Acute toxic exposures in children: analysis of a three year registry managed by a Pediatric poison control Center in Italy.

INTRODUCTION: Acute pediatric poisoning is an emerging health and social problem. The aim of this study is to describe the characteristics of a large pediatric cohort exposed to xenobiotics, through the analysis of a Pediatric Poison Control Center (PPCc) registry. METHODS: This study, conducted in the Pediatric Hospital Bambino Gesù of Rome, a reference National Pediatric Hospital, collected data of children whose parents or caregivers contacted the PPCc by phone (group "P"), or who presented to the Emergency Department (group "ED"), during the three-year period 2014-2016. Data were prospectively and systematically collected in a pre-set electronic registry. Comparisons among age groups were performed and multivariable logistic regression models used to investigate associations with outcomes (hospital referral for "P", and hospital admission for "ED"group). RESULTS: We collected data of 1611 children on group P and 1075 on group ED. Both groups were exposed to both pharmaceutical and non-pharmaceutical agents. Pharmaceutical agent exposure increased with age and the most common route of exposure was oral. Only 10% among P group were symptomatic children, with gastrointestinal symptoms. Among the ED patients, 30% were symptomatic children mostly with gastrointestinal (55.4%) and neurologic symptoms (23.8%). Intentional exposure (abuse substance and suicide attempt), which involved 7.7% of patients, was associated with older age and Hospital admission. CONCLUSIONS: Our study describes the characteristics of xenobiotics exposures in different paediatric age groups, highlighting the impact of both pharmacological and intentional exposure. Furthermore, our study shows the utility of a specific PPCc, either through Phone support or by direct access to ED. PPCc phone counselling could avoid unnecessary access to the ED, a relevant achievement, particularly in the time of a pandemic.

Visceral leishmaniasis revealing chronic granulomatous disease in a child.

We report the first description of visceral leishmaniasis (VL) infection as a harbinger of chronic granulomatous disease (CGD) in a 3-year old child. Although VL is not frequently suspected in CGD patients, our case emphasises the importance of a complete evaluation of the immune system in children presenting with VL in order to exclude underlying immunodeficiency states. As the prognosis of CGD is poor, with high morbidity and mortality, establishing an early diagnosis has important practical implications in the successful treatment of these patients. Following the diagnosis, the patient received Human Leukocyte Antigen (HLA) identical sibling bone marrow transplantation (BMT). The child is now 2 years post-transplant and is in good general conditions with normal blood counts, and evidence of full-donor chimerism in repeated fluorescence in situ hybridization (FISH) studies.

Restriction in T-cell receptor repertoire in a patient affected by trichothiodystrophy and CD4+ lymphopenia.

Molecular analysis of T-cell receptor (TCR) repertoire, by measuring the CDR3 heterogeneity length of beta-variable regions (spectratyping), is useful for acquiring novel information on the status of immune system in primary immunodeficiency. Here, we evaluate TCR repertoire in a child with trichothiodystrophy (TTD) and combined immunodeficiency (CID). Spectratyping revealed marked alterations of TCR repertoire distribution: 21 and 10 out of 27 TCR Vbeta (TCRBV) families and subfamilies were skewed in CD8+ and CD4+ subsets, respectively. These findings revealed, for the first time in a TTD patient with CID, a marked reduction in the TCR repertoire complexity, which may reflect alterations in the mechanisms regulating the generation and homeostasis of T cells.

Defective dendritic cell maturation in a child with nucleotide excision repair deficiency and CD4 lymphopenia.

