The CD₂₃ Expressions On B Lymphocytes In Wheezing Infants

Background and Objective:wheezing in infancy is very common. One third of all children have at least one wheezing episode by their third birthday, which represent the onset of asthma in some of them. Asthma generally starts during the first years of life. Its pathogenesis is very complex. Both genetic factors and environmental factors contribute to its inception and evolution. Many different genes are likely involved. Expression of specific phenotypes may depend on interaction with environmental factors prenatally and/or postnatally. Moreover, different genes may be important in differentsubjects and in different ethnic groups. They complicate the diagnosis, especially in early childhood. But no reliable index that could predict whether the wheezing infant is subsequently likely to experience bronchialasthma exists. The investigation into immunologic processes indicates that asthma results from an interaction with environmental factors, with the transition from T helper 2 (TH2)-type to T helper 1 (THl)-type immunity delayed and with a cytokine imbalance or dysregulation of a predominant TH2-type immunity. The increase of interleukin [IL]-4 (Th2 cytokines) and decrease of interferon [IFN]-r (type 1 cytokines) directly upregulate CD23 expression on peripheral blood lymphocytes. The expression of CD23 and the activation of B-cell may enhance production of IgE. It was reported that the severity of asthma correlated positively with the CD23 expressions on peripheral blood lymphocytes in adult, but has not been reported in infants with asthma. We investigated whether CD23 expressions on B lymphocytes (CD23+/CD|9+) is increased in infants with asthma and studied their expresses in infants experiencing their early episodes of wheezing.MethodsIn a prospective trial, the CD23+/CD19+, CD23 expressions on peripheral blood mononuclear cells (PBMC) from infants with wheezing of uncertain etiology (n=53), infants with asthma (n=17), infants withpneumonia (n=18) and healthy nonatopic infants(n=22) were tested by flow cytometry (FCM). the CD23 expressions minus CD23+/CDi9+ expressions leave CD23+/CD19- expressions. Their serum total IgE levels were tested by chemiluminescence immunoassay (CLIA). At a three-year follow-up, fifty-three children with wheezing of uncertain etiology were re-evaluated for a diagnosis of infantile asthma. They were classified in two groups: Group I , those with asthma; and Group II, those without asthma. The data before the follow-up were analysed and compared with those of the other infants. Their data before the follow-up were analysed and compared with those of the other infants.Results1 The number of the infants in Group I is 20 and 33 in Group II. 2 All the parameters except CD23+/CD19- among the infants with asthma, infants with pneumonia and healthy nonatopic infants showed significant differences( P < 0.01). The CD23+/CD19+ CD23 expressions were increased in infants with asthma[[(12.12+4.74)%, 445 + 222/ mm3] ; [(12.89 + 3.37)%, 475 + 253/ mm3]] as compared with infants with pneumonia [[(7.22+1.36)%, (232 + 85)/ mm3] [(8.39+1.71)%, (273 + 114)/ mm3]]and healthy nonatopic infants[[(7.08+2.71)%, (246+132)/ mm3] [(7.95 +3.35)%, (280+ 165)/ mm3]]](P < 0.01).3 There were no difference between the infants with pneumonia and thehealthy subjects about the CD23+/CD19+ CD23 expressions.4 The CD23+/CD19+ CD23 expressions were increased in the infants inGroup I [[(10.46+1.60)%, (405 + 80)/ mm3] [(11.74 + 2.18)%, (453 + 87)/mm3] %] and as high as that infants with asthma as compared withwheezing infants with pneumonia and healthy nonatopic infants( P < 0.01).5. There were no difference among the Group II [[(7.36 + 2.48)%, 235 + 63/mm3] [(8.28 + 2.63)%, 264 + 74/ mm3]] and the infants with pneumoniaand the healthy subjects, about the CD23+/CD19+ CD23 expressions(P >0.05).6 The CD23+/CD19+ CD23 expressions were increased in the infants inGroup I as compared with those of the infants in Group II ( P < 0.01). 7...