Bilirubin levels predict renal cortical changes in jaundiced neonates with urinary tract infection

Neonatal jaundice is associated with increased risks of congenital anomalies of the kidney and urinary tract and concomitant urinary tract infection

The link between neonatal jaundice and urinary tract infection (UTI) remains debated, with congenital kidney and urinary tract anomalies (CAKUT) potentially playing a role. This population-based study aimed to analyze the correlations between neonatal jaundice, CAKUT, and concomitant UTI. The study cohort consisted of 2,078,122 live births from 2004 to 2014. We linked several population-based datasets in Taiwan to identify infants with unexplained neonatal jaundice and their mothers. The primary outcome was the rate of CAKUT occurring within 3 years after delivery, and the presence of concomitant UTI during neonatal jaundice hospitalization. Infants with neonatal jaundice had a significantly higher risk of CAKUT (adjusted odds ratio [aOR] 1.24, 95% confidence interval [CI] 1.11-1.39) during early childhood. Among the subtypes of CAKUT, obstructive uropathy, vesicoureteral reflux and other CAKUT were associated with an increased risk of neonatal jaundice. Infants who underwent intensive phototherapy, had a late diagnosis (> 14 days of postnatal age) or underwent a prolonged duration of phototherapy (> 3 days) exhibited a higher risk of concomitant UTI compared to other infants with jaundice. Our findings indicate a notable association between neonatal jaundice and increased risks of UTIs in the context of CAKUT. This study underscore the importance of vigilant monitoring and timely interventions for neonates presenting with jaundice, while acknowledging the complexity and variability in the progression of CAKUT and its potential connection to UTIs.

Impact of Diagnostic Criteria on UTI Prevalence in Young Infants With Jaundice: A Meta-analysis

BACKGROUND AND OBJECTIVE

Previously reported prevalence of urinary tract infections (UTIs) in infants with jaundice range from <1% to 25%. However, UTI criteria are variable and, as demonstrated in a meta-analysis on UTI prevalence in bronchiolitis, disease prevalence is greatly impacted by disease definition. The objective of this study was to conduct a systemic review and meta-analysis examining the impact of including positive urinalysis (UA) results as a diagnostic criterion on the estimated UTI prevalence in young infants with jaundice.

METHODS

The data sources used were Medline (1946-2020) and Ovid Embase (1976-2020) through January 2020 and bibliographies of retrieved articles. We selected studies reporting UTI prevalence in young infants with jaundice. Data were extracted in accordance with meta-analysis of observational studies in epidemiology guidelines. Random-effects models produced a weighted pooled event rate with 95% confidence intervals (CI).

RESULTS

We screened 526 unique articles by abstract and reviewed 53 full-text articles. We included 32 studies and 16 contained UA data. The overall UTI prevalence in young infants with jaundice from all 32 studies was 6.2% (95% CI, 3.9-8.9). From the 16 studies with UA data, the overall UTI prevalence was 8.7% (95% CI, 5.1-13.2), which decreased to 3.6% (95% CI, 2.0-5.8) with positive UA results included as a diagnostic criterion.

CONCLUSIONS

The estimated UTI prevalence in young infants with jaundice decreases substantially when UA results are incorporated into the UTI definition. Due to the heterogeneity of study subjects' ages and definitions of jaundice, positive UA results, and UTI, there is uncertainty about the exact prevalence and about which infants with hyperbilirubinemia warrant urine testing.

Factors Affecting Prevalence of Urinary Tract Infection in Neonates with Unexplained Hyperbilirubinemia: A Systematic Review and Meta-Analysis Study in Iran

Background:

The prevalence and risk factors of urinary tract infection (UTI) in neonates with unexplained hyperbilirubinemia are not studied thoroughly. Since the prevalence of UTI is highly variable in different areas and countries, this study aimed to review the existing data of Iranian neonates with UTI presented with unexplained hyperbilirubinemia.

Methods:

This study is a meta-analysis of Iranian newborns with unexplained hyperbilirubinemia. We identified all studies indexed in international (Web of Science, PubMed, Scopus, Google Scholar) and national (Science Information Database, Magiran) databases from 2000–2018. Search terms included: Urinary Tract Infections OR UTI AND urine OR culture OR microbio, jaundice OR icter OR hyperbili, AND Iran.

Results:

Overall, 4210 neonates from 17 studies were included. The pooled prevalence of UTI in neonates with unexplained hyperbilirubinemia was 6.81% (95% CI: 4.86–8.77). Considering the subgroups analyses; the prevalence of UTI was higher in the prolonged vs. not-prolonged state (8.34% vs. 4.00%), low birth weight vs. normal birth weight (7.81% vs. 4.51%), and exclusive vs. non-exclusive breastfeeding (8.84% vs. 4.72%). Male gender and low birth weight increased the risk of UTI about two times compared to the female gender and normal birth weight, respectively. The results of the analyses in neonates with unconjugated hyperbilirubinemia also showed the above-mentioned subgroup differences.

