Plasma and urinary adrenomedullin levels in children with acute pyelonephritis

Urinary Tract Infections: Renal Intercalated Cells Protect against Pathogens

Urinary tract infections affect more than 1 in 2 women during their lifetime. Among these, more than 10% of patients carry antibiotic-resistant bacterial strains, highlighting the urgent need to identify alternative treatments. While innate defense mechanisms are well-characterized in the lower urinary tract, it is becoming evident that the collecting duct (CD), the first renal segment encountered by invading uropathogenic bacteria, also contributes to bacterial clearance. However, the role of this segment is beginning to be understood. This review summarizes the current knowledge on CD intercalated cells in urinary tract bacterial clearance. Understanding the innate protective role of the uroepithelium and of the CD offers new opportunities for alternative therapeutic strategies.

A Review of Adrenomedullin in Pediatric Patients: A Useful Biomarker

Adrenomedullin has several properties. It acts as a potent vasodilator, has natriuretic effects, and reduces endothelial permeability. It also plays a role in initiating the early hyperdynamic phase of sepsis. Since its discovery, many articles have been published studying the uses and benefits of this biomarker. The aim of this review is to determine the usefulness of adrenomedullin in pediatric patients. Relevant studies covering adrenomedullin in pediatrics (<18 years) and published up until August 2021 were identified through a search of MEDLINE, PubMed, Embase, Web of Science, Scopus, and Cochrane. Seventy studies were included in the present review, most of them with a low level of evidence (IV to VI). Research on adrenomedullin has primarily been related to infection and the cardiovascular field. The performance of adrenomedullin to quantify infection in children seems satisfactory, especially in sepsis. In congenital heart disease, this biomarker seems to be a useful indicator before, during, and after cardiopulmonary bypass. Adrenomedullin seems to be useful in the pediatric population for a large variety of pathologies, especially regarding infection and cardiovascular conditions. However, it should be used in combination with other biomarkers and clinical or analytical variables, rather than as a single tool.

Diagnostic value of mid-regional pro-Adrenomedullin as a biomarker of invasive bacterial infection in children: a systematic review

Background

Invasive bacterial infections (IBI) in children present a difficult clinical challenge. They are often life-threatening, however in the early stages they can be hard to differentiate from benign viral infections. This leaves clinicians with the risk of missing a serious IBI diagnosis or inappropriately using antimicrobials in a child with a viral infection- contributing to the ongoing development of increased antimicrobial resistance. Hence, biomarkers which could aid in early detection of IBI and differentiation from viral infections are desirable. Mid-Regional pro-Adrenomedullin (MR-proADM) is a biomarker which has been associated with IBI. The aim of this systematic review was to determine its diagnostic accuracy in identifying children with IBI.

Methods

A strategy was devised to search online databases MEDLINE, Embase, Web of Science and Scopus for human clinical trials reporting the accuracy of MR-proADM in children. Against predesigned inclusion and exclusion criteria full texts were selected for inclusion and data extraction. True positives, false positives, true negatives and false negatives were extracted from each included study to fill 2 × 2 tables. Using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool methodological quality of each study was assessed.

Results

A total of 501 articles were initially identified. After the removal of duplicates and abstract screening 11 texts were fully reviewed and four texts (totaling 1404 patients) were included in the systematic analysis. Only one study was of a high quality and that study accounted for the vast majority of patients. A single study reported the diagnostic accuracy of MR-proADM for invasive bacterial infection reporting an Area under the Curve of 0.69. The paucity of available studies made meta-analysis and studies of heterogeneity impossible.

Conclusion

There is a paucity of research regarding the diagnostic accuracy of MR-proADM in the diagnosis of invasive bacterial infections in children. Initial results would suggest that MR-proADM testing alone is poor at identifying IBI in young children. It remains unclear if MR-proADM performs differently in older children or in children with signs and symptoms of IBI.

Trial registration

PROSPERO CRD42018096295.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03255-9.

Urinary Proadrenomedullin and Disease Severity in Children With Suspected Community-acquired Pneumonia

BACKGROUND

Plasma proadrenomedullin (proADM) is a promising biomarker to predict disease severity in community-acquired pneumonia (CAP). Urinary biomarkers offer advantages over blood, including ease of collection. We evaluated the association between urinary proADM and disease severity in pediatric CAP.

