Urine soluble TLR4 levels may contribute to predict urinary tract infection in children: the UTILISE Study.

BACKGROUND: One of the most common bacterial infections in childhood is urinary tract infection (UTI). Toll-like receptors (TLRs) contribute to immune response against UTI recognizing specific pathogenic agents. Our aim was to determine whether soluble TLR4 (sTLR4), soluble TLR5 (sTLR5) and interleukin 8 (IL-8) can be used as biomarkers to diagnose UTI. We also aimed to reveal the relationship between urine Heat Shock Protein 70 (uHSP70) and those biomarkers investigated in this study. METHODS: A total of 802 children from 37 centers participated in the study. The participants (n = 282) who did not meet the inclusion criteria were excluded from the study. The remaining 520 children, including 191 patients with UTI, 178 patients with non-UTI infections, 50 children with contaminated urine samples, 26 participants with asymptomatic bacteriuria and 75 healthy controls were included in the study. Urine and serum levels of sTLR4, sTLR5 and IL-8 were measured at presentation in all patients and after antibiotic treatment in patients with UTI. RESULTS: Urine sTLR4 was higher in the UTI group than in the other groups. UTI may be predicted using 1.28 ng/mL as cut-off for urine sTLR4 with 68% sensitivity and 65% specificity (AUC = 0.682). In the UTI group, urine sTLR4 levels were significantly higher in pyelonephritis than in cystitis (p < 0.0001). Post-treatment urine sTLR4 levels in the UTI group were significantly lower than pre-treatment values (p < 0.0001). CONCLUSIONS: Urine sTLR4 may be used as a useful biomarker in predicting UTI and subsequent pyelonephritis in children with UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Urinary HSP70 improves diagnostic accuracy for urinary tract infection in children: UTILISE study.

BACKGROUND: The accuracy of conventional urinalysis in diagnosing urinary tract infection (UTI) in children is limited, leading to unnecessary antibiotic exposure in a large fraction of patients. Urinary heat shock protein 70 (uHSP70) is a novel marker of acute urinary tract inflammation. We explored the added value of uHSP70 in discriminating UTI from other infections and conditions confused with UTI. METHODS: A total of 802 children from 37 pediatric centers in seven countries participated in the study. Patients diagnosed with UTI (n = 191), non-UTI infections (n = 178), contaminated urine samples (n = 50), asymptomatic bacteriuria (n = 26), and healthy controls (n = 75) were enrolled. Urine and serum levels of HSP70 were measured at presentation in all patients and after resolution of the infection in patients with confirmed UTI. RESULTS: Urinary (u)HSP70 was selectively elevated in children with UTI as compared to all other conditions (p < 0.0001). uHSP70 predicted UTI with 89% sensitivity and 82% specificity (AUC = 0.934). Among the 265 patients with suspected UTI, the uHSP70 > 48 ng/mL criterion identified the 172 children with subsequently confirmed UTI with 90% sensitivity and 82% specificity (AUC = 0.862), exceeding the individual diagnostic accuracy of leukocyturia, nitrite, and leukocyte esterase positivity. uHSP70 had completely normalized by the end of antibiotic therapy in the UTI patients. Serum HSP70 was not predictive. CONCLUSIONS: Urine HSP70 is a novel non-invasive marker of UTI that improves the diagnostic accuracy of conventional urinalysis. We estimate that rapid urine HSP70 screening could spare empiric antibiotic administration in up to 80% of children with suspected UTI. A higher resolution version of the Graphical abstract is available as Supplementary information.

The clinical follow-up and management of COVID-19 in children and adolescents with an immunocompromised state or a malignancy.

BACKGROUND: It is still not known how an immunosuppressive state affects the response to coronavirus disease 2019 (COVID-19) in children and adolescents. The aim of this study was to evaluate clinical characteristics, outcomes, and follow-up results of COVID-19 in pediatric patients with a history of immunocompromise or malignancy, retrospectively. METHODS: Patients with a diagnosis of COVID-19 who were under 18 years of age and had a history of immunosuppressive chronic disease or under immunosuppressant treatment were included in the study. Patients were applied to our outpatient clinic or consulted to our department in a tertiary center during the first year of the pandemic. RESULTS: We evaluated 18 patients with a median age of 15.0 (0.6-17.8) years. Twelve patients (66.6%) were tested because of a symptom and the most common symptom was fever (44.4%, n = 8). Ten of the symptomatic patients (55.5% of all cohort) had a mild disease, the remaining two patients (11.1%) with an end-stage malignancy had critical diseases. Twelve patients (66.7%) were managed on an outpatient basis and were followed up at home, while the remaining six (33.3%) required hospitalization. One patient, who had Ewing sarcoma, died during the follow-up in the intensive care unit, and others were recovered without any morbidities. Lymphocyte (LYM) counts were significantly lower, C-reactive protein (CRP), and ferritin levels were higher in the individuals that needed hospitalization (p = 0.039, 0.027, and 0.039, respectively). DISCUSSION: Immunocompromised children and adolescents with COVID-19 should be monitored closely, especially those with an end-stage malignancy, low LYM count, or high CRP and ferritin levels.

