The association between serum levels of vitamin D and recurrent urinary tract infections in premenopausal women

The Critical Role of Intracellular Bacterial Communities in Uncomplicated Recurrent Urinary Cystitis: A Comprehensive Review of Detection Methods and Diagnostic Potential

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide and are particularly prevalent in women. Recurrent UTIs significantly diminish quality of life due to their symptoms and frequent relapses. Patients often experience immediate relapse following slightly strenuous activities or intense psychological stress. In this review, we explore why infections persist despite the advent of various treatments and suggest strategies to manage recurrent cystitis by targeting the mechanisms of adhesion and infection. Vitamin D levels and the expression of neutrophil gelatinase-associated lipocalin are linked to the recurrence of UTIs. During a UTI, bacteria employ adhesins to invade the urinary tract, adhere to urothelial cells, and then penetrate these cells, where they rapidly multiply to establish intracellular bacterial communities. Bacteria can also form quiescent intracellular reservoirs that escape immune responses and antibiotic treatments, leading to recurrence under certain conditions. The surface proteins of bacteria and D-mannose are crucial in the adhesion of bacteria to the urothelium. Understanding these processes provides valuable insights into potential therapeutic approaches that focus on preventing bacterial attachment and cluster formation. By disrupting the ability of bacteria to adhere to and form clusters on cells, we can better manage recurrent UTIs and improve patient outcomes.

A Systematic Review of the (Un)known Host Immune Response Biomarkers for Predicting Recurrence of Urinary Tract Infection

Recurrent urinary tract infections (rUTI) represent a major healthcare and economic burden along with a significant impact on patient’s morbidity and quality of life, even in the absence of well-known risk factors, such as vesicoureteral reflux. Despite numerous attempts to find a suitable therapeutic option, there is no clear benefit of any currently available intervention for prevention of UTI recurrence and its long-term consequences such as hypertension, renal scarring and/or insufficiency. The common treatment practice in many centers around the globe involves the use of continuous low-dose antibiotic prophylaxis, irrespective of various studies indicating increased microbial resistance against the prophylactic drug, leading to prolonged duration and escalating the cost of UTI treatment. Moreover, the rapid appearance of multi-drug resistant uropathogens is threatening to transform UTI to untreatable disease, while impaired host-microbiota homeostasis induced by a long-term use of antibiotics predisposes patients for various autoimmune and infectious diseases. New biomarkers of the increased risk of UTI recurrence could therefore assist in avoiding such outcomes by revealing more specific patient population which could benefit from additional interventions. In this light, the recent findings suggesting a crucial role of urothelial innate immunity mechanisms in protection of urinary tract from invading uropathogens might offer new diagnostic, prognostic and even therapeutic opportunities. Uroepithelial cells detect uropathogens via pattern recognition receptors, resulting in activation of intracellular signaling cascade and transcription factors, which ultimately leads to an increased production and secretion of chemokines, cytokines and antimicrobial peptides into the urinary stream. Emerging evidence suggest that the disturbance of a single component of the urinary tract innate immunity system might increase susceptibility for rUTI. The aim of the current review is to update clinicians and researchers on potential biomarkers of host immune response alterations predisposing for rUTI and propose those well worth exploring further. For this purpose, over a hundred original papers were identified through an extensive PubMed and Scopus databases search. This comprehensive review might enrich the current clinical practice and fill the unmet clinical needs, but also encourage the development of therapeutic agents that would facilitate urinary bacterial clearance by enhancing the host immune response.

The Predictive Role of Vitamin D Deficiency in Urinary Tract Infection at Reproductive Age in Women

BACKGROUND: Urinary tract infections (UTIs) are common health infections in pregnant women with high complications. Many of the worldwide population suffer from vitamin D deficiency (VDD) due to insufficient exposure to sunlight. The relationship between VDD and UTI and giving vitamin D supplementation contributes to preventing UTI. AIM: The present study aims to find the effect of VDD and UTIs in women of reproductive age as risk factors during pregnancy. METHODS: The samples were collected from May 2020 to February 2021 from gynecology clinic outpatients and private clinics in Basrah city. A 104 sample was collected from females of reproductive age between 15 and 45 years divided into three age groups suffering recurrent UTI and VDD. RESULTS: Of 104 women who followed up with UTIs during the study period, the deficiency of vitamin D levels in women was 62.5%. The levels of deficiency were significantly higher in the age group 25-34y is 71.1%, followed by 15-24y is 63.2%, and 35-45 y is 50% with mean 24 ± 6.8 years. In addition, the results showed the vitamin D levels at an insufficient level (30.8%) higher in the age group 35-45 y is 42.9% with a mean of 10 ± 1.2. Furthermore, the results showed that the vitamin D levels at an insufficient level (30.8%) higher in the age group 35–45 years are 42.9% with a mean of 10 ± 1.2. CONCLUSION: Our current study revealed that there is a clear correlation between women who suffer from VDD and UTIs, whether severe or frequent infection at reproductive age and this affects their fertility and pregnancy. In addition, the study concluded that adolescent girls and young women are the most vulnerable to VDD and UTIs.

