Expert consensus on the diagnosis, treatment, and prevention of respiratory syncytial virus infections in children.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading global cause of respiratory infections and is responsible for about 3 million hospitalizations and more than 100,000 deaths annually in children younger than 5 years, representing a major global healthcare burden. There is a great unmet need for new agents and universal strategies to prevent RSV infections in early life. A multidisciplinary consensus development group comprising experts in epidemiology, infectious diseases, respiratory medicine, and methodology aims to develop the current consensus to address clinical issues of RSV infections in children. DATA SOURCES: The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, and the Cochrane Library, using variations in terms for "respiratory syncytial virus", "RSV", "lower respiratory tract infection", "bronchiolitis", "acute", "viral pneumonia", "neonatal", "infant" "children", and "pediatric". RESULTS: Evidence-based recommendations regarding diagnosis, treatment, and prevention were proposed with a high degree of consensus. Although supportive care remains the cornerstone for the management of RSV infections, new monoclonal antibodies, vaccines, drug therapies, and viral surveillance techniques are being rolled out. CONCLUSIONS: This consensus, based on international and national scientific evidence, reinforces the current recommendations and integrates the recent advances for optimal care and prevention of RSV infections. Further improvements in the management of RSV infections will require generating the highest quality of evidence through rigorously designed studies that possess little bias and sufficient capacity to identify clinically meaningful end points.

[Association of Haemophilus influenzae infection with environmental and climatic factors in Suzhou, China]. / è‹å·žåœ°åŒºæµæ„Ÿå—œè¡€æ†èŒæ„ŸæŸ“ä¸ŽçŽ¯å¢ƒæ°”å€™çš„ç›¸å ³å› ç´ åˆ†æž.

OBJECTIVES: To investigate the epidemiological characteristics of respiratory Haemophilus influenzae (HI) infection in children in Suzhou, China and its association with climatic factors and air pollutants. METHODS: The data on air pollutants and climatic factors in Suzhou from January 2016 to December 2019 were collected. Respiratory secretions were collected from 7 940 children with acute respiratory infection who were hospitalized during this period, and bacterial culture results were analyzed for the detection of HI. A stepwise regression analysis was used to investigate the association of HI detection rate with air pollutants (PM2.5, PM10, NO2, SO2, CO, and O3) and climatic factors (monthly mean temperature, monthly mean humidity, monthly total rainfall, monthly total sunshine duration, and monthly mean wind speed). RESULTS: In 2016-2019, the 4-year overall detection rate of HI was 9.26% (735/7 940) among the children in Suzhou. The children aged <1 year and 1-<3 years had a significantly higher HI detection rate than those aged ≥3 years (P<0.01). The detection rate of HI in spring was significantly higher than that in the other three seasons, and the detection rate of HI in autumn was significantly lower than that in the other three seasons (P<0.001). The multiple linear regression analysis showed that PM10 and monthly mean wind speed were independent risk factors for the detection rate of HI: the detection rate of HI was increased by 0.86% for every 10 µg/m3 increase in the concentration of PM10 and was increased by 5.64% for every 1 m/s increase in monthly mean wind speed. Air pollutants and climatic factors had a lag effect on the detection rate of HI. CONCLUSIONS: HI is an important pathogen for acute respiratory infection in children in Suzhou and is prevalent in spring. PM10 and monthly mean wind speed are independent risk factors for the detection rate of HI.

Association of children wheezing diseases with meteorological and environmental factors in Suzhou, China.

