The effect of vitamin A on renal damage following acute pyelonephritis in children

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

The Role of Urinary Nitrite in Predicting Bacterial Resistance in Urine Culture Analysis Among Patients With Uncomplicated Urinary Tract Infection

Objective

This study aims to determine the relationship between the presence of urinary nitrite and bacterial resistance to antimicrobial therapy in patients with uncomplicated urinary tract infections.

Methods

During a six-month time period (April-October, 2020), we reviewed the urine samples of 59 adult outpatients from the Urology Department of Tbilisi State Medical University the First University Clinic with the diagnosis of urinary tract infection. The infecting microorganisms and the presence of urine nitrite were recorded. Resistance rates to the antibiotics were compared between the positive and negative nitrite groups. Chi-squared test was used to perform the statistical analysis using Prism software version 9.3.1 (GraphPad Software, Inc., San Diego, California).

Results

We examined the correlation between the nitrite-positive and -negative groups with the resistance pattern to ceftriaxone, trimethoprim/sulfamethoxazole (TMP-SMX), ampicillin-sulbactam, fosfomycin, amikacin, doxycycline, cefuroxime, cefotaxime, ceftazidime, and nitrofurantoin.

A total of 59 outpatients with a mean age of 37 years met the inclusion criteria between April and October 2020. In the positive and negative nitrite groups, there were 23 and 36 patients, respectively. Three (17.6%) of the 17 gram-positive organisms and 20 (62.5%) of the 42 gram-negative organisms yielded positive nitrite results.

In nitrite-positive group, resistance rates to ceftriaxone, TMP-SMX, ampicillin-sulbactam, fosfomycin, amikacin, doxycycline, cefuroxime, cefotaxime, ceftazidime, and nitrofurantoin were 52.2%, 70.8%, 63.5%, 67.7%, 25.8%, 31.9%, 29.6%, 32.5%, 22.5% and 83.8%, respectively. These values in the nitrite-negative group were 6.5%, 41.3%, 60.7%, 72.9%, 49%, 3%, 2.3%, 3.3%, 4.3% and 81.9%, respectively.

Highest relative resistance rate was recorded against cefuroxime (12.9), followed by doxycycline (10.6), cefotaxime (9.8), ceftriaxone (8.03), ceftazidime (5.2), TMP-SMX (1.71), ampicillin-sulbactam (1.05), nitrofurantoin (1.02), fosfomycin (0.93), and amikacin (0.53).

The most commonly isolated pathogen was Escherichia coli, which was detected in 35 (71%) isolates. Other bacteria commonly found were Proteus spp in five (12%) isolates, Klebsiella spp in two (5%) isolates, and Enterococcus in five (12%) isolates.

Conclusion

The findings revealed that out of 10 antibiotics, nitrite-positive groups demonstrated higher resistance only against ceftriaxone, cefuroxime, cefotaxime, and doxycycline. Other antibiotics showed no statistically significant differences in resistance. Furthermore, the highest relative resistance rate was recorded against cefuroxime, whereas amikacin revealed the lowest. Therefore, we suggest physicians to not adjust antibiotic therapy for urinary tract infections (UTIs) based on the presence of nitrite. Urine bacteriology should be ordered. 

Deep insights into urinary tract infections and effective natural remedies

Background

Urinary tract infection (UTI) is a common occurrence in females, during pregnancy, and in peri- and postmenopausal women. UTIs are associated with significant morbidity and mortality, and they affect the quality of life of the affected patients. Antibiotic therapy is an effective approach and reduces the duration of symptoms. Development of resistance, adverse effects of antibiotics, and other associated problems lead to establishing the research framework to find out the alternative approaches in controlling UTIs. Natural approaches have been extensively used for the management of various diseases to improve symptoms and also improve general health.

Main body

Different databases were employed to identify studies reporting on natural options including herbal medicines, vitamins, trace elementals, sugars, and probiotics without time limitations.