Atypical comorbidities in a child considered to have type 1 diabetes led to the diagnosis of SLC29A3 spectrum disorder.

INTRODUCTION: SLC29A3 spectrum disorder is an autosomal, recessively inherited, autoinflammatory, multisystem disorder characterized by distinctive cutaneous features, including hyperpigmentation or hypertrichosis, hepatosplenomegaly, hearing loss, cardiac anomalies, hypogonadism, short stature, and insulin-dependent diabetes. CASE PRESENTATION: Herein, we report a 6-year-old boy who presented with features resembling type 1 diabetes mellitus, but his clinical course was complicated by IgA nephropathy, pure red cell aplasia, and recurrent febrile episodes. The patient was tested for the presence of pathogenic variants in 53 genes related to monogenic diabetes and found to be compound heterozygous for two SLC29A3 pathogenic variants (p. Arg386Gln and p. Leu298fs). CONCLUSION: This case demonstrated that SLC29A3 spectrum disorder should be included in the differential diagnosis of diabetes with atypical comorbidities, even when the distinctive dermatological hallmarks of SLC29A3 spectrum disorder are entirely absent.

COVID-19 in pediatric nephrology centers in Turkey.

BACKGROUND: There is limited data on COVID-19 disease in children with kidney disease. We aimed to investigate the characteristics and prognosis of COVID-19 in pediatric nephrology patients in Turkey. METHODS: This was a national, multicenter, retrospective cohort study based on an online survey evaluating the data between 11th March 2020 and 11th March 2021 as an initial step of a detailed pediatric nephrology COVID-19 registry. RESULTS: Two hundred and three patients (89 girls and 114 boys) were diagnosed with COVID-19. One-third of these patients (36.9%) were between 10-15 years old. Half of the patients were on kidney replacement therapy: kidney transplant (KTx) recipients (n = 56, 27.5%), patients receiving chronic hemodialysis (n = 33, 16.3%) and those on peritoneal dialysis (PD) (n = 18, 8.9%). Fifty-four (26.6%) children were asymptomatic. Eighty-two (40.3%) patients were hospitalized and 23 (28%) needed intensive care unit admission. Fifty-five percent of the patients were not treated, while the remaining was given favipiravir (20.7%), steroid (16.3%), and hydroxychloroquine (11.3%). Acute kidney injury developed in 19.5% of hospitalized patients. Five (2.4%) had MIS-C. Eighty-three percent of the patients were discharged without any apparent sequelae, while 7 (3.4%) died. One hundred and eight health care staff were infected during the study period. DISCUSSION: COVID-19 was most commonly seen in patients who underwent KTx and received HD. The combined immunosuppressive therapy and frequent exposure to the hospital setting may increase these patients' susceptibility. Staff infections before vaccination era were alarming, various precautions should be taken for infection control, particularly optimal vaccination coverage.

Predictors of poor kidney outcome in children with C3 glomerulopathy.

BACKGROUND: C3 glomerulopathy (C3G) is characterized by heterogeneous clinical presentation, outcome, and predominant C3 accumulation in glomeruli without significant IgG. There is scarce outcome data regarding childhood C3G. We describe clinical and pathological features, treatment and outcomes, and risk factors for progression to chronic kidney disease stage 5 (CKD5) in the largest pediatric series with biopsy-proven C3G. METHODS: Sixty pediatric patients with C3G from 21 referral centers in Turkey were included in this retrospective study. Patients were categorized according to CKD stage at last visit as CKD5 or non-CKD5. Demographic data, clinicopathologic findings, treatment, and outcome data were compared and possible risk factors for CKD5 progression determined using Cox proportional hazards model. RESULTS: Mean age at diagnosis was 10.6 ± 3.0 years and follow-up time 48.3 ± 36.3 months. Almost half the patients had gross hematuria and hypertension at diagnosis. Nephritic-nephrotic syndrome was the commonest presenting feature (41.6%) and 1/5 of patients presented with nephrotic syndrome. Membranoproliferative glomerulonephritis was the leading injury pattern, while 40 patients had only C3 staining. Patients with DDD had significantly lower baseline serum albumin compared with C3GN. Eighteen patients received eculizumab. Clinical remission was achieved in 68.3%. At last follow-up, 10 patients (16.6%) developed CKD5: they had lower baseline eGFR and albumin and higher frequency of nephrotic syndrome and dialysis requirement than non-CKD5 patients. Lower serum albumin and eGFR at diagnosis were independent predictors for CKD5 development. CONCLUSIONS: Children with C3G who have impaired kidney function and hypoalbuminemia at diagnosis should be carefully monitored for risk of progression to CKD5. Graphical abstract.

