Antibiotic Prophylaxis in Infants with Grade III, IV, or V Vesicoureteral Reflux.

BACKGROUND: The efficacy of continuous antibiotic prophylaxis in preventing urinary tract infection (UTI) in infants with grade III, IV, or V vesicoureteral reflux is controversial. METHODS: In this investigator-initiated, randomized, open-label trial performed in 39 European centers, we randomly assigned infants 1 to 5 months of age with grade III, IV, or V vesicoureteral reflux and no previous UTIs to receive continuous antibiotic prophylaxis (prophylaxis group) or no treatment (untreated group) for 24 months. The primary outcome was the occurrence of the first UTI during the trial period. Secondary outcomes included new kidney scarring and the estimated glomerular filtration rate (GFR) at 24 months. RESULTS: A total of 292 participants underwent randomization (146 per group). Approximately 75% of the participants were male; the median age was 3 months, and 235 participants (80.5%) had grade IV or V vesicoureteral reflux. In the intention-to-treat analysis, a first UTI occurred in 31 participants (21.2%) in the prophylaxis group and in 52 participants (35.6%) in the untreated group (hazard ratio, 0.55; 95% confidence interval [CI], 0.35 to 0.86; P = 0.008); the number needed to treat for 2 years to prevent one UTI was 7 children (95% CI, 4 to 29). Among untreated participants, 64.4% had no UTI during the trial. The incidence of new kidney scars and the estimated GFR at 24 months did not differ substantially between the two groups. Pseudomonas species, other non-Escherichia coli organisms, and antibiotic resistance were more common in UTI isolates obtained from participants in the prophylaxis group than in isolates obtained from those in the untreated group. Serious adverse events were similar in the two groups. CONCLUSIONS: In infants with grade III, IV, or V vesicoureteral reflux and no previous UTIs, continuous antibiotic prophylaxis provided a small but significant benefit in preventing a first UTI despite an increased occurrence of non-E. coli organisms and antibiotic resistance. (Funded by the Italian Ministry of Health and others; PREDICT ClinicalTrials.gov number, NCT02021006; EudraCT number, 2013-000309-21.).

Kidney involvement and histological findings in two pediatric COVID-19 patients.

BACKGROUND: Histological findings of kidney involvement have been rarely reported in pediatric patients with SARS-CoV-2 infection. Here, we describe clinical, laboratory, and histological findings of two pediatric cases with almost exclusive kidney involvement by SARS-CoV-2. RESULTS: A 10-year-old girl with IgA vasculitis nephritis underwent kidney biopsy, showing diffuse and segmental mesangial-proliferative glomerulonephritis, and steroid therapy was initiated. After the worsening of the clinical picture, including an atypical skin rash, she was diagnosed with SARS-CoV-2. The re-evaluation of initial biopsy showed cytoplasmatic blebs and virus-like particles in tubular cells at electron microscopy. Despite SARS-CoV-2 clearance and the intensification of immunosuppression, no improvement was observed. A second kidney biopsy showed a crescentic glomerulonephritis with sclerosis, while virus-like particles were no longer evident. The second patient was a 12-year-old girl with a 3-week history of weakness and weight loss. Rhinitis was reported the month before. No medications were being taken. Blood and urine analysis revealed elevated serum creatinine, hypouricemia, low molecular weight proteinuria, and glycosuria. A high SARS-CoV-2-IgG titre was detected. Kidney biopsy showed acute tubular-interstitial nephritis. Steroid therapy was started with a complete resolution of kidney involvement. CONCLUSION: We can speculate that in both cases SARS-CoV-2 played a major role as inflammatory trigger of the kidney damage. Therefore, we suggest investigating the potential kidney damage by SARS-CoV-2 in children. Moreover, SARS-CoV-2 can be included among infectious agents responsible for pediatric acute tubular interstitial nephritis.

Atypical IgM on T cells predict relapse and steroid dependence in idiopathic nephrotic syndrome.