Conclusion

Herbal medicines can be effective at the first sign of the infection and also for short-term prophylaxis. Using vitamins, trace elementals, and/or sugars is an effective approach in preventing UTIs, and a combination of them with other antibacterial agents shows positive results. Probiotics have great potential for the threat of antibiotic over-usage and the prevalence of antibiotic-resistant microorganisms. This study may be of use in developing the efficient formulation of treatment of UTI.

Collecting duct cells show differential retinoic acid responses to acute versus chronic kidney injury stimuli

Retinoic acid (RA) activates RA receptors (RAR), resulting in RA response element (RARE)-dependent gene expression in renal collecting duct (CD). Emerging evidence supports a protective role for this activity in acute kidney injury (AKI) and chronic kidney disease (CKD). Herein, we examined this activity in RARE-LacZ transgenic mice and by RARE-Luciferase reporter assays in CD cells, and investigated how this activity responds to neurotransmitters and mediators of kidney injury. In RARE-LacZ mice, Adriamycin-induced heavy albuminuria was associated with reduced RA/RAR activity in CD cells. In cultured CD cells, RA/RAR activity was repressed by acetylcholine, albumin, aldosterone, angiotensin II, high glucose, cisplatin and lipopolysaccharide, but was induced by aristolochic acid I, calcitonin gene-related peptide, endothelin-1, gentamicin, norepinephrine and vasopressin. Compared with age-matched normal human CD cells, CD-derived renal cystic epithelial cells from patients with autosomal recessive polycystic kidney disease (ARPKD) had significantly lower RA/RAR activity. Synthetic RAR agonist RA-568 was more potent than RA in rescuing RA/RAR activity repressed by albumin, high glucose, angiotensin II, aldosterone, cisplatin and lipopolysaccharide. Hence, RA/RAR  in CD cells is a convergence point of regulation by neurotransmitters and mediators of kidney injury, and may be a novel therapeutic target.

Consequences of Vitamin A Deficiency: Immunoglobulin Dysregulation, Squamous Cell Metaplasia, Infectious Disease, and Death

Vitamin A is an important regulator of immune protection, but it is often overlooked in studies of infectious disease. Vitamin A binds an array of nuclear receptors (e.g., retinoic acid receptor, peroxisome proliferator-activated receptor, retinoid X receptor) and influences the barrier and immune cells responsible for pathogen control. Children and adults in developed and developing countries are often vitamin A-deficient or insufficient, characteristics associated with poor health outcomes. To gain a better understanding of the protective mechanisms influenced by vitamin A, we examined immune factors and epithelial barriers in vitamin A deficient (VAD) mice, vitamin D deficient (VDD) mice, double deficient (VAD+VDD) mice, and mice on a vitamin-replete diet (controls). Some mice received insults, including intraperitoneal injections with complete and incomplete Freund’s adjuvant (emulsified with PBS alone or with DNA + Fus-1 peptide) or intranasal inoculations with Sendai virus (SeV). Both before and after insults, the VAD and VAD+VDD mice exhibited abnormal serum immunoglobulin isotypes (e.g., elevated IgG2b levels, particularly in males) and cytokine/chemokine patterns (e.g., elevated eotaxin). Even without insult, when the VAD and VAD+VDD mice reached 3–6 months of age, they frequently exhibited opportunistic ascending bacterial urinary tract infections. There were high frequencies of nephropathy (squamous cell hyperplasia of the renal urothelium, renal scarring, and ascending pyelonephritis) and death in the VAD and VAD+VDD mice. When younger VAD mice were infected with SeV, the predominant lesion was squamous cell metaplasia of respiratory epithelium in lungs and bronchioles. Results highlight a critical role for vitamin A in the maintenance of healthy immune responses, epithelial cell integrity, and pathogen control.

Association between vitamin D and urinary tract infection in children

Purpose

The present study aimed to determine the relationship between serum 25-hydroxyvitamin D (25(OH)D) level and Urinary tract infections (UTIs) in children.

