Metagenomic sequencing expedites diagnosis of disseminated BCG in an infant with BRAFV600E mutation.

INTRODUCTION: Disseminated bacillus Calmette-Guérin (BCG) disease is a rare but serious BCG complication in children. Early diagnosis and timely interventions are essential to improve prognosis. However, its manifestations can closely mimic those of Langerhans cell histiocytosis (LCH), which usually leads to a high rate of misdiagnoses. Herein we report the first case of successful application of biopsy tissue metagenomic next-generation sequencing (mNGS) in the differential diagnosis of disseminated BCG disease and LCH. CASE STUDY: A 5-month-old female infant was transferred to our center for the treatment of paroxysmal cough, intermittent hematochezia and trunk rash. Examination on admission showed moderate anemia, erythropenia, thrombocytopenia and hepatosplenomegaly. The immunohistochemistry of her intestinal biopsy samples showed CD1a (+) and Langerin (+). Genetic testing of both peripheral blood and bone marrow samples suggested BRAFV600E mutation. Hence, she was initially diagnosed with LCH. However, no improvement was observed after a course of systemic chemotherapy. The left axillary lymph node and colonic mucosal biopsy specimens were sent for mNGS which resulted in sequence reads of Mycobacterium bovis-BCG. Triple antimycobacterial therapy was started according to the diagnosis. RESULTS: The diagnosis of this case was corrected as disseminated BCG disease by mNGS. Currently, she is doing well clinically and continues to follow-up at our outpatient clinic. CONCLUSIONS: This case suggests that mNGS is a valuable tool in the differential diagnosis of disseminated BCG disease and LCH, which can improve the early diagnosis rate of disseminated BCG disease.

Determinants for asthma control, quality of life and use of complementary and alternative medicine in asthmatic pediatric patients in four cities.

BACKGROUND: Asthma is a significant chronic health problem worldwide. Management aims at disease control by reducing functional impairment and exacerbations and improving quality of life (QoL). We report a multi-center study to survey asthma control and QoL in four cities in the Pearl River Delta. METHODS: The conjoint survey involved ten Hong Kong pediatric hospitals/units, two Shenzhen hospitals, two Macau hospitals, and two Guangzhou hospitals on asthma control (using Asthma Control Test) and QoL (Pediatric Allergic Disease Quality of Life Questionnaire, PADQLQ). Acceptability of a treatment is graded as very good/good/fair/poor. RESULTS: Good asthma control was only reported in 80% subjects in Hong Kong, but higher in sister cities (85-94%, P < 0.001). Allergic rhinitis, "incense burning", and "smoker in family" were prevalent among the four cities. Logistic regression showed better control of asthma was associated with better PADQLQ (B = - 0.029, P < 0.001), better acceptability of bronchodilator (B = - 1.488, P = 0.025), negatively with "smoker in family" (B = - 0.83, P = 0.015) and various PADQLQ domains. Conversely, worse PADQLQ was associated with allergic rhinitis severity (B = 4.77, P < 0.001), poor control of asthma (B = 7.56, P < 0.001), increased frequency of traditional Chinese medicine use (B = 1.7, P < 0.05), increased frequency of bronchodilator usage (B = 1.05, P < 0.05), "smoker in family" (B = 4.05, P < 0.05), and incense burning at home (B = 3.9, P < 0.05). CONCLUSIONS: There are some clinical and cultural differences among the four southern Chinese cities within the Guangdong province. This study identifies potentially modifiable environmental and treatment factors associated with poor asthma control and QoL for health-care interventions. Having a smoker in the family is independently associated with poor asthma control and QoL.

Effects of IFN-γ on cell growth and the expression of ADAM33 gene in human embryonic lung Mrc-5 fibroblasts in vitro.

OBJECTIVE: To investigate the effects of interferon-γ (IFN-γ) on the proliferation and viability of human embryonic lung Mrc-5 fibroblasts in vitro and the expression of the A Disintegrin and Metalloprotease 33 (ADAM33) gene and to explore the mechanism of airway remodeling. METHODS: Mrc-5 fibroblasts were sensitized with Dermatophagoides farinae 1 (Derf1) in vitro to mimic in vivo conditions observed in bronchial asthma. An inverted fluorescence microscope was used to observe changes in cell morphology before and after treatment. The viability of Mrc-5 cells was tested using the Cell Counting kit-8 (CCK8). Expression of the ADAM33 gene and protein in Mrc-5 cells was assessed using qPCR and Western blotting, respectively. RESULTS: Different concentrations of Derf1 increased cell growth and the expression of the ADAM33 gene in Mrc-5 cells, and these changes were most obvious in the 10 µg/ml group. In contrast, IFN-γ decreased cell growth and the expression of the ADAM33 gene in both Mrc-5 cells and Derf1-induced Mrc-5 cells, and these changes were most obvious in the 10 ng/ml group. The negative effects of 10 ng/ml IFN-γ were the most significant at 32 hours. CONCLUSIONS: Derf1-induced Mrc-5 cells successfully imitated the in vivo conditions observed in patients with asthma. IFN-γ inhibited the proliferation and viability of Mrc-5 cells, and Derf1-induced Mrc-5 cells were more sensitive to IFN-γ treatment. IFN-γ treatment significantly downregulated the expression of the ADAM33 gene in a concentration- and time-dependent manner. IFN-γ may participate in airway remodeling in asthma by regulating the expression of the ADAM33 gene.

