The Etiologic Landscape of Lymphoproliferation in Childhood: Proposal for a Diagnostic Approach Exploring from Infections to Inborn Errors of Immunity and Metabolic Diseases.

Lymphoproliferation is defined by lymphadenopathy, splenomegaly, hepatomegaly, or lymphocytic organ and tissue infiltration. The most common etiologies of lymphoproliferation are represented by infectious diseases and lymphoid malignancies. However, it is increasingly recognized that lymphoproliferative features can be the presenting sign of rare conditions, including inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Among IEI, lymphoproliferation is frequently observed in autoimmune lymphoproliferative syndrome (ALPS) and related disorders, common variable immunodeficiency (CVID), activated phosphoinositide 3-kinase δ syndrome, and Epstein-Barr virus (EBV)-related disorders. Gaucher disease and Niemann-Pick disease are the most common IEMs that can present with isolated lymphoproliferative features. Notably, other rare conditions, such as sarcoidosis, Castleman disease, systemic autoimmune diseases, and autoinflammatory disorders, should be considered in the differential diagnosis of patients with persistent lymphoproliferation when infectious and malignant diseases have been reasonably ruled out. The clinical features of lymphoproliferative diseases, as well as the associated clinical findings and data deriving from imaging and first-level laboratory investigations, could significantly help in providing the correct diagnostic suspicion for the underlying etiology. This paper reviews the most relevant diseases associated with lymphoproliferation, including infectious diseases, hematological malignancies, IEI, and IEM. Moreover, some practical indications to orient the initial diagnostic process are provided, and two diagnostic algorithms are proposed for the first-level assessment and the approach to persistent lymphoproliferation, respectively.

Case report: Clinical and neuroradiological longitudinal follow-up in Leukoencephalopathy with Calcifications and Cysts during treatment with bevacizumab.

Leukoencephalopathy with Calcifications and Cysts (LCC) is a rare genetic microangiopathy exclusively affecting the central nervous system caused by biallelic mutations in SNORD118. Brain magnetic resonance imaging (MRI) is often diagnostic due to the highly characteristic triad of leukoencephalopathy, intracranial calcifications, and brain cysts. Age at onset, presentation and disease evolution can all vary, ranging from pauci-symptomatic disease to rapid evolution of signs with loss of motor and cognitive abilities. No specific therapies for LCC are currently licensed. According to the literature, bevacizumab might represent an effective modality to improve the clinical and MRI features of the disease. However, uncertainty remains as to the true efficacy of this approach, when to begin therapy, appropriate dosing, and the consequences of drug withdrawal. According to CARE guidelines, we describe the long-term clinical and neuro-radiological follow-up of a 10-year-old child with LCC. We report disease evolution following repeated cycles of treatment with bevacizumab. Our case report suggests that repeated cycles of bevacizumab might effectively modify disease progression, possibly indicating a time-dependent effect.

ß3-adrenergic receptor on tumor-infiltrating lymphocytes sustains IFN-γ-dependent PD-L1 expression and impairs anti-tumor immunity in neuroblastoma.

Neuroblastoma (NB) is a heterogeneous extracranial tumor occurring in childhood. A distinctive feature of NB tumors is their neuroendocrine ability to secrete catecholamines, which in turn, via ß-adrenergic receptors ligation, may affect different signaling pathways in tumor microenvironment (TME). It was previously demonstrated that specific antagonism of ß3-adrenergic receptor (ß3-AR) on NB tumor cells affected tumor growth and progression. Here, in a murine syngeneic model of NB, we aimed to investigate whether the ß3-AR modulation influenced the host immune system response against tumor. Results demonstrated that ß3-AR antagonism lead to an immune response reactivation, partially dependent on the PD-1/PD-L1 signaling axis involvement. Indeed, ß3-AR blockade on tumor-infiltrating lymphocytes (TILs) dampened their ability to secrete IFN-γ, which in turn reduced the PD-L1 expression, caused by TILs infiltration, on NB tumor cells. Further investigations, through a genomic analysis on NB patients, showed that high ADRB3 gene expression correlates with worse clinical outcome compared to the low expression group, and that ADRB3 gene expression affects different immune-related pathways. Overall, results indicate that ß3-AR in NB TME is able to modulate the interaction between tumor and host immune system, and that its antagonism hits multiple pro-tumoral signaling pathways.

The Clinical Impact of Methotrexate-Induced Stroke-Like Neurotoxicity in Paediatric Departments: An Italian Multi-Centre Case-Series.

