Our purpose was to determine whether numbers of CD4⁺CD25⁺ T [T regulatory (T_reg)] cells and mRNA expression of functional molecules of T_reg are related to airway allergy and disease severity in 51 paediatric patients with allergic rhinitis or bronchial asthma and 47 healthy controls. Surface markers were evaluated with flow cytometry, and mRNA was determined with real-time polymerase chain reaction. Children with allergic disease had fewer CD4⁺CD25⁺ T cells (8·49% ± 2·41% versus 9·58% ± 2·43%, P < 0·05) and CD4⁺CD25^hi T cells (1·32% ± 0·68% versus 1·70% ± 0·68%, P < 0·01) than control subjects. Numbers of CD4⁺CD25⁺ and CD4⁺CD25^hi T lymphocytes were higher in children with persistent allergic rhinitis and/or moderate–severe bronchial asthma than in those with respective milder disease. The number of T_reg cells was correlated positively with total immunoglobulin E level. The mRNA expression of forkhead box P3 (FoxP3) was increased in moderate–severe versus mild asthma (2·93 ± 0·38 versus 1·60 ± 0·31, P < 0·01). Patients with moderate–severe bronchial asthma also had increased mRNA expression of interleukin (IL)-10 compared with patients with mild asthma (15·24 ± 4·07 versus 3·77 ± 2·18, P < 0·01). The suppressive function of T_reg cells from patients with more severe asthma was competent in vitro. On average, decreased numbers of T_reg cells in children with allergic airway disease might represent a defect of the T_reg population. With increased expression of FoxP3 and IL-10 in T_reg from patients with relatively severe allergic disease, adaptive and functional T_reg might be generated in response to aggravated atopy and disease severity.

Objective. To evaluate the annual incidence and other epidemiological characteristics of Henoch–Schönlein purpura (HSP) among children in Taiwan. Methods. The records of patients were derived from the research database of the Bureau of National Health Insurance, Taiwan, Republic of China, from January 1999 to December 2002. Children younger than 17 yr of age with the diagnosis of HSP were included into this study. Data for each patient including sex, age, date of onset and length of hospitalization were recorded and analysed. Results. A total of 2759 cases were included with an annual incidence of 12.9 (11.8–13.4) per 100 000 children <17 yr of age. The occurrence of HSP had a peak at the age of 5 to 6 yr. In this study, 1118 (40.5%) patients had been hospitalized at some stage. There were 1454 males and 1305 females, for a male to female ratio of 1.11. Males had a higher annual incidence before the age of 10 yr (P = 0.04), and had a lower incidence than females at older ages (P = 0.02). Disease onset was more common in autumn and winter, and no apparent change in seasonal pattern was noted over 4 yr. Conclusions. Insurance claim data provide useful information on the epidemiology of HSP in Taiwan. Childhood HSP in Taiwan, with an incidence of 12.9 per 100 000 children, occurs commonly in autumn and winter; and at the age of 5 to 6 yr. The characteristics presented in this study may provide valuable data for understanding and further studies of HSP.

Atopic dermatitis (AD) is a common chronic, relapsing, pruritic inflammatory skin disease affecting 15% to 30% of all children and 2% to 10% of all adults.¹ Disturbed sleep is reported in 47% to 60% of children with AD and is a major factor leading to an impaired quality of life.^2-4 At present, limited studies are available to guide effective clinical management of sleep disturbances in AD. Some investigators^5,6 have studied whether treatment targeted at skin inflammation in patients with AD also improves their sleep, but the results have been inconsistent, and most of these studies used a subjective visual analog scale rather than objective measures to evaluate sleep.

BACKGROUND AND OBJECTIVES: Sleep disturbance is common in patients with atopic dermatitis (AD). However, studies have largely been questionnaire-based, and the pathophysiology remains unclear. The aims of this study were to determine objective characteristics of sleep disturbance in children with AD and explore contributing factors and clinical predictors. METHODS: Sleep parameters were measured by actigraphy and polysomnography in 72 patients with AD and 32 controls ages 1 to 18 years. Urinary 6-sulfatoxymelatonin levels, serum cytokines, and total and allergen-specific immunoglobulin E (IgE) levels were also measured. RESULTS: The patients with AD had significantly reduced sleep efficiency, longer sleep onset latency, more sleep fragmentation, and less nonrapid eye movement sleep. Results from actigraphy correlated well with those from polysomnography. The AD disease severity was associated with sleep disturbance (r = 0.55−0.7), and a Scoring Atopic Dermatitis index of ≥48.7 predicted poor sleep efficiency with a sensitivity of 83.3% and a specificity of 75% (area under the curve = 0.81, P = .001). Lower nocturnal melatonin secretion was significantly associated with sleep disturbance in the patients with AD. Other correlates of sleep disturbance included pruritus, scratching movements, higher total serum IgE levels, and allergic sensitization to dust mite and staphylococcal enterotoxins. CONCLUSIONS: Poor sleep efficiency is common in children with AD and can be predicted by the Scoring Atopic Dermatitis index. Melatonin and IgE might play a role in the sleep disturbance. Further studies are required to explore the mechanisms and clinical implications, and actigraphy could serve as a useful evaluating tool.

Summary: CD4⁺ CD25⁺ regulatory T cells (Tregs) are critical in maintaining self‐tolerance and preventing organ‐specific autoimmunity. Their role in paediatric systemic lupus erythematosus (SLE), an autoimmune disease characterized by inappropriate regulation of hyperactivated B and T cells, has not been clearly defined. Using flow cytometry to determine cell populations and real‐time polymerase chain reaction to assay mRNA expression for FOXP3, CTLA‐4, and GITR, we characterized CD4⁺ CD25⁺ T cells in paediatric SLE patients and healthy subjects. The frequency of CD4⁺ CD25⁺ Tregs was significantly decreased in patients with active SLE compared with patients with inactive SLE and with controls (7·27% ± 2·50%, 9·59% ± 2·80% and 9·78% ± 2·11%, respectively; P = 0·027 and P < 0·001, respectively), and was inversely correlated with disease activity, as assessed with the Systemic Lupus Erythematosus Disease Activity Index 2000 scores (r = −0·59, P = 0·001) and serum anti‐double‐stranded DNA levels (r = −0·65, P < 0·001). Our preliminary investigations found elevated surface expression of GITR in CD4⁺ CD25⁺ T cells, elevated mRNA expression of CTLA‐4 in CD4⁺ T cells and higher amounts of mRNA expression for FOXP3 in CD4⁺ cells in patients with active SLE compared with patients with inactive disease and controls. We demonstrated reduced CD4⁺ CD25⁺ Treg levels were inversely correlated with disease activity, indicating a defective Treg population in paediatric SLE patients. The differences in the expression of FOXP3, CTLA‐4 and GITR imply the possible role of CD4⁺ Tregs in the pathogenesis of SLE.