Does Ethnicity Influence Fractional Exhaled Nitric Oxide in Healthy Individuals?: A Systematic Review.

BACKGROUND: Fractional exhaled nitric oxide (Feno) is used clinically as a biomarker of eosinophilic airway inflammation. Awareness of the factors influencing Feno values is important for valid clinical interpretation. METHODS: We undertook a systematic review of PubMed, Cochrane Library, Scopus, and Web of Science databases and reference lists of included articles to evaluate whether ethnicity influences Feno values, and to determine if this influence affects clinical interpretation according to current guidelines. We included all studies that performed online Feno measurements on at least 25 healthy, non-Caucasian individuals, and examined the effect of ethnicity on Feno. RESULTS: From 62 potential studies, 12 studies were included. One study recruited only children (< 12 years of age), six studies recruited children and/or adolescents, four studies recruited adults only, and a single study involved children, adolescents, and adults. In total, 16 different ethnic populations representing 11 ethnicities were studied. Ethnicity was considered a significant influencing factor in 10 of the included studies. We found the geometric mean Feno to be above the normal healthy range in two studies. We also identified five studies in which at least 5% of participants had Feno results above the age-specific inflammatory ranges. CONCLUSIONS: Ethnicity influences Feno values, and for some ethnic groups this influence likely affects clinical interpretation according to current guidelines. There is a need to establish healthy Feno reference ranges for specific ethnic groups to improve clinical application.

[Chronic eosinophilic pneumopathy in a black African patient]. / Pneumopathie chronique à éosinophiles chez un patient Africain de race noire.

The authors report a case of a black African patient who suffers from a chronic eosinophilic pneumonia. In view of the lack of precise reporting in the literature of such a case in black Africans, the initial difficulty of strictly excluding a parasitologic etiology is discussed. From the comparison of paraclinical and clinical data with those of the literature, the authors emphasize the close relationship between asthma and chronic eosinophilic pneumonia and the role of alveolar eosinophils in the physiopathology of that illness.

Increase of activated T-cells in BAL fluid of Japanese patients with bronchiolitis obliterans organizing pneumonia and chronic eosinophilic pneumonia.

To study the role of T cells in bronchiolitis obliterans organizing pneumonia (BOOP) and chronic eosinophilic pneumonia (CEP) and to examine the influence of differing racial background, T-cell subsets in bronchoalveolar lavage (BAL) fluid (BALF) and in peripheral blood of 8 Japanese patients with idiopathic BOOP and 5 with CEP were compared with those of 15 normal subjects. The BALF pattern in BOOP was characterized by a significantly high number and percentage of lymphocyte and by a low CD4 to CD8 ratio compared with patients with CEP and healthy volunteers. Patients with CEP showed a significantly higher percentage of BALF eosinophils compared with other groups. There was no significant difference in BALF CD4 to CD8 ratio between patients with CEP and volunteers. Two-color analysis of T-cell subsets revealed that CD3+HLA-DR+ cells (activated T cell) in BALF of patients with BOOP and CEP increased significantly compared with volunteers, while BALF CD3+CD25+ cells (interleukin 2 receptor+ T-cell) did not. In addition, BALF CD8+HLA-DR+ cells (activated suppressor/cytotoxic T cell) in patients with BOOP and CD4+HLA-DR+ cells (activated helper T cell) in patients with CEP were significantly higher than levels detected in healthy subjects. The percentage of CD8+CD57+ cells and the number of CD8+CD11b- cells (cytotoxic T cell) in BALF were significantly higher in patients with BOOP compared with patients with CEP and healthy volunteers. There were no significant differences in the expression of peripheral blood T-lymphocyte surface antigens among the groups. These findings indicate that cytotoxic T cells in Japanese patients with idiopathic BOOP and helper T cells in CEP appear in the lungs is consistent with a previous report in Caucasians, supporting the hypothesis that T cells may play an important role in the pathogenesis of these diseases.