Conclusion:

Due to considerable prevalence of UTI in neonates with unexplained hyperbilirubinemia and risk factors in this age group, investigation for UTI is essential for the workup in this situation.

Incidence of urinary tract infection in neonates with significant indirect Hyperbilirubinemia of unknown etiology: case-control study

BACKGROUND

Indirect hyperbilirubinemia is frequently encountered during neonatal period. Although it has different causes, in some cases it can't be explained. Previous studies have illustrated that jaundice could be a major sign of urinary tract infection (UTI) in neonates.

AIM OF THE WORK

We aimed to determine the association between UTI and significant unexplained neonatal indirect hyperbilirubinemia.

METHODS

This prospective controlled study was performed on 150 neonates divided in two groups (100 as cases and 50 as controls) to investigate the incidence of UTI in neonates with significant unexplained hyperbilirubinemia. Urine sample was obtained using urine catheterization technique from neonates and full urine analysis was done and cases with pyuria had urine culture to confirm UTI. Immediate renal ultrasonography (USG) was performed for neonates with UTI.

RESULTS

UTI incidence was 11% in cases while none of neonates in control group had UTI with statistical significance between cases and controls (P value < 0.05). The most common (36.4%) pathogen was Escherichia coli. Posterior urethral valve with mild hydronephrosis was diagnosed in 18.2% of UTI positive patients by renal ultrasonography.

CONCLUSION

In neonates with unexplained indirect hyperbilirubinemia, UTI should be considered as a pathological cause.

Etiology and therapeutic management of neonatal jaundice in Iran: a systematic review and meta-analysis

BACKGROUND

Jaundice is a life-threatening disorder in the neonates. In the present study, we aimed to assess systematically available evidence on causes and management of jaundice in Iranian newborn patients.

METHODS

We searched the databases of PubMed, Web of Sciences, Scopus and Google Scholar for English articles published since inception until May 2019. A search was also done for Persian articles in Magiran and Scientific Information Database. Studies were evaluated based on predefined criteria by two reviewers. Data analysis was performed by STATA software.

RESULTS

A total of 33 articles were finally included. The overall pooled prevalence of causes of jaundice among Iranian neonates was as follows: ABO blood groups incompatibility, 16.9% [95% confidence interval (CI) 10.9-22.8]; Rh blood group incompatibility, 4% (95% CI 2.5-5.5); ABO and Rh blood groups incompatibility, 3.6% (95% CI 0-7.7); glucose-6-phosphate dehydrogenase (G6PD) deficiency, 6.3% (95% CI 5.1-7.5); infection, 6.6% (95% CI 5.2-8.1); hypothyroidism, 4.2% (95% CI 0.1-8.3); infant of diabetic mother: 2.3% (95% CI 0.1-4.5); unknown, 50.7% (95% CI 33.4-68); cephalohematoma, 0.6% (95% CI 0.3-0.9). Regarding treatment of icterus, seven and eight articles were found on phototherapy and exchange transfusion, respectively. In five studies, all patients underwent phototherapy, but rate of exchange transfusion use was between 6.6% and 50.9%.

CONCLUSIONS

According to the results, unknown factors were the most common causes of icterus in Iranian neonates, followed by ABO blood groups incompatibility, infections and G6PD deficiency. By the way, phototherapy and exchange transfusion were found as therapeutic choices of neonatal jaundice.

Unusual Case of an Infant with Urinary Tract Infection Presenting as Cholestatic Jaundice

Neonatal jaundice is considered one of the most common reasons for admission to the pediatric medical ward. We report a case of a 1-month-old infant who presented with jaundice but no fever or any other signs of systemic illnesses. Laboratory test results revealed high direct hyperbilirubinemia, and urine culture showed a urinary tract infection with Enterobacter cloacae as the causative agent. He was admitted to the pediatric medical ward where he was treated with a course of antibiotics for 14 days, and cholestasis resolved completely following a course of antibiotics. We conclude that direct hyperbilirubinemia can be related to urinary tract infection in neonates. It is unusual for urinary tract infection to present clinically and biochemically as cholestatic jaundice.

Is screening for urine infection in well infants with prolonged jaundice required? Local review and meta-analysis of existing data

BACKGROUND

The National Institute for Health and Care Excellence (NICE) neonatal jaundice guidance recommends a urine culture for investigation of babies with prolonged jaundice. However, the evidence cited for this guidance is limited. We aimed to review local data and the existing literature to identify evidence to either support or refute this guidance.