Methods

In this case-control study, 70 children with UTI (case group) were compared with 70 healthy children (control group) in terms of serum 25(OH)D levels. The children were between 1 month and 12 years of age. Serum 25(OH)D levels were measured using enzyme-linked immunosorbent assay (ELISA). The results were analyzed and compared between both groups.

Results

Among 70 children with UTI (case group), 5 children (7.2%) were male and 65 (92.8%) were female. Among the healthy children (control group), 9 (12.8%) and 61 children (87.2%) were male and female, respectively (P=0.39). The mean±standard deviation of age in the case and control groups were 53.2±35.6 and 36.1±60.2 months, respectively (P=0.24). The mean level of serum 25(OH)D in the case group was significantly higher than that of the control group (20.4±8.6 ng/mL vs. 16.9±7.4 ng/mL, P=0.01).

Conclusion

This study showed that there was a relationship between serum 25(OH)D levels and UTI in children. It seems that 25(OH)D plays a role in the pathogenesis of UTI.

The impact of obesity on pediatric inpatients with urinary tract infections in the United States

INTRODUCTION

Urinary tract infections (UTI) are common infectious disorders, and obesity is an increasing public health problem worldwide. Several studies have suggested that childhood obesity may be associated with the development of UTI. However, the potential effects of obesity on the clinical outcomes of UTI in children remain unknown.

MATERIALS AND METHODS

Hospital discharge records for patients aged 18 years or younger with a diagnosis of UTI were extracted from the 2012 Kids' Inpatient Database. We used the International Classification of Diseases, Ninth Revision, Clinical Modification codes, and classified each patient as obese or not. We compared the total hospitalization costs, total length of hospital stay in days, and risks of hypertension, acute kidney injury, and septicemia between obese and non-obese patients, using propensity score matching and stabilized inverse probability weighting methods.

RESULTS

Of 51,918 patients with UTI, 1488 were obese and 50,430 were non-obese. A multivariable logistic regression model calculated propensity scores using baseline characteristics as dependent variables. One-to-one propensity matching created 1488 pairs. In the propensity-matched analyses, a significant difference was observed between the obese and the non-obese for risks of hypertension (8.1% vs. 1.8%; risk ratio 4.44; 95% CI 2.95-6.71). The total mean hospitalization cost in the obese group was 1.29 times higher than that in the non-obese group (95% CI 1.13-1.47). The total mean length of hospital stay in the obese group was 1.29 times longer than that in the non-obese group (95% CI 1.16-1.44). Stabilized inverse probability weighting analyses showed similar results to the propensity matched analyses (Table), except for a significant result for the risk ratio for acute kidney injury (risk ratio 1.64; 95% CI 1.18-2.26.

CONCLUSIONS

These findings indicate that obesity may be an important risk factor for hypertension and acute kidney injury among hospitalized children with UTI. Obesity may also be an economically complicating factor for their hospitalizations, which indicates the importance of the prevention for obesity.

Use of antioxidants in urinary tract infection

Pyelonephritis is an inflammatory process, and oxidative stress plays a major role in it. Anti-inflammatory or antioxidant therapy given concomitantly with antibiotics should lower the risk of postpyelonephritic scarring. As the lack of review studies in the use of antioxidants in urinary tract infections was detected, this study was designed. We conducted a review of available articles in PubMed and Google Scholar with a simple review, using keywords of “antioxidant” and “pyelonephritis” with all their possible synonyms and combinations. Only interventional studies were collected. There were neither limitations on time, nor the location of the study, type of subjects, administration rout of the antioxidant drug, and the antioxidant drug used. After studying the abstracts or in some cases the full text of articles, they were categorized based on the type of antioxidant, type and number of subjects, rout of administration, dosing, duration of treatment, year of publication of the paper, and the results. A total of 66 articles published from 1991 to 2015 were found by studying just the title of the papers. Studying the abstracts reduced this number to 51 studies. Antioxidants used for this condition were Vitamins A, E, and C, cytoflavin, caffeic acid phenethyl ester, ebselen, allopurinol, melatonin, N-acetylcysteine, oleuropein, montelukast, oxytocin, ozon, dapsone, pentoxifyllin, tadalafil, bilirubin, cranberry, meloxicam, L-carnitine, colchicine, perfluoran, methylprednisolone, and dexamethasone. Studies show that antioxidants are capable of reducing oxidative stress and can be used effectively along with antibiotics to reduce the scar formation.