Wheezing diseases are one of the major chronic respiratory diseases in children. To explore the effects of meteorological and environmental factors on the prevalence of children wheezing diseases, clinical data of children hospitalized with wheezing diseases in Suzhou, China from 2013 to 2017 were collected. Meteorological and environmental factors from 2013 to 2017 were obtained from the local Meteorological Bureau and Environmental Protection Bureau. Relationships between wheezing diseases and meteorological and environmental factors were evaluated using Pearson's correlation and multivariate regression analysis. An autoregressive integrated moving average (ARIMA) model was used to estimate the effects of meteorological and environmental variables on children wheezing diseases. Children wheezing diseases were frequently presented in infants less than 12 months old (1897/2655, 58.28%), and the hospitalization rate was highest in winter (1024/3255, 31.46%). In pathogen-positive specimens, the top three pathogens were respiratory syncytial virus (21.35%), human rhinovirus (16.28%) and mycoplasma pneumoniae (10.47%). The seasonality of wheezing children number showed a distinctive winter peak. Children wheezing diseases were negatively correlated with average temperature (P < 0.001, r = - 0.598). The ARIMA (1,0,0)(0,0,0)12 model could be used to predict temperature changes associated wheezing diseases. Meteorological and environmental factors were associated with the number of hospitalized children with wheezing diseases and can be used as early warning indicators for the occurrence of wheezing diseases and prevalence of virus.

[Comparative Study of Clinical Manifestations and Sleep Structure in Children with Obstructive Sleep Apnea-hypopnea Syndrome with Different BMI].

OBJECTIVE: To compare and analyze the clinical manifestations and sleep structure of children with obstructive sleep apnea-hypopneasyndrome (OSAHS) with different body mass index (BMI). METHODS: 452 children who were diagnosed with OSAHS between December 2016 and February 2021 by the Department of Respiratory Medicine, Children's Hospital of Soochow University were included in the study. All of them did polysomnography (PSG). They were divided, according to their BMI, into the normal BMI group, the overweight group, and the obesity group. Their clinical data and PSG results were collected. RESULTS: 287 boys (63.5%) and 165 girls (36.5%) were enrolled, with their age ranging between 3 and 15, and the median age being 5.5 (4.5, 7.0). Their BMI ranged between 12.09 kg/m 2 and 38.48 kg/m 2, with the median being 16.29 kg/m 2. 275 cases (60.8%) had normal BMI, 76 cases (16.8%) were overweight, and 101 cases (22.3%) were obese. There was no significant difference in the distribution of clinical manifestations and severity of OSAHS among the three groups. The duration and proportion of rapid eye movement (REM) stage sleep in the obese group was lower than that of the overweight and the normal BMI groups ( P<0.05). The lowest oxyhemoglobin saturation (LSaO 2) of children in the overweight group was lower than that of the normal BMI group ( P=0.050). The oxygen desaturation index (ODI) of the obese group was higher than that of the normal BMI and the overweight groups ( P<0.05). CONCLUSION: Obesity worsens the degree of hypoxia in children with OSAHS and affects their sleep structure.

The diagnostic value of serological tests and real-time polymerase chain reaction in children with acute Mycoplasma pneumoniae infection.

BACKGROUND: This study set out to evaluate the clinical significance and diagnostic effectiveness of serological tests and real-time polymerase chain reactions (RT-PCR) in children of different age groups and disease durations infected with Mycoplasma pneumoniae (MP). METHODS: Pediatric patients with lower respiratory tract infection (LRTI) confirmed by polymerase chain reaction (PCR) were enrolled and subjected to bronchoalveolar lavage fluid PCR (BALF-PCR) for MP infection. The diagnostic values of the serum immunoglobulin M (IgM) test, paired sera immunoglobulin G (IgG) test, RT PCR applied to nasopharyngeal aspirates (NPA-PCR), and combined IgM and NPA-PCR test were evaluated. RESULTS: When BALF PCR was used as the gold standard, the MP positivity rate of combined IgM and NPA PCR was 78.85%in children aged 3-5 years. The positivity rates of IgM, NPA PCR, and combined IgM and NPA PCR in children older than 5 years were 71.21%, 72.72%, and 84.85%, respectively. The detection rate of combined IgM and NPA PCR was consistent with BALF PCR (Kappa =0.727). The MP positivity rates of combined IgM and NPA PCR at 1-2 weeks was as high as 91.11%, and was consistent with the BALF PCR (Kappa =0.756). Moreover, the positivity rates of IgM or NPA PCR at 2-3 weeks were 63.16%, and were consistent with each other (Kappa =0.771). CONCLUSIONS: Combined IgM and NPA PCR is the optimal test to confirm MP infection among children aged 3-5 years in cases with a disease duration of less than2 weeks, and either NPA PCR or IgM is recommended for children older than 5 years with a disease duration of 2-3 weeks. KEYWORDS: Mycoplasma pneumoniae pneumonia (MPP); diagnosis; children; age; disease duration.

c.753_754delAG, a novel CFTR mutation found in a Chinese patient with cystic fibrosis: A case report and review of the literature.