Emerging Roles of Vitamin D-Induced Antimicrobial Peptides in Antiviral Innate Immunity

Vitamin D deficiency, characterized by low circulating levels of calcifediol (25-hydroxyvitamin D, 25D) has been linked to increased risk of infections of bacterial and viral origin. Innate immune cells produce hormonal calcitriol (1,25-dihydroxyvitamin D, 1,25D) locally from circulating calcifediol in response to pathogen threat and an immune-specific cytokine network. Calcitriol regulates gene expression through its binding to the vitamin D receptor (VDR), a ligand-regulated transcription factor. The hormone-bound VDR induces the transcription of genes integral to innate immunity including pattern recognition receptors, cytokines, and most importantly antimicrobial peptides (AMPs). Transcription of the human AMP genes β-defensin 2/defensin-β4 (HBD2/DEFB4) and cathelicidin antimicrobial peptide (CAMP) is stimulated by the VDR bound to promoter-proximal vitamin D response elements. HDB2/DEFB4 and the active form of CAMP, the peptide LL-37, which form amphipathic secondary structures, were initially characterized for their antibacterial actively. Notably, calcitriol signaling induces secretion of antibacterial activity in vitro and in vivo, and low circulating levels of calcifediol are associated with diverse indications characterized by impaired antibacterial immunity such as dental caries and urinary tract infections. However, recent work has also provided evidence that the same AMPs are components of 1,25D-induced antiviral responses, including those against the etiological agent of the COVID-19 pandemic, the SARS-CoV2 coronavirus. This review surveys the evidence for 1,25D-induced antimicrobial activity in vitro and in vivo in humans and presents our current understanding of the potential mechanisms by which CAMP and HBD2/DEFB4 contribute to antiviral immunity.

Lower serum levels of vitamin D in adults with urinary tract infection

PURPOSE

We aimed to explore the association between urinary tract infection (UTI) in adults and serum 25-hydroxyvitamin D (25OHD), which was used to access vitamin D status.

METHODS

Serum levels of 25OHD were retrospectively analyzed in 234 subjects (190 females and 44 males): 120 UTI patients (females = 103) and 114 age- and sex-matched healthy controls (females = 87). Serum 25OHD concentrations were categorized as follows: (1) < 20 ng/mL, 20 to < 30 ng/mL, and ≥ 30 ng/mL; (2) < 20 ng/mL and ≥ 20 ng/mL.

RESULTS

Serum 25OHD levels were lower in patients with UTI (p < 0.01). Women with UTI presented significantly lower 25OHD concentrations than those without UTI (p < 0.01). No association between serum 25OHD levels and UTI in men was found (p > 0.05). The multivariable logistic regression models showed significant associations between UTI and 25OHD, female sex, neutrophilic lymphocyte ratio and C-reactive protein (p < 0.05).

CONCLUSION

Lower 25OHD concentrations associated with UTI were most prominent among women. The associations between UTI and low serum 25OHD levels as well as female sex were independent of each other.

Serum vitamin D levels in females with urinary incontinence: a meta-analysis of observational trials

INTRODUCTION AND HYPOTHESIS

The association of vitamin D deficiency with female urinary incontinence is unclear.

METHODS

A systematic review of English and non-English articles was conducted. All observational studies in databases including PubMed, EMBASE, the Cochrane Library Trials Register, and Google Scholar were searched until 5 October 2020. Additional studies were identified by contacting clinical experts and searching the bibliographies and abstracts of the compiled articles. Search terms included urinary incontinence and vitamin D. Article data, including study quality indicators, were independently extracted by two authors using predefined data fields.

RESULTS

Two cohort studies, four case-control studies and five cross-sectional studies were included in the qualitative synthesis. Two cohort studies and one cross-sectional study, with a total of 2501 females, were included in the meta-analysis. Heterogeneity among the three studies was not observed (I2 = 0.0%, P = 0.69). All pooled analyses were based on fixed-effects models. No difference in vitamin D level was observed between the urinary incontinence group and the control group (mean difference 0.07 ng/ml; 95% confidence interval [CI] -0.57-0.72, P = 0.81, I2 = 0%).

CONCLUSIONS

Our meta-analysis revealed that adult females with urinary incontinence did not have lower serum vitamin D levels than control females.

