Immune Function of T-lymphocyte and Erythocyte in Children with Febrile Convulsion

Objective To study the immune function of T-lymphocyte and erythrocyte in the peripheral blood of children with febrile convulsion. Methods Eighty-two children with typical febrile convulsion, 40 children with acute upper respiratory tract infection (URI) and 40 normal children were enrolled. The proliferation reaction of T-lymphocyte to PHA, distribution of T-lymphocyte phenotype subsets, expression of activation markers CD25 (IL-2R) and HLA-DR, and level of γ-interferon induced by PHA were assayed. Erythrocyte immune function was simultaneously measured by rosette formation rates of RBC-C3bR and RBC-IC. Results The counts per minute (CPM) and stimulation index (SI), the measurements expressing T-lymphocyte proliferation assay in simple febrile convulsion (SFC) children, were 5 609.4± 3 587.4 and 20.5± 15.6, and 2 817.3± 2 422.8 and 11.0± 8.4 in complex febrile convulsion (CFC) children. They were significantly lower than those in the normal controls ( 20 305.9± 12 810.3 and 69.2± 45.2) and in the URI group ( 9 785.2± 7 509.8 and 44.5± 39.8) (P 0.05). The CD3, CD4 and CD4/CD8 ratio in the SFC children were ( 40.0± 8.2)%, ( 26.1± 9.0)% and 1.1± 0.4 and ( 932.8± 6.9)%, ( 17.8± 4.9)% and 0.8± 0.1 in the CFC children. They were all significantly lower than those in the normal controls [( 64.1± 6.7)%, ( 47.7± 5.5)% and 1.9± 0.8] and in the URI group [( 63.0± 9.3), ( 42.4± 8.2)% and 1.6± 0.4] (P 0.01). The expression rates of CD25 (IL-2R) and HLA-DR antigen in the spontaneous condition in the SFC children were ( 8.9± 3.6)% and ( 16.2± 5.6)% and ( 6.3± 1.9)% and ( 12.4± 3.4)% in the CFS children. They were lower than those in the normal controls [( 12.8± 2.5)% and ( 20.2± 5.2)%]and in the URI group [( 15.0± 3.0)% and ( 20.5± 2.8)%] (P 0.01) and there were also differences in the SFC children and in the CFS children (P 0.05). After PHA induction, the expression rates of CD25 (IL-2R) and HLA-DR antigen in the SFC children were ( 57.0± 5.1) and ( 57.8± 6.0) and ( 53.0± 12.0)% and ( 54.7± 9.7)% in the CFC children. They were significantly lower than those in the normal controls [( 65.7± 5.7)% and ( 68.8± 6.2)%] (P 0.05) and in the URI group [( 64.3± 6.4)% and ( 67.1± 8.6)%](P 0.01). The γ-IFN level of PBMC induced by PHA in the SFC and CFC children [( 1.80± 0.4) and ( 1.6± 0.1) ng/ml] was significantly lower than that in the normal controls [( 2.4± 0.9) ng/ml](P 0.05). No difference was found compared with the URI group. The rate of rosette formation of RBC-C3b in the SFC children was ( 9.1± 4.9)% and it was significantly lower than that in the normal controls and the URI group [( 15.8± 5.7)% and ( 13.5± 5.1)%](P 0.01), but there was no difference in the SFC children, the normal controls and the URI group. The rate of rosette formation of RBC-IC in the SFC children and the CFC children [( 3.0± 1.0) and ( 2.6± 0.7)%] was significantly lower than that in the normal controls [( 3.7± 1.3)%] and the URI group [( 3.9± 1.4)%](P 0.05). Conclusions Both T-lymphocyte immune function and erythrocyte immune function in the children with FC were significantly impaired. The impair was more severe in the CFC children than that in the SFC children.