Double-blind, randomized, placebo-controlled trial of effect of nedocromil sodium on clinical and inflammatory parameters of asthma in children allergic to dust mite

Nedocromil sodium for chronic asthma in children

BACKGROUND

Currently inhaled corticosteroids are the main stay in the maintenance treatment of chronic asthma in children. Although inhaled corticosteroids play a crucial role in the management of childhood asthma, the long-term side effects of inhaled corticosteroids used in the management of chronic asthma in children are not clearly known.

OBJECTIVES

The objective of this review is to compare the safety and efficacy of inhaled nedocromil sodium with placebo in the treatment of chronic asthma in children.

SEARCH STRATEGY

We searched the Cochrane airway group trials register, Cochrane controlled trials register, Current contents, review articles, reference lists of articles. We also contacted the drug manufacturer and primary authors for additional citations. We also searched abstracts of major respiratory society meetings. The last search was carried out in October 2004

SELECTION CRITERIA

Randomised placebo controlled trials comparing nedocromil sodium to placebo in the treatment of chronic asthma in children (0 to 18 years).

DATA COLLECTION AND ANALYSIS

Both authors independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Fifteen trials (twelve parallel group studies; three crossover trials recruiting 1422 children (837 males and 585 females)) were included. The studies were generally of good methodological quality. Two large long term studies used nedocromil for six months and four to six years and showed conflicting results in symptom free days. Short term studies (duration between 4 weeks to 12 weeks) showed that nedocromil sodium produced some improvement in a number of efficacy measures compared to placebo including FEV(1), FVC, FEV(1) % predicted, PC20 FEV(1), evening PEF and symptom scores. The parent's assessment of efficacy was in favour of nedocromil (odds ratio (OR) 0.5 (95% CI 0.3 to 0.8). Nedocromil sodium has a good safety profile. The only significant side effect observed was unpleasant taste. There was little evidence for a clinically dose response effect and only a few studies recruited participants with severe asthma.

AUTHORS' CONCLUSIONS

A limited number of small studies have shown that nedocromil is of benefit in improving lung function and some measures of symptoms, but the evidence with regard to the primary outcome of the review was conflicting. Two long-term trials did not show consistent effects on lung function outcomes, whereas several small short-term trials have shown benefit in these outcomes. Differing severities at baseline may explain this difference with milder participants experiencing less benefit, although the discrepancy between study findings may also reflect publication bias. Nedocromil sodium is associated with a very good safety profile with no significant short term or long- term adverse side effects. Although nedocromil may have advantages over inhaled corticosteroids in terms of side effects, there is a need for head to head trials of nedocromil and inhaled corticosteroids to establish whether asthma control is similar, especially in mild asthma. It is not yet clear where nedocromil should sit in relation to other therapies in the treatment of asthma in children.

CD34+ cells in peripheral blood of healthy human beings and allergic subjects: clue to acute and minimal persistent inflammation

BACKGROUND

There is compelling evidence that hemopoietic precursor cells (HPC) play a crucial role in establishing cellular inflammation in allergic diseases. Increased levels of circulating CD34+ HPC committed to the myeloid lineage have been extensively reported in allergic rhinitis, asthma and eczema, whereas CD34+ cells have been identified within the cellular infiltrates of tissues, at peripheral sites of inflammation.

METHOD

We conducted a pilot study to evaluate CD34+ traffic in the peripheral blood of 22 consecutive patients (13 men and nine women; mean age 28.9 years), independently of treatment. The patients presented rhinitis, asthma, eczema, urticaria and adverse food reactions of suspected allergic origin. Allergic reactions were extrinsic in 18 patients and intrinsic in four. In 12 patients who underwent sublingual specific immunotherapy, CD34+ cells were quantified at enrollment (T0), one year later (T1) and two years later (T2). The severity of symptoms was graded on a five-point scale (0 = absence of symptoms and 4 = severe symptoms). Twenty healthy human subjects (10 men and 10 women; mean age 24.5 years) were evaluated as controls. To obtain information about the total amount of circulating HPC, independently of the lineage commitment (Lin+/-) and the degree of differentiation (CD34bright/dim), we used a modification of the Milan protocol of peripheral blood CD34+ cell estimation. The cells were analyzed using a BD FACScan or FACSCalibur and the results were expressed as the percentage of positive cells.

RESULTS

CD34+ cell traffic in the control group was very low since all values were < 0.10 (median value: 0.03 %). Values in the patient group were increased in both extrinsic and intrinsic forms with a median value of 0.25 % (interquartile range: 0.13- 0.33 %). The relationship between CD34+ traffic and the severity score was highly significant (Spearman's rho = 0.954; test of Ho: CD34; independent score: Pr > t = 0.000).

CONCLUSIONS

The data reported herein suggest that the method employed is effective in assessing acute allergic inflammation, as well as minimal persistent inflammation underlying an asymptomatic clinical condition. Evaluation of CD34bright/dim peripheral traffic, if confirmed by the outcomes of a multicenter study currently being planned together with traditional study of circulating IgE, could be a reliable non-invasive laboratory tool for monitoring allergic inflammation.