BACKGROUND: Cystic fibrosis (CF) is rare in Asian populations relative to the Caucasian population. In this paper, we report the cystic fibrosis transmembrane conductance regulator (CFTR) variation in a family of Chinese CF patients, and systematically review the previous literature. CASE SUMMARY: Here we report a 30-month-old Chinese girl who was diagnosed with CF based on her history and symptoms such as recurrent productive cough, wheezing with repeated infection of Pseudomonas aeruginosa, and parasinusitis. Chest computed tomography (CT) scanning revealed obvious exudative lesions and bilateral bronchiectasis. Liver CT scanning revealed a low-density lesion in the left lobe of the liver. A diagnosis of CF was made based upon CFTR gene tests. The CFTR gene was sequenced using the blood samples of her and her parents and showed a heterozygous novel missense mutation of c.753_754delAG in exon 7. In addition, a heterozygous c.1240 C>T mutation was found in exon 10 of the CFTR. The mutation c.753_754delAG was verified to have been inherited from her mother, and the c.1240 C>T mutation was from her father who was diagnosed with congenital absence of vas deferens. CONCLUSION: A novel mutation of CFTR, c.753_754delAG, was found in a Chinese CF child. c.2909G>A is the most common mutation among Chinese CF patients.

[Detection of viral pathogens and allergens in infants and young children at high risk of asthma during a wheezing episode].

OBJECTIVE: To investigate the viral etiology and allergen distribution in infants and young children at high risk of asthma during a wheezing episode. METHODS: A total of 135 infants and young children at high risk of asthma were enrolled who were admitted due to asthmatic bronchitis or asthmatic bronchopneumonia between April 2016 and August 2017. Fluorescent probe PCR was used to measure influenza A (Flu A), respiratory syncytium virus (RSV), adenovirus (ADV), parainfluenza virus (PinF), human rhinovirus (HRV), human partial lung virus (hMPV) and human bocavirus (HBoV) in nasopharyngeal aspirates. ImmunoCAP was used to measure inhaled allergens, food allergens, and total IgE concentration. RESULTS: Among the 135 patients, the overall virus detection rate of nasopharyngeal aspirates was 49.6%, and HRV had the highest detection rate of 25.2%, followed by HBoV (9.6%), RSV (8.1%), PinF (5.9%), Flu-A (3.7%), ADV (1.5%) and hMPV (0.7%). The 1-3 years group had a significantly higher detection rate of HRV than the <1 year group (P<0.05). The positive rate of allergen screening was 59.3%, with 44% for inhaled allergens and 89% for food allergens. Among the inhaled allergens, dust mites had the highest positive rate of 77%, followed by mould (37%), pollen (26%) and animal dander (9%). Among the food allergens, egg white had a positive rate of 73% and milk had a positive rate of 68%. The <1 year group had a significantly higher positive rate of inhaled allergens than the 1-3 years group (P<0.05). The 1-3 years age group had a significantly higher level of T-IgE than the <1 year group (P<0.05). The positive virus group had a significantly higher positive rate of inhaled allergens than the non-virus group (P<0.05). The children with the second wheezing episode had significantly higher positive rates of inhaled allergens and food allergens and level of T-IgE than those with the first wheezing episode (P<0.05). The children with the second wheezing episode also had significantly higher positive rates of dust mites and mould than those with the first wheezing episode (P<0.05). CONCLUSIONS: Early HRV infection and inhaled allergen sensitization are closely associated with the development of wheezing in infants and young children at high risk of asthma.

