Characteristic of COVID-19 infection in pediatric patients: early findings from two Italian Pediatric Research Networks.

Detailed data on clinical presentations and outcomes of children with COVID-19 in Europe are still lacking. In this descriptive study, we report on 130 children with confirmed COVID-19 diagnosed by 28 centers (mostly hospitals), in 10 regions in Italy, during the first months of the pandemic. Among these, 67 (51.5%) had a relative with COVID-19 while 34 (26.2%) had comorbidities, with the most frequent being respiratory, cardiac, or neuromuscular chronic diseases. Overall, 98 (75.4%) had an asymptomatic or mild disease, 11 (8.5%) had moderate disease, 11 (8.5%) had a severe disease, and 9 (6.9%) had a critical presentation with infants below 6 months having significantly increased risk of critical disease severity (OR 5.6, 95% CI 1.3 to 29.1). Seventy-five (57.7%) children were hospitalized, 15 (11.5%) needed some respiratory support, and nine (6.9%) were treated in an intensive care unit. All recovered.Conclusion:This descriptive case series of children with COVID-19, mostly encompassing of cases enrolled at hospital level, suggest that COVID-19 may have a non-negligible rate of severe presentations in selected pediatric populations with a relatively high rates of comorbidities. More studies are needed to further understand the presentation and outcomes of children with COVID-19 in children with special needs. What is Known: • There is limited evidence on the clinical presentation and outcomes of children with COVID-19 in Europe, and almost no evidence on characteristics and risk factors of severe cases. What is New: • Among a case series of 130 children, mostly diagnosed at hospital level, and with a relatively high rate (26.2%) of comorbidities, about three-quarter had an asymptomatic or mild disease. • However, 57.7% were hospitalized, 11.5% needed some respiratory support, and 6.9% were treated in an intensive care unit.

Using a high-flow nasal cannula provided superior results to low-flow oxygen delivery in moderate to severe bronchiolitis.

AIM: An observational study was carried out on infants with moderate to severe bronchiolitis to compare the clinical outcomes following treatment with a high-flow nasal cannula (HFNC) or standard low-flow oxygen. METHODS: We enrolled subjects below 12 months of age who were affected by their first bronchiolitis episode. Non-formal randomisation, based on HFNC availability, was used to assign subjects to either the HFNC or standard oxygen groups. Respiratory rate, respiratory effort and the ability to feed were compared between the two groups at enrolment and at regular time points. The oxygen requirements and the length of hospital stay were also analysed. RESULTS: Overall, 36 of the 40 enrolled infants completed the study: 18 treated with HFNC (mean age 3.2 months, range 1.2-5.4 months) and 18 with low-flow oxygen delivery (mean age 3.6 months, range 1.3-5.0 months). Improvements in the respiratory rate, respiratory effort and ability to feed were significantly faster in the HFNC group than the low-flow oxygen group. The HNFC group needed oxygen supplementation for two days less than the other group and hospital stays were three days shorter. CONCLUSION: HFNC provided superior clinical outcomes for infants under 12 months with moderate-to-severe bronchiolitis compared to low-flow oxygen.

HIV-1 envelope-dependent restriction of CXCR4-using viruses in child but not adult untransformed CD4+ T-lymphocyte lines.

Phytohemagglutin-stimulated child and adult leukocytes equally supported CCR5-dependent (R5) and CXCR4-dependent (X4) HIV-1 replication. In contrast, when phytohemagglutin-stimulated leukocytes from either healthy or congenitally immunodeficient children were cultured on feeder cells, they well supported R5, but not X4 HIV-1 replication, whereas both viruses equally spread in adult cells maintained in similar conditions. Both child and adult cells showed similar levels of proliferation and surface expression of CD4, CCR5, CXCR4, CD25, CD69, and HLA-DR. Lack of X4 HIV-1 replication in child versus adult cells was not caused by a differential expression of several known HIV-1 restriction factors. Similar levels of HIV DNA synthesis occurred in child cells infected with R5 and X4 viruses up to 48 hours after infection when R5 HIV-1 showed a significantly superior capacity to spread in culture than X4 virus. Cultured child cells well supported single round vescicular stomatitis virus-G pseudotyped virus replication, whereas superinfection of R5-infected cells with X4 HIV-1 (or vice versa) rescued the replication of this latter virus. Thus, child cells exposed to feeder cell culture represent a novel model system in which the superior capacity of R5 versus X4 viruses to spread can be investigated in primary, untransformed CD4(+) cells.

