Acute kidney injury in children hospitalised for febrile urinary tract infection

AIM

To determine (i) prevalence and the risk factors for acute kidney injury (AKI) in children hospitalised for febrile urinary tract infection (fUTI) and (ii) role of AKI as indicator of an underlying VUR. AKI, in fact, is favoured by a reduced nephron mass, often associated to VUR.

METHODS

This retrospective Italian multicentre study enrolled children aged 18 years or younger (median age = 0.5 years) discharged with a primary diagnosis of fUTI. AKI was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria.

RESULTS

Of 849 children hospitalised for fUTI (44.2% females, median age 0.5 years; IQR = 1.8), 124 (14.6%) developed AKI. AKI prevalence rose to 30% in the presence of underlying congenital anomalies of the kidney and urinary tract (CAKUT). The strongest AKI predictors were presence of CAKUT (OR = 7.5; 95%CI: 3.8-15.2; p = 9.4e-09) and neutrophils levels (OR = 1.13; 95%CI: 1.08-1.2; p = 6.8e-07). At multiple logistic regression analysis, AKI during fUTI episode was a significant indicator of VUR (OR = 3.4; 95%CI: 1.7-6.9; p = 0.001) despite correction for the diagnostic covariates usually used to assess the risk of VUR after the first fUTI episode. Moreover, AKI showed the best positive likelihood ratio, positive predictive value, negative predictive value and specificity for VUR.

CONCLUSION

AKI occurs in 14.6% of children hospitalised for fUTI and is a significant indicator of VUR.

Lymphocytic myocarditis: a genetically predisposed disease?

Background

Clinical presentation of myocarditis is extremely heterogeneous from asymptomatic to overt severe heart failure (HF). A complex interaction between pre-existing genetic background and inflammation might be responsible for this heterogeneity.

Purpose

The aim of the present study was to investigate whether positive genetic background for pathogenic cardiomyopathy-related variants might underlie a higher susceptibility to left ventricular dysfunction in patients with active lymphocytic myocarditis.

Methods

We prospectively performed genetic tests in 36 patients (46±15 years; 61% males; no relatives included) with biopsy-proven active lymphocytic myocarditis according to Dallas criteria and immunohistochemistry. Only pathogenic (P) or likely pathogenic (LP) variants were considered.

Results

After genetic test, 31% of patients (n=11) were carriers of P/LP truncating variants in structural Cardiomyopathy related genes: Titin (TTN, n=8, 73%), Desmoplakin (DSP, n=1), Filamin C (FLNC, n=1) and RNA binding protein 20 (RBM20, n=1). Among the 27 patients presenting with HF and LV dysfunction, the positive genetic yield was similar to the total cohort (n=9, 34%; 90% with TTN). Two out of six arrhythmic patients (30%) were carriers in arrhythmogenic genes (i.e. DSP and FLNC), whereas no patients with infarct-like presentation were carriers. During follow-up, 44% of patients (n=16) presented normal Left Ventricular Ejection Fraction (LVEF). Carriers had a lower rate of LVEF normalization compared to non-carriers (18% vs 56%, respectively; p=0.035).

Conclusion

Positive genetic testing for cardiomyopathy-related-genes might be found in a non-negligible percentage of patients with biopsy-proven myocarditis, especially if presenting with heart failure and LV dysfunction. Compared to non-carriers, carriers of P/LP variants show lower likelihood of LVEF normalization during follow-up.

Funding Acknowledgement

Type of funding source: None