The effect of vitamin A on renal damage following acute pyelonephritis in children: a meta-analysis of randomized controlled trials

BACKGROUND

Renal scarring after acute pyelonephritis (APN) in children is of concern and in the worst cases leads to long-term cardiovascular morbidity. There are reports that vitamin A may alleviate renal damage following APN. We conducted a meta-analysis to investigate the role of vitamin A in the alleviation of renal damage.

METHODS

We searched PubMed, EMBASE, the Cochrane Central Register of Controlled trials (CENTRAL, the Cochrane Library) and the Wang Fang database (Chinese) from their inception to February 3, 2015 for randomized controlled trials (RCTs) investigating vitamin A and renal damage. Primary outcome was number of patients/kidneys with renal damage, defined as persistence of photopenic lesions based on technetium-99m dimercaptosuccinic acid renal scintigraphy. We calculated pooled relative risks for renal damage in the vitamin A group.

RESULTS

Four RCTs, involving a total of 248 patients aged 1-144 months (120 in experimental group, 128 in control group), were included in the meta-analysis. Vitamin A was inversely associated with renal damage (relative risk 0.53, 95 % confidence interval 0.43, 0.67) when compared with placebo group after an average follow-up of 5 months.

CONCLUSIONS

Current evidence indicates that vitamin A may exert a preventive effect on renal damage in children with APN. However, this finding largely relies on a few studies of low methodological quality, i.e., high risk of selection bias, performance bias and attrition bias. Hence, high-quality and adequately powered RCTs are warranted.

Serum interleukin -8 is not a reliable marker for prediction of vesicoureteral reflux in children with febrile urinary tract infection

OBJECTIVE

In view of the side effects of voiding cystourethrography (VCUG), identification of noninvasive markers predicting the presence of vesicoureteral reflux (VUR) is important. This study was conducted to determine the predictive value of serum interleukin-8 (IL-8) in diagnosis of VUR in children with first febrile urinary tract infection (UTI).

MATERIALS AND METHODS

Eighty children with first febrile UTI were divided into two groups, with and without VUR, based on the results of VCUG .The sensitivity, specificity, positive and negative predictive value positive and negative likelihood ratio, and accuracy of IL-8 for prediction of VUR were investigated.

RESULTS

Of the 80 children with febrile UTI, 30 (37.5%) had VUR. There was no significant difference between the children with and without VUR and also between low and high-grade VUR groups in terms of serum concentration of IL-8 (P>0.05). Based on ROC curve, the sensitivity, specificity, likelihood ratio positive, and accuracy of serum IL-8 was lower than those of erythrocyte sedimentation rate and C-reactive protein. Multivariate logistic regression analysis showed significant positive correlation only between erythrocyte sedimentation rate and VUR.

CONCLUSIONS

This study showed no significant difference between the children with and without VUR in terms of the serum concentration of IL-8. Therefore, it seems that serum IL-8 is not a reliable marker for prediction of VUR.

Are clinical, laboratory, and imaging markers suitable predictors of vesicoureteral reflux in children with their first febrile urinary tract infection?

Purpose

This study was conducted to determine the predictive value of clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux in children with their first febrile urinary tract infection.

Materials and Methods

One hundred fifty-three children with their first febrile urinary tract infection were divided into two groups according to the results of voiding cystourethrography: 60 children with vesicoureteral reflux and 93 children without. The sensitivity, specificity, positive and negative predictive value, likelihood ratio (positive and negative), and accuracy of the clinical, laboratory, and imaging variables for the diagnosis of vesicoureteral reflux were determined.