METHOD

We retrospectively reviewed 3 years of urine cultures from our outpatient prolonged jaundice clinic. We then conducted literature review with meta-analysis of studies presenting original data on urine tract infection (UTI) rates in jaundiced and prolonged jaundiced babies.

RESULTS

From our local data, none of the 279 patients met our unit clinical criteria for UTI. Literature review revealed considerable differences worldwide in UTI rates in both jaundiced and prolonged jaundiced cases. Using pooled data from our literature review and our local population, the incidence of UTI in prolonged jaundiced babies is 0.21% (95% CI 0.0% to 0.73%) in the UK. This is significantly lower than the figure indicated from the data from elsewhere in the world, 8.21% (95% CI 4.36% to 13.0%).

CONCLUSIONS

The findings both from our local data and the current literature do not support the practice of routine screening for urine infection in well babies with prolonged jaundice. In view of the above, we no longer include urine culture in screening of well infants with prolonged jaundice. We hope that NICE will re-examine the evidence and recommend changes to their guidance on the role of routine screening for urine infection in babies with prolonged jaundice.

Urinary tract infections in the infant

Urinary tract infection (UTI) in an infant may be the first indication of an underlying renal disorder. Early recognition and initiation of adequate therapy for UTI is important to reduce the risk of long-term renal scarring. Ampicillin and gentamicin are traditionally the empiric treatment of choice; however, local antibiotic resistance patterns should be considered. Maternal antibiotics during pregnancy also increase the risk of resistant pathogens during neonatal UTI. Long-term management after the first UTI in infants remains controversial because of lack of specific studies in this age group and the risk-benefit issues for antibiotic prophylaxis between reduced recurrent disease and emergent antibiotic resistance.

Urinary tract infections in neonates with jaundice in their first two weeks of life

BACKGROUND

Hyperbilirubinemia is a frequently seen condition in neonates. This study was undertaken to determine the role of urinary tract infections (UTIs) in the etiology of indirect hyperbilirubinemia in neonates with jaundice in their first two weeks of life.

METHODS

The study was conducted prospectively. The subjects were neonates aged 4-14 days with hyperbilirubinemia which could not be detected by routine tests and was sufficiently severe to necessitate phototherapy.

RESULTS

The study was performed in 104 neonates, of whom 18% (n=19) had UTI. The most frequently identified micro-organism was Escherichia coli (43%). Phototherapy duration and rebound bilirubin level were higher in neonates with UTI (P<0.05).

CONCLUSION

UTI should be investigated in neonates with hyperbilirubinemia of unknown etiology in the first two weeks of life.

Hyperbilirubinemia and urinary tract infection: the effect of indirect hyperbilirubinemia on the in vitro growth of uropathogen Escherichia coli in newborn urine

High serum bilirubin is antioxidant and cytoprotective. We evaluated if urine samples of hyperbilirubinemic newborns impede uropathogenic Escherichia coli growth. Bag-urine samples of hyperbilirubinemic newborns (study group) were cultured at presentation and during remission. Urine sample were obtained only once from healthy newborns (control group). Escherichia coli [2 × 104 colony-forming unit (cfu)/mL] was inoculated into the sterile urine samples and colony counts were determined after 24 h. Bilirubin levels at presentation and remission were also recorded. Escherichia coli colony counts of the control versus study groups and of the presentation versus remission samples in the study group were compared. There were 13 study and 17 control cases. Escherichia coli colony counts were not different in the study group at presentation versus remission (5.4 ± 0.7 vs. 5.5 ± 0.8 log10, respectively; p = 0.659). Escherichia coli colony count of the control group (5.2 ± 0.6 log10) was also not different from the study group. In conclusion, the urine of hyperbilirubinemic newborns did not affect the growth rate of uropathogenic E. coli.

[Jaundice and urinary tract infection in neonates: simple coincidence or real consequence?]

In neonates, jaundice may be one of the initial symptoms related to urinary tract infection (UTI). The routine testing of the urine in jaundiced neonates is controversial. This study aimed to evaluate the related factors of neonatal infants with the initial presentation of hyperbilirubinemia and the final diagnosis of UTI by evaluating data that help diagnose UTI early in apparently healthy newborns with jaundice.

PATIENTS AND METHODS

We retrospectively investigated the medical records of neonates who had been admitted for management of jaundice (n=26) and compared with neonates with jaundice but without UTI (n=26).