Rituximab-induced serum sickness and anaphylaxis in a child with nephrotic syndrome.

BACKGROUND: Rituximab is effective for treatment of children with refractory nephrotic syndrome (NS). However, the drug may cause serum sickness characterized by fever, rash, and arthralgia 10-14 days after primary antigen exposure or within a few days after secondary antigen exposure. Rituximab may also lead to anaphylaxis. It is important to recognize rituximab-induced serum sickness (RISS) clinically, as it may mimic various infectious or vasculitic diseases. CASE: A six-year-old male with NS treated with rituximab presented with diffuse arthralgia and myalgia eight days after the first dose. He developed an urticarial rash and arthralgia one week after the second dose, while he had swelling of lips and periorbital regions, choking sensation and erythematous rash in whole body within minutes after the third dose of rituximab. The first two reactions resemble typical serum sickness whereas the third reaction seem to be an anaphylaxis/anaphylactoid reaction. CONCLUSIONS: Although rituximab-induced serum sickness is typically self-limited, further infusions of rituximab should be avoided as it may provoke more severe symptoms. Most of the previous reported cases of RISS are patients with autoimmune or hematologic disorders. We present the first pediatric case with membranous nephropathy and RISS. The patient also developed anaphylactoid reaction during the third rituximab infusion.

Obesity is associated with severe clinical course in children with Henoch-Schonlein purpura.

BACKGROUND: We aimed to evaluate the role of obesity on the clinical course and response to treatment in patients with Henoch-Schonlein purpura (HSP). METHODS: Data charts of children with HSP followed in a tertiary hospital between 2000 and 2018 were reviewed retrospectively. Persistent purpura was defined as skin involvement persisting for ≥ 30 days. Mild nephropathy was defined as the presence of microscopical hematuria and/or non-nephrotic proteinuria, while severe nephropathy as nephrotic proteinuria, nephritic syndrome, and/or kidney insufficiency. Obese and non-obese patients were compared for demographic, clinical, and laboratory parameters. RESULTS: There were 199 patients (M/F, 104/95; median (IQR) presenting age 7.1 (5.0-9.2) years; follow-up period 17.5 (6-50) months). Obese patients (n = 35 (17.6%)) had significantly higher rate of persistent purpura (46% vs 21%), severe renal involvement (58% vs 31%), high-grade renal histopathological lesions (83% vs 39%), hypertension (29% vs 9%), and increased erythrocyte sedimentation rate (79% vs 56%). Obese patients also showed delayed improvement of cutaneous (25 vs 14 days), articular (12.5 vs 10.0 days), and kidney (280 vs 57 days) symptoms. Obese children used steroids for significantly longer period of time (236 vs 40 days). Furthermore, need for immunosuppressive medications were higher in obese patients (40% vs 9%). CONCLUSIONS: Obese children with HSP had higher erythrocyte sedimentation rate, hypertension, and severe renal involvement; showed delayed improvement of skin, joint, and kidney findings; and need more immunosuppressive medications and a longer period of steroid treatment. These findings may be associated with the effect of adipose tissue on inflammation.

Clinical and histopathological prognostic factors affecting the renal outcomes in childhood ANCA-associated vasculitis.