A Differential Immune Modulating Role of Vitamin D in Urinary Tract Infection

Vitamin D is known as an important modulator of numerous immune functions. We aimed to investigate the association of 25-hydroxyvitamin D [25(OH)D] with several humoral mediators of the immune system in the patients with urinary tract infection (UTI) caused by uropathogenic E. coli (UPEC). Serum levels of 25(OH)D, cytokines (interferon (IFN)-γ, interleukin (IL)-4, IL-6, IL-10, IL-17A, tumor necrosis factor transforming growth factor (TNF)-α, and tumor growth factor (TGF)-β), immunoglobulin (Ig) isotypes (IgG, IgM, and IgM), complement proteins (C3 and C4) with hemolytic activities (CH50 and AP50), and nitric oxide (NO) were evaluated in 65 patients, compared to 45 age- and sex-matched healthy controls. An insignificant decrease in 25(OH)D levels was observed in patients, compared to controls. In the patient group, elevated levels of IFN-γ, IL-17A, and IL-10 had a significant association with the serum levels of 25(OH)D, while the levels of TGF-β, IL-6, and TNF-α showed an insignificant association. The levels of IgG, C3, and NO also displayed such a statistically significant association with serum 25(OH)D levels. The AP50 levels which had significant difference were found to be not associated with serum 25(OH)D levels. Vitamin D might mediate a link between the innate and adaptive immune responses via the induction of Th1/Th17 polarization of cytokine responses and isotype regulation of antibody production, along with the maintenance of the capacity of the alternative complement pathway, in response to a UPEC infection. However, further studies are needed to validate the defined nature of the host immune response.

Vitamin D and Streptococci: The Interface of Nutrition, Host Immune Response, and Antimicrobial Activity in Response to Infection

Streptococcus species are common causes of human infection. These Gram-positive, encapsulated bacterial pathogens infect diverse anatomic spaces, leading to infections including skin and soft tissue infection, endocarditis, pneumonia, meningitis, sinusitis, otitis media, chorioamnionitis, sepsis, and even death. Risk for streptococcal infection is highest in low- and middle-income countries where micronutrient deficiency is common. Epidemiological data reveal that vitamin D deficiency is associated with enhanced risk of streptococcal infection and cognate disease outcomes. Additionally, vitamin D improves antibacterial defenses by stimulating innate immune processes such as phagocytosis and enhancing production of reactive oxygen species (oxidative burst) and antimicrobial peptides (including cathelicidin and lactoferrin), which are important for efficient killing of bacteria. This review presents the most recent published work that studies interactions between the micronutrient vitamin D, the host immune system, and pathogenic streptococci as well as comparisons with other relevant infection models.

Symptoms, risk factors, diagnosis and treatment of urinary tract infections

Urinary tract infection (UTI) is a common microbial infection found in all ages and sexes which involves inflammation of the urinary tract. These infections can range from simple bladder inflammation, that is, cystitis, to severe cases of uroseptic shock. UTI ranks as the number 1 infection that leads to a prescription of antibiotics after a doctor's visit. These infections are sometimes distressing and even life threatening, and both males (12%) and females (40%) have at least one symptomatic UTI throughout their lives. Diagnostic failures in case of bacterial infections are the main contributing factor in improper use of antibiotics, delay in treatment and low survival rate in septic conditions. So, early diagnosis and appropriate therapy with antibiotics are the most significant requirements for preventing complicated UTI conditions such as urosepsis. This review article summarises the symptoms of the UTIs and the associated risk factors to it. The various conventional and recent diagnostic methods were also discussed in this review, along with treatment therapies with or without antibiotics.

Vitamin D deficiency as a risk factor for urinary tract infection in women at reproductive age

Vitamin D deficiency is a pandemic problem and an ever-increasing issue in human nutrition and health. Vitamin D (serum 25-hydroxyvitamin D) deficiency causes many health problems such as autoimmune diseases, Crohn's disease, diabetes, inflammation, asthma, hypertension, and cancer. Vitamin D3 (cholecalciferol) deficiency has been documented as a persistent problem among adults, children, and elderly persons in most of the countries. Our main objective of this study was to determine the hypothesis that the vitamin D deficiency among women can lead to them developing frequent urinary tract infections. Vitamin D has a potential role in immune regulation and it prevents infections especially urinary tract infections (UTI). Therefore it has positive regulatory role in both acute and recurrent infections especially in women of reproductive ages. As women at this age group have specific differences in their urinary tract and the reproductive organ anatomy, make them more prone for micro-organisms' invasion, The present study was carried out to ascertain certain relation between serum 25-hydroxyvitamin D levels and UTI in women while contemplating the significance of knowing the risk factors associated with UTI and also finding ways to avoid serious complications. 75 women with (case group) UTI were differentiated with 35 healthy with no UTI (control group) and 40 women with UTI and their serum 25-hydroxyvitamin D levels were checked in a case control study. The women were between at 17-52 years of age. Using ELISA, Serum 25-hydroxyvitamin D levels were measured. Analysis and comparison of the results were done among the two groups. Vitamin D mean levels in the case group was considerably lower when in comparison with the control group (11.09 ± 7.571 ng/mL vs. 24.08 ± 11.95 ng/mL, P < 0.001).

Serum Concentrations of Emerging Vitamin D Biomarkers and Detection of Prevalent High-Risk HPV Infection in Mid-adult Women

BACKGROUND

Vitamin D has potential immunomodulating benefits in infection. One prior population-based cross-sectional study showed a protective association between serum concentrations of 25(OH)D and high-risk human papillomavirus (hrHPV) detection. Additional biomarkers present at different stages along the vitamin D metabolic pathway may more completely characterize vitamin D status but have not yet been evaluated in relation to hrHPV infection.

