Atypical hemolytic uremic syndrome(aHUS) has recently been shown to be a rare disease of genetic predisposition, including genes of complement factor H(CFH), membrane cofactor protein(MCP, CD46)and complement factor Ⅰ(CFI), which are complement regulatory genes. Genes mutation is about 50%,involving the three genes mutation, including nonsense mutation, missen mutation, silent mutation, splice mutation and insertion mutation. Autosomal dominant inheritance and autosomal recessive inheritance have been reported, however, for autosomal dominant inheritance, the three genes mutations are incomplete penetrance.

p300/CBP-associated factor (PCAF)is an important histone acetyltransferase in eukaryotic cells. PCAF can acetylizes histone and non-histone. PCAF participates in various biological processes of cells and in the interaction between virus and cells. The imbalance of PCAF would lead to abnormal development of various organs, and related to the development of some tumors.

The intestinal mucosa is the biggest lymph organ in human body, which consists of the first line of defensive system with the respiratory mucosa and urinary mucosa. The intestinal mucosa is responsible to defend bacteria, viruses, dietary pathogens, non-steroid anti-inflammatory drug and so on. If the intestinal mucosal immune system is destroyed, the human will suffer many diseases such as infectious diseases,autoimmune diseases. Therefore, it plays an important part in physical health. T helper type 17 (Th17) cells different from Th1 cells and Th2 cells are a distinct lineage of T cells. The discovery of Th17 cells has ruined the constitutional pattern of Th1/Th2. Th17 cells, which are important parts of intestinal mucosal immune system,play critical roles in intestinal autoimmune diseases, tissue inflammation and the infection of various pathogenic bacteria. This paper will review the differentiation of Th17 cell and its function in intestinal mucosal barrier,intestinal autoimmune diseases and intestinal infectious diseases.

Ankylosing spondylitis (AS) is a chronic rheumatic disease involving the spine and sacral hip.AS is the prototype disease of seronegative arthritis of the spine.Besides the violations of the spine,AS can also lead to violations of the peripheral joints,even the eyes,intestine,aortic root,and other tissues and organs.The pathogenesis of AS has remained unclear.AS,a genetic disease,is influenced by the genetic and environmental factors.Studies have suggested that HLA-B27 is the most critical genes to AS,and forming three kinds of hypotheses associated with HLA-B27.This paper reviews the molecular genetics and pathogenesis of AS.

Children aerophagia is a relatively rare functional gastrointestinal disease.Its main clinical manifestations are swallowing air,chronic bloating,belching and increased anal exhaust.Since lack of understanding of children aerophagia in pediatricians,it can be very easily missed or misdiagnosed in clinic.Understanding of the research status about children aerophagia means to pediatric clinical guidance.This review summarizes the causes,clinical manifestation,diagnosis and treatment of children aerophagia.

Periventricular leukomalacia in premature infants is the most common brain injury.It often results in spastic cerebral palsy,cognitive and behavioral abnormalities and other sequelae.The microglia is the primary immune response cell in brain,and it plays an important role in balancing mechanism for the defense response and brain injury.The suppression of its activated reaction can reduce the cytotoxic effect and pathological damage in the early phase.

With the development of mycoplasma pneumonia (MP) pathogenesis research,the dynamic observation of changes of cytokines on judgement of the infection of mycoplasma is of certain guiding significance.Domestic and foreign studies showed that MP infection was closely related with IL-17 and its receptor.IL-17 and its receptor may be involved in neutrophil recruitment,and in resistance to MP infection on the immune response.In this paper,the relationship between IL-17and its recepter and mycoplasma infection are reviewed.

Hemophagocytic lymphohistiocytosis (HLH) is classified into primary and secondary HLH according to the etiology.Primary HLH includes familial HLH and primary immunodeficiency HLH.Primary immunodeficiency HLH includes Chediak-higashi syndrome,Griscelli syndrome Ⅱ,Hermansky-Pudlak syndrome Ⅱ,X-linked lymphoproliferative syndrome I,X-linked lymphoproliferative syndrome Ⅱ and so on.These diseases may develop into HLH because of mutations in genes resulting in impaired function of natural killer cells and T cells,macrophage activation and extreme inflammation.The common clinical manifestations are repeated infection,prolonged fever,hepatosplenomegaly,cytopenia,hemophagocytosis in bone marrow,elevated ferritin,low fibrinogen and so on.The immunochemotherapy of dexamethasone,etoposide,cyclosporine A can be an effective remission-inducing treatment.Hematopoietic stem cell transplantation is the only known cure of the primary immunodeficiency HLH.

Malnutrition and high nutrition risk exist in children with chronic diseases due to the prolonged course.Malnutrition can not only affect children's growth,but also can increase the risk of nutritionrelated complications,infection,time of hospitalization,hospital costs.Children with chronic diseases have inadequate intake and malabsorption,as well as the increased consumption caused by infection and inflammation.Different diseases need to be given special nutritional support and management,which help improve the clinical outcome and get well for children with chronic diseases.This review summarizes the progresses of nutritional status,nutrition risk assessment and nutritional management of children with chronic diseases.

Bronchiectasis is one of the common chronic lung diseases in children.Now chest high resolution CT is the best method for the diagnosis of bronchiectasis.Chest MRI is an accurate,radiation-free technique,and it contributes to finding early lung lesions.Lung function and airway inflammation test are used for effectively assessing the disease status.This review focuses on the main diagnostic methods of bronchiectasis in children.