Urinary tract infection in children with nephrotic syndrome: A systematic review and meta-analysis

Diagnostic value of serum CRP, PCT and IL-6 in children with nephrotic syndrome complicated by infection: a single center retrospective study

OBJECTIVE

The purpose was to look into the diagnostic value of serum CRP, PCT and IL-6 in children with nephrotic syndrome co-infection.

METHODS

One hundred and forty-nine children with nephrotic syndrome who met the inclusion and exclusion criteria were included in this study. The children were divided into three groups: bacterial infection group, non-bacterial infection group, and non-infection group. The diagnostic value was analyzed and compared using the ROC curve.

RESULTS

There was no statistically significant difference in the Leukocyte counts among three groups. The mean results of serum CRP, PCT and IL-6 were significantly higher in the bacterial infection group compared to those in the non-infection group (p < 0.05). AUC of CRP, PCT, IL-6 in bacterial infection were 0.791, 0.859, 0.783. The following combinations CRP + PCT + IL-6, IL-6 + PCT, CRP + PCT significantly increased the efficiency of bacterial infection diagnosis, the AUCs were 0.881, 0.884, and 0.884, respectively. AUC of PCT in non-bacterial infection was 0.663. The combinations of these three clinical indicators performed no better than PCT in ROC analysis.

CONCLUSION

Normal CRP or IL-6 levels do not rule out the diagnosis of bacterial infection in children on long-term glucocorticoid therapy. The appropriate combination of two or three indicators can improve the diagnostic value.

IMPACT

This study evaluated the diagnostic value of the serum concentrations of CRP, PCT and IL-6 and assessed whether the value of their combined application is better than when used alone for diagnosing primary nephrotic syndrome complicated by infection. The elevation in leukocyte count cannot be used to diagnose children with nephrotic syndromes on long-term glucocorticoid treatment who have bacterial infections. Normal CRP or IL-6 levels do not rule out the diagnosis of bacterial infection in children on long-term glucocorticoid therapy. The appropriate combination of two or three indicators can improve diagnostic value, sensitivity, and specificity.

Nephrotic syndrome: pathophysiology and consequences

In patients with kidney disease, nephrotic syndrome can lead to several complications including progressive kidney dysfunction. Proteinuria may lead to the formation of cellular or fibrous crescents with reciprocal development of rapidly progressive glomerulonephritis or focal glomerulosclerosis. Proteinuria may also cause overload and dysfunction of tubular epithelial cells, eventually resulting in tubular atrophy and interstitial fibrosis. Hypoalbuminemia is usually associated with increased risk of mortality and kidney dysfunction. Dyslipidemia may increase the risk of atherosclerotic complications, cause podocyte dysfunction and contribute to vascular thrombosis. Urinary loss of anticoagulants and overproduction of coagulation factors may facilitate a hypercoagulable state. Edema, hypogammaglobulinemia, loss of complement factors, and immunosuppressive therapy can favor infection. Treatment of these complications may reduce their impact on the severity of NS. Nephrotic syndrome is a kidney disorder that can worsen the quality of life and increase the risk of kidney disease progression.

Morganella morganii : An unusual analysis of 11 cases of pediatric urinary tract infections

Background

The increase in rare opportunistic microbial infections caused by Morganella morganii is alarming across the globe. It has been reported that in cases of urinary tract infections (UTIs) caused by M. morganii, however, few studies investigated children. Our study aimed to analyze the risk factors, antimicrobial susceptibility, and clinical characteristics, so as to improve the clinical diagnosis and therapy of M. morganii infection.

Methods

Between April 1, 2017 and April 1, 2021, 11 cases of pediatric UTIs caused by M. morganii were included in this retrospective study. Medical records were reviewed and analyzed.