We report a case of a combined immunodeficiency (CID) in a child affected by trichothiodystrophy (TTD) characterized by an altered response to ultraviolet (UV) light due to a defect in the XPD gene. The XPD gene encodes a subunit of the transcription factor II H (TFIIH), a complex involved in nucleotide-excision repair (NER) and basal transcription. Our patient showed neurological and immune system abnormalities, including CD4 + lymphopenia never previously reported in TTD patients. In vitro immunological studies revealed a marked reduction in T-cell proliferation in response to mitogens and CD3 cross-linking which was partially recovered by the addition of anti-CD28 antibody or exogenous interleukin-2. The patient's T cells displayed alterations in T-cell receptor (TCR/CD3) proximal signalling characterized by marked reduction in Lck kinase activity coupled with a constitutive hyperactivation of Fyn kinase. Despite these alterations, normal levels of Lck and Fyn proteins were detected. The role of antigen-presenting cells (APCs) in the pathogenesis of the T-cell defect was investigated by analysing dendritic cells (DCs) generated from the patient's blood monocytes. In these cells, flow cytometry revealed significantly reduced expression of the CD86 co-stimulatory molecules and HLA glycoproteins. In addition, the patient's DCs showed a decreased ability to stimulate naive T lymphocytes. Overall, the results of our study suggest that a defective TFIIH complex might result in alterations in T cells and DC functions leading to a severe immunodeficiency.

X-chromosome inactivation and mutation pattern in the Bruton's tyrosine kinase gene in patients with X-linked agammaglobulinemia. Italian XLA Collaborative Group.

BACKGROUND: The diagnosis of X-linked agammaglobulinemia (XLA) is not always clearcut. Not all XLA conform to the classic phenotype and less than 50% of affected boys have a family history of immunodeficiency. Mutations in the gene for Bruton's tyrosine kinase (BTK) are responsible for the majority of agammaglobulinemia cases. However, a certain proportion of patients may have mutations involving other genes, although they show with an XLA phenotype. We performed BTK gene mutation analysis in 37 males with presumed XLA and analyzed the pattern of X-chromosome inactivation (XCI) in 31 mothers to evaluate the relevance of these approaches to diagnosis and genetic counseling. MATERIALS AND METHODS: Twenty affected males with a sporadic occurrence and 17 familial cases belonging to nine families were enrolled within the framework of the Italian Multicenter Clinical Study on XLA. We used non-isotopic RNase cleavage assay (NIRCA), followed by cDNA sequence determination to screen for BTK mutations and X-chromosome inactivation analysis for carrier detection. RESULTS: Using the cDNA-based approach, the identification of BTK gene abnormalities confirmed the clinical diagnosis of XLA in 31 of 37 affected infants. Missense was the most frequent mutational event and the kinase domain was mostly involved. In addition, nine novel mutations were identified. In sporadic cases, BTK gene abnormalities were identified in 9 out of 10 patients whose mothers had a nonrandom pattern of XCI and in 5 out of 6 patients whose mother had a random pattern of XCI. With the exception of one family, all patients with a familial occurrence and born to mothers with a nonrandom pattern of XCI had mutations of the BTK gene. CONCLUSIONS: Our findings indicate that in sporadic cases BTK gene sequencing is the only reliable tool for a definitive diagnosis of XLA and support XCI as the first diagnostic tool in the mothers of affected males in multiple generations. Furthermore, our molecular analysis confirms that 10-20% of BTK-unaltered patients have disorders caused by defects in other genes.

Analysis of HIV-1 reverse transcriptase gene mutations in infected children treated with zidovudine.

Prolonged treatment with antiretroviral agents directed against reverse transcription (RT) in patients with HIV-1 infection results in the emergence of virus variants with reduced sensitivity containing mutations in the HIV-1 RT gene. Development of zidovudine (ZDV)-related mutations was studied in a cohort of 24 vertically infected pediatric patients receiving ZDV therapy. Monthly clinical and immunologic evaluation was accompanied by direct sequencing of the HIV-1 RT gene every 4 months. A correlation was observed between the emergence of mutations and the duration of therapy. Mutation at codon 41 was found only in the presence of mutation at codon 215. The presence of the mutations Met41-->Leu and Thr215-->Tyr/Phe did not appear to be related to disease progression. These findings suggest that the mere presence of mutations in the HIV-1 RT gene alone during ZDV monotherapy is not a reliable prognostic marker in the absence of other clinical and virologic information.