The clinical heterogeneity of idiopathic nephrotic syndrome in childhood may reflect different mechanisms of disease that are as yet unclear. Here, we evaluated the association between an atypical presence of IgM on the surface of T cells (T-cell IgM) and the response to steroid therapy in a total of 153 pediatric patients with idiopathic nephrotic syndrome in different phases of disease. At disease onset, T-cell IgM median levels were significantly elevated and predictive of risk of relapse in 47 patients. They were also significantly increased comparing 58 steroid-dependent to 8 infrequently relapsing and 14 frequently relapsing patients, especially during relapse, whereas they were within the normal range in 7 genetic steroid-resistant patients. T-cell IgM in vivo was not affected by the amount of total circulating IgM, nor by concomitant acute infections or oral immunosuppression. However, it was affected by rituximab treatment in 21 steroid-dependent patients. By in vitro experiments, elevated T-cell IgM was not influenced by total circulating IgM levels or by the presence of other circulating factors, and there was no distinctive antigen-specificity or atypical IgM polymerization. Rather, we found that increased T-cell IgM correlates with reduced IgM sialylation, which influences T-cell response to steroid inhibition and T-cell production of podocyte-damaging factors. Thus, the atypical presence of IgM on the surface of T cells may predispose a subset of steroid-sensitive pediatric patients with idiopathic nephrotic syndrome to a poor response to steroid therapy since disease onset.

Idiopathic neutropenia of infancy: Data from the Italian Neutropenia Registry.

Autoimmune neutropenia of infancy (AIN) is characterized by low risk of severe infection, tendency to spontaneously resolve and typically onset at ≤4-5 years of age; it is due to auto-antibodies whose detection is often difficult. In case of negativity of 4 antineutrophils autoantibody tests, after having excluded ethnic, postinfection, drug induced, or congenital neutropenia, according to the Italian guidelines the patients will be defined as affected by "idiopathic neutropenia" (IN). We describe the characteristics of 85 IN patients enrolled in the Italian neutropenia registry: they were compared with 336 children affected by AIN. The 2 groups were clinically very similar and the main differences were detection age (later in IN), length of disease (longer in IN) and, among recovered patients, age of spontaneous recovery: the median age at resolution was 2.13 years in AINs and 3.03 years in INs (P = .00002). At bivariate analysis among AIN patients earlier detection age (P = .00013), male sex (P = .000748), absence of leucopenia (P = .0045), and absence of monocytosis (P = .0419) were significantly associated with earlier recovery; in the IN group only detection age (P = .013) and absence of monocytosis (P = .0333) were significant. At multivariate analysis detection age and absence of monocytosis were independently significant (P = 6.7e-05 and 4.4e-03, respectively) in the AIN group, whereas in the IN group only detection age stayed significant (P = .013).

B cell phenotype in pediatric idiopathic nephrotic syndrome.

BACKGROUND: A pathogenic role of B cells in non-genetic nephrotic syndrome has been suggested by the efficacy of rituximab, a B cell depleting antibody, in maintaining a prolonged remission. However, little information is available on B cell homeostasis in nephrotic syndrome patients. METHODS: We retrospectively analyzed by flow cytometry the distribution of different B cell subpopulations in 107 steroid-sensitive and in 6 genetic steroid-resistant nephrotic syndrome pediatric patients, compared with age- and sex-matched controls. RESULTS: Fifty-one steroid-sensitive patients at disease onset, before starting immunosuppression, presented significantly increased levels of total, transitional, memory, and switched memory B cells compared to controls. Oral immunosuppression strongly affected transitional and mature B cell levels in 27 patients in relapse and also in 29 patients in remission, whereas memory B cells were significantly higher compared to controls during relapse, despite the immunosuppressive treatment, and were normalized only in patients in remission. Children with genetic forms of steroid-resistant nephrotic syndrome presented no differences in B cell profile from controls. CONCLUSIONS: Our study indicates that memory B cells, more than other B cell subsets, are increased and appear to be pathogenically relevant in steroid-sensitive nephrotic syndrome pediatric patients.

Next-Generation Sequencing Reveals A JAGN1 Mutation in a Syndromic Child With Intermittent Neutropenia.

BACKGROUND: Jagunal homolog 1 (JAGN1) gene was identified as a novel responsible for severe congenital neutropenia. The protein encoded by this gene is required for neutrophil differentiation, survival and function in microbial activity. JAGN1-deficient human neutrophils are characterized by alterations in trafficking within the endoplasmic reticulum and golgi compartments because of ultrastructural defects in endoplasmic reticulum and susceptibility to apoptosis. OBSERVATIONS: We report a patient exhibiting an intermittent neutropenia, for which a next-generation sequencing revealed a homozygous mutation in the JAGN1 gene. CONCLUSIONS: The patient extends the clinical variability associated to JAGN1 mutations, and this case highlights the importance of genetic investigations in patients with suspected neutropenia.

