Massimo Pifferi

Human Metapneumovirus Associated with Respiratory Tract Infections in a 3-Year Study of Nasal Swabs from Infants in Italy

ABSTRACT The newly described human metapneumovirus (hMPV) is reported here to be more commonly associated with lower respiratory tract disease. The present study examined nasal swab specimens from 90 infants with acute respiratory tract infections in Pisa, Italy, over a period of three respiratory virus seasons. The incidence of infection varied in each of the 3 years, with the rates of positivity for hMPV being 7% in 2001 but 37 and 43% in 2000 and 2002, respectively. hMPV was noted to occur seasonally in a pattern typical of the frequency of occurrence of respiratory syncytial virus. More than one-half (14 of 23) of the infants infected with hMPV had bronchopneumonia. One-third (9 of 23) of the hMPV-infected patients were also infected with another respiratory virus, a relationship that has not previously been reported. Mixed infections did not account for a higher percentage of cases of bronchopneumonia than hMPV infection alone did. Furthermore, 7 of 17 infants whose plasma was also tested for hMPV RNA were demonstrated to have virus in both nasal swab and blood specimens. The study indicates that hMPV is seen as commonly as other respiratory viruses, may be associated with severe respiratory disease in infants, can establish mixed infections with other respiratory viruses, and has a seasonal occurrence.

TT virus in the nasal secretions of children with acute respiratory diseases: relations to viremia and disease severity.

ABSTRACT The natural history and pathogenic potential of the recently identified TT virus (TTV) are currently a matter of intensive investigation. In an attempt to shed some light on these issues, nasal and blood specimens of 1- to 24-month-old children hospitalized with a clinical diagnosis of acute respiratory disease (ARD) were examined for the presence, load, and genetic characteristics of TTV. The results have indicated that at least in young children, the respiratory tract not only represents a route by which abundant TTV can be shed into the environment but also may be a site of primary infection and continual replication. Although we found no compelling evidence that TTV was the direct cause of ARD in some of the children studied, the average loads of TTV were considerably higher in patients with bronchopneumonia (BP) than in those with milder ARD, raising interesting questions about the pathophysiological significance of TTV at this site. Furthermore, group 4 TTV was detected almost exclusively in children with BP.

Foreign body aspiration in children

Abstract Background : The aim was to investigate the role of physical and radiological findings before bronchoscopy in the diagnosis of foreign body aspiration (FBA).

Benefits of immunotherapy with a standardized Dermatophagoides pteronyssinus extract in asthmatic children: a three‐year prospective study

Background: Although widely practiced for over 80 years, the role of specific immunotherapy (SIT) in pediatric asthma treatment is still controversial. We assessed the effects of a 3‐year period of subcutaneous administration of a standardized preparation of Dermatophagoides pteronyssinus (D pt) on the respiratory health in a group of asthmatic children monosensitized to house dust mite (HDM).

TT virus loads and lymphocyte subpopulations in children with acute respiratory diseases

ABSTRACT TT virus (TTV) produces chronic plasma viremia in around 90% of healthy individuals of all ages and has, therefore, been proposed as a commensal human virus. We recently demonstrated that in children hospitalized for acute respiratory diseases high TTV loads were associated with severe forms of disease. Here, we report that in such children TTV loads showed an inverse correlation with the percentage of circulating total T and helper T cells and a direct correlation with the percentage of B cells. Thus, florid TTV replication might contribute to lymphocyte imbalances and, possibly, immunosuppressive effects, thus resembling related animal viruses.

Associations between Nasal Torquetenovirus Load and Spirometric Indices in Children with Asthma

Fifty-nine children with well-controlled, mild to moderate persistent asthma were studied for the presence and load of torquetenovirus (TTV) in nasal fluid. Rates of TTV positivity and mean nasal TTV loads were not dissimilar to those observed in the general population and in a group of 30 age- and residence-matched healthy control children without a history of asthmatic disease. However, in the children with asthma, 3 important indices of lung function--forced expiratory flow (FEF) in which 25% and 75% of forced vital capacity (FVC) is expired (FEF(25%-75%)), forced expiratory volume in 1 s/FVC, and FEF(25%-75%)/FVC--showed an inverse correlation with nasal TTV load. Furthermore, signs of reduced airflow were more frequent in the children with asthma who had high nasal TTV loads (> or =6 log(10) DNA copies/mL of nasal fluid) than they were in those who had low nasal TTV loads (<6 log(10) DNA copies/mL of nasal fluid), despite similar therapy regimens. In contrast, the control children showed no associations between nasal TTV load and the spirometric indices. Levels of eosinophil cationic protein in sputum were also greater in the children with asthma who had higher nasal viral burdens than they were in those who had lower nasal viral burdens. These findings are the first report of TTV infection status in children with asthma and suggest that TTV might be a contributing factor in the lung impairment caused by this condition.

Nasal nitric oxide in atypical primary ciliary dyskinesia.