METHODS

Stored sera from women aged 30-50 years (N = 404) enrolled in an HPV natural history study from 2011-2012 were tested for 25(OH)D and 4 novel vitamin D biomarkers: 1,25(OH)₂D, 24,24(OH)₂D₃, free vitamin D, and vitamin D-binding protein. Cross-sectional associations between vitamin D serum concentrations and cervicovaginal hrHPV detection were estimated using logistic regression.

RESULTS

25(OH)D serum concentrations were not associated with hrHPV. After adjusting for age, race, season, education, oral contraceptive use, smoking status, body mass index, and serum concentrations of calcium and phosphate, each 1 ng/mL increase in 24,25(OH)₂D₃ was nearly statistically significantly associated with higher likelihood of hrHPV detection [aOR = 1.22; 95% confidence interval (CI), 0.97-1.52]. No significant associations were observed for other biomarkers.

CONCLUSIONS

25(OH)D serum concentrations were unassociated with prevalent hrHPV. Higher levels of one novel biomarker, 24,25(OH)₂D₃, were positively associated with hrHPV, an unexpected finding.

IMPACT

Inconsistent with previous findings of a protective association between 25(OH)D and prevalent hrHPV infection, these results suggest serum concentrations of 4 vitamin D biomarkers are unassociated with detection of hrHPV in mid-adult women.

Bacteriuria and vitamin D deficiency: a cross sectional study of 385 nursing home residents

Background

Up to half of elderly people at nursing homes have asymptomatic bacteriuria, and concentrations of 25-hydroxyvitamin D (25OHD) are generally low. Vitamin D is a modulator of the immune system and involved in protection of the epithelium in the urinary tract as well. The objective was to determine a possible association between bacteriuria and vitamin D deficiency among elderly people at nursing homes.

Methods

Cross-sectional study: Voided urine specimens and blood samples for cultivation and analysis of 25OHD were collected from elderly people at nursing homes in Sweden. Exclusion criteria were: urinary catheter, ongoing antibiotic treatment, incontinence or dementia too severe to provide a voided urine specimen or leave a blood sample, unwillingness to participate or terminal illness. Urine cultures and serum 25OHD concentrations were outcome measures and the association of bacteriuria with vitamin D deficiency was determined by logistic regression.

Results

Twenty-two nursing homes participated and 385 of 901elderly people provided voided urine specimens and blood samples. The mean age was 87 (SD 6.7), 69% women, 19% received vitamin D supplement, 13% had diabetes mellitus, and 54% were diagnosed with dementia. There was significant growth of potentially pathogenic bacteria in 32% (123/385) of voided urine specimens. Escherichia coli were present in 83% of positive urine cultures. The mean concentration of 25OHD in serum was 35 nmol/L (SD 21). Thirty-seven per cent (143/385) had 25OHD < 25 nmol/L, and 3.1% (12/385) 25OHD < 12.5 nmol/L. No association between bacteriuria and 25OHD < 25 nmol/L, OR 1.4 (0.86–2.3; p = 0.18) adjusted for age, gender, diabetes mellitus and dementia was found. However, if using 25OHD < 12.5 nmol/L as a cut-off for vitamin D deficiency the adjusted odds-ratio was 4.4 (1.1–17; p = 0.031).

Conclusions

Bacteriuria and vitamin D deficiency was common. No association between bacteriuria and 25OHD < 25 nmol/L was found. If using 25OHD < 12.5 nmol/L as cut-off for vitamin D deficiency there was an association. However, this has to be interpreted with caution as causality cannot be evaluated as well as only few residents had 25OHD < 12.5 nmol/L.

Vitamin D Status in Women with Pelvic Floor Disorders: A Meta-Analysis of Observational Studies

The current evidence regarding the association between vitamin D status and pelvic floor disorder (PFD) are inconclusive. This meta-analysis was aimed to summarize existing data demonstrating the association between Vitamin D status and PFD using published observational studies. All national and international databases including Web of Science, PubMed, Google Scholar, and Scopus were searched up until January 30, 2018, and related published studies retrieved for meta-analysis. The effect sizes of Vitamin D status were presented as standardized mean difference (SMD) with 95% confidence interval (CI), using random-effect models and inverse variance method. The Cochran Q statistic and I² tests were used to evaluate the heterogeneity across included studies. Seven studies with 3219 women were included our meta-analysis. There was heterogeneity existing among included studies (I² = 96.4%, P < 0.001), so a random-effect model was used. The findings of this meta-analysis revealed that the mean serum Vitamin D levels in women with PFD were significantly lower than healthy women (SMD −0.60; 95% CI, −1.06, −0.13; P = 0.01). This meta-analysis demonstrates lower levels of serum Vitamin D in women with PFD rather than healthy women. Additional prospective studies regarding the association between Vitamin D status and PFD are required to confirm our findings.

Association between vitamin D level and hematuria from a dipstick test in a large scale population based study: Korean National Health and nutrition examination survey

BACKGROUND

Vitamin D deficiency is an important health concern because it is related to several comorbidities and mortality. However, its relationship with the risk of hematuria remains undetermined in the general population. In this study, we analyzed the association between vitamin D deficiency and hematuria.

