ml) at post-KTx day 1, but was within the reference range. In contrast, the intraoperative T-cell depletion by antilymphocyte antibodies resulted in a significant ( P<0.01) increase to 25.8+/-11.4 microg/ml (range: 13.3-47.2 microg/ml). In recipients with immediate ( n=14) or delayed ( n=9) graft function without any other complications, all post-KTx values (except the post-KTx peak) were within the reference range. In 10 recipients with steroid-sensitive rejections and in 11 recipients with steroid-resistant rejections, no rejection-associated changes of the LBP levels could be shown. In six recipients with cytomegalovirus infection, the detection of an antigenemia (pp65) also was not associated with alterations of the LBP levels. In addition, there was no correlation between LBP levels and the number of pp65-positive leukocytes in peripheral blood. In contrast, a strong elevation of LBP levels was seen in five recipients with gram-positive bacteremia as well as in other severe bacterial infections (e.g., purulent extravasate, heavily infected grafts, bacterial pneumonia and contaminated hematoma). In two recipients with superinfected (bacterial and mycotic or viral) Pneumocystis carinii pneumonias requiring assisted ventilation, LBP levels were elevated, too. Thus, in our study only systemic non-viral infections and massive lymphocytolysis were associated with elevated LBP serum levels.     

Value of procalcitonin as a marker of surgical site infection following spinal surgery

Aim

To compare the value of Procalcitonin (PCT) as a marker of surgical site infection to other inflammatory markers, including C-Reactive Protein (CRP), White Cell Count (WCC) and Erythrocyte Sedimentation Rate (ESR) in patients undergoing a number of spinal procedures. This study also aims to describe the biokinetic profile of the above-named markers in patients developing surgical site infection and those remaining infection-free post-operatively.

Feasibility of nasal epithelial brushing for the study of airway epithelial functions in CF infants.

BACKGROUND: For a better understanding of the early stages of cystic fibrosis (CF), it is of major interest to study respiratory epithelial cells obtained as early as possible. Although bronchoalveolar lavage has been proposed for this purpose, nasal brushing, which is a much less invasive technique, has seldom been used in CF infants. The aim of the present study was to examine in a few infants the feasibility of a nasal brushing technique for studies of airway epithelial functions in very young CF infants. METHODS: In 5 CF (median age 12, range 1-18 months) and 10 control infants (median age 5, range 1-17 months), a nasal brushing was performed by means of a soft sterile cytology brush, after premedication with oral paracetamol (15 mg/kg body weight) and rectal midazolam (0.2 mg/kg body weight). Samples were used for microbiological, cytological and functional studies. RESULTS: The procedure was well tolerated. Number of cells collected was similar in CF and non-CF patients (CF: median 230x10(3), range 42x10(3)-900x10(3); non-CF: median 340x10(3), range 140x10(3)-900x10(3)). Median number of viable cells was 67% (range 31-84%). Freshly obtained samples were successfully used for studies of ciliary beating frequency and cAMP-dependent chloride efflux. In 7 out of 17 cell cultures, confluence was obtained (CF: 2 out of 7; non-CF: 5 out of 10). The feasibility of studying protein release and mRNA expression of IL-8, IL-6 and TNF-alpha, under basal conditions and after stimulation by Pseudomonas aeruginosa, was demonstrated. CONCLUSIONS: By means of a simple nasal brushing technique easily performed and well tolerated, it is feasible, in infants, to harvest respiratory cells in sufficient amounts to study the airway epithelium using a broad range of techniques including cell culture.