Introduction: Stroke-like syndrome (SLS) is a rare subacute neurological complication of intrathecal or high-dose (≥500 mg) Methotrexate (MTX) administration. Its clinical features, evoking acute cerebral ischaemia with fluctuating course symptoms and a possible spontaneous resolution, have elicited interest among the scientific community. However, many issues are still open on the underlying pathogenesis, clinical, and therapeutic management and long-term outcome. Materials and Methods: We retrospectively analyzed clinical, radiological and laboratory records of all patients diagnosed with SLS between 2011 and 2021 at 4 National referral centers for Pediatric Onco-Hematology. Patients with a latency period that was longer than 3 weeks between the last MTX administration of MTX and SLS onset were excluded from the analysis, as were those with unclear etiologies. We assessed symptom severity using a dedicated arbitrary scoring system. Eleven patients were included in the study. Results: The underlying disease was acute lymphoblastic leukemia type B in 10/11 patients, while fibroblastic osteosarcoma was present in a single subject. The median age at diagnosis was 11 years (range 4-34), and 64% of the patients were women. Symptoms occurred after a mean of 9.45 days (± 0.75) since the last MTX administration and lasted between 1 and 96 h. Clinical features included hemiplegia and/or cranial nerves palsy, paraesthesia, movement or speech disorders, and seizure. All patients underwent neuroimaging studies (CT and/or MRI) and EEG. The scoring system revealed an average of 4.9 points (± 2.3), with a median of 5 points (maximum 20 points). We detected a linear correlation between the severity of the disease and age in male patients. Conclusions: SLS is a rare, well-characterized complication of MTX administration. Despite the small sample, we have been able to confirm some of the previous findings in literature. We also identified a linear correlation between age and severity of the disease, which could improve the future clinical management.

Toxocariasis in a Child with Autism Spectrum Disorder.

A boy affected by autism spectrum disorder was admitted for persistent high fever, without shiver, for two weeks. The boy referred to abdominal pain, in the first week of fever, and to mild anorexia in the last days before admittance to our hospital centre. The father reported that the boy suffered by geophagia and coprophagia and he has been going to a didactical farm (where he has been exposed to several kinds of animals) to improve his neuropsychiatric condition. Blood analysis shows severe eosinophilia and high levels of total IgE, and abdominal echocardiography showed hepatic lesions. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) confirmed the suspicion of toxocariasis, linked to the habit of the boy to ingest ground or animal faeces in a didactic farm frequented by the boy. Treatment with albendazole and prednisone was administered with a rapid improvement of the symptoms and the laboratory findings and significant reduction of the hepatic lesion.

Cone Beam CT study of a case of eosinophilic granuloma of the mandible in a young patient.

Eosinophilic granuloma (EG) is a rare bony disease deriving from abnormal proliferation of histiocytes, and is the most common form of presentation of Langerhans cell histiocytosis. EG predominantly affects the axial skeleton. However, when localised in the head and neck district, mandibular lesions account for the majority of cases. Mandibular lesions can mimic other pathological conditions, making biopsy fundamental for differential diagnosis. Treatment depends on the severity of the disease, ranging from pharmacological treatment to surgical approach. However, EG is also reported to possibly undergo spontaneous resolution. In this case report, we describe a rare case of EG with particularly aggressive behaviour in a young patient. Initially, local pharmacological treatment with intralesional administration of corticosteroids lead to worsening of the symptoms, increase in lesion's dimensions, and disruption of the cortical bone. A more invasive therapeutic approach involving radical surgery was then performed, with consequent resolution of the disease.

Hypogonadism in DM1 and its relationship to erectile dysfunction.

Myotonic dystrophy type 1 (DM1) is characterized by both a premature appearance of age-related phenotypes and multiple organ involvement, which affects skeletal and smooth muscle as well as the eye, heart, central nervous system, and endocrine system. Although erectile dysfunction (ED) is a frequent complaint in patients with DM1, it has not been investigated in great depth. Hypogonadism, which is reported to be one of the physical causes of ED in the general population, frequently occurs in DM1. We planned this case-control study to evaluate the relationship between hypogonadism, as defined by the sexual hormone profile (FSH, LH, testosterone (T) and prolactin) and ED, as assessed by means of an internationally validated self-administered questionnaire (IIEF). DM1 patients had significantly increased mean levels of both gonadotropins (FSH and LH) (p < 0.0001) and a reduced mean level of T (p < 0.0001) when compared to controls. Twelve patients were eugonadic (normal LH, T, and FSH), while 18 displayed hormonal evidence of hypogonadism, characterized by tubular failure (increased FSH) in all the subjects and associated with interstitial failure in 14 subjects: seven with primary hypogonadism (increased LH and reduced T) and seven with compensated hypogonadism (increased LH and normal T). Patients with hormonal evidence of interstitial failure had a larger CTG expansion (p = 0.008), longer disease duration (p = 0.013), higher grade of disease (p = 0.004) and lower erectile function score (p = 0.02) than eugonadic patients. Impotence occurred in 13/14 hypogonadic patients with interstitial failure and in 5/12 eugonadic patients (p = 0.017, OR = 18.2).