METHODS

We performed a prospective cohort study of children 3 months to 18 years with CAP. Urinary proADM/creatinine (Cr) was calculated. Disease severity was defined as: mild (discharged home), mild-moderate (hospitalized but not moderate-severe or severe), moderate-severe (eg, hospitalized with supplemental oxygen and complicated pneumonia) and severe (eg, vasopressors and invasive ventilation). Outcomes were examined using logistic regression within the cohort with suspected CAP and in a subset with radiographic CAP.

RESULTS

Of the 427 children included, higher proADM/Cr was associated with increased odds of severe disease compared with nonsevere disease [suspected CAP, odds ratio (OR) 1.02 (95% confidence interval (CI) 1.003, 1.04); radiographic CAP, OR 1.03 (95% CI 1.01, 1.06)] when adjusted for other covariates. ProADM/Cr had an area under the receiver operating characteristic curve of 0.56 (threshold 0.9 pmol/mg) to differentiate severe from nonsevere disease in suspected CAP and 0.65 in radiographic CAP (threshold 0.82 pmol/mg). Healthy controls had less proADM in their urine (median, 0.61 pmol/mg) compared with suspected (0.87 pmol/mg, P = 0.018) and radiographic (0.73 pmol/mg, P = 0.016) CAP.

CONCLUSIONS

Urinary proADM/Cr ratio measured at the time of emergency department visit was statistically associated with the development of severe outcomes in children with CAP, with stronger discriminatory performance in radiographic disease.

MR-Proadrenomedullin as biomarker of renal damage in urinary tract infection in children

Background

Midregional-proadrenomedullin (MR-proADM) is a useful prognostic peptide in severe infectious pathologies in the adult population. However, there are no studies that analyze its utility in febrile urinary tract infection (fUTI) in children. An accurate biomarker would provide an early detection of patients with kidney damage, avoiding other invasive tests like renal scintigraphy scans. Our objective is to study the usefulness of MR-proADM as a biomarker of acute and chronic renal parenchymal damage in fUTI within the pediatric population.

Methods

A prospective cohort study was conducted in pediatric patients with fUTI between January 2015 and December 2018. Plasma and urine MR-proADM levels were measured at admission in addition to other laboratory parameters. After confirmation of fUTI, renal scintigraphy scans were performed during the acute and follow-up stages. A descriptive study has been carried out and sensitivity, specificity and ROC curves for MR-proADM, C-reactive protein, and procalcitonin were calculated.

Results

62 pediatric patients (34 female) were enrolled. Scintigraphy showed acute pyelonephritis in 35 patients (56.5%). Of those patients, the median of plasmatic MR-proADM (P-MR-proADM) showed no differences compared to patients without pyelonephritis. 7 patients (11.3%) developed renal scars (RS). Their median P-MR-proADM levels were 1.07 nmol/L (IQR 0.66–1.59), while in patients without RS were 0.48 nmol/L (0.43–0.63) (p < 0.01). The AUC in this case was 0.92 (95% CI 0.77–0.99). We established an optimal cut-off point at 0.66 nmol/L with sensitivity 83.3% and specificity 81.8%.

Conclusion

MR-ProADM has demonstrated a poor ability to diagnose pyelonephritis in pediatric patients with fUTI. However, P-MR-proADM proved to be a very reliable biomarker for RS prediction.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02765-2.

The Role of Pro-Adrenomedullin as a Marker of Severe Bacterial Infection in Children: A Review

Sepsis is still related to high mortality and hospitalization rates in the paediatric population despite medical progress. Prompt recognition of sepsis and consequent initiation of an appropriate treatment are essential elements in securing a positive outcome in adults and children. In such scenario, various biomarkers have been studied to support the clinician in the diagnosis of severe infections, in the identification of patients at risk of progression towards sepsis as well as in the evaluation of the response to treatment. In children, the performance of C-reactive protein and procalcitonin has been largely investigated, whereas data on newer biomarkers of sepsis are scant. The aim of the present review is to summarise the available data on the use of pro-adrenomedullin in the paediatric age.

Adrenomedullin Function in Vascular Endothelial Cells: Insights from Genetic Mouse Models

Adrenomedullin is a highly conserved peptide implicated in a variety of physiological processes ranging from pregnancy and embryonic development to tumor progression. This review highlights past and present studies that have contributed to our current appreciation of the important roles adrenomedullin plays in both normal and disease conditions. We provide a particular emphasis on the functions of adrenomedullin in vascular endothelial cells and how experimental approaches in genetic mouse models have helped to drive the field forward.