Serum soluble ST2 as a marker of renal scar in pediatric upper urinary tract infection.

BACKGROUND AND OBJECTIVES: Upper urinary tract infection is the most common serious bacterial infection in childhood. Patients with upper urinary tract infection have a risk for renal scarring with subsequent complications including hypertension, proteinuria, and progressive renal failure. However, the predictive biomarkers of renal scarring in children with upper urinary tract infection are still unknown. In this study, we evaluated whether soluble ST2 levels can be biomarkers of subsequent renal scarring in patients with upper urinary tract infection. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We retrospectively studied pediatric patients with upper urinary tract infection at a tertiary center. Twenty-eight children had an upper urinary tract infection with (n = 14) and without (n = 14) renal scarring and underwent 99mtechnetium dimercaptosuccinic acid imaging. In addition, 13 control subjects were enrolled. The clinical data and serum cytokine levels, including soluble ST2 levels, were compared between those with and without renal scars. RESULTS: Serum soluble ST2 levels were significantly higher in the scar group than in the non-scar group, whereas there was no difference in the levels of serum interferon-γ, interleukin-6, interleukin-10, soluble tumor necrosis factor receptor 1, and transforming growth factor-ß between the scar and non-scar groups. The area under the curve for differentiating between the non-scar and scar groups on the basis of measurements of serum soluble ST2 was 0.79, with a sensitivity and specificity of 92.9% and 64.3%, respectively. CONCLUSION: These results suggest that serum soluble ST2 levels on admission could be a useful biomarker of subsequent renal scarring in pediatric patients with upper urinary tract infection.

Distinctive inflammatory profile between acute focal bacterial nephritis and acute pyelonephritis in children.

BACKGROUND: Acute focal bacterial nephritis (AFBN) is a severe form of upper urinary tract infection (UTI) with neurological manifestations and focal renal mass lesions on computed tomography (CT). Prolonged antibiotic therapy may improve the renal outcome, but the early differential diagnosis of AFBN from acute pyelonephritis (APN) is challenging. We searched for effective biomarkers of AFBN based on the pathophysiology of upper UTIs. METHODS: Of 52 upper UTI cases treated at Yamaguchi University between 2009 and 2016, 38 pediatric patients with AFBN (n=17) or APN (n=21) who underwent ultrasonography and/or CT were enrolled. The clinical data and serum cytokine concentrations were analyzed to differentiate AFBN from APN. RESULTS: AFBN patients tended to be older, and have a higher body temperature, longer febrile period, more frequent neurological symptoms, higher immature neutrophil count, lower lymphocyte count, higher procalcitonin and urine ß2-microglobulin levels. AFBN patients showed higher serum levels of IFN-γ, IL-6, IL-10 and soluble TNF-receptor 1 (sTNFR1) (all p<0.05). Although the cytokine levels were variably correlated among each other, multiple logistic regression analysis revealed that combination of IFN-γ and IL-6 levels were most relevant for distinguishing AFBN from APN. The discriminant power of the logistic equation was 0.86 in terms of the area under the curve by the ROC analysis. CONCLUSIONS: Circulating 4 out of 7 cytokines in AFBN patients were at higher levels compared with those in APN patients. IFN-γ and IL-6 levels might most effectively distinguish AFBN from APN.

Serum levels of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinases-1 in human herpesvirus-6-infected infants with or without febrile seizures.

Human herpesvirus-6 (HHV-6) is a cause of exanthema subitum and, sometimes, of febrile seizures. However, the pathogenesis of febrile seizures associated with HHV-6 infection remains unclear. We investigated serum matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in infants with HHV-6 infection. Serum levels of both MMP-9 and TIMP-1 were significantly higher in infants with HHV-6 infection than in controls. Serum TIMP-1 levels were significantly higher in infants with febrile seizures than in infants without febrile seizures. Serum MMP-9/TIMP-1 ratios were significantly lower in infants with febrile seizures than in infants without febrile seizures. In infants with HHV-6 infection, positive correlations were found between serum MMP-9 concentrations and the white blood cells (WBC) count, and between serum TIMP-1 concentrations and the WBC count. Positive correlations were also found between the amounts of HHV-6 DNA and the ratios of MMP-9/TIMP-1 in infants with HHV-6 infection. In conclusion, we suggest that high serum levels of MMP-9 and TIMP-1 in infants with HHV-6 infection may induce dysfunction of the blood-brain barrier, eventually causing febrile seizures.

1α,25-Dihydroxyvitamin D(3) inhibits vascular cellular adhesion molecule-1 expression and interleukin-8 production in human coronary arterial endothelial cells.

Kawasaki disease is an acute febrile vasculitis of childhood that is associated with elevated production of inflammatory cytokines, causing damage to the coronary arteries. The production of proinflammatory cytokines and expression of adhesion molecules in human coronary arterial endothelial cells (HCAECs) is regulated by nuclear transcription factor-κB (NF-κB) activation. We have previously reported that the active form of vitamin D, 1α,25-dihydroxyvitamin D(3) (1α,25-(OH)(2)D(3)), inhibits tumor necrosis factor-α (TNF-α)-induced NF-κB activation. In this study, we examined the anti-inflammatory effects of 1α,25-(OH)(2)D(3) on TNF-α-induced adhesion molecule expression (vascular cellular adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1)) and cytokine production (interleukin-6 (IL-6) and IL-8) in HCAECs. Pretreatment with 1α,25-(OH)(2)D(3) significantly inhibited TNF-α-induced VCAM-1 expression and IL-8 production in HCAECs. Our results suggest that adjunctive 1α,25-(OH)(2)D(3) therapy may modulate the inflammatory response during Kawasaki disease vasculitis.