OBJECTIVE: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are very rare in childhood with an increased risk of morbidity and mortality. We aimed to evaluate renal prognostic factors in childhood AAV from the perspective of ANCA serotype, histopathological classification, and five-factor score (FFS). METHODS: Pediatric AAV patients from 11 referral centers in Turkey had been included to the study. The demographics, clinical findings, AAV subtypes, outcomes, and FFS were evaluated retrospectively. Kidney biopsies were classified histopathologically. RESULTS: Totally, 39 patients were enrolled in the study. Among all patients, 74.4% had renal involvement, 56.4% ear-throat-nose involvement, and 51.3% had musculoskeletal involvement. Proteinase 3 (PR3)-ANCA was positive in 48.7%, and myeloperoxidase (MPO)-ANCA was positive in 30.8%. 69.2% of patients had impaired renal function, and 28.2% had progressed to end-stage renal disease (ESRD) during the follow-up. At the time of diagnosis, FFS was ≥ 2 in 53.8%. The most common histopathologic classifications were as follows: crescentic type in 40.7% and sclerotic type in 25.9%. Gastrointestinal and renal involvement, MPO-ANCA positivity, serum creatinine levels, and impaired renal function during the follow-up were significantly higher in patients with FFS ≥ 2, compared to patients with FFS < 2. Patients with FFS ≥ 2 had more common crescentic, mixed and sclerotic histopathologic findings in biopsies. By logistic regression analysis forward method, the strongest single-risk factor among all the parameters was the initial level of creatinine in patients with ESRD, compared to the other patients (p = 0,007). CONCLUSIONS: Evaluation of the FFS, ANCA serology, and the creatinine levels may help to predict renal prognosis.

Bioelectric Impedance Analysis in the Diagnosis of Vesicoureteral Reflux.

BACKGROUND: Vesicoureteral reflux (VUR) is a common abnormality of the urinary tract in childhood. OBJECTIVES: As urine enters the ureters and renal pelvis during voiding in vesicoureteral reflux (VUR), we hypothesized that change in body water composition before and after voiding may be less different in children with VUR. PATIENTS AND METHODS: Patients were grouped as those with VUR (Group 1) and without VUR (Group 2). Bioelectric impedance analysis was performed before and after voiding, and third space fluid (TSF) (L), percent of total body fluid (TBF%), extracellular fluid (ECF%), and intracellular fluid (ICF%) were recorded. After change of TSF, TBF, ECF, ICF (ΔTSF, ΔTBF%, ΔECF%, ΔICF%), urine volume (mL), and urine volume/body weight (mL/kg) were calculated. Groups 1 and 2 were compared for these parameters. In addition, pre- and post-voiding body fluid values were compared in each group. RESULTS: TBF%, ECF%, ICF%, and TSF in both pre- and post-voiding states and ΔTBF%, ΔECF%, ΔICF%, and ΔTSF after voiding were not different between groups. However, while post-voiding TBF%, ECF% was significantly decreased in Group 1 (64.5 ± 8.1 vs 63.7 ± 7.2, P = 0.013 for TBF%), there was not post-voiding change in TSF in the same group. On the other hand, there was also a significant TSF decrease in Group 2. CONCLUSIONS: Bladder and ureter can be considered as the third space. Thus, we think that BIA has been useful in discriminating children with VUR as there was no decreased in patients with VUR, although there was decreased TSF in patients without VUR. However, further studies are needed to increase the accuracy of this hypothesis.

Risk factors for subclinical inflammation in children with Familial Mediterranean fever.

Familial Mediterranean fever (FMF) is the most common autosomal recessive inherited inflammatory disease characterized by attacks of painful inflammation. Some patients with FMF have subclinical inflammation persisting between the attacks. We aimed to identify the demographic, clinical and genetic risk factors for subclinical inflammation in children with FMF. The medical records of the children with FMF were evaluated retrospectively for acute-phase response along with gender, age at the onset of symptoms and at the time of diagnosis, clinical signs and symptoms, the presence of amyloidosis and MEFV genotype. Patients with persistently elevated acute-phase response between the attacks were considered to have subclinical inflammation. Patients with or without subclinical inflammation (Group 1 and Group 2, respectively) were compared for the parameters defined above. Independent risk factors for subclinical inflammation were identified by multivariate logistic regression analysis. There were 105 children (male/female: 52/53) who were compliant on colchicine treatment. Subclinical inflammation was detected in 22 (20 %) patients. Group 1 had significantly higher rate of myalgia, arthritis/arthralgia, erysipelas like erythema, amyloidosis, protracted febrile myalgia and M694V mutation compared with Group 2. However, only the presence of myalgia and erysipelas like erythema were found to be independent risk factors for subclinical inflammation (OR 9.8 and 5.9, respectively). Children with FMF who have myalgia and erysipelas like erythema during the attacks are particularly at risk of ongoing inflammation and should be closely monitored for subclinical inflammation even during attack-free periods.

Clinical and radiological course of simple renal cysts in children.

