Susanna Livadiotti

A hypermorphic IκBα mutation is associated with autosomal dominant anhidrotic ectodermal dysplasia and T cell immunodeficiency

X-linked anhidrotic ectodermal dysplasia with immunodeficiency (XL-EDA-ID) is caused by hypomorphic mutations in the gene encoding NEMO/IKKgamma, the regulatory subunit of the IkappaB kinase (IKK) complex. IKK normally phosphorylates the IkappaB-inhibitors of NF-kappaB at specific serine residues, thereby promoting their ubiquitination and degradation by the proteasome. This allows NF-kappaB complexes to translocate into the nucleus where they activate their target genes. Here, we describe an autosomal-dominant (AD) form of EDA-ID associated with a heterozygous missense mutation at serine 32 of IkappaBalpha. This mutation is gain-of-function, as it enhances the inhibitory capacity of IkappaBalpha by preventing its phosphorylation and degradation, and results in impaired NF-kappaB activation. The developmental, immunologic, and infectious phenotypes associated with hypomorphic NEMO and hypermorphic IKBA mutations largely overlap and include EDA, impaired cellular responses to ligands of TIR (TLR-ligands, IL-1beta, and IL-18), and TNFR (TNF-alpha, LTalpha1/beta2, and CD154) superfamily members and severe bacterial diseases. However, AD-EDA-ID but not XL-EDA-ID is associated with a severe and unique T cell immunodeficiency. Despite a marked blood lymphocytosis, there are no detectable memory T cells in vivo, and naive T cells do not respond to CD3-TCR activation in vitro. Our report highlights both the diversity of genotypes associated with EDA-ID and the diversity of immunologic phenotypes associated with mutations in different components of the NF-kappaB signaling pathway.

Fungal Infections in Children With Cancer A Prospective, Multicenter Surveillance Study

Background: Data on epidemiology and survival after fungal infections in patients with cancer are primarily based on studies in adults, whereas few data are available on children. Methods: A prospective, multicenter, 2-year surveillance of fungal infections in children receiving antineoplastic treatment was performed in 15 Italian centers. For each case, defined by means of EORTC-IFIG/NIAID-MSG, information was collected on age, phase of treatment, presence of neutropenia or lymphocytopenia, administration of antifungal drugs and survival. Results: Ninety-six episodes (42 proven [19 fungemias, 23 deep tissue infections], 17 probable and 37 possible invasive mycoses) were reported. Most of them (73%) followed aggressive chemotherapy, 21% allogeneic hematopoietic stem cell transplantation and only 6% moderately aggressive treatment. Neutropenia was present in 77% of the episodes, and it had a longer duration before deep tissue mycosis as compared with fungemia (P = 0.020). Lymphocytopenia was present in 75% of the episodes observed in nonneutropenic patients. As compared with children with fungemia, patients with probable invasive mycoses had a 25.7-fold increased risk of death, whereas it was 7.7-fold greater in children with possible invasive mycoses and 5-fold higher in those with proven deep tissue infection (P = 0.004). The risk of death was also 3.8-fold higher in patients already receiving antifungals at the time of diagnosis of infection as compared with those not receiving antimycotic drugs. Conclusions: In children with cancer, aggressive antineoplastic treatment, severe and longlasting neutropenia and lymphocytopenia are associated with fungal infections. These features as the clinical pictures are similar to those reported in adults, but in children, the overall and the infection-specific (fungemia or mycosis with deep tissue infection) mortalities are lower.

EPI-743 reverses the progression of the pediatric mitochondrial disease—Genetically defined Leigh Syndrome

BACKGROUND Genetically defined Leigh syndrome is a rare, fatal inherited neurodegenerative disorder that predominantly affects children. No treatment is available. EPI-743 is a novel small molecule developed for the treatment of Leigh syndrome and other inherited mitochondrial diseases. In compassionate use cases and in an FDA Expanded Access protocol, children with Leigh syndrome treated with EPI-743 demonstrated objective signs of neurologic and neuromuscular improvement. To confirm these initial findings, a phase 2A open label trial of EPI-743 for children with genetically-confirmed Leigh syndrome was conducted and herein we report the results. METHODS A single arm clinical trial was performed in children with genetically defined Leigh syndrome. Subjects were treated for 6 months with EPI-743 three times daily and all were eligible for a treatment extension phase. The primary objective of the trial was to arrest disease progression as assessed by neuromuscular and quality of life metrics. Results were compared to the reported natural history of the disease. RESULTS Ten consecutive children, ages 1-13 years, were enrolled; they possessed seven different genetic defects. All children exhibited reversal of disease progression regardless of genetic determinant or disease severity. The primary endpoints--Newcastle Pediatric Mitochondrial Disease Scale, the Gross Motor Function Measure, and PedsQL Neuromuscular Module--demonstrated statistically significant improvement (p<0.05). In addition, all children had an improvement of one class on the Movement Disorder-Childhood Rating Scale. No significant drug-related adverse events were recorded. CONCLUSIONS In comparison to the natural history of Leigh syndrome, EPI-743 improves clinical outcomes in children with genetically confirmed Leigh syndrome.

