Pseudomonas (Burkholderia) cepacia in children with cystic fibrosis: epidemiological investigation by analysis or restriction fragment length polymorphism

Since 1987, Pseudomonas cepacia has been isolated with an increasing frequency in the expectorants of children with cystic fibrosis followed at the Hôpital d'enfants Armand Trousseau (Paris, France). Colonization by P. cepacia may be responsible for serious secondary infections and rapid deterioration in respiratory function in these patients. Among the 130 children attending our centre, 14 (8 girls and 6 boys) aged 3 to 18, exhibited chronic colonization. 132 isolates, originating from sputum obtained between 1992 and 1994 were studied. Nine biochemical patterns and 6 antibiotic susceptibility patterns at least were defined, therefore exhibiting great polymorphism. Chromosome restriction patterns with Xba I after pulsed field gel electrophoresis enabled 4 pulsotypes to be identified: A, B, C and D. Thirteen patients harboured pulsotypes A, C and D, and 1 patient pulsotype B, the last being quite distinct from the first three. Pulsotypes A, C and D were almost similar, suggesting that closely related strains, probably the same strain, was harboured by 13 of the 14 patients. The origin could be contamination from a single source, or stem from patient-to-patient crossed transmission.

[Bronchopulmonary aspergillosis and mucoviscidosis]

Patients with cystic fibrosis often suffer from aspergillosis infection (basically due to Aspergillus fumigatus) which frequently colonizes their respiratory tract, but its role in the respiratory insufficiency are poorly understood. Several clinical situations occur. Allergic bronchopulmonary aspergillosis rarely occurs in a typical form, and is usually difficult to diagnose from the atypical manifestations. Finally indications and treatment modalities are still subject to debate.

[New pharmacological approaches: rhDNase]

rhDNase (Pulmozyme) is a new agent in the therapeutic strategy for patients with cystic fibrosis. It is one of the first specific treatments aimed at the respiratory tract. It affects the extracellular DNA which is present in abundant quantities in the bronchial secretions of these patients. rhDNase significantly reduces the incidence of infections and improves respiratory function. It should be used as a major treatment in combination with all other treatments in patients over 5 years of age with a vital capacity of at least 40% the theoretical value. It is important to schedule the respiratory exercises as a function of rhDNase intake. The long-term therapeutic benefit remains to be evaluated.

Cytotoxic drug-induced pulmonary disease in infants and children

The increased survival rate of malignant diseases due to more aggressive treatments contributes to the occurrence of drug-induced pulmonary diseases (DIPD). We reviewed, retrospectively over a 10-year period, 15 children (8 girls) who presented a DIPD. Their mean age was 9 years (range, 1 to 17 years), with an underlying malignant disease in 14 (9 leukemias). Three typical patterns have emerged from this analysis: (1) acute hypersensitivity lung disease caused by methotrexate (in 6 patients) or azathioprine (in 1 patient). This acute syndrome consisted of alveolar-interstitial infiltrate with a hypercellularity on bronchoalveolar lavage (BAL) (mean, 714,286 cells/mL; range, 180,000-2,940,000 cells/mL) and an increase of lymphocyte counts (mean, 39%; range 11-64%) with predominantly CD8-suppressor/cytotoxic lymphocytes. Inhibition of leukocyte migration or leukocyte aggregation in the presence of low drug concentrations was positive in the 5 cases tested. Lung function tests showed a restrictive pattern and the outcome of DIPD was always favorable. (2) Chronic pneumonitis/fibrosis was seen in 6 patients who received a variable association of cyclophosphamide (3 patients), bleomycin (2 patients), BCNU (2 patients), and melphalan (1 patient). Symptoms of an alveolar-interstitial pneumonitis developed progressively. BAL showed a moderate increase of total cell numbers (mean, 495,000 cells/mL; range, 150,000-900,000 cells/mL). Lung function tests showed a restrictive pattern. Despite corticosteroid treatment in 4 children, one died after bleomycin lung injury and 2 had functional lung impairment. (3) Noncardiogenic pulmonary edema occurred in 2 patients with leukemia treated with recombinant interleukin II. BAL showed hypercellularity and outcome was rapidly favorable.(ABSTRACT TRUNCATED AT 250 WORDS)