Mucocutaneous manifestations in children with HIV infection and AIDS.

Mucocutaneous diseases are more frequent in HIV/AIDS-infected children than in the normal population. We analyze mucocutaneous disorders with atypical presentations in a large population of HIV-infected children, with or without full-blown AIDS, compared to a population of HIV seroreverted children. The majority of these cutaneous disorders have an infectious etiology and their frequency is related to the degree of deterioration of the immune system. Some diseases commonly observed in adults are rare in children; neoplasms are an exception.

Role of immunity in maternal-infant HIV-1 transmission.

Factors influencing human immunodeficiency virus type 1 (HIV-1) mother-to-child transmission include both immunological and virological parameters: higher viral loads have been associated with clinical stage of HIV-1-infected individuals as well as higher risk of mother-to-child transmission. Furthermore, we have shown that transmitting mothers more frequently harbour HIV-1 isolates with rapid/high syncytium-inducing (SI) biological phenotype than non-transmitting mothers do. Genetically homogeneous virus populations have been found in HIV-1-infected children at birth, in contrast to the heterogeneous virus populations often found in their infected mothers. This observation suggests that a few virus variants are transmitted or initially are replicating in the child. By comparing the HIV-1 gp120 V3 region of sequentially obtained samples from infected children with samples obtained from their mothers at delivery we found, however, that multiple variants of HIV-1 with different outgrowth kinetics can be transmitted. In addition, we have obtained results indicating an impaired ability of the immune response to adapt to the sequence evolution of HIV-1 in transmitting mothers, as assessed by measuring serum reactivities to peptides representing selected yet closely related V3 sequences. By analysing the presence of antibodies in maternal serum at delivery, which neutralize autologous isolates as well as other primary virus isolates, we have indications that a protective immunity in HIV-1 mother-to-child transmission might exist. Immunotherapy has been assessed in infected adult individuals by passive immunization with a variety of HIV-1-specific antibody products. Data from these studies indicated a differential response to therapy according to the stage of the disease. Active vaccine strategies, including envelope glycoproteins, pursued so far in seronegative adult subjects have shown limitations because broadly neutralizing antibodies, such as can be found in infected individuals, have not been evoked. Further investigations are therefore needed to give support for the potential use of either passive and/or active immunization for the prevention of HIV-1 mother-to-child transmission.

Mother to infant transmission of coinfection by human immunodeficiency virus and hepatitis C virus: prevalence and clinical manifestations.

The prevalence and the clinical course of hepatitis C virus (HCV) infections were studied in 23 HIV-1-infected children, who were born to 22 mothers with HIV-1/HCV coinfection. During the follow-up only two children (8.7%) showed persistent anti-HCV antibodies and circulating HCV RNA. Both children, who were aged 10 and 10.6 years respectively at the end of follow-up, had chronically-evolving liver disease and autoimmune thrombocytopenia but no signs of progressive HIV disease. Based on our experience, vertically-acquired HIV-1/HCV coinfection is less frequent than is generally reported and may be associated with the development of chronic thrombocytopenia in addition to liver disease. Moreover, perinatal HIV-1/HCV coinfection appears to be associated with a slow progression of HIV disease.

HIV-1 transmission through breast-milk: appraisal of risk according to duration of feeding.