The role of miR-29c/B7-H3/Th17 axis in children with Mycoplasma pneumoniae pneumonia.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired pneumonia in children. Recent studies demonstrated that the incidence of severe or fatal M. pneumoniae was gradually increasing, which may be related to the excessive inflammation. However, the exact pathogenesis of excessive inflammation in Mycoplasma pneumoniae pneumonia(MPP) is still unclear. This study aimed to reveal the role of miR-29c/B7-H3/Th17 axis in children with MPP. METHODS: Children hospitalized in Respiratory Department during Jan. 2014 to Dec. 2015 were enrolled. All children enrolled was confirmed with MP infection using real-time PCR and ELISA. Children were excluded if they were co-infected with other pathogens. A total of 52 children with MPP and 26 controls were enrolled. miR-29c expression in monocytes of children with MPP was determined by real-time PCR and soluble B7-H3 (sB7-H3) and IL-17 were determined by ELISA, and explore their clinical significance. miR-29c overexpression and silencing technology and luciferase reporter assay were performed to confirm whether B7-H3 is the direct target of miR-29c. The levels of transcription factor ROR-γt in CD4+ T cells and cytokine IL-17A in supernatant were detected after stimulated by different concentrations of B7-H3 fusion protein in vitro. RESULTS: Of all 52 children with MPP, the mean age of the children were 77 ± 33 months, and 23 cases were male accounting for 44.2%. Nineteen cases had pleural effusion accounting for 36.5%. Children with MPP had significantly lower level of miR-29c and higher level of sB7-H3 and IL-17 compared to controls (both P < 0.05). The level of miR-29c significantly increased during convalescent phase compared to that of acute phase while sB7-H3 and IL-17 significantly decreased during convalescent phase (both P < 0.05). There was a positive correlation between the level of sB7-H3 and IL-17 in children with MPP during acute-stage (r = 0.361,P = 0.009). Children with MPP combined with pleural effusion had significantly higher level of sB7-H3 compared to those without pleural effusion (9952.3 ± 3065.3 vs. 7449.7 ± 2231.5, pg/ml), and the levels of sB7-H3 was positively correlated with the number of days of fever. The level of miR-29c was negatively correlated with M. pneumoniae specific IgG, IgM level. High concentrations of B7-H3(15µg/ml) could enhance ROR-γt expression and increase IL-17A. Functional studies based on luciferase reporter assay and immunofluorescence staining suggested that B7-H3 is the direct target of miR-29c, and miR-29c silencing or overexpression could up- or down-regulate the expression of B7-H3 in THP-1 cells. CONCLUSIONS: The axis of miR-29c/B7-H3/Th17 plays a vital role in children with MPP through excessive inflammation. miR-29c and B7-H3 may be the new target for the prevention and treatment of MPP, and may be the novel and potential biomarkers for the assessment of prognosis.

Multisystem smooth muscle dysfunction syndrome in a Chinese girl: A case report and review of the literature.

BACKGROUND: Multisystemic smooth muscle dysfunction syndrome (MSMDS) is a rare genetic disease worldwide. The main mutation is the actin alpha 2 (ACTA2) gene p.R179H. In this paper, we report a Chinese MSMDS patient and systematically review the previous literature. CASE SUMMARY: Here, we report a 9.6-month-old Chinese girl who was diagnosed with MSMDS based on her history and symptoms, such as recurrent cough, wheezing, and complications with congenital fixed dilated pupils. Chest high-resolution computed tomography revealed inhomogeneous lung transparency, obvious exudative lesions, and some lung fissures that were markedly thickened. Cranial magnetic resonance imaging excluded bleeding and infarction but showed abnormal signals in the centrum ovale majus and bilateral periventricular regions. Echocardiography only showed patent foramen ovale, and no patent ductus arteriosus, pulmonary artery dilatation, or pulmonary hypertension was found. Bronchoscopy indicated moderate bronchial malacia. These examinations in conjunction with the typical eye abnormality suggested a diagnosis of MSMDS, and sequencing of exon 6 of the ACTA2 gene demonstrated the heterozygous mutation c.536G>A, p.R179H. However, her parents' gene analyses were normal. CONCLUSION: MSMDS is a rare genetic disease mainly caused by the mutation of the ACTA2 gene p.R179H. Early genetic diagnosis should be performed for children presenting with congenital fixed dilated pupils and patent ductus arteriosus. During the process of diagnosis and treatment, clinicians should be on high alert for cerebrovascular, cardiovascular, and pulmonary complications.