Severe lactic acidosis and persistent diastolic hypotension following standard dose of intermittent nebulized salbutamol in a child: a case report.

BACKGROUND: Salbutamol is a selective ß2-receptor agonist widely used to treat asthma in both emergency and outpatient settings. However, it has been associated with a broad spectrum of side effects. Lactic acidosis and diastolic hypotension are rarely reported together following intermittent salbutamol nebulization in children, even less so at standard therapeutic doses. CASE PRESENTATION: We present the case of a 12-year-old Italian boy, 34 kg body weight, who experienced a serious drug reaction during a moderate asthma exacerbation with associated dehydration (blood urea nitrogen/creatinine 0.25), following intermittent inhaled (0.2 mg at 3-hour intervals-overall 1.4 mg in 24 hours before arrival) and nebulized treatment (3.25 mg at 20-minute intervals in 60 minutes, overall 11.25 mg in our emergency department). The patient developed hyperglycemia (peak concentration 222 mg/dL), hypokalemia (lowest concentration 2.6 mEq/L), electrocardiogram alterations (corrected QT interval 467 ms), long-lasting arterial hypotension despite fluid boluses (lowest value 87/33 mmHg), and elevated blood lactate levels (peak concentration 8.1 mmol/L), following the third nebulized dose. Infections, liver dysfunction, and toxicity following other medications were ruled out. The aforementioned alterations improved within 24 hours after discontinuation of salbutamol. CONCLUSIONS: We reinforce the message that even the use of intermittent nebulized salbutamol for acute moderate asthma can lead to severe transient complications in children. Then, healthcare providers should pay attention not only in emergency settings, to achieve prompt recognition and proper management of this adverse reaction. Careful reassessment could prevent similar reactions.

Continuous HIV-1 Escape from Autologous Neutralization and Development of Cross-Reactive Antibody Responses Characterizes Slow Disease Progression of Children.

The antibodies with different effector functions evoked by Human Immunodeficiency Virus type 1 (HIV-1) transmitted from mother to child, and their role in the pathogenesis of infected children remain unresolved. So, too, the kinetics and breadth of these responses remain to be clearly defined, compared to those developing in adults. Here, we studied the kinetics of the autologous and heterologous neutralizing antibody (Nab) responses, in addition to antibody-dependent cellular cytotoxicity (ADCC), in HIV-1 infected children with different disease progression rates followed from close after birth and five years on. Autologous and heterologous neutralization were determined by Peripheral blood mononuclear cells (PBMC)- and TZMbl-based assays, and ADCC was assessed with the GranToxiLux assay. The reactivity to an immunodominant HIV-1 gp41 epitope, and childhood vaccine antigens, was assessed by ELISA. Newborns displayed antibodies directed towards the HIV-1 gp41 epitope. However, antibodies neutralizing the transmitted virus were undetectable. Nabs directed against the transmitted virus developed usually within 12 months of age in children with slow progression, but rarely in rapid progressors. Thereafter, autologous Nabs persisted throughout the follow-up of the slow progressors and induced a continuous emergence of escape variants. Heterologous cross-Nabs were detected within two years, but their subsequent increase in potency and breadth was mainly a trait of slow progressors. Analogously, titers of antibodies mediating ADCC to gp120 BaL pulsed target cells increased in slow progressors during follow-up. The kinetics of antibody responses to the immunodominant viral antigen and the vaccine antigens were sustained and independent of disease progression. Persistent autologous Nabs triggering viral escape and an increase in the breadth and potency of cross-Nabs are exclusive to HIV-1 infected slowly progressing children.

COVID-19 in 17 Italian Pediatric Emergency Departments.