METHODS

We conducted cross-sectional analysis using data of participants from the Korean National Health and Nutrition Examination Survey (KNHANES) 2010-2014. A total of 20,240 participants, aged ≥18 years old, were analyzed. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in a central laboratory and hematuria was defined as ≥1+ on a dipstick test. Multivariate logistic regression was conducted to calculate the odds ratio (OR) of hematuria risk according to serum 25(OH)D quartiles, after adjusting several covariates.

RESULTS

A total 3144 (15.5%) participants had hematuria. The mean 25(OH)D level was 17.4 ± 6.2 ng/mL (median, 16.6 ng/mL (interquartile range, 13.1-20.8 ng/mL)). The 3rd and 4th quartiles had a higher risk of hematuria than the 1st quartile, with adjusted ORs 1.26 (1.114-1.415) and 1.40 (1.240-1.572) in the 3rd and 4th quartiles, respectively. However, this relationship was only significant in women, not in men. When stratified analyses were conducted according to menopausal status, there was a significant increase of hematuria risk according to quartiles in postmenopausal but not in premenopausal women.

CONCLUSION

We found that vitamin D deficiency is correlated with hematuria in women, particularly after menopause. Further interventional studies are warranted to address whether correcting vitamin D deficiency can lower the risk of hematuria.

Association between vitamin D, antimicrobial peptides and urinary tract infection in infants and young children

AIM

Vitamin D stimulates production of the endogenous antimicrobial peptides cathelicidin and β-defensin-2, which are expressed in the urinary tract. We investigated vitamin D status and levels of cathelicidin and β-defensin-2 and their association with urinary tract infection (UTI).

METHODS

The study included 120 children under three years of age: 76 children with UTIs and 44 otherwise healthy children with congenital hydronephrosis. Serum 25-hydroxycholecalciferol levels were measured by direct competitive electro-chemiluminescence immunoassay, and plasma cathelicidin and β-defensin-2 concentrations were analysed by enzyme-linked immunosorbent assay.

RESULTS

We found that vitamin D insufficiency and deficiency are prevalent in young children (21%). Serum vitamin D levels negatively correlated with age and were significantly lower in girls. Levels of vitamin D positively correlated with levels of cathelicidin but not with β-defensin-2. Low concentrations of vitamin D were associated with UTIs in girls, but we did not see any correlation with the recurrence of infection at one-year follow-up.

CONCLUSION

Vitamin D deficiency is common and may prove to be a risk factor for UTIs especially in girls. We hypothesise that adequate supplementation with vitamin D may become a way to prevent first-time UTIs.

Is Vitamin D Supplementation Effective in Prevention of Recurrent Urinary Tract Infections in the Pediatrics? A Randomized Triple-Masked Controlled Trial

Background:

This study aimed to evaluate the impact of Vitamin D supplementation on prevention of recurrent urinary tract infections (UTIs) in the pediatrics.

Materials and Methods:

This randomized, triple-blind, placebo-controlled clinical trial was conducted in 2014 among 68 children and adolescents with recurrent UTI. They were randomly assigned to two groups, receiving either Vitamin D (1000 IU/daily) or placebo for 6 months. The serum concentration of Vitamin D before and after the study and the frequency of UTI during the study were recorded.

Results:

Overall 33 patients in the group of receiving Vitamin D and 32 in the placebo group completed the trial. The mean serum level of Vitamin D had a significant increase in the intervention group (15.80 ± 8.7 vs. 20.56 ± 8.30 ng/mL, P < 0.001) and significant decrease in the placebo group (20.43 ± 13.28 vs. 17.43 ± 9.99 ng/mL, P = 0.041). During the trial, the frequency of UTI was not significantly different between the two groups studied (P = 0.72). Both before and after the trial, the frequency of Vitamin D deficiency, insufficiency, and adequacy was not significantly different within and between groups (P > 0.05).

Conclusion:

The findings of this trial revealed that Vitamin D supplementation with the mentioned dose have not significant impact on preventing recurrent UTI. Future studies with higher doses of Vitamin D and longer follow-up are suggested.

Clinical implications of the anatomical position of the urethra meatus in women with recurrent post-coital cystitis: a case-control study

INTRODUCTION AND HYPOTHESIS

Recurrent post-coital urinary infection (rUTI)-usually cystitis-is a common entity among otherwise healthy young women. However, little is known about the possible influence of genital anatomical variations. Only a shorter urethral meatus-anus distance has been described as a risk factor. The aim of this study was to evaluate our hypothesis that a shorter urethra-vagina distance is involved in the etiology of post-coital urinary infection.

METHODS

In this prospective case-control study, 61 young women aged between 18 and 40 years with an acute post-coital UTI and a history of intercourse-related rUTI were consecutively recruited between January 2013 and February 2018. Fifty-six age-matched, sexually active women with no history of UTI served as controls. Perineal measurements included the distances between the clitoris-urethra (C-U), urethra-vagina (U-V), urethra-anus (U-A) and perineum. Demographic and sexual behavior characteristics and the morphology of the urethral meatus were also noted. Univariate analysis compared variables between groups. ROC analysis was used to define the efficiency of perineal measurements in predicting outcome. Odds ratios and 95% confidence intervals for UTI-predisposing variables were estimated using logistic regression analysis.