OBJECTIVE: To evaluate the clinical and, particularly, radiological course of simple renal cysts in children. MATERIALS AND METHODS: Children with simple renal cysts were retrospectively evaluated, especially for change in the cyst diameter during follow-up and complications. In addition, the rate of increase in cyst size per year was calculated, and those characteristics of the cyst were analyzed to predict aggressiveness. RESULTS: Simple renal cysts were detected in 45 (21 male) patients. Mean ages at diagnosis and follow-up period were 7.4 ± 4.9 and 2.9 ± 1.8 years, respectively. Forty-one of the 45 patients were followed up for longer than 1 year. Diameter of the cyst increased in 20 (49%), decreased in 4 (10%), unchanged in 13 (31%), and disappeared in 4 (10%) of patients. The average size increase and average rate of enlargement in simple cysts were 0.3 mm and 1.0% per year, respectively. Furthermore, in 19 (95%) patients, the cyst size increased in the first 2 years. Among baseline parameters, only initial cyst size was an independent predictor of annual growth rates (beta = 0.628; P <.001). The relationship between the initial cyst size and annual growth rates was determined as positive (r = 0.459, P = .003). Two patients with large cysts developed severe complication in the first 6 months. One of these underwent nephrectomy because of rapid increase in cyst diameter (170 mm), renal artery/vein compression, and massive hematuria. In the other patient with severe loin pain regarding simple cyst (73 mm), percutaneous aspiration was performed. CONCLUSION: Simple renal cysts in childhood tend to slowly increase in size. However, regular radiological follow-up might be important, especially in children with large size of cyst at diagnosis, because of more rapid increase in cyst size.

Place of ultrasonography in predicting vesicoureteral reflux in patients with mild renal scarring.

OBJECTIVE: To evaluate the role of renal ultrasonography (USG) in predicting vesicoureteral reflux (VUR) in children with mild renal scarring determined by dimercaptosuccinic acid scintigraphy performed after attack of urinary tract infections (UTI). METHODS: Dimercaptosuccinic acid scintigraphy, voiding cystourethrography (VCUG), and renal USG findings were evaluated retrospectively in children with UTI. Each kidney was evaluated as a separate renal unit (RU). RUs with severe scarring were excluded from the study. RUs having mild scarring with and without abnormal USG findings (group 1 and group 2, respectively) were compared in terms of the presence of VUR. RESULTS: There were a total of 228 patients (70 men, mean age 47.06 ± 44.14 months) and 456 RUs. Of the 185 RUs with mild scarring, 55 had abnormal USG findings (group 1), whereas 130 had normal USG findings (group 2). The rates of VUR and severe VUR (≥grade 4) were higher in group 1 compared with group 2 (69% vs 43%, P = .001 and 35% vs 7% respectively, P <.001). The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratio of USG findings in predicting VUR in RU with mild scarring were 68%, 80%, 38%, 93%, and 8.2, respectively. CONCLUSION: Normal renal USG findings exclude a diagnosis of high-grade VUR to a large extend in children with UTI and mild renal scarring. Refraining from invasive VCUG might be a reasonable approach in these patients provided that no other predisposing factors for UTI and/or renal scarring present.

TLR-4 polymorphisms and leukocyte TLR-4 expression in febrile UTI and renal scarring.

BACKGROUND: In this study, we aimed to determine the relation of TLR-4 Asp299Gly and Thr399Ile polymorphisms and monocyte/neutrophil TLR-4 expression to febrile urinary tract infection (UTI) and renal scar development in children. METHODS: The study was performed in children with a history of febrile UTI. Patients with and without renal scarring were classified as group 1 and group 2, respectively, while the control cases in our previous study were used as the control group (group 3). All three groups were compared for the rate of TLR-4 Asp299Gly and Thr399Ile polymorphisms, and for basal and lipopolysaccharide-stimulated monocyte/neutrophil TLR-4 expression levels. RESULTS: There were 168 patients (86 in group 1, 82 in group 2) and 120 control cases. Monocyte/neutrophil TLR-4 expression levels were similar in groups 1 and 2. However, both groups had lower TLR-4 expression than group 3. The rate of TLR-4 Asp299Gly polymorphism was not different in all groups. TLR-4 Thr399Ile polymorphism was higher in groups 1 and 2 than in group 3 (14.0, 12.2, and 2.0 %, respectively), while group 1 and group 2 were not different. Furthermore, monocyte TLR-4 expression level was lower in those having TLR-4 Thr399Ile polymorphism than in those without this polymorphism. CONCLUSIONS: Patients with febrile UTI had more frequent TLR-4 Thr399Ile polymorphism and lower monocyte/neutrophil TLR-4 expression. These findings indicate that children carrying TLR-4 Thr399Ile polymorphism and/or having low level of monocyte/neutrophil TLR-4 expression have a tendency to develop febrile UTI. However, we could not show the association of TLR-4 polymorphisms and of TLR-4 expression level to renal scarring.