RESULTS

There was a significant difference between the two groups in male gender and maternal conditions (prolonged rupture of membranes, maternal UTI). There was also a significant difference between the two groups in their age at the time jaundice started (4 ± 3 days vs 2 ± 1 days) in the UTI and non-UTI groups, respectively (P>0.05). The cases in the UTI group had significantly lower total bilirubin levels (183 ± 71 mg/l) vs (227 ± 40 mg/l) in the non-UTI group, but a higher indirect bilirubin rate than the non-UTI group (P<0.05). Type B blood group was more common in neonates with UTI (P<0.01). In the cases presented herein, none of the jaundiced infants with UTI presented conjugated hyperbilirubinemia. Therefore, urinary tests for UTI should not be absolutely excluded or neglected in neonates in the early stage with unconjugated hyperbilirubinemia. Performing urinary tests to exclude the possibility of coincidental UTI may be necessary for admitted jaundiced infants younger than if they have a high level of indirect bilirubin, especially in male newborns with group B blood and in the presence of maternal urinary infection.

Is There Any Relationship between Hyperbilirubinemia and Pelvicaliceal Dilatation in Newborn Babies?

OBJECTIVE

A recent study reported association of high bilirubin concentrations with decrease in basal vesical tonicity and relaxation of pre-contracted ureteral and vesical smooth muscles in vitro, and authors discussed that recovery of antenatal hydronephrosis might partly be associated with decreased bladder resistance to the urine flow due to hyperbilirubinemia. We aimed to investigate whether any relationship between serum bilirubin levels and antero-posterior renal pelvic diameters or pelvicaliceal dilatations exist during newborn period.

METHODS

Neonates with hyperbilirubinemia (group 1) and healthy neonates (group 2) were randomly selected to the study. Capillary blood samples were used to measure micro-bilirubin. Urinary system ultrasound (US) was performed in both groups by an experienced radiologist.

FINDINGS

Group 1 (31 neonates, 16 males, 15 females) and group 2 (22 neonates, 11 males, 11 females) were identical by means of postnatal age, gender and weight (P>0.05). Mean serum bilirubin levels were 11.1±3.1 mg/dl and 1.4±0.2 mg/dl in group 1 and 2, respectively. Renal length and renal pelvis antero-posterior (AP) diameters were not different between study groups. Pelvis AP diameters of right kidney were 2.1±0.7 mm in group 1 and 1.9±0.7mm in group 2, and of left kidney were 2.4±0.8 mm in group 1 and 2.3±0.6 mm in group 2. There was no correlation between bilirubin levels and renal length and renal pelvis AP diameters (P>0.05).

CONCLUSION

In this study we were not able to demonstrate any relationship between serum bilirubin levels and renal pelvic diameters and pelvicaliceal dilatation in hyperbilirubinemic neonates. So, it is thought that hyperbilirubinemia might not have a direct effect on outcome of the pelvicaliceal dilatation.

Protective effects of bilirubin in an experimental rat model of pyelonephritis

OBJECTIVE

To investigate the effects of bilirubin in a rat model of pyelonephritis.

METHODS

Experimental pyelonephritis was induced in 32 wistar rats and 4 groups were formed: group 1 (no treatment), group 2 (antibiotic), group 3 (bilirubin), and group 4 (antibiotic + bilirubin). Antibiotic was given on days 3 to 8, and bilirubin was administered between days 0 and 8 of bacterial inoculation. Half of the rats were killed on the 9th day (early period) and histopathological parameters, immunohistochemical renal fibrosis markers, apoptosis, and oxidant/antioxidant system activities were evaluated. The rest of the rats were killed at the 6th week of the study and evaluated for histopathological parameters and renal fibrosis markers.

RESULTS

Inflammatory activity was significantly lower in rats treated with antibiotic + bilirubin vs no treatment group both in the early and late periods. In the late period, inflammatory cell intensity was lower in rats treated with bilirubin vs no treatment and the antibiotic + bilirubin groups. Interstitial fibrosis/tubular atrophy was lower in the antibiotic + bilirubin group vs the no treatment and antibiotic groups, and in bilirubin vs antibiotic group. Tissue inhibitor of metalloproteinase-1 expression was lower in the bilirubin vs antibiotic group. Terminal deoxynucleotidyl transferase mediated 2'-deoxyuridine, 5'-triphosphate nick end labeling(+) cells were significantly lower in bilirubin and antibiotic + bilirubin groups vs no treatment group. Malondialdehyde levels were significantly lower in the antibiotic + bilirubin vs the no treatment group and superoxide dismutase activity was significantly higher in the antibiotic and antibiotic + bilirubin groups vs the no treatment group.

CONCLUSION

Bilirubin may have protective effects on pyelonephritis-associated inflammation in both early and late periods in addition to fibrosis and apoptosis when applied with antibiotics. When used alone, bilirubin may also prevent inflammation (in the late period) and apoptosis.