RESULTS

The U-V and U-A distance was shorter in patients compared with controls [median (interquatile range): 16 mm (14-18) vs. 21 mm (19-23) and 51 mm (47-53) vs. 59 mm (55-62), respectively, p < 0.001]. The U-V performed better in ROC analysis than the U-A distance (AUC 0.952 vs. 0.875, p = 0.023). The only statistically significant parameters in multivariate analysis influencing UTI were BMI (OR: 0.702; 0.510-0.967, p = 0.030) and U-V (OR: 0.297; 0.161-0.549, p < 0.001).

CONCLUSIONS

Our results indicate an association between shorter urethra-vagina distance and post-coital rUTIs.

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.

Vitamin D deficiency is associated with urinary tract infection in children

INTRODUCTION

In humans, vitamin D has been shown to play a role in infectious diseases, but its association with acquisition and a complicated course of febrile urinary tract infections (UTIs) has not been investigated. We aimed to investigate the association between 25-hydroxyvitamin D (25(OH)D₃) levels and the risk of first time febrile UTI in children.

MATERIAL AND METHODS

This prospective case-control study included 50 children with first febrile UTI, with no risk factors for UTI, and 50 age- and sex-matched healthy siblings as controls. White blood cell count, serum C-reactive protein, calcium, phosphorus, alkaline phosphatase and parathormone were measured in all studied children. Vitamin D status was determined by measuring plasma 25(OH)D₃ level. Deficiency was defined as a plasma 25(OH)D₃ level ≤ 25 nmol/l.

RESULTS

Children with UTI had significantly lower mean serum levels of 25(OH)D₃ (10.5 ±2.7 nmol/l) than those of controls (25.9 ±5.6 nmol/l) (p < 0.05). Patients with lower UTI had significantly higher serum levels of 25(OH)D₃ compared to those with acute pyelonephritis (12.4 ±2.59 vs. 8.2 ±3.2 nmol/l; p < 0.001). Mean serum levels of 25(OH)D₃ were significantly lower (p = 0.001) in the female patients compared with males, and this difference was not found within the control group. Multivariate analysis showed that a serum 25(OH)D₃ level of ≤ 25 nmol/l is associated with UTI (OR = 1.94, 95% CI: 1.61-2.82; p = 0.04).

CONCLUSIONS

Vitamin D deficiency (≤ 25 nmol/l) was an independent risk factor for UTI in children.

UroPathogenic Escherichia coli (UPEC) Infections: Virulence Factors, Bladder Responses, Antibiotic, and Non-antibiotic Antimicrobial Strategies

Urinary tract infections (UTIs) are one of the most common pathological conditions in both community and hospital settings. It has been estimated that about 150 million people worldwide develop UTI each year, with high social costs in terms of hospitalizations and medical expenses. Among the common uropathogens associated to UTIs development, UroPathogenic Escherichia coli (UPEC) is the primary cause. UPEC strains possess a plethora of both structural (as fimbriae, pili, curli, flagella) and secreted (toxins, iron-acquisition systems) virulence factors that contribute to their capacity to cause disease, although the ability to adhere to host epithelial cells in the urinary tract represents the most important determinant of pathogenicity. On the opposite side, the bladder epithelium shows a multifaceted array of host defenses including the urine flow and the secretion of antimicrobial substances, which represent useful tools to counteract bacterial infections. The fascinating and intricate dynamics between these players determine a complex interaction system that needs to be revealed. This review will focus on the most relevant components of UPEC arsenal of pathogenicity together with the major host responses to infection, the current approved treatment and the emergence of resistant UPEC strains, the vaccine strategies, the natural antimicrobial compounds along with innovative anti-adhesive and prophylactic approaches to prevent UTIs.

Recent advances in recurrent urinary tract infection from pathogenesis and biomarkers to prevention

Recurrent urinary tract infection (UTI) might be one of the most common problems in urological clinics. Recent research has revealed novel evidence about recurrent UTI and it should be considered a different disease from the first infection. The pathogenesis of recurrent UTI might include two mechanisms, bacterial factors and deficiencies in host defense. Bacterial survival in the urinary bladder after antibiotic treatment and progression to form intracellular bacterial communities might be the most important bacterial factors. In host defense deficiency, a defect in pathogen recognition and urothelial barrier function impairment play the most important roles. Immunodeficiency and urogenital tract anatomical abnormalities have been considered the essential risk factors for recurrent UTI. In healthy women, voiding dysfunction and behavioral factors also increase the risk of recurrent UTI. Sexual intercourse and estrogen deficiency in postmenopausal women might have the strongest association with recurrent UTI. Traditional lifestyle factors such as fluid intake and diet are not considered independent risk factors now. Serum and urine biomarkers to predict recurrent UTI from the first infection have also attracted a wide attention recently. Current clinical evidence suggests that serum macrophage colony-stimulating factor and urinary nerve growth factor have potential predictive value for recurrent UTI. Clinical trials have proven the efficacy of the oral immunoactive agent OM-89 for the prevention of UTI. Vaccines for recurrent UTI are recommended by the latest guidelines and are available on the market.