Sarcoidosis of the upper respiratory tract in children

Sarcoidosis is a multisystemic granulomatosis of unknown etiology which mainly affects young adults. It is characterized primarily by bilateral hilar adenopathies, a pulmonary infiltrate and cutaneous and ocular lesions. It rarely occurs in children under the age of 16. Localization in the upper respiratory tract (URT) is infrequent and sarcoidosis of the URT in children is exceptional, with only 13 cases reported in the literature. In the present report we describe the clinical, diagnostic explorations, histological and therapeutic aspects of 2 new cases in children.

Resting energy expenditure in infants with cystic fibrosis

To evaluate the contribution of energy expenditure to the energy imbalance seen in cystic fibrosis patients, resting energy expenditure was measured using open-circuit indirect calorimetry in eight infants with cystic fibrosis, aged 2-7 months (mean, 4), without overt lung disease and in 10 healthy age-matched controls. In both groups, we found close, significant, linear correlations between resting energy expenditure and body weight and between resting energy expenditure and fat-free mass as measured by anthropometry. Cystic fibrosis patients had a 26% increase in resting energy expenditure per kilogram of fat-free mass as compared with controls and a 32% increase in resting energy expenditure as compared with predicted values for fat-free mass. These data from young infants free of clinical symptoms suggest a constitutional metabolic disorder in cystic fibrosis and support the need for early nutritional therapy in cystic fibrosis patients.

[Tuberculosis in children]

In developed countries like France, the incidence of tuberculosis is low, 5 to 6% in patients under 15 years of age. At the present time, tuberculosis has been irradicated in 11 French regions. Inversely, tuberculosis is still found in the Paris area. Half of the children with tuberculosis are under 5 years of age, underscoring the high risk at this age. Lung and lymph node infection is most often encountered in children with typical complications of endobronchial fistulization and segmentary or lobular atelectasy. Direct examination does not reveal germs in more than 80% of the cases. Other forms are more rarely found in children although congenital, meningeal, serofibrinous pleural, and cervical lymph node tuberculosis are sometimes observed. Latent primary infection, by far the most frequent, can only be recognized by the intradferal tuberculin test. Systematic treatment modalities would now center on the use of combined chemotherapy using two bacteriocidal antibiotics for 2 or 3 years.

Pulmonary sarcoidosis in children: serial evaluation of bronchoalveolar lavage cells during corticosteroid treatment

The clinical course of sarcoidosis in children has not been well defined. Eight children with symptomatic sarcoidosis included in this study underwent pulmonary function tests and bronchoscopy with bronchoalveolar lavage (BAL) before treatment and during steroid therapy. At the start of therapy, functional parameters, mostly dynamic lung compliance and lung transfer factor for CO, were impaired. This was associated with abnormalities of BAL cell populations: increased total cell number with a high proportion of lymphocytes, modifications of lymphocyte subpopulation with an elevated CD4+/CD8+ ratio, and enhanced ability of alveolar macrophages to release hydrogen peroxide. Although respiratory abnormalities seemed to be similar at the initial stage of sarcoidosis in children and adults, the course of the disease appeared to be different. Despite the absence of respiratory symptoms and disappearance of chest radiographic abnormalities on prolonged steroid treatment, we found slow improvement of pulmonary functions associated with persistence of BAL lymphocytosis and elevated CD4+/CD8+ ratios. However, the ability of alveolar macrophages to release hydrogen peroxide was significantly reduced after 6 months of steroid treatment, and it remained identical to the control group. Therefore, the evaluation of disease activity appears to be critical for therapy in pediatrics, and for this purpose studies of alveolar macrophage activation may be of particular interest.