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

ObjectivesTo 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 methodsThe 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 serostatus 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. ResultsBreast-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. ConclusionsThese 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.

Successful Allogeneic Hemopoietic Stem Cell Transplantation in a Child Who Had Anhidrotic Ectodermal Dysplasia With Immunodeficiency

Anhidrotic ectodermal dysplasia with immunodeficiency is associated with multiple infections and a poor clinical outcome. Hypomorphic mutations in nuclear factor κB essential modulator (NEMO)/IκB kinase complex and a hypermorphic mutation in inhibitor α of nuclear factor κB (IκBα) both result in impaired nuclear factor κB activation and are associated with X-recessive and autosomal-dominant forms of anhidrotic ectodermal dysplasia with immunodeficiency, respectively. Autosomal-dominant anhidrotic ectodermal dysplasia with immunodeficiency is also associated with a severe T-cell phenotype. It is not known whether hematopoietic stem cell transplantation can cure immune deficiency in children with anhidrotic ectodermal dysplasia with immunodeficiency. A boy with autosomal-dominant anhidrotic ectodermal dysplasia with immunodeficiency and a severe T-cell immunodeficiency underwent transplantation at 1 year of age with haploidentical T-cell–depleted bone marrow after myeloablative conditioning. Engraftment occurred, with full hematopoietic chimerism. Seven years after transplantation, clinical outcome is favorable, with normal T-cell development. As expected, the developmental features of the anhidrotic ectodermal dysplasia syndrome have appeared and persisted. This is the first report of successful hematopoietic stem cell transplantation in a child with anhidrotic ectodermal dysplasia with immunodeficiency. Hematopoietic stem cell transplantation is well tolerated and efficiently cures the profound immunodeficiency associated with autosomal-dominant anhidrotic ectodermal dysplasia with immunodeficiency.

Incidence of bacteremias and invasive mycoses in children with acute non-lymphoblastic leukemia: results from a multi-center Italian study.

Data on the epidemiology of bacteremias and invasive fungal diseases (IFD) in children with acute myeloid leukemia (AML) are scarce.

Malignancies in children with human immunodeficiency virus type 1 infection

Cancer has been closely associated with human immunodeficiency virus (HIV) infection but this is less frequent in children. Non‐Hodgkins 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‐Hodgkins B‐cell lymphoma (four cases); and Kaposis 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‐Hodgkins 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. 68:2473‐2477, 1991.

Morbidity of pandemic H1N1 influenza in children with cancer

To define the mortality and the current impact of the H1N1 pandemic in pediatric hematology‐oncology centers, we performed a specific survey.

Epidemiology and clinical outcomes of multidrug-resistant, gram-negative bloodstream infections in a European tertiary pediatric hospital during a 12-month period.

Background: Bloodstream infections caused by multidrug-resistant, Gram-negative (MDRGN) bacteria represent a significant cause of morbidity and mortality. Prompt diagnosis and appropriate empiric treatment are the most important determinants of patient outcome. The objective of our study was to assess the epidemiology and clinical outcome of MDRGN sepsis in a tertiary-care pediatric hospital during a 12-month period. Methods: It was a retrospective, observational study of MDRGN bacteremia including all patients <18 years of age, hospitalized during 2011, with documented bacteremia caused by Enterobacteriaceae or non-fermentative bacteria. Results: Overall, 136 blood cultures in 119 patients were included. The median age of patients was 1.1 years; 86.3% of patients had an underlying disease. The cumulative incidence of Gram-negative bloodstream infections was 5.4/1000 hospital admissions and the infection rate was 0.65/1000 hospital days. Most frequently isolated strains were Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa; 67.6% of infections were hospital acquired. The percentage of multidrug-resistant (MDR) organisms among isolated species was 39%. The crude rate of mortality was 16% and sepsis-related mortality was 9.2%. The mortality rate among patients with an antibiotic-resistant isolate was 22.6%. Factors significantly associated with sepsis-related mortality were antibiotic resistance (odds ratio: 4.26, 95% confidence interval: 1.07–16.9) and hospital acquisition of infection (odds ratio: 1.13, 95% confidence interval: 1.05–1.22). Conclusions: This study demonstrates the high mortality of hospital-acquired MDRGN bacteremia in children. International networks focusing on clinical management and outcomes of MDRGN in children are required. Study of novel antibiotics active against Gram-negative bacteria should include children early in the clinical trial development programs.

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 patients 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 patients blood monocytes. In these cells, flow cytometry revealed significantly reduced expression of the CD86 co‐stimulatory molecules and HLA glycoproteins. In addition, the patients 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.