BACKGROUND: Variability in presentation of children with coronavirus disease 2019 (COVID-19) is a challenge in emergency departments (EDs) in terms of early recognition, which has an effect on disease control and prevention. We describe a cohort of 170 children with COVID-19 and differences with the published cohorts. METHODS: Retrospective chart reviews on children (0-18 years) evaluated in 17 Italian pediatric EDs. RESULTS: In our cohort (median age of 45 months; interquartile range of 4 months-10.7 years), we found a high number of patients <1 year with COVID-19 disease. The exposure happened mainly (59%) outside family clusters; 22% had comorbidities. Children were more frequently asymptomatic (17%) or with mild diseases (63%). Common symptoms were cough (43%) and difficulty feeding (35%). Chest computed tomography, chest radiograph, and point-of-care lung ultrasound were used in 2%, 36%, and 8% of cases, respectively. Forty-three percent of patients were admitted because of their clinical conditions. The minimal use of computed tomography and chest radiograph may have led to a reduced identification of moderate cases, which may have been clinically classified as mild cases. CONCLUSIONS: Italian children evaluated in the ED infrequently have notable disease symptoms. For pediatrics, COVID-19 may have rare but serious and life-threatening presentations but, in the majority of cases, represents an organizational burden for the ED. These data should not lower the attention to and preparedness for COVID-19 disease because children may represent a source of viral transmission. A clinically driven classification, instead of a radiologic, could be more valuable in predicting patient needs and better allocating resources.

Biological and genetic evolution of HIV type 1 in two siblings with different patterns of disease progression.

To investigate the immunological and virological factors that may lead to different patterns of disease progression characteristic of HIV-1-infected children, two HIV-1-infected siblings, a slow and a fast progressor, were followed prospectively before the onset of highly active antiretroviral therapy. Viral coreceptor usage, including the use of CCR5/CXCR4 chimeric receptors, macrophage tropism, and sensitivity to the CC-chemokine RANTES, has been studied. An autologous and heterologous neutralizing antibody response has been documented using peripheral blood mononuclear cells- and GHOST(3) cell line-based assays. Viral evolution was investigated by env C2-V3 region sequence analysis. Although both siblings were infected with HIV-1 of the R5 phenotype, their viruses showed important biological differences. In the fast progressor there was a higher RANTES sensitivity of the early virus, an increased trend to change the mode of CCR5 receptor use, and a larger genetic evolution. Both children developed an autologous neutralizing antibody response starting from the second year with evidence of the continuous emergence of resistant variants. A marked viral genetic and phenotypic evolution was documented in the fast progressor sibling, which is accompanied by a high viral RANTES sensitivity and persistent neutralizing antibodies.

Electrical impedance tomography in children with community acquired pneumonia: preliminary data.

BACKGROUND: Electrical impedance tomography (EIT) is a noninvasive pulmonary function test that provides spatial and temporal information of changes in regional lung ventilation. We aimed to assess the feasibility of EIT as a supplementary tool in the evaluation of community acquired pneumonia in children. Furthermore, we performed a prospective evaluation of regional lung ventilation changes during a six-month follow-up period. METHODS: We enrolled otherwise healthy children aged 2-15 years with radiological diagnosis of community acquired pneumonia on admission at pediatric emergency department. Chest EIT was performed at enrollment, at three and six-months from baseline. RESULTS: Nineteen children were enrolled. A significant agreement between EIT and chest radiography in identifying the affected lung (left or right) was observed (Cohen K statistic = 0.73, 95% CI 0.5-0.98). Ventilation improvement was documented at three-month follow-up, but a full recovery only at six months. CONCLUSION: EIT reliably provides additional information on lung ventilation disorders due to CAP in children. It further allows bedside, real time and radiation free monitoring of lung functional recovery. Future studies are needed to expand the generalizability of this method and evaluate effectiveness on clinical practice.

Structural defects and variations in the HIV-1 nef gene from rapid, slow and non-progressor children.

OBJECTIVES: Evaluation of sequence evolution as well as structural defects and mutations of the human immunodeficiency virus-type 1 (HIV-1) nef gene in relation to disease progression in infected children. DESIGN: We examined a large number of nef alleles sequentially derived from perinatally HIV-1-infected children with different rates of disease progression: six non-progressors (NPs), four rapid progressors (RPs), and three slow progressors (SPs). METHODS: Nef alleles (182 total) were isolated from patients' peripheral blood mononuclear cells (PBMCs), sequenced and analysed for their evolutionary pattern, frequency of mutations and occurrence of amino acid variations associated with different stages of disease. RESULTS: The evolution rate of the nef gene apparently correlated with CD4+ decline in all progression groups. Evidence for rapid viral turnover and positive selection for changes were found only in two SPs and two RPs respectively. In NPs, a higher proportion of disrupted sequences and mutations at various functional motifs were observed. Furthermore, NP-derived Nef proteins were often changed at residues localized in the folded core domain at cytotoxic T lymphocytes (CTL) epitopes (E(105), K(106), E(110), Y(132), K(164), and R(200)), while other residues outside the core domain are more often changed in RPs (A(43)) and SPs (N(173) and Y(214)). CONCLUSIONS: Our results suggest a link between nef gene functions and the progression rate in HIV-1-infected children. Moreover, non-progressor-associated variations in the core domain of Nef, together with the genetic analysis, suggest that nef gene evolution is shaped by an effective immune system in these patients.