[Mechanical ventilation by nasal mask in children with cystic fibrosis. Initial results of a non-invasive method]

BACKGROUND

Chronic respiratory failure (CRF) with hypoxia and hypercapnia is the last ineluctable phase in cystic fibrosis (CF). Nasal positive pressure ventilation (NPPV), a non-invasive method, may be given to CF children with CRF, especially to patients accepted for transplantation (T). This method improves ventilatory function by resting the chronically exhausted respiratory muscles, facilitates bronchial drainage by physiotherapy, prevents the exacerbations of the illness and prepares patients for T.

METHODS AND PATIENTS

NPPV was used in 6 CF patients (mean age 13 years 6 months). One of them was transplanted 15 days later, two of them were accepted for T. All had hypoxia. Five of them had hypercapnia.

RESULTS

NPPV was given to four patients for 3 to 14 months. The preliminary results were positive. One patient gained weight, two had more fluid sputum. One patient showed an increase in functional respiratory tests (FRT: PaO2, vital capacity, FEV-1) while these tests were stabilized in the others.

CONCLUSIONS

NPPV in an effective non-invasive method for use with CF children. It is indicated for CF patients accepted for T and also earlier, for CF patients with CRF in order to prevent acute exacerbations and functional respiratory deterioration.

[Heart or heart-lung transplantation and toxoplasmosis]

Among all organ transplantations, those of heart or heart-lung carry the greatest risk of toxoplasmosis. The disease is observed mainly when the donor is seropositive and the recipient seronegative. In these mismatched couples the risk may be as high as 57 percent. Cardiac tissue transplants are responsible for most contaminations. A subclinical serological reactivation can be observed in seropositive recipients. Patent forms are associated with seroconversion in seronegative subjects. Toxoplasmosis is often severe with multivisceral foci; interstitial pneumonia is possible. The serological diagnosis is easy in cases with significant antibody movements, but it may be difficult if the titre is low or stable. The parasitological diagnosis rests on the isolation of toxoplasma in blood, cerebrospinal fluid, bronchoalveolar lavage fluid and cardiac or cerebral biopsy. Immune defence against toxoplasmosis is primarily cellular, with lymphocytosis and inversion of the CD4/CD8 ratio. Macrophages play a crucial role. Interferon-gamma is the major mediator of cellular resistance. In spite of its immunosuppressive action, cyclosporin clearly has an antiparasitic action in vitro and in vivo. A cytomegalovirus infection might facilitate toxoplasma reactivation. Prevention of toxoplasmosis in transplant recipients includes systematic serology of the recipient and, if possible, the donor, detection of mismatched couples and systematic treatment with pyrimethamine of recipients at risk (in seronegative recipients, this drug has reduced the risk from 57 to 14 percent). Cyclosporin should be used as immunosuppressant in preference to other drugs of this kind. Corticosteroids administered in rejections increase the risk of toxoplasmosis.

Miliary tuberculosis with acute respiratory failure and histiocytic hemophagocytosis. Successful treatment with extracorporeal lung support and epipodophyllotoxin VP 16-213

A 14-year-old girl with high fever, dyspnea and bilateral miliary nodules on chest X-ray, developed a rapidly progressive respiratory failure associated with histiocytic hemophagocytosis. Histologic examination of bone marrow biopsy revealed tuberculous granulomas with caseating necrosis. We report a pediatric case in which treatment with extracorporeal lung support and epipodophyllotoxin VP 16-213 was successful.

[Respiratory form mof myasthenia gravis]

BACKGROUND

Extraocular, facial, bulbar and intercostal muscles are frequently affected in juvenile myasthenia gravis, especially during exacerbations. Acetylcholine receptor antibodies are often present in the blood in this type of myasthenic syndrome.

CASE REPORT

A girl presented with an exertional dyspnea at the age of 13 years, that improved after rest. All investigations were negative, except for lung function tests that showed a restrictive pattern. The diagnosis of juvenile myasthenia gravis was finally made at the age of 15 years because of the recurrence of sudden exertional dyspnea and a history of subtle weakness on repetitive movement leading to poor suckling, together with vocal and occasional swallowing difficulties. Dyspnea immediately improved after intravenous injection of 1 mg neostigmine, but the response was transient. No acetylcholine receptor antibody was found and a search for thymoma proved negative. Ambenonium chloride (Mytelase) was effective on clinical exacerbations, but the only improved test after 9 months of treatment was the functional residual capacity.