Results

Of the 153 children with febrile urinary tract infection, 60 patients (39.2%) had vesicoureteral reflux. There were significant differences between the two groups regarding fever>38℃, suprapubic pain, C-reactive protein quantitative level, number of red blood cells in the urine, and results of renal ultrasound and dimercaptosuccinic acid renal scanning (p<0.05). There were significant positive correlations between fever>38.2℃ and dimercaptosuccinic acid renal scanning and vesicoureteral reflux. Also, there were significant positive correlations between the erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound and high-grade vesicoureteral reflux.

Conclusions

This study revealed fever>38.2℃ and dimercaptosuccinic acid renal scanning as the best predictive markers for vesicoureteral reflux in children with their first febrile urinary tract infection. In addition, erythrocyte sedimentation rate, positive urinary nitrite test, hyaline cast, and renal ultrasound are the best predictive markers for high-grade vesicoureteral reflux.

Are serum procalcitonin and interleukin-1 beta suitable markers for diagnosis of acute pyelonephritis in children?

Rapid diagnosis of acute pyelonephritis is important because of its association with long-standing complications. This study was conducted to compare the reliability of serum procalcitonin (PCT) and interleukin-1 beta (IL-1β) with conventional laboratory parameters for diagnosis of acute pyelonephritis in children. Seventy nine children with urinary tract infection were divided into two groups based on the result of Tc-99m dimercaptosuccinic acid renal scan: acute pyelonephritis (n=33) and lower UTI (urinary tract infection) (n=46) groups. White blood cell (WBC) count, neutrophil count, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), PCT and IL-1β concentrations of both groups were measured and compared. WBC count, neutrophil count, ESR, serum CRP, PCT and IL-1β concentrations were higher in acute pyelonephritis patients than in the lower UTI group (P<0.05). The sensitivity and specificity of serum PCT and IL-1β for diagnosis of acute pyelonephritis were 31, 84.7% and 27.2, 90% respectively (using a cut-point value of 0.5 ng/ml for PCT and 6.9 pg/ml for IL-1β). The sensitivity of PCT and IL-1β for diagnosis of acute pyelonephritis was less than that of conventional markers such as ESR and CRP. This study revealed that serum PCT and IL-1β are not good biologic markers for differentiating acute pyelonephritis from lower UTI. It seems that conventional inflammatory markers such as ESR and CRP besides the clinical findings are more reliable for the diagnosis of acute pyelonephritis in children.

Serum levels of interleukin-6 and interleukin-8 as diagnostic markers of acute pyelonephritis in children

Purpose

Early diagnosis and treatment of acute pyelonephritis in children is of special importance in order to prevent serious complications. This study was conducted to determine the diagnostic value of serum interleukin (IL)-6 and IL-8 in children with acute pyelonephritis.

Methods

Eighty-seven patients between 1 month to 12 years old with urinary tract infection (UTI) were divided into 2 groups based on the result of 99m-technetium dimercapto-succinic acid renal scan: acute pyelonephritis (n=37) and lower UTI (n=50) groups. White blood cell (WBC) count, neutrophil (Neutl) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) concentration, platelet count, and serum IL-6 and IL-8 concentrations of both groups were measured and compared.

Results

There was a significant difference between two groups regarding WBC count, Neutl count, ESR, and CRP concentration (P<0.05). In addition, the difference between the two groups regarding serum IL-6 and IL-8 concentrations was not significant (IL-6, 60 and 35.4 pg/mL and IL-8, 404 and 617 pg/mL, respectively). The sensitivity and specificity of serum IL-6 and IL-8 for diagnosis of acute pyelonephritis were 73%, 42% and 78%, 32%, respectively. Sensitivity, specificity, negative and positive predictive values of serum IL-6 and IL-8 were less than those of acute phase serum reactants such as CRP.

Conclusion

This study showed that there was no significant difference between acute pyelonephritis and lower UTI groups regarding serum IL-6 and IL-8 levels. Therefore, despite confirming results of previous studies, it seems that IL-6 and IL-8 are not suitable markers for differentiating between acute pyelonephritis and lower UTI.

