A family history of rheumatoid arthritis, type 1 diabetes mellitus, or celiac disease is associated with a higher risk of developing autism spectrum disorders in children, a recent study found.

    A group of Danish and U.S. researchers collected medical data on all children born in Denmark to Danish mothers between 1993 and 2004 and matched these children with their parents' and siblings' hospital records. Any diagnoses of autoimmune diseases identified before the children were diagnosed with an autism spectrum disorder were analyzed for possible correlations with the children's risk for such a disorder.

    Among 689,196 children, 3,325 had a diagnosis of an autism spectrum disorder. Rheumatoid arthritis in mothers was associated with a 70 percent increase in the risk of autism spectrum disorders in children （risk ratio 1.70, 95 percent confidence interval [CI] 1.07 to 2.54）. Mothers'celiac disease was associated with nearly three times the risk of autism spectrum disorders compared with children of mothers who did not have celiac disease （risk ratio 2.97, 95 percent CI 1.27 to 5.75）. Family history of type 1 diabetes, with parents and siblings included, was associated with a statistically significant increase in the risk of the childhood autism diagnosis （risk ratio 1.78, 1.16 to 2.61）, but not the risk of the overall class of autism spectrum disorders.

    These risk associations remained statistically significant even after the authors limited the analyses to children who were born neither pre-term nor underweight and who had no obvious distress at birth （Apgar score above 6）. This suggests that the observations cannot be entirely explained by detrimental effects on the fetus due to the mother's autoimmune disease. Combined with other research evidence, the authors speculated that certain autoimmune diseases may share a common genetic root with autism.

    Other autoimmune diseases, such as multiple sclerosis, psoriasis, and Crohn's disease, in parents and siblings were not significantly associated with autism spectrum disorders in the study children. Furthermore, a family history of thyrotoxicosis was the only autoimmune disease studied that was associated with a lower risk of autism spectrum disorder.

    The study was published in the August Pediatrics and was funded by grants from the U.S. National Institute of Mental Health and the Aarhus University Research Foundation in Denmark.

    Because of the nationalized health care and central medical registries in Denmark, decades of complete medical data of all Danish citizens in the databases provide a valuable resource for epidemiologic research. In a study published in the February 21, 2004, British Medical Journal, Eaton and colleagues found that a parental history of celiac disease was associated with increased risk of schizophrenia in offspring, also using theDanish national health care registries.

    Celiac disease is an often-undiagnosed autoimmune disease triggered by gluten in wheat-containing foods. Patients usually suffer from gastrointestinal symptoms and nutritional deficiencies because the intestinal linings are attacked and damaged by immune responses to even a minute amount of gluten intake. According to a recent Mayo Clinic study, the prevalence of celiac disease has increased fourfold from the 1950s. The study was published in the July Gastroenterology. The reason for the trend remains unknown.

    最近的一項研究發現，具有家族病史，如類風濕型關節炎、1型糖尿病或乳糜瀉的兒童患孤獨癥的的可能更高。

    一組來自丹麥及美國的研究人員收集了所有1993至2004年間，出生在丹麥、其生母也為丹麥人的兒童的醫學數據資料，并與其父母及兄弟姐妹的病史進行比對。在比對中，任何在兒童被診斷患有孤獨癥之前對于其自身免疫系統疾病的確診，都經過分析以建立兒童免疫系統疾病與孤獨癥之間可能的關聯性。

    在689,196名兒童中，3,325名被診斷患有孤獨癥。當兒童的母親患有類風濕性關節炎，她們的孩子患孤獨癥的幾率增高了百分之七十。當兒童的母親患有乳糜瀉，她們的孩子患孤獨癥的幾率三倍于那些未患此病母親的孩子。具有家族1型糖尿病史（包括父母及兄弟姐妹的病史）的兒童，患有孤獨癥的幾率最高。

    即便研究者將分析研究局限于那些既沒有早產也在分娩時沒有明顯的痛苦跡象（既Apgar值高于6）的兒童，然而這種患病的關聯性表現在數據上依然很顯著。這說明了之前的調查不能將所有對新生兒的不良影響都歸咎與其生母所患的自身免疫系統疾病。結合其他研究結果，研究人員們猜想這種免疫系統疾病也許與孤獨癥具有相同的基因來源。

    然而，兒童的父母、兄弟姐妹是否患有其他的自身免疫系統疾病，比如多發性硬化、牛皮癬以及克隆氏病，這與兒童患孤獨癥并沒有很顯著的關聯性。另外，研究發現，具有家族甲亢病史是目前為止唯一一種與較低的孤獨癥患病率相關聯的自身免疫系統疾病。

    這項研究發表在八月的《小兒科》期刊上，并且此研究受到了凱子美國國家心理健康機構以及丹麥奧胡思大學的資助。

    得益于丹麥來自國家的健康保障以及統一的醫療信息記錄措施，由全部丹麥公民的信息資料庫中幾十年完整的醫療記錄檔案為這項流行病學研究提供了非常有價值的資源。在一項于2004年2月21日發表于《英國醫療期刊》的調查中，伊頓以及同事發現父母具有乳糜瀉病史，與其孩子患精神癥的幾率的增高有關。調查也參考了來自丹麥國家健康保障機構的記錄數據。

    乳糜瀉是一種多發的由含小麥的食物中麩質誘發的自身免疫系統疾病。病患往往表現為腸胃不適癥狀以及營養不良，這是由于因微量麩質引起的自身免疫系統反應作用攻擊并損害了腸道。根據最近的一項來自Mayo醫療機構的研究，乳糜瀉愈發廣泛的流行，從50年代起至今，發病率已經翻了四倍。這項調查發表在四月的《腸胃病學》期刊上。造成這種流行趨勢的原因至今還不清楚。