Differentiation between mycoplasma and viral community-acquired pneumonia in children with lobe or multi foci infiltration: a retrospective case study.

OBJECTIVES: To analyse the clinical features, inflammatory markers and radiographs of community-acquired pneumonia (CAP) cases with lobe or multi foci infiltration; with a special focus on factors which allow the differential diagnosis of viral and mycoplasma pneumonia. SETTING: Retrospective chart review of CAP cases in a large university teaching hospital. PARTICIPANTS: 126 paediatric CAP cases, with lobe or multi foci infiltration, presenting between May 2012 and April 2013. Demographic data, clinical presentation on admission or referral, laboratory tests, prior history, and radiography were collected for each case if available. PRIMARY AND SECONDARY OUTCOME MEASURES: We used univariate and multivariate logistic regression to determine the significant factors which allow the differential diagnosis of viral and mycoplasma CAP with lobe or multi foci infiltration. RESULTS: There were 71 (56%) male and 55 (44%) female CAP cases with lobar or multi foci infiltration. 70 pneumonia cases were caused by Mycoplasma pneumoniae and 18 by viruses. Univariate analysis of the mycoplasma and viral causes of the CAP revealed that increased respiratory rate, wheeze, male gender and lymphocyte percentage were the factors associated with the differentiation of mycoplasma and viral aetiologies of pneumonia (p<0.05). A stepwise logistic regression analysis was performed to assess independent factors which allow the differential diagnosis of viral and mycoplasma pneumonia. Increased respiratory rate, wheeze, and lymphocyte percentage were reliable independent factors which allow the differential diagnosis of viral and mycoplasma CAP with lobar or multi foci infiltration. CONCLUSIONS: Whether the CAP with lobar or multi foci infiltration was caused by mycoplasma species or viruses could not be inferred from the radiological patterns. Wheeze, lymphocyte percentage and respiratory rate were independent factors which allowed the differential diagnosis of viral and mycoplasma CAP with lobar or multi foci infiltration.

[Comparison of clinical features and co-infection between pneumonia caused by influenza virus A and pneumonia caused by influenza virus B among children].

OBJECTIVE: To compare the clinical features and co-infection between pneumonia caused by influenza virus A (IVA) and pneumonia caused by influenza virus B (IVB) among children. METHODS: A total of 165 children with pneumonia caused by influenza virus (IV) were included in the study. These subjects were divided into IVA(n=71) and IVB pneumonia groups (n=94) according to the subtypes of IV. The IVA pneumonia group was further divided into simple infection (n=14) and co-infection subgroups (n=57), and the IVB pneumonia group was also further divided into simple infection (n=27) and co-infection subgroups (n=67). Co-infection rate and pathogen spectrum were analysed in children with IV pneumonia. RESULTS: The IVB pneumonia group had significantly increased mean age of onset and significantly prolonged mean duration of fever compared with the IVA pneumonia group (P<0.05). Co-infection rate among children with IV pneumonia was 75.2%, who were co-infected with bacteria (44.2%), Mycoplasma pneumoniae (MP, 21.8%) and other viruses (45.5%). Respiratory syncytial virus (RSV) was most common in children co-infected viruses (89% ). The rate of co-infection with RSV was significantly higher in the IVA pneumonia group than in the IVB pneumonia group. There were no significant differences in age, length of hospital stay, duration of fever, percentage of neutrophils, prealbumin, C-reactive protein, alanine aminotransferase, and creatine kinase-MB between the simple infection and co-infection subgroups of each group. CONCLUSIONS: Children with IVB pneumonia have prolonged duration of fever and increased age of onset compared with those with IVA pneumonia. Co-infection rate is high among children with IV pneumonia, who may be co-infected with bacteria, viruses and MP. Co-infection with RSV is more common in children with IVA pneumonia. It is difficult to identify the presense of co-infection using clinical indices.

[Changes of exhaled nitric oxide and peripheral blood eosinophils in children with asthma].