The Association between Serum 25-Hydroxy Vitamin D Level and Urine Cathelicidin in Children with a Urinary Tract Infection

OBJECTIVE

Cathelicidin is an important antimicrobial peptide in the urinary tract. Cathelicidin expression is strongly stimulated by 1,25-dihydroxy vitamin D in epithelial cells, macrophages/monocytes, and neutrophils. Vitamin D and cathelicidin status in children with urinary tract infection (UTI) caused by Escherichia coli is unknown. To establish the relationship between serum vitamin D and urine cathelicidin levels in children with a UTI caused by Escherichia coli.

METHODS

Serum 25-hydroxy vitamin D and urine cathelicidin levels were measured in 36 patients with UTI (mean age 6.8±3.6 years, range: 0.25-12.6 years) and 38 controls (mean age 6.3±2.8 years, range: 0.42-13 years).

RESULTS

There were no significant differences in urine cathelicidin levels between the study and control groups (p>0.05). Eight (22.2%) patients in the study group and 21 (58.3%) children in the control group were found to have sufficient vitamin D (≥20 ng/mL). Patients with sufficient vitamin D had higher urine cathelicidin levels than the controls with sufficient vitamin D (respectively 262.5±41.1 vs. 168±31.6 ng/mL, p=0.001). There were no significant differences between the patients and controls with insufficient vitamin D (p>0.05).

CONCLUSION

The children with vitamin D insufficiency may not be able to increase their urine cathelicidin level during UTI caused by Escherichia coli. There is a need of prospective studies in order to prove a beneficial effect of vitamin D supplementation for the restoration of cathelicidin stimulation and consequently for prevention of UTI recurrence.

Low serum 25-hydroxyvitamin D level and risk of urinary tract infection in infants

The aim of the study is to determine whether serum 25-hydroxyvitamin D (25(OH)D) deficiency in infants increased odds of urinary tract infection (UTI). A total of 238 infants including 132 patients experiencing a first episode of UTI and 106 controls, aged from 1 to 12 months, were enrolled. Serum 25(OH)D levels were tested through blood sampling. The serum 25(OH)D levels were significantly lower in cases with UTI than controls. The mean serum 25(OH)D levels were 29.09 ± 9.56 ng/mL in UTIs and 38.59 ± 12.41 ng/mL in controls (P < 0.001). Infants with acute pyelonephritis (APN) had lower serum 25(OH)D than those with lower UTI. The multivariate logistic regression analyses showed that serum 25(OH)D < 20 ng/mL (OR 5.619, 95% CI 1.469-21.484, P = 0.012) was positively related to an increased odds of UTI. Vitamin D supplementation (OR 0.298, 95% CI 0.150-0.591; P = 0.001) was associated with a decreased likelihood of UTI. Vitamin D deficiency in infants was associated with an increased odds of UTI. Interventional studies evaluating the role of vitamin D supplementation to reduce the burden of UTI are warranted.

Association Between Serum 25-Hydroxyvitamin D Level and Human Papillomavirus Cervicovaginal Infection in Women in the United States

BACKGROUND

A sufficient level of vitamin D enhances protection against several infectious diseases; however, its association with cervicovaginal human papillomavirus (HPV) infection has not been studied.

METHODS

Data for this cross-sectional study were from National Health and Nutrition Examination Survey 2003-2006. A total of 2353 sexually active women for whom cervicovaginal HPV infection status and serum 25-hydroxyvitamin D (25[OH]D) level were known were studied. Associations between serum 25(OH)D levels (continuous and categorical forms) and cervicovaginal HPV infection (due to high-risk HPV or vaccine-type HPV) were estimated using weighted logistic regression.

RESULTS

After adjustment for age, race/ethnicity, and marital status, the odds of high-risk HPV infection were increased per each 10 ng/mL decrease in serum 25(OH)D level (adjusted odds ratio [aOR], 1.14; 95% confidence interval [CI], 1.02-1.27). Similarly, the odds of vaccine-type HPV infection were increased in women with vitamin D levels that were severely deficient (serum 25[OH]D level, <12 ng/mL; aOR, 2.90; 95% CI, 1.32-6.38), deficient (12-19 ng/mL; aOR, 2.19; 95% CI, 1.08-4.45), and insufficient (20-29 ng/mL; aOR, 2.19; 95% CI, 1.22-3.93), compared with those with vitamin D levels that were sufficient (≥30 ng/mL).

CONCLUSIONS

Cervicovaginal HPV prevalence is associated with less-than-optimal levels of serum vitamin D.