High torquetenovirus loads are correlated with bronchiectasis and peripheral airflow limitation in children.

BACKGROUND: The aim of the study was to evaluate the prevalence of torquetenovirus (TTV) infection in a group of children with recurrent lower respiratory tract infections and radiologic evidence of bronchiectasis. Correlations between TTV loads and severity of bronchiectasis and between TTV loads and lung function were evaluated. METHODS: In 38 subjects, high-resolution computed tomography (HRCT) and plasma tests for TTV detection and quantification were done. In 21/38 subjects, spirometry was also performed. RESULTS: TTV was found in 31/38 (81.6%) patients. The correlation between TTV loads and severity of bronchiectasis was statistically significant (r = 0.548; P = 0.01). TTV loads showed inverse correlation with FEF25-75% (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.512; P = 0.018). Inverse correlation was found also between severity of bronchiectasis and functional lung parameters: FEF25-75% (r = -0.635; P = 0.002), FEV1/FVC (r = -0.541; P = 0.011), and FEF25-75%/FVC (r = -0.645; P = 0.002). CONCLUSIONS: This study demonstrated the high prevalence of TTV infection in children with bronchiectasis. Moreover, we have shown a significant correlation between TTV loads and airflow limitation within the peripheral airways, as well as between severity of bronchiectasis and decrease of lung function.

Montelukast and airway remodeling in children with chronic persistent asthma: an open study.

We report a 4 yr follow up study of seven asthmatic children with chronic persistent asthma, high-residual volume and low-density areas at high-resolution computerized tomography after treatment with salmeterol and fluticasone. Improvement of lung function with disappearance of low-density areas in six patients after treatment with fluticasone and montelukast was obtained.

Coseasonal sublingual immunotherapy reduces the development of asthma in children with allergic rhinoconjunctivitis.

BACKGROUND: We wondered whether short-term coseasonal sublingual immunotherapy (SLIT) can reduce the development of asthma in children with hay fever in an open randomized study. OBJECTIVE: We sought to determine whether SLIT is as effective as subcutaneous immunotherapy in reducing hay fever symptoms and the development of asthma in children with hay fever. METHODS: One hundred thirteen children aged 5 to 14 years (mean age, 7.7 years) with hay fever limited to grass pollen and no other clinically important allergies were randomized in an open study involving 6 Italian pediatric allergy centers to receive specific SLIT for 3 years or standard symptomatic therapy. All of the subjects had hay fever symptoms, but at the time of study entry, none reported seasonal asthma with more than 3 episodes per season. Symptomatic treatment was limited to cetirizine, loratadine, nasal budesonide, and salbutamol on demand. The hay fever and asthma symptoms were quantified clinically. RESULTS: The actively treated children used less medication in the second and third years of therapy, and their symptom scores tended to be lower. From the second year of immunotherapy, subjective evaluation of overall allergy symptoms was favorable in the actively treated children. Development of asthma after 3 years was 3.8 times more frequent (95% confidence limits, 1.5-10.0) in the control subjects. CONCLUSIONS: Three years of coseasonal SLIT improves seasonal allergic rhinitis symptoms and reduces the development of seasonal asthma in children with hay fever.

Correlation between Torque tenovirus infection and serum levels of eosinophil cationic protein in children hospitalized for acute respiratory diseases.

Children with bronchopneumonia have considerably higher Torque tenovirus (TTV) loads than do children with milder acute respiratory diseases (ARDs). Moreover, in children with ARDs, high TTV loads correlate with low percentages of circulating CD3+ and CD4+ T cells and with elevated percentages of B cells, suggesting that TTV might be immunomodulatory. Here, we show that, in children with ARDs, the presence of TTV and TTV load correlate with concentrations of serum eosinophil cationic protein. The possible mechanisms whereby TTV infection might lead to augmented activity of eosinophils and the implications for pathogenesis are discussed.