OBJECTIVES: To estimate the risk of HIV-1 transmission through breast-milk in children born to infected mothers, and to determine the relationship between duration of breast-feeding and risk. DESIGN AND METHODS: The study population included 168 breast-fed and 793 bottle-fed children born to seropositive mothers. All subjects were enrolled and followed-up in the Italian Register for HIV Infection in Children; HIV sero-status was defined in all children. Multivariate analysis was performed using a logistic regression model. Independent variables included biological factors (duration of breast-feeding, gestational age, clinical condition of mother at delivery, mode of delivery, birth-weight and sex). Year of birth and age when HIV infection was diagnosed were also considered in the analysis attempting to control for possible selection biases. RESULTS: Breast-feeding increased the risk of HIV-1 transmission. The estimated adjusted odds ratio for 1 day of breast- versus bottle-feeding was 1.19 (95% confidence interval, 1.10-1.28). The infection odds ratio of breast- versus bottle-feeding increased with the natural logarithm of the duration of practice. CONCLUSIONS: These results are the first to provide an appraisal of the additional risk of HIV-1 transmission associated with a seropositive mother breast-feeding her child. Biological significance of this route of transmission was supported by demonstration of a relationship between duration of breast-feeding and risk of HIV-1 transmission.

Patterns of immunoglobulin G subclass reactivity to HIV-1 envelope peptides in children born to HIV-1-infected mothers.

OBJECTIVE: To analyse the pattern of immunoglobulin (Ig) G subclasses specific for HIV-1 envelope peptides in sera from HIV-1-infected mothers and their newborns. We sought to determine whether there was a selective transfer of antibodies from mother to child, and to establish diagnostic or prognostic properties by analysing HIV-1 peptide-specific IgG isotypes. DESIGN AND METHODS: Parallel sera from 12 HIV-1-infected mothers and their newborn children were analysed for IgG subclass responses to six HIV-1 envelope peptides by enzyme-linked immunosorbent assay. Levels of IgG were compared with levels of IgG1 and IgG3 to an immunodominant gp41 peptide in children's sera obtained during the first months of life. In a longitudinal study of 16 children born to HIV-1-seropositive mothers, of whom 11 were infected, the IgG1 and IgG3 responses to peptides representing an immunodominant epitope of gp41 and the principal neutralizing determinant of the gp120 V3 region were analysed. RESULTS: IgG1 and IgG3 were found to constitute the predominant peptide-specific antibody responses. A parallel distribution of IgG subclass reactivity was seen in maternal and paediatric sera. There was no evidence of selective antibody transfer. Comparable levels of IgG and IgG1 to the immunodominant peptide were seen in infected and uninfected children, while the IgG3 had disappeared in the majority of uninfected children. A decrease in peptide-specific IgG1 and IgG3 levels was observed in sequential sera from uninfected children, although the kinetic profile varied. Sera from infected children showed de novo synthesis of IgG1 and/or IgG3 binding to the selected HIV-1 peptides. Most children with rapid disease progression failed to produce IgG1 and/or IgG3 to the V3 peptide. CONCLUSION: Analysis of IgG subclass kinetics to selected HIV-1 peptides might be a useful additional diagnostic and prognostic tool in evaluating HIV-1 infection in children born to seropositive mothers.

Malignancies in children with human immunodeficiency virus type 1 infection. The Italian Multicenter Study on Human Immunodeficiency Virus Infection in Children.

Cancer has been closely associated with human immunodeficiency virus (HIV) infection but this is less frequent in children. Non-Hodgkin's lymphomas represent the most frequently reported single tumor. The authors report seven cases of malignant tumors resulting from the analysis of all (n = 1321) children enrolled in the Italian Register for HIV Infection in Children. Tumors were distributed as follows: non-Hodgkin's B-cell lymphoma (four cases); and Kaposi's sarcoma, hepatoblastoma, acute B-cell lymphoblastic leukemia (one case each). Hepatoblastoma had never been previously reported in HIV-infected children. Also in the current series, non-Hodgkin's B-cell lymphoma is the most frequent single tumor. Five of the seven cancers belonged to the B-cell line. All but one of the seven children have died. Specific chemotherapy was provided in three cases, with some clinical improvement. The treatment of malignancies in HIV-infected children is hampered by increased risk of opportunistic infections often fatal even in children with apparent remission from the tumor.