Effect of highly active antiretroviral therapy on cardiovascular involvement in children with human immunodeficiency virus infection.

The impact of highly active antiretroviral therapy (HAART) on cardiovascular involvement was evaluated in 38 vertically human immunodeficiency virus-infected children followed up for 5 years. This study demonstrates for the first time in a cohort of children the resolution of previous dilated cardiomyopathy after the start of HAART and the absence of cardiovascular events related to metabolic abnormalities during the period of its administration.

Pandemic influenza A/H1N1 vaccine administered sequentially or simultaneously with seasonal influenza vaccine to HIV-infected children and adolescents.

In order to evaluate the immunogenicity, safety and tolerability of the 2009 A/H1N1 MF59-adjuvanted influenza vaccine administered sequentially or simultaneously with seasonal virosomal-adjuvanted influenza vaccine to HIV-infected children and adolescents, 36 HIV-infected children and adolescents, and 36 age- and gender-matched healthy controls were randomised 1:1 to receive the pandemic vaccine upon enrollment and the seasonal vaccine one month later, or to receive the pandemic and seasonal vaccines simultaneously upon enrollment. Seroconversion and seroprotection rates against the pandemic influenza A/H1N1 virus were 100% two months after vaccine administration in both groups, regardless of the sequence of administration. Geometric mean titres against pandemic and seasonal antigens were significantly higher when the seasonal and pandemic vaccines were administered simultaneously than when the seasonal vaccine was administered alone. Local and systemic reactions were mild and not increased by simultaneous administration. In conclusion, the 2009 pandemic influenza A/H1N1 MF59-adjuvanted vaccine is as immunogenic, safe and well tolerated in HIV-infected children and adolescents as in healthy controls. Its simultaneous administration with virosomal-adjuvanted seasonal antigens seems to increase immune response to both pandemic and seasonal viruses with the same safety profile as that of the pandemic vaccine alone. However, because this finding cannot be clearly explained by an immunological viewpoint, further studies are needed to clarify the reasons of its occurrence.

Flexible use of CCR5 in the absence of CXCR4 use explains the immune deficiency in HIV-1 infected children.

DESIGN: CCR5-using HIV-1 (R5 viruses) are usually isolated during acute infection from both adults and children. We have recently demonstrated that R5 viruses with a flexible use of CCR5 (called R5broad) can be detected in children close to birth and are predictive of a fast immunological failure. The aim of the present work was to investigate viral phenotype variation during disease progression in HIV-1 infected children, six slow and eight fast progressors. METHODS: A total of 74 viral isolates obtained sequentially from 14 HIV-1 infected children were tested for their ability to infect U87.CD4 cells expressing a set of six different CCR5/CXCR4 chimeric receptors or wild-type coreceptors. The sensitivity of 35 R5 viruses to inhibition with the CC-chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) was evaluated in a peripheral blood mononuclear cells based assay. RESULTS: Viral evolution to R5broad or to R5X4 phenotype occurred with one exception, in all children, although at a different time point according to rate of disease progression. Immune deficiency in the children was significantly associated with the appearance of R5broad phenotype or R5X4 viruses. Analysis of the sensitivity to inhibition by RANTES revealed a significant correlation between the R5broad phenotype and an augmented resistance to this CC-chemokine. CONCLUSION: We demonstrate that the viral evolution to a more flexible CCR5-use is sufficient to explain the immunological failure in the absence of CXCR4 usage. These results warrant detailed analysis of the R5 phenotype in forthcoming clinical studies introducing CCR5 inhibitors for the treatment of pediatric HIV-1 infection.

HIV-1 with multiple CCR5/CXCR4 chimeric receptor use is predictive of immunological failure in infected children.