Eltrombopag-Induced Acute Liver Failure in a Pediatric Patient: A Pharmacokinetic and Pharmacogenetic Analysis.

Eltrombopag is an oral thrombopoietin receptor agonist approved for the treatment of patients with chronic idiopathic thrombocytopenic purpura (ITP), who are more than 1 year old, and show poor response to first-line therapy. ITP is a hematological disorder characterized by isolated thrombocytopenia in the absence of secondary causes or disorders. Eltrombopag is generally well tolerated in the pediatric population; therefore, therapeutic drug monitoring (TDM) is not usually performed in clinical practice.We presented the case study of a 3-year-old girl with chronic ITP. She arrived in the pediatric intensive care unit with acute liver failure due to eltrombopag toxicity despite taking the standard drug dosage. A very high eltrombopag plasma concentration, indicating drug toxicity, was found through TDM. The patient also carried the allelic variations that are involved in drug metabolism [CYP2C8 and UDP glucuronosyltransferase (UGT) 1A1 (UGT1A1)] and drug cellular transportation [ABCG2 (ATP-binding cassette G2)]. This observation highlights the importance of using TDM and pharmacogenetic approaches to manage patients' unusual complications associated with standard pharmacological treatment regimens.

Ofatumumab in two pediatric nephrotic syndrome patients allergic to rituximab.

BACKGROUND: Rituximab, a chimeric anti-CD20 monoclonal antibody, is an effective treatment in steroid-dependent nephrotic syndrome (SDNS). However, some patients develop adverse reactions. CASE-DIAGNOSIS/TREATMENT: Patient 1, a 14-year-old boy with SDNS since the age of 2, was treated with oral prednisone, cyclosporine A (CsA) and mycophenolate mofetil. A first infusion of rituximab at age 12 years was well tolerated, but this was followed by a prolonged relapse unresponsive to oral prednisone, mycophenolate mofetil and CsA. A second rituximab infusion was attempted, but treatment was interrupted due to severe dyspnea. Treatment with a humanized anti-CD20 monoclonal antibody, ofatumumab, was then attempted. The patient experienced a mild allergic reaction and maintained remission despite interruption of all treatment at >12 months of follow-up. Patient 2, a 3-year-old boy who presented at 18 months with nephrotic syndrome initially resistant to treatment with oral prednisone, was given with three intravenous boluses of methylprednisolone followed by CsA and achieved remission. Upon steroid discontinuation, the NS relapsed. Prednisone was restarted and treatment with a single dose of rituximab was never completed due to a severe allergic reaction. Ofatumumab infusion was uneventful, and he maintained remission during the follow-up period (>12 months) despite interruption of prednisone therapy. B cells reappeared at 7 months in both patients. CONCLUSIONS: Ofatumumab may be a therapeutic option in severe forms of NS with allergy to rituximab.

Single, Double and Triple Blockade of RAAS in Alport Syndrome: Different Tools to Freeze the Evolution of the Disease.

BACKGROUND: The goal of the treatment of Alport syndrome (AS) is to delay the progression of kidney damage. The current standard of care is the use of Renin Angiotensin Aldosterone System (RAAS) blockers: angiotensin-converting enzyme inhibition (ACEi), angiotensin receptor blockade, and, recently, spironolactone (SP). AIM OF THE STUDY: the purpose of this retrospective study is to evaluate the efficacy (reduction of proteinuria and changes of glomerular function) and safety of a sequential introduction of RAAS blockers up to a triple RAAS blockade in pediatric proteinuric patients with AS. METHODS: in this retrospective study (1995 to 2019), we evaluated proteinuria values in AS patients, during the 12 months following the beginning of a new RAAS blocker, up to a triple blockade. ACEi was always the first line of treatment; then ARB and SP were sequentially added if uPCR increased by 50% from the basal level in 2 consecutive samples during a 3-months observation period, or when uPCR ratio was >2 mg/mg. RESULTS: 26 patients (mean age at treatment onset was 10.55 ± 5.02 years) were enrolled. All patients were on ACEi, 14/26 were started on a second drug (6/14 ARB, 8/14 SP) after a mean time of 2.2 ± 1.7 years, 7/26 were on triple RAAS blockade after a further period of 5.5 ± 2.3 years from the introduction of a second drug. Repeated Measure Anova analysis of log-transformed data shows that the reduction of uPCR values after Time 0 from the introduction of the first, second and third drug is highly significant in all three cases (p values = 0.0016, 0.003, and 0.014, respectively). No significant changes in eGFR were recorded in any group, apart from a 15-year-old boy with X-linked AS, who developed kidney failure. One patient developed mild hyperkaliemia, and one gynecomastia and symptomatic hypotension. No life-threatening events were recorded. CONCLUSIONS: double and triple RAAS blockade is an effective and safe strategy to reduce proteinuria in children with AS. Nevertheless, we suggest monitoring eGFR and Kaliemia during follow-up.