Corticosteroid in Combination with Leflunomide and Mesenchymal Stem Cells for Treatment of Pediatric Idiopathic Pulmonary Hemosiderosis.

Background: This study evaluated the efficiency of corticosteroid, leflunomide and mesenchymal stem cells (MSCs) in the treatment of pediatric idiopathic pulmonary hemosiderosis (IPH). Methods: Ten patients were included in the study. The diagnosis of IPH was based on clinical symptoms, laboratory examinations and pulmonary hemosiderosis. Induction therapy consisted of methylprednisolone pulse therapy, followed by prednisone plus leflunomide. Maintenance therapy consisted of low-dose prednisone, leflunomide and administration of MSCs. Results: All the patients achieved complete response after treatment with corticosteroid, leflunomide and MSCs. The median follow-up was 23 months (range: 4-34 months). Moreover, administration of MSCs induced an increase in the percentage of CD4+ CD25+ regulatory T cells but a decrease in the percentage of Th17 cells. Conclusion: Treatment with corticosteroid, leflunomide and MSCs for pediatric IPH was safe and effective.

A novel common gamma chain mutation in a Chinese family with X-linked severe combined immunodeficiency (X-SCID; T(-)NK(-)B(+)).

X-linked severe combined immunodeficiency (X-SCID) is one of the most common causes of primary immunodeficiencies in humans. A 4-month-old boy with recurrent pulmonary infection had decreased numbers of CD3(+), CD4(+), CD8(+) T lymphocytes, and NK cells and increased levels of CD19(+) B cells but no memory B cells or plasma cells. The production of cytokines by T cells and the activation of T and B cells were either absent or inefficient. While B cell levels were high, they were all IgM-positive, and the secretion of all Ig isotypes by activated B cells in vitro was defective. Genomic DNA sequencing revealed that the patient had missense mutations in the IL2RG (exon 5, 718 T > C) and IL7R genes (exon 2, 197 T > C; exon 4, 412G > A). Although the patient's father and one of his sisters have the same missense homozygous mutations of the IL7R gene, neither of them exhibited the immunological phenotype of SCID. The results indicate that the IL2RG gene mutation or a combination of the IL7R and IL2RG mutations in the sick boy had resulted in T(-)NK(-)B(+) SCID.

[Effect of dexamethasone on the expression of aquaporin-5 in the lungs of mice with acute allergic asthma].

OBJECTIVE: To detect the expression of lung aquaporin 5 (AQP5) in mice with acute allergic asthma and the effect of dexamethasone (DEX) treatment on AQP5 expression, and investigate the role of AOP5 in asthma pathogenesis. METHODS: Mouse models of acute allergic asthma were randomly divided into acute asthma group, normal control group and DEX treatment group. The total number of white blood cells, the subpopulations, and the levels of IL-5 and IFN-gamma were detected in the bronchoalveolar larvage fluid (BALF). The lung tissue AQP5 mRNA expression was detected by RT-PCR, and AQP5 distribution by immunohistochemical method. RESULTS: In asthma group, the total white blood cells, eosinophils and IL-5 levels were all significantly higher (P<0.01) and IFN-gamma levels lower than those of the control group (P<0.01). After DEX treatment, the levels underwent a significant reverse change (P<0.05, P<0.01, P<0.01, and P<0.01, respectively). AQP5 mRNA expression in the asthma group was significantly higher than that in the control group (P<0.01), and was significantly lowered with DEX treatment (P<0.01). Extensive inflammatory changes, mucus hypersecrection, several edema and inflammatory cell infitration around the blood vessels were observed in the lung tissue of the mice in the asthma group. The morphological changes of the treatment group were significantly ameliorated. AQP5 protein was detected in the type I alveolar epithelial cells, the airway columnar epithelial cells and the apical membranes of the submucosal gland acinar cells in the control group. Stronger AQP5 protein expression was found in the asthma group. CONCLUSION: AQP5 is over-expressed in mice with acute asthma which is possibly associated with mucus hypersecrection. DEX can inhibit AQP5 expression and ameliorate allergic airway inflammation, edema and mucus hypersecrection.