OBJECTIVE: This study examined the levels of exhaled nitric oxide (eNO) and peripheral blood eosinophils (EOS) as well as the correlation between the two markers in children with bronchial asthma (AS),AS complicated by allergic rhinitis (AS/AR) and chronic cough variant asthma (CVA), in order to explore the value of eNOS detection in children with AS. METHODS: The eNO level was measured using light-emitting electrochemical photometry in 12 children with AS, 29 children with AS/AR and 10 children with CVA. Peripheral blood EOS was counted by blood cell counter (Coulter JT). Forced expiratory volume in one second (FEV1) was assessed by lung function measurement. Thirty children without atopic disease and acute respiratory infection as well as without a family history of atopic diseasea served as the control group. RESULTS: The levels of eNO and blood EOS in the AS, the AS/AR and the CVA groups were significantly higher than those in the control group (p<0.01). The AS/AR group showed increased levels of eNO (50.3 + or - 6.7 ppb) and EOS (5.9 + or -4.2 x 109 ) compared with the AS (30.5 + or - 8.8 ppb and 4.2 + or - 3.2 x 109 respectively) and the CVA groups (26.0 + or - 3.2 ppb and 3.7 + or - 6.9 x 109 respectively) (p<0.05). There were no significant differences in eNO and EOS levels between the AS and the CVA groups. The eNO level was positively correlated with the EOS level (r=0.51, p<0.05), but not with FEV1 (r=0.144, p>0.05) in the AS group. CONCLUSIONS: NO is highly expressed in children with symptoms of atopy and can reflect the levels of eosinophilic airway inflammation in children with AS.

[Etiology of pneumonia in hospitalized patients less than 3 years of age].

OBJECTIVE: To understand the etiology of pneumonia in hospitalized patients less than 3 years of age. METHODS: A total of 316 children with pneumonia admitted to the Children's Hospital of Suzhou University in Jiangsu Province from March, 2006 to January, 2007 were enrolled in this study. Sputum samples were obtained by deep nasotracheal aspiration technique for bacterial and viral cultures. RESULTS: Of the 316 samples, specific microbial etiology was obtained in 192 cases (60.8%). Bacterial infection was found in 162 cases (51.3 %), viral infection in 19 cases (6.3%)and compound infection with virus and bacteria in 11 cases (3.5 %). Haemophilus influenzae was the most common agent (46 cases; 14.6%) in bacterial infection, followed by Streptococcus pneumoniae (32 cases; 10.1%). Respiratory syncycial virus (RSV) was the most common agent (12 cases; 4.0%) in viral infection, followed by adenovirus (11 cases; 3.6%). CONCLUSIONS: Bacterial infection was a leading cause of pneumonia in children less than 3 years of age in Suzhou area. Haemophilus influenzae was the most common agent, followed by Streptococcus pneumoniae.

[Effect of 1-year specific immunotherapy with standardized house dust mite vaccine on mild to moderate allergic asthmatic patients].