BACKGROUND Atypical cases of primary ciliary dyskinesia (PCD) may present with minimal transmission electron microscopy (TEM) defects. The diagnostic role of nasal nitric oxide (nNO) levels was evaluated in those patients. METHODS Sixty-four children with recurrent pneumonia were studied with ciliary motion analysis, TEM, and nNO. RESULTS Investigations indicated PCD in 12 patients, secondary ciliary dyskinesia (SCD) in 50 patients, and normal results in 2 patients. In 4 of 50 children with SCD, atypical PCD was considered possible. The mean (+/- SD) nNO was 130 +/- 46.95 parts per billion in children affected by PCD, 127.79 +/- 68.58 parts per billion in atypical patients, and 760 +/- 221 parts per billion in children with SCD. Three to 5 months later, the nNO level was 132.75 +/- 55.76 parts per billion in children with atypical disease and 778.00 +/- 197 parts per billion in children with SCD. CONCLUSION Low levels of nNO may help to identify patients with atypical PCD.

Primary ciliary dyskinesia: Diagnosis in children with inconclusive ultrastructural evaluation

The purpose of this study was to distinguish between acquired and genetically determined ciliary abnormalities in children with severe chronic respiratory diseases. Samples of nasal ciliated epithelium from 50 subjects (25 male, 25 female; age‐range 2–19 years) with severe chronic respiratory diseases were examined using transmission electron microscopy (TEM). Based on TEM findings, patients were divided into two groups: A and B. Group A comprised 39 children with ciliary alterations compatible with a condition probably occuring secondary to chronic inflammation (alterations of peripheral pairs, swollen cilia, and compound cilia). The other 11 patients, Group B, exhibited a greater number of alterations of the central pair and dynein arms (p< 0.001), which were qualitatively similar to, but less numerous than, those observed in primary ciliary dyskinesia (PCD). In both groups, analysis of ciliary beat frequency and waveform was performed by phase contrast microscopy (PCM). All the children with a ciliary beat frequency of < 7 Hz were treated with daily physiotherapy and with antibiotics, as recommended for PCD, for a 6‐month period. After this treatment, the children were reexamined by PCM. Almost 50% of the children from Group B (i.e. those with a small proportion of specific ultrastructural defects) showed permanence of low ciliary beat frequency. This was also observed in two children of Group A. These children were considered to be affected by PCD. Our study describes a method for the diagnosis of PCD in the absence of specific ultrastructural defects or when these defects are present in only a small proportion of the cilia.

Agenesis of paranasal sinuses and nasal nitric oxide in primary ciliary dyskinesia

Agenesis of paranasal sinuses has only been described in case reports of patients with primary ciliary dyskinesia (PCD). As agenesis of paranasal sinuses may contribute to low nasal nitric oxide levels, a common finding in PCD, we speculated that this condition might frequently occur in PCD patients. Patients referred for PCD evaluation were consecutively recruited for 30 months. In addition to standard diagnostic testing for PCD, a computed tomography (CT) scan of paranasal sinuses was performed in all subjects. 86 patients (46 children aged 8–17 yrs) were studied. PCD was diagnosed in 41 subjects and secondary ciliary dyskinesia (SCD) was diagnosed in the remaining 45 subjects. Frontal and/or sphenoidal sinuses were either aplastic or hypoplastic on CT scans in 30 (73%) out of 41 PCD patients, but in only 17 (38%) out of 45 with SCD (p = 0.002). There was a significant inverse correlation between the score for aplasia/hypoplasia of each paranasal sinus and nasal NO values in the PCD patients (p = 0.008, r = −0.432) but not in SCD (p = 0.07, r = −0.271). The findings of aplasia/hypoplasia of the frontal and or sphenoidal sinuses may be part of the spectrum of PCD and this finding should prompt exclusion of this condition.

A Descriptive Study of Non-Cystic Fibrosis Bronchiectasis in a Pediatric Population from Central and Southern Italy

Background: Non-cystic fibrosis (CF) bronchiectasis is now identified more often than in the past. Objectives: It was the aim of this study to assess the high-resolution computed tomography (HRCT) localization and extent of bronchiectasis and to determine whether asthma status, atopy and bronchiectasis distribution are associated with the etiology of bronchiectasis. Methods: We retrospectively analyzed clinical, laboratory, functional and HRCT data of 105 children with non-CF bronchiectasis at 2 tertiary respiratory units in Italy. Forty cases had bronchiectasis associated with ongoing underlying conditions, namely primary ciliary dyskinesia, primary immunodeficiency or aspiration. Results: Age at the onset of chronic cough/wheeze and at the first X-ray-documented pneumonia as well as atopy prevalence were lower in patients with ongoing underlying conditions than in those without (p = 0.049, p = 0.003 and p = 0.0008, respectively). In most cases, bronchiectasis was multilobar, and a mean of 2.5 lobes were involved. The right side was more often involved than the left (88 vs. 70%; p = 0.002), and the upper lobes were relatively spared (p < 0.000001). Right lung involvement and multilobar disease were more prevalent in children younger than 2 years at first pneumonia (p < 0.05). Conclusions: Clinical information combined with laboratory data provides additional insights into the characteristics of non-CF bronchiectasis in a large population of Italian children. This study highlights the need for longitudinal evaluations, also using HRCT, of severe and non-resolving pneumonia in children.