BACKGROUND: HIV-1 R5 viruses are characterized by a large phenotypic variation, that is reflected by the mode of coreceptor use. The ability of R5 HIV-1 to infect target cells expressing chimeric receptors between CCR5 and CXCR4 (R5(broad) viruses), was shown to correlate with disease stage in HIV-1 infected adults. Here, we ask the question whether phenotypic variation of R5 viruses could play a role also in mother-to-child transmission (MTCT) of HIV-1 and pediatric disease progression. METHODOLOGY/PRINCIPAL FINDINGS: Viral isolates obtained from a total of 59 HIV-1 seropositive women (24 transmitting and 35 non transmitting) and 28 infected newborn children, were used to infect U87.CD4 cells expressing wild type or six different CCR5/CXCR4 chimeric receptors. HIV-1 isolates obtained from newborn infants had predominantly R5(narrow) phenotype (n = 20), but R5(broad) and R5X4 viruses were also found in seven and one case, respectively. The presence of R5(broad) and R5X4 phenotypes correlated significantly with a severe decline of the CD4+ T cells (CDC stage 3) or death within 2 years of age. Forty-three percent of the maternal R5 isolates displayed an R5(broad) phenotype, however, the presence of the R5(broad) virus was not predictive for MTCT of HIV-1. Of interest, while only 1 of 5 mothers with an R5X4 virus transmitted the dualtropic virus, 5 of 6 mothers carrying R5(broad) viruses transmitted viruses with a similar broad chimeric coreceptor usage. Thus, the maternal R5(broad) phenotype was largely preserved during transmission and could be predictive of the phenotype of the newborn's viral variant. CONCLUSIONS/SIGNIFICANCE: Our results show that R5(broad) viruses are not hampered in transmission. When transmitted, immunological failure occurs earlier than in children infected with HIV-1 of R5(narrow) phenotype. We believe that this finding is of utmost relevance for therapeutic interventions in pediatric HIV-1 infection.

Effects of nutritional rehabilitation on intestinal function and on CD4 cell number in children with HIV.

BACKGROUND: A complex interplay of malnutrition, intestinal dysfunction, and immune impairment increases the progression of human immunodeficiency virus (HIV) disease in children. The authors tested the hypothesis that nutritional support improves intestinal and immune functions in children infected with human immunodeficiency virus (HIV). METHODS: A questionnaire was circulated through reference centers for pediatric HIV infection to evaluate the effects of nutritional rehabilitation, total parenteral nutrition (TPN) and enteral nutrition (EN), in children. Information included changes in body weight, CD4 cell numbers, and intestinal absorption-as judged by the xylose load-before and after clinical nutritional support and the outcome of children. RESULTS: Sixty-two children underwent nutritional support: 46 received TPN and 16 received EN. All but three had full-blown acquired immunodeficiency syndrome, and all were severely malnourished. Baseline clinical conditions were worse in children receiving TPN than in those receiving EN. Intestinal dysfunction was detected in all children who received xylose oral load. A significant increase in CD4 cell count, xylose levels, and body weight followed EN. A similar pattern was observed after TPN, but none of the parameters significantly changed. Twenty-seven children who received TPN and three who received EN eventually died. Fourteen who received TPN and eight who received EN were shifted to oral feeding, and five who received TPN and five who received EN continued with clinical nutritional support at the end of the observation period. CONCLUSIONS: Nutritional intervention may restore intestinal absorption and increase CD4 cell numbers. The efficacy of nutritional intervention is enhanced if provided before a terminal stage of HIV infection. These data provide evidence of a close association among nutritional condition, intestinal absorption, and immune impairment.

Prognostic value of the stromal cell-derived factor 1 3'A mutation in pediatric human immunodeficiency virus type 1 infection.

A mutation of the stromal cell-derived factor 1 gene (SDF-1 3'A) was shown to protect adults exposed to human immunodeficiency virus type 1 (HIV-1) from infection and to affect HIV disease progression in adults. The presence of this mutation in HIV-1-infected Kenyan children did not predict mother-to-child virus transmission. The SDF-1 3'A polymorphism was studied in 256 HIV-1-infected, 118 HIV-1-exposed but uninfected, and 170 unexposed and uninfected children of Italian origin, and the frequency of SDF-1 3'A heterozygosity and homozygosity in each of the 3 groups was similar. Of the 256 HIV-1-infected children, 194 were regularly followed up and were assigned to groups according to disease progression. The frequency of the SDF-1 3'A allele was substantially lower among children with long-term nonprogression than among children with rapid (P =.0329) or delayed (P =.0375) progression. We show that the presence of the SDF-1 3'A gene correlates with accelerated disease progression in HIV-1-infected children born to seropositive mothers but does not protect against mother-to-child HIV-1 transmission.