Sunday, May 08, 2005

Two new Autism Spectrum Disorder studies

Blood proteins and immune-system components in children with autism differ from those in normal children, found a couple of studies presented Thursday at the Fourth International Meeting for Autism Research, in Boston.Because of the difference, a diagnostic blood test may someday be performed to detect autism in early infancy or at birth. Researchers hope that early detection may lead to better treatment and maybe better prevention of autism. But for now, diagnosis of autism is based on behavioral observations at age 2 through 4 years.In the first study, David Amaral and colleagues at the University of California, Davis M.I.N.D. Institute tested the blood samples from 70 children with autism and 35 normal children aged 4 to 6 years for their immune cells, proteins and metabolites.The researchers found that proteins, immune system components and metabolites in the children with autism were different from those in the normal children. For example, compared with the normal children, the autistic children had their antibody-producing B cells and natural killer cells increased by 20 percent and 40 percent respectively. Albeit all the difference, researchers suggested that evidence was not enough to pick an autism marker from the tested proteins, immune-system components and metabolites while the study certainly revealed that autism makes a difference at a cellular level.The second study, conducted by Judy Van de Water and colleagues at the UC-Davis School of Medicine and the UC Davis M.I.N.D. Institute, found that among others, the immune system responses in children with autism differed from that of normal children.In their study, blood samples from 30 children with autism and 26 healthy children aged 2 to5 years were exposed to bacterial and viral agents including vaccine antigens.The researchers found that T-cells, B-cells, and macrophages generated in children with autism in response to exposure to the antigens were different from those of the healthy children.One finding is that levels of cytokines in the autism group were lower than that in the healthy children. Cytokines facilitate communications between different cells. Among other things, they affect sleep. That explains why many autism children have sleep disorder.The results of both studies suggest that the immune system is dysfunctional in the children with autism although it’s unclear what dysfunction it is.The cause of autism remains unknown. What people know is that autism was rare a couple of decades ago and now one in 160 American children suffer from autism.