CONCLUSION

Anticholinesterase drugs must be tried in patients who present exertional dyspnea without bronchopulmonary or cardiac disease on the presumption of myasthenia gravis even when ocular or bulbar manifestations are absent.

[Recurrent bronchopneumopathies in the infant due to swallowing dyspraxia. Two cases]

In two infants with recurrent lower respiratory tract infections starting within a few weeks of birth, dynamic electromyographic studies of sucking and swallowing evidenced a disorder of lingual and pharyngeal activities responsible for the episodes of aspiration. The central location of the anomaly was demonstrated by the absence of peripheral neuromuscular anomalies and by the presence of impaired blinking reflexes and brain stem potential anomalies. These neurofunctional anomalies improved over time and magnetic resonance imaging failed to disclose and structural anomalies of the central nervous system. The occurrence of the swallowing disorder as an isolated manifestation and its long duration, with follow-ups of 23 months and 4 years, are two unique features in these cases. Neurophysiologic investigations are essential for documenting the neurologic etiology of the swallowing disorders, demonstrating their location above or within the medulla oblongata, and differentiating functional and organic anomalies.

[Asthma in infants. Clinical and functional aspects]

BACKGROUND

The incidence of asthma in infancy is rising but its clinical and physiological components remain unclear.

METHODS

A total of 24 infants, aged less than 48 months, in whom the first wheezing episode (WE) appeared before the age of 30 months (mean age: 9 months) underwent clinical examination and pulmonary function tests at least 2 weeks after the last WE.

RESULTS

The mean WE frequency was 1.1 per month and the mean number of admissions for WE was 1.8. 63% of patients showed symptoms between WE and 50% had an allergic profile. There was no evidence of thoracic distension. Bronchial obstruction (BO) occurred in 71% of patients; among these, BO was distal or generalized in 59% and medium or severe in 47%. 12.5% of patients were hypoxemic at testing. BO was less severe in patients treated with theophylline; it was more frequent (87%) in those with symptoms between WE and/or several admissions, and/or admission to the intensive care unit.

CONCLUSION

This study provides additional evidence that infants presenting with asthma at an early age have severe clinical and physiological profiles.

[Value of accelerated hyposensitization with mixed allergens in severe childhood asthma]

The value (in terms of decreased numbers of attacks and of hospitalizations for attacks, decreased need for asthma medications, and improved tolerance to allergens) of rush immunotherapy to a mixture of allergens was studied in children with multiple sensitizations and severe asthma (as evaluated on the number of attacks, number of hospitalizations, and dependence on corticosteroids) already receiving optimal medical therapy. Because syndromic reactions are common, rush immunotherapy should be performed in the hospital and premedication with corticosteroids may be warranted in the most severe cases.

[Mediastino-pulmonary sarcoidosis in children. Clinical study, analysis of data of bronchoalveolar fluid lavage and respiratory function tests, therapeutic trends]

A series of 27 children (mean age: 12 yrs, 5 mos.) presenting with thoracic sarcoidosis is reported. This series, collected from 1961 to 1988 shows the rarity of the disease at that age. However the low rate of asymptomatic forms (22%) suggests that the frequency of the disease is underestimated, as it is not diagnosed. The histological proof is necessary for the diagnosis. When peripheral lesions available for biopsy are lacking, a liver needle biopsy is helpful (93% of positivity). This study shows the frequency of multivisceral types, the intensity of the macrophagic and lymphocytic alveolitis. The therapeutic indications depend on the comparison of the radiological stage, the results of pulmonary function tests (PFT), those of the bronchoalveolar lavages (BAL) and of the serum granulomatous activity markers, especially concerning angiotensin converting enzyme (ACE). When present at the beginning of evolution, several risk factors lead to use a corticosteroid treatment: age of onset before 4 years, multivisceral involvement, presence of functional pulmonary signs, delayed diagnosis and onset of treatment, impaired respiratory function (especially concerning the alveolo-capillary diffusion), PMN cells greater than or equal to 2% in the initial BAL, and IgG proteins greater than 4 SD. Thus sarcoidosis in children differs from that seen in adults as it has a more marked evolutive tendency and leaves severe sequelae in one third of patients.