Low-Dose Antibiotic Prophylaxis Induces Rapid Modifications of the Gut Microbiota in Infants With Vesicoureteral Reflux.

Background and Objectives: Maturation of the gut microbiota (GM) in infants is critically affected by environmental factors, with potential long-lasting clinical consequences. Continuous low-dose antibiotic prophylaxis (CAP) is the standard of care for children with vesicoureteral reflux (VUR), in order to prevent recurrent urinary tract infections. We aimed to assess short-term GM modifications induced by CAP in infants. Methods: We analyzed the GM structure in 87 infants (aged 1-5 months) with high-grade VUR, previously exposed or naïve to CAP. Microbial DNA was extracted from stool samples. GM profiling was achieved by 16S rRNA gene-based next-generation sequencing. Fecal levels of short- and branched-chain fatty acids were also assessed. Results: 36/87 patients had been taking daily CAP for a median time of 47 days, while 51/87 had not. In all patients, the GM was predominantly composed by Bifidobacteriaceae and Enterobacteriaceae. Subgroup comparative analysis revealed alterations in the GM composition of CAP-exposed infants at phylum, family and genus level. CAP-exposed GM was enriched in members of Enterobacteriaceae and Bacteroidetes, especially in the genera Bacteroides and Parabacteroides, and showed a trend toward increased Klebsiella, often associated with antibiotic resistance. In contrast, the GM of non-CAP children was mostly enriched in Bifidobacterium. No differences were found in fatty acid levels. Conclusions: In infants with VUR, even a short exposure to CAP definitely alters the GM composition, with increased relative abundance of opportunistic pathogens and decreased proportions of health-promoting taxa. Early low-dose antibiotic exposure might bear potential long-term clinical risks.

Clinical and Pathophysiological Insights Into Immunological Mediated Glomerular Diseases in Childhood.

The kidney is often the target of immune system dysregulation in the context of primary or systemic disease. In particular, the glomerulus represents the anatomical entity most frequently involved, generally as the expression of inflammatory cell invasion or circulant or in situ immune-complex deposition. Glomerulonephritis is the most common clinical and pathological manifestation of this involvement. There are no universally accepted classifications for glomerulonephritis. However, recent advances in our understanding of the pathophysiological mechanisms suggest the assessment of immunological features, biomarkers, and genetic analysis. At the same time, more accurate and targeted therapies have been developed. Data on pediatric glomerulonephritis are scarce and often derived from adult studies. In this review, we update the current understanding of the etiologic events and genetic factors involved in the pathogenesis of pediatric immunologically mediated primitive forms of glomerulonephritis, together with the clinical spectrum and prognosis. Possible new therapeutic targets are also briefly discussed.

Prolonged Impairment of Immunological Memory After Anti-CD20 Treatment in Pediatric Idiopathic Nephrotic Syndrome.