OBJECTIVE: To evaluate the clinical efficacy and safety of specific immunotherapy (SIT) with standardized house dust mite (HDM) vaccine on allergic asthmatic patients. METHODS: The investigation was a multicentre, randomized, double-blind, placebo-controlled clinical study. 132 patients with mild to moderate asthma who were allergic to HDM, recruited from three hospitals of China (The First Affiliated Hospital of Guangzhou Medical College, Shenyang General Military Hospital, Suzhou Children's Hospital), were randomly allocated to the active group (n = 66) or the control group (n = 66) respectively. The active group received SIT with a standardized depot Dermatophagoides pteronyssinus (Der p) extract absorbed to aluminium hydroxide (Alutard SQ, ALK-Abelló, Denmark), while the control group received a placebo containing histamine dihydrochloride by subcutaneous injections for 1 year. Treatment of each group was started from the initial concentration. Updosing was performed with weekly injections from four 10-fold dose-increase vials (active group: 100, 1,000, 10,000, 100,000 SQ-U/ml, control group: 0.01, 0.1, 1.0, 10 microg/ml. 100,000 SQ-U/ml of Der p extract contains 9.8 microg/ml of the majoy allergen Der p1). The single-dose was injected weekly with 0.2, 0.4, 0.8 ml of each concentration in turn from the preceding 3 vials, totally for 9 weeks. Subsequently, the dose with 0.1, 0.2, 0.4, 0.6, 0.8 ml of the highest concentration was injected weekly from the 10th-14th week and a maintenance dose with 1 ml was reached at the 15th week. The dosing interval was then gradually increased to 2, 4, 6 weeks until the end of the first 26-weeks updosing phase (phase I, H(1)). Thereafter, the dosing continued at 6-week intervals for maintenance phase (phase II, H(2)) till the end of the complete treatment. The patient was observed for at least 30 minutes in the clinic after each injection. RESULTS: A total of 132 subjects were randomized and 129 subjects (64 in the active group, 65 in the control group) completed the whole study. Dropouts included three females because of poor compliance, being afraid of the epidemic of Severe Acute Respiratory Syndrome (SARS) and emigration respectively. Both groups were comparable at baseline in all clinical and laboratory parameters. The mean daily symptom scores in 4-weekly began to diverge at the 29th-32nd week with the active group showing a significant lower scores (0.17 +/- 0.33) than the control group (0.39 +/- 0.74, Z = 2.031, P < 0.05) till the end of the study. Significant difference was found in average daily symptom scores between H(1) (0.29 +/- 0.39) and H(2) (0.19 +/- 0.27) in the active group (Z = 2.923, P < 0.01), while no significant difference was found between H(1) (0.45 +/- 0.62) and H(2) (0.40 +/- 0.68) in the placebo group (Z = 1.885, P > 0.05). There were significant differences in subjective judgement of the improvement about overall asthmatic symptoms, exacerbation severity and exacerbation frequency between the active group (96.9%, 95.3%, 95.4%) and the control group (80.0%, 75.4%, 83.1%) with the self-evaluation questionnaire (chi(2) = 13.246, 11.576, 16.204, all P < 0.01). The trend line of daily medication scores in weekly intervals showed a significant decline. The mean daily medication score of phase II (0.20 +/- 0.36) was significant lower than that of phase I (0.33 +/- 0.67, Z = 3.344, P < 0.01), whereas the control group did not show a significant difference between phase II (0.35 +/- 0.96) and phase I (0.32 +/- 0.95, Z = 0.744, P > 0.05). After 1-year treatment, no significant differences were found in morning and evening peak expiratory flow of predicted value (PEF%), forced expiratory volume in one second of predicted value (FEV(1)/FVC), forced vital capacity of predicted value (FVC%), forced expiratory volume in one second to forced vital capacity ratio (FEV(1)/FVC), provoking dose decreasing FEV(1) by 20% (PD(20)-FEV(1)) between the active group [(97 +/- 17)%, (98 +/- 18)%, (91 +/- 11)%, (98 +/- 9)%, (82 +/- 10)%, 2.35 (7.9) micromol] and the control group [(99 +/- 19)%, (100 +/- 19)%, (90 +/- 14)%, (99 +/- 13)%, (82 +/- 9)%, 1.80 (7.8) micromol] (t = 0.170 - 0.630, Z = 0.264, all P > 0.05). Skin index (SI) to Der p in the active group (1.2 +/- 0.5) was significantly lower than that of the control group (1.5 +/- 0.6) after treatment (t = 2.395, P < 0.05). There was no significant difference in the level of serum sIgE against Der p between groups, which was 76.80 (97.0) kU/L in active group and 66.50 (99.3) kU/L in the control group (Z = 0.232, P > 0.05). The frequency of systemic adverse reactions graded by guidelines based on the position paper of European Academy of Allergology and Clinical Immunology (EAACI), was 5.7% and 1.8% of the total injections in the active group and the control group, respectively. Although significant difference was found in adverse reactions between groups (chi(2) = 4.705, P < 0.05), all were mild or moderate. The majority occurred within 30 minute after injection and were controlled well with symptomatic therapy. No any severe systemic adverse reaction was shown in the study. CONCLUSION: One year specific immunotherapy with standardized house dust mite (HDM) vaccine significantly improved symptoms and reduced medication use in mild to moderate allergic asthmatic patients. SIT also reduced skin prick test reactivity to Der p. Complying with the EAACI immunotherapy guidelines, SIT with standardized HDM vaccine was a safe treatment.