[6 cases of toxoplasmosis in twins]

Studies of congenital toxoplasmosis in twins confirm the definite role of the placenta in the modalities and mechanism of fetal contamination. In single-chorion twin pregnancies, clinical manifestations are generally identical in both infants. Conversely, twins from double-chorion pregnancies usually have different clinical patterns; occasionally, only one of the twins is affected (1 case). The diagnosis can be ascertained antenatally by sampling blood from each of the fetuses (2 cases). The cases reported herein illustrate some of the diagnostic pitfalls that may lead to inappropriate discontinuation of monitoring and treatment: negative placental studies, absence of specific IgM antibodies, transient fall in IgG antibody titers, delayed fetal contamination after a negative fetal blood study, and need for routine tests for increased CSF albumin levels.

[Cystic fibrosis in infants revealed by severe respiratory distress. Mid-term course]

We report the follow-up of 13 infants aged 2.5 to 24 months in whom cystic fibrosis disease presented as respiratory distress. All infants received an intensive treatment. Mean clinical, radiological and microbiological follow-up was 3.1 years. Ten children aged 1.5 to 8.5 years are still alive. One of them presents with serious respiratory failure, with a Shwachman score of 50. The Shwachman score is between 85 and 70 for 8 of 13 and 65 for one. The prognosis of this group did not differ from the one usually observed in the disease. It depends partially on early intensive care management and is not altered by mechanical ventilation.

[Cutaneous reactions to tuberculin and BCG vaccine]

The only available method for quantitative exploration of skin allergy to tuberculin is intradermal injection, since there is no other satisfactory method to evaluate the induration observed. Below 5 mm the induration has no significance. Between 5 and 10 mm it corresponds to an allergic reaction induced by BCG vaccine or by usually inapparent infections due to atypical mycobacteria. A diameter of 10 mm or more suggests either M. tuberculosis infection or allergy to BCG. The intensity of allergic reaction varies under the influence of numerous factors which may be genetic or nutritional, or associated with viral infections, antiviral vaccines and medicinal treatments. Exploring this allergy is of interest on the scores: (1) for epidemiological purposes, to obtain information on the annual risk tuberculosis infection or on the quality of the protection conferred by the vaccine in a given population; (2) for diagnostic purposes, to detect tuberculosis, and especially primary tuberculosis in children; (3) for vaccinal purposes, to determine the limitation of BCG. In subjects who have been vaccinated tuberculosis is rare but remains possible, and in such cases reactions to tuberculin may be difficult or even impossible to interpret.

Alveolar macrophage status in bronchopulmonary dysplasia

The predominant inflammatory cell type within the alveolar structure in bronchopulmonary dysplasia (BPD) is the alveolar macrophage (AM). AM ability to release hydrogen peroxide, a way to evaluate the cell status, was studied in nine infants who developed clinical and radiological evidence of BPD, and was compared to those from infants without lung parenchymal disorders (n = 6). AM were collected by bronchoalveolar lavage which was done after the mechanical ventilation stage in the BPD group. The experiments were performed on unstimulated AM and on AM stimulated by phorbol myristate acetate. Results revealed that the amount of hydrogen peroxide accumulated in the culture medium was significantly enhanced in the BPD group, in both experimental conditions (p less than 0.01 and less than 0.001, respectively). Furthermore, improvement of patients treated with glucocorticoids was closely related to a reduction of the alveolitis with a decrease of AM ability to generate hydrogen peroxide. These data indicate that AM activation is a central component of alveolitis in BPD and that extracellular production of oxidants by stimulated AM may play a critical role in the pathogenesis of the disease.