Anti-CD20 therapy is effective in idiopathic nephrotic syndrome (INS). However, transient or sustained hypogammaglobulinemia predisposing to an increased risk of infectious diseases can follow treatment in some patients. We analyzed the long-term effects of anti-CD20 therapy on immunological memory in 27 frequently-relapsing/steroid-dependent INS pediatric patients after more than 4 years from the first and at least 2 years from the last anti-CD20 infusion. Twenty-one INS children, never treated with anti-CD20 and under an intense oral immunosuppression with prednisone, mycophenolate mofetil, and calcineurin inhibitors were also included as control group. Levels of circulating B-cell subpopulations, total serum immunoglobulins and IgG and memory B cells directed against hepatitis B virus (HBV) and tetanus were determined and correlated with clinical characteristics. Nine patients never relapsed after more than 2 years from the last anti-CD20 administration (5 after the first, 3 after the second, and 1 after the fifth infusion). At last follow-up, most patients showed a complete recovery and normalization of total (27/27), transitional (27/27), and mature-naïve B cells (25/27). However, a sustained and significant reduction of total memory (20/27) and switched memory (21/27) B cells was found in most patients. 11/27 patients showed hypogammaglobulinemia at last follow-up and, among these, four presented with a severe hypogammaglobulinemia (IgG < 160 mg/dl). In contrast, no patient in the control group developed a severe hypogammaglobulinemia. Age at the time of first anti-CD20 administration was positively associated with IgG levels at last follow-up (p = 0.008); accordingly, younger patients had an increased risk of hypogammaglobulinemia (p = 0.006). Furthermore, severe hypogammaglobulinemia and delayed switched memory B-cell reconstitution were more frequent in non-relapsing patients. Reduced IgG levels against HBV and tetanus were observed at baseline and further declined at last follow-up. Antigen-specific memory B-cells were induced by re-immunization, but specific IgG titers remained low. In conclusion, anti-CD20 therapy can be disease-modifying in some INS patients. However, a prolonged impairment of immunological memory occurs frequently, independently from the number of anti-CD20 infusions, particularly in younger patients. Re-immunization may be necessary in these patients.

First Case of Patient With Two Homozygous Mutations in MYD88 and CARD9 Genes Presenting With Pyogenic Bacterial Infections, Elevated IgE, and Persistent EBV Viremia.

We described for the first time a female patient with the simultaneous presence of two homozygous mutations in MYD88 and CARD9 genes presenting with pyogenic bacterial infections, elevated IgE, and persistent EBV viremia. In addition to defective TLR/IL1R-signaling, we described novel functional alterations into the myeloid compartment. In particular, we demonstrated a defective production of reactive oxygen species exclusively in monocytes upon E. coli stimulation, the inability of immature mono-derived DCs (iDCs) to differentiate into mature DCs (mDCs) and the incapacity of mono-derived macrophages (MDMs) to resolve BCG infection in vitro. Our data do not provide any evidence for digenic inheritance in our patient, but rather for the association of two monogenic disorders. This case illustrates the importance of using next generation sequencing (NGS) to determine the most accurate and early diagnosis in atypical clinical and immunological phenotypes, and with particular concern in consanguineous families. Indeed, besides the increased susceptibility to recurrent invasive pyogenic bacterial infections due to MYD88 deficiency, the identification of CARD9 mutations underline the risk of developing invasive fungal infections emphasizing the careful monitoring for the occurrence of fungal infection and the opportunity of long-term antifungal prophylaxis.

Susceptibility to allergy in adoptive children: a cross-sectional study at "Bambino Gesù Children's Hospital".

BACKGROUND: Prevalence of allergy has steeply increased during the past few decades, particularly in high-income countries. The development of atopy could present different characteristics in internationally adopted children with regard to incidence, specific patterns of allergies and timing of occurrence. We aimed to investigate the occurrence of allergic diseases among adopted children in Italy. METHODS: We collected demographic information, preadoption immunization data, infectious diseases screening results, immunological status, and performed hematological and biochemical tests according to a standardized protocol in 108 adopted children. RESULTS: At initial visit (mean age was 5.7 ± 3.2 years), 48 children displayed elevated total serum IgE levels with a prevalence of 56.5% (95%CI: 0.45; 0.67). The prevalences of children screened positive for one or more food allergens and inhalants were 30.1% (95%CI: 19.9%; 42.0%) and 34.3% (95%CI: 23.3%; 46.6%) respectively, only 9 children exhibited abnormal absolute eosinophil counts, 23 (21.3%) had a parasitic infection and 60 (55.6%) had received at least one dose of vaccine. CONCLUSIONS: Children without medical records or with a past medical history suggestive of atopy should perform a thorough allergy evaluation at the time of adoption. Our study offers also a glimpse at the vaccination status and immune-allergic profiles of recent migrant children in Italy.

Chronic granulomatous disease presenting with salmonella brain abscesses.

Chronic granulomatous disease is a rare primary immunodeficiency caused by phagocytic cell defect. We describe the case of 43-month-old boy with chronic granulomatous disease presenting with Salmonella spp brain abscesses, together with a review of the 13 cases reported in the literature.