Computed tomography in children with cystic fibrosis: a new way to reduce radiation dose

AIMS

To determine whether the monitoring of respiratory disease progression in children with cystic fibrosis (CF) can be made using six pre-selected computed tomography (CT) cuts in lieu of the conventional full study.

METHODS

Forty one lung CT scans from 21 paediatric patients with CF were analysed. The Bhalla and Nathanson scores of the total lung CT and the six pre-selected CT cuts were compared.

RESULTS

The Bhalla mean score of the total lung CT evaluated by two radiologists was 5.62. It was 5.36 when just the six pre-selected sections were evaluated. The difference between means was not statistically significant. The Nathanson mean score of the total lung CT evaluated by both radiologists was 66.11; it was 66.51 when just the six pre-selected sections were evaluated. The difference between means was not statistically significant. The mean total radiation dose from a single whole lung CT scan was 716.22 mGy.cm. A dose of 250.66 mGy.cm was estimated if only six sections were used, with a reduction in radiation of about 65%.

CONCLUSION

It is possible to obtain the same radiological information from six pre-selected CT cuts as it is from a full pulmonary CT scan, thereby markedly reducing radiation exposure for children who will require repeat investigations in the future.

MHC class I chain related gene A (MICA) modulates the development of coeliac disease in patients with the high risk heterodimer DQA1*0501/DQB1*0201

BACKGROUND AND AIMS

Coeliac disease (CD) is an enteropathic disorder characterised by a strong association with major histocompatibility complex (MHC) heterodimer HLA-DQ2. It has been suggested that other HLA class I genes in combination with DQ may also contribute to CD susceptibility. The aim of this study was to investigate whether other candidate genes modify the risk of developing different clinical forms of CD.

PATIENTS AND METHODS

We studied 133 Spanish coeliac patients, divided according to their clinical presentation into typical and atypical groups, and 116 healthy controls. All were typed by polymerase chain reaction-sequence specific primers (PCR-SSP) at HLA-B, DRB1, DQA1, and DQB1 loci and for exon 5 of the MHC class I chain related gene A (MICA).

RESULTS

No differences were found in the frequency of the DQA1*0501/DQB1*0201 heterodimer in either group. The risk of typical CD was significantly associated with the DR7/DQ2 haplotype (p(c)=0.02, odds ratio (OR)=3.4, ethiological fraction (EF)=0.4). Extended haplotype (EH) 8.1 (B8/DR3/DQ2) was found to be overrepresented in the atypical form compared with the typical form (p(c)=0.001, OR=4.19, EF=0.56). The trinucleotide repeat polymorphism MICA-A5.1 was found to be increased in the atypical group of patients compared with the typical group (p(c)=0.00006, OR=8.63, EF=0.81). This association was independent of linkage disequilibrium with EH8.1 as this was also found to be increased in EH8.1 negative atypical patients compared with the typical group (p(c)=0.004, OR=6.66, EF=0.56).

CONCLUSIONS

Our results showed that the risk of developing typical forms of CD was associated with DR7/DQ2 haplotype, and the presence of B8/DR3/DQ2 was significantly increased in atypical patients. In these, the MICA-A5.1 allele confers an additive effect to the DR3/DQ2 haplotype that may modulate the development of CD.

[Cystic fibrosis in Asturias: an elevated frequency of the delta F508 mutation]

BACKGROUND

Cystic fibrosis (CF) is the most common autosomic-recessive inherited disorder. More than 300 different mutations in the CF gene (CFTR) have been described, being delta F508 and G542X the most common in the Spanish population. The frequencies of these mutations vary between the different European populations.

METHODS

We have studied the delta F508 and G542X mutations in 20 CF-patients from Asturias. These mutations were analysed through the polymerase chain reaction (PCR).

RESULTS

The frequency of the delta F508 mutation in Asturias was 77.5%, higher than those found in most of the other Spanish populations. The frequency found in Asturias is close to the frequency described for the Basque Country population. Patients homozygous for the delta F508 mutation showed clinical symptoms similar to those described in studies on other populations.

CONCLUSIONS

The high frequency of two mutations in the CFTR gene in Asturias makes possible the direct diagnostic in most families. The delta F508 mutation is associated to severe clinical manifestations, like early pancreatic insufficiency and Pseudomonas infection.

[C-reactive protein and orosomucoid as parameters of developmental monitoring and therapeutic effectiveness in neonatal sepsis]

Authors develop a comparative study of two acute phase reactants behaviour, in the follow up on 27 neonates with confirmed sepsis of favourable evolution and in 15 cases with fatal evolution. Results show that sera levels C-reactive-protein follow a parallel course with clinical significance in patients reaching normal concentrations soon after favourable evolution and persisting in high level or even increasing previous ones, in cases of lethal evolution. Orosomucoid did show the same clinical-biological correlation maintaining generally in high levels independent of normalization of symptoms and C-reactive protein. They propose serial determination of C-reactive-protein and an efficient control of treatment in neonatal sepsis.

[Karyotype in GPG bands: description of a elementaly technique for routine (author's transl)]

A new technic for banded chromosomes, with similar results (100%) to those obtained with chromatids modification by trypsin (G bands), is described. The key consists in Pyronin addition (20 mg.%) to distilled water at hypotonic shock, following then a standard karyotype technic assayed with micro-method, reaching banding after Giemsa tinction at 3% in 6.7 phosphate pH. Its interest radicates in chromosome modification in vivo, simplicity, fiability (80% of excellent results) and reproductibility, allowing any cytogenetic laboratory a routine obtention of G bands in only four days.