Results

The study population included 10 males and one female between 11 months and 13 years old (mean age: 4 years 9 months). The most common comorbidity was nephrotic syndrome (72.7%, 8/11). Six patients (54.5%) were in the immunosuppressed state due to chemotherapy or immunosuppressant therapy. Ten cases defined as lower UTIs with no specific clinical manifestations had normal or slightly elevated leukocyte counts and procalcitonin (PCT) levels, and normal C‐reactive protein (CRP) levels. One child diagnosed upper UTIs accompanied with fever, high level of leukocyte counts, CRP, and PCT. The M. morganii presented 100% susceptibility to aztreonam, ertapenem, meropenem, piperacillin/tazobactam, cefepime, ceftazidime, cefotetan, ticarcillin/clavulanic acid, and cefoperazone/sulbactam. Almost all patients had good responses to third‐generation cephalosporins antibiotic therapy.

Conclusion

Clinical vigilance for the possibility of M. morganii in pediatric UTIs in combination with underlying disease or immunosuppression is warranted. Treatment strategies should be proposed according to the clinical condition and the antibiotic susceptibility results.

The risk factors for children with primary nephrotic syndrome: a systematic review and meta-analysis

BACKGROUND

To evaluate the risk factors of primary nephrotic syndrome (PNS) with urinary tract infection (UTI) in children.

METHODS

Multiple databases including PubMed, Excerpta Medica Database (EMBASE), Web of Science (WOS), the Cochrane Library, and China National Knowledge Infrastructure (CNKI) were used to search for relevant studies, which were full-text articles involved in the evaluation of differences between PNS with UTI and without UTI. All included articles were assessed for quality and the data analyses were conducted with Review Manager (5.4). Forest plots, sensitivity analysis, and bias analysis were also performed on the included articles.

RESULTS

Eight studies were included in this meta-analysis, with a total of 3,274 patients. Meta-analysis showed that a low level of serum albumin [mean difference (MD): -0.32 g/dL; 95% confidence interval (CI): (-0.55, -0.08); P=0.008], a low level of serum total protein [MD: -0.16 g/dL; 95% CI: (-0.20, -0.12); P<0.00001], a high level of urinary protein [MD: 5.09 mg/d; 95% CI: (3.13, 7.05); P<0.00001], a lower level of serum urea nitrogen [MD: -0.10 mg/dL; 95% CI: (-0.18, -0.02); P=0.01], and a higher level of serum cholesterol [MD: 2.26 mg/dL; 95% CI: (0.74, 3.78)] had a higher risk of PNS with UTI. There was no obvious publication bias among included studies.

DISCUSSION

Our research demonstrated that a low level of serum albumin, a low level of serum total protein, a high level of urinary protein, a low level of serum urea nitrogen, and a high level of serum cholesterol were the risk factors of PNS with UTI in children.

Infections and risk of end-stage renal disease in patients with nephrotic syndrome: a nationwide population-based case-control study

Background

Infections are a major cause of morbidity in patients with nephrotic syndrome (NS); however, the risk of infections in NS and its subsequent effect on adverse renal outcomes are not well established.

Methods

From 2000–2013 claims data, 4,856 patients with NS were identified from the Taiwanese National Health Insurance Research Database (NHIRD). In the study group, 554 patients progressing to end-stage renal disease (ESRD), as identified during follow-up, were enrolled. In the control group, two patients with NS without progression to ESRD, during the same period, matched with one patient from the study group were included. The correlation between rates of infections and risk of ESRD in patients with NS was estimated using conditional logistic regression analysis.

Results

The proportion of outpatient visits for infections in patients with NS with and without progression to ESRD was 61.2% and 32.8%, respectively, and the proportion of hospitalization due to infections was 28.9% and 1.7%, respectively. The risk of ESRD was higher in patients with frequent outpatient visits for infections (>10 outpatient visits), with a relative risk of 3.20 [95% confidence interval (CI), 1.84–5.57]. Additionally, a significant association was found between severe infections requiring hospitalization and ESRD, with a relative risk of 7.01 (95% CI, 3.65–13.44). Subgroup analysis stratified by sex or age indicated that the risk associated with ESRD was significantly higher in female and elderly patients with NS.

Conclusions

The risk of ESRD in patients with NS was linked to the incidence of infection, especially those requiring hospitalization due to more severe bacterial infections. Implications of study results are important for clinicians who should be aware of the possibility of ESRD development in patients with NS with infectious complications.