The effect of vitamin E or vitamin A on the prevention of renal scarring in children with acute pyelonephritis

BACKGROUND

Numerous factors may contribute to renal tissue injury after urinary tract infection. We have evaluated the effects of vitamins A or E supplementation in combination with antibiotics for the prevention of renal scarring in acute pyelonephritis.

METHODS

A simple non-blind randomized clinical trial was conducted on 61 children aged 1 month to 10 years between 2004 and 2006. The inclusion criteria were positive urine culture, clinical findings, and 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy-based evidence in favor of acute pyelonephritis. The children were randomized into three treatment groups: 10-day treatment with only antibiotics (control group; n = 25) and 10-day treatment with supplements of vitamin A (n = 17) or vitamin E (n = 18) in addition to antibiotics during the acute phase of infection. The final analysis was performed after excluding male patients. Each patient was evaluated twice by 99mTc-DMSA scintigraphy performed at least 6 months apart. P < 0.05 was considered to be statistically significant.

RESULTS

The analysis included 108 kidney units. The frequency of inflammation at the beginning of therapy was not significantly different in the three groups (63.3 % in vitamin A, 61 % in vitamin E, and 76.2 % in the control group). A worsening of lesions, based on the second 99mTc-DMSA scan, was observed in 42.5, 0, and 23.3 % of the control, vitamin E, and vitamin A patients, respectively (LR = 26.3, P < 0.001).

CONCLUSION

Vitamins A or E supplements were effective in reducing renal scarring secondary to acute pyelonephritis.

Can postpyelonephritic renal scarring be prevented?

Pyelonephritis in childhood may, in the worst cases, lead to long-term cardiovascular morbidity due to tubulointerstitial renal scarring. Renal damage is the end result of an interplay between (1) urinary tract anatomy and function, (2) bacterial virulence factors, and (3) the host innate immune system, which on the one hand manages bacterial clearance, but on the other causes tubulointerstitial inflammation, which underlies the renal scarring. It is unclear how common postpyelonephritic scarring is, and how many of the "scars" in fact represent congenital renal hypoplasia. We do, however, know that some situations have an increased risk for scars, i.e., large renal-uptake defects on initial renal scintigraphy or pyelonephritis in young girls with dilating vesicoureteral reflux. It seems logical that antiinflammatory or antioxidant therapy given concomitantly with antibiotics should lower the risk of postpyelonephritic scarring. Animal studies give some support to this idea, but research on humans has been surprisingly scant. In this issue of Pediatric Nephrology, we publish a study that indicates that antioxidant therapy with vitamin A or E given to children with pyelonephritis may indeed lower the risk for renal scarring. This is a track that needs to be pursued further.

Advances in non-surgical treatments for urinary tract infections in children

OBJECTIVE

With growing antibiotics failure due to emerging resistance of bacteria, non-surgical management of pediatric UTI plays a more important role because of its non-invasive characteristics and little adverse effects.

METHODS

We searched the Pubmed for management of UTI in children other than surgical correction and antibiotics using terms: risk factor, prepuce/phimosis, steroid cream/steroid, behavioral therapy, urotherapy, biofeedback/pelvic floor exercise, adrenergic antagonist, anticholinergics, diet/dietary, dysfunctional voiding/dysfunctional elimination syndrome, constipation, dietary, clean intermittent catheterization, probiotics/lactobacillus, cranberry, vitamin supplement, breastfeeding, breast milk, with infant/child/children/pediatrics/pediatrics and urinary tract infection.

RESULTS

The proposed non-surgical management of pediatric UTI included behavioral modification (timed voiding and adequate fluids intake), topical steroid for phimosis, nutrient supplements (breast milk, cranberry, probiotics, and vitamin A), biofeedback training for dysfunctional voiding, anticholinergics for reducing intravesical pressure, alpha-blockers in dysfunctional voiding and neurogenic bladder, and intermittent catheterization for children with large PVR.

CONCLUSION

The published reports usually included small number of patients and were lacking of randomization and controlled group. Further well-designed studies are warranted to support the concepts of non-operative management for pediatric UTI.