Novel Strategies in the Prevention and Treatment of Urinary Tract Infections

Urinary tract infections are one of the most common bacterial infections, especially in women and children, frequently treated with antibiotics. The alarming increase in antibiotic resistance is a global threat to future treatment of infections. Therefore, alternative strategies are urgently needed. The innate immune system plays a fundamental role in protecting the urinary tract from infections. Antimicrobial peptides form an important part of the innate immunity. They are produced by epithelial cells and neutrophils and defend the urinary tract against invading bacteria. Since efficient resistance mechanisms have not evolved among bacterial pathogens, much effort has been put into exploring the role of antimicrobial peptides and possibilities to utilize them in clinical practice. Here, we describe the impact of antimicrobial peptides in the urinary tract and ways to enhance the production by hormones like vitamin D and estrogen. We also discuss the potential of medicinal herbs to be used in the prophylaxis and the treatment of urinary tract infections.

The Association between Vitamin D Levels and Urinary Tract Infection in Children

AIM

We aimed to examine whether there is any association between serum levels of 25-hydroxyvitamin D [25(OH)D3] and urinary tract infection (UTI) among children.

METHODS

White blood cell count, serum C-reactive protein, calcium, phosphorus, alkaline phosphatase, parathormone, and serum 25(OH)D3 levels were measured in 82 children experiencing a first episode of UTI, with no risk factors for UTI, and 64 healthy control children.

RESULTS

The mean serum levels of 25(OH)D3 among children with UTI were significantly lower than those of controls (11.7 ± 3.3 vs. 27.6 ± 4.7 ng/ml; p < 0.001). The serum levels of 25(OH)D3 were significantly lower in patients with acute pyelonephritis compared to patients with lower UTI (8.6 ± 2.8 vs. 14.2 ± 3.0 ng/ml; p < 0.001). Within the study group, mean serum levels of 25(OH)D3 among girls were lower than those of boys (10.9 ± 3.4 ng/ml vs. 13.2 ± 4.4 ng/ml; p < 0.001). Multivariate analysis showed that a serum 25(OH)D3 level of <20 ng/ml (odds ratio 3.503, 95% confidence interval 1.621-7.571; p = 0.001) was associated with UTI in children.

CONCLUSIONS

Our results suggest that vitamin D deficiency may be a risk factor for UTI in children.

The role of the antimicrobial peptide cathelicidin in renal diseases

The balance between the human body and surrounding microorganisms is crucial for homeostasis and health. A disturbance in host-pathogen interactions causes disease. Two important diseases of the kidney and urinary tract are directly caused by bacteria or bacterial toxins: urinary tract infection (UTI) and diarrhea-associated hemolytic uremic syndrome (HUS). In the majority of cases, UTIs are caused by bacteria ascending from the perineum through the urethra to the urinary tract. In contrast, HUS is caused by non-invasive bacteria, such as enterohemorrhagic Escherichia coli, which colonize the gut and do not enter the blood stream. In this latter case, the bacteria release Shiga toxin, which binds to blood cells and thus reaches the target organs, mainly kidneys. Interactions between Shiga toxin, blood cells and endothelial cells in the kidney lead to cell apoptosis and inflammation. Innate immunity and the antimicrobial peptide cathelicidin seem to play important roles in the pathogenesis of both UTI and HUS. Moreover, influencing cathelicidin production and release might offer new therapeutic and prophylactic strategies for both diseases.

Urinary proteins, vitamin D and genetic polymorphisms as risk factors for febrile urinary tract infection and relation with bacteremia: a case control study

Objective/Purpose

Febrile urinary tract infection (UTI) is a common bacterial disease that may lead to substantial morbidity and mortality especially among the elderly. Little is known about biomarkers that predict a complicated course. Our aim was to determine the role of certain urinary cytokines or antimicrobial proteins, plasma vitamin D level, and genetic variation in host defense of febrile UTI and its relation with bacteremia.

Methods

A case-control study. Out of a cohort of consecutive adults with febrile UTI (n = 787) included in a multi-center observational cohort study, 46 cases with bacteremic E.coli UTI and 45 cases with non-bacteremic E.coli UTI were randomly selected and compared to 46 controls. Urinary IL-6, IL-8, LL37, β-defensin 2 and uromodulin as well as plasma 25-hydroxyvitamin D were measured. In 440 controls and 707 UTI patients polymorphisms were genotyped in the genes CXCR1, DEFA4, DEFB1, IL6, IL8, MYD88, UMOD, TIRAP, TLR1, TLR2, TLR5 and TNF.

Results

IL-6, IL-8, and LL37 are different between controls and UTI patients, although these proteins do not distinguish between patients with and without bacteremia. While uromodulin did not differ between groups, inability to produce uromodulin is more common in patients with bacteremia. Most participants in the study, including the controls, had insufficient vitamin D and, at least in winter, UTI patients have lower vitamin D than controls. Associations were found between the CC genotype of IL6 SNP rs1800795 and occurrence of bacteremia and between TLR5 SNP rs5744168 and protection from UTI. The rare GG genotype of IL6 SNP rs1800795 was associated with higher β-defensin 2 production.

Conclusion

Although no biomarker was able to distinguish between UTI with or without bacteremia, two risk factors for bacteremia were identified. These were inability to produce uromodulin and an IL6 rs1800795 genotype.