重疊綜合征(Overlapsyndrome):指的是患有兩(liang)種或兩(liang)種以上結締(di)(di)(di)組織(zhi)病(bing)間(jian)病(bing)情(qing)的重(zhong)(zhong)疊(die),亦(yi)稱為重(zhong)(zhong)疊(die)結締(di)(di)(di)組織(zhi)病(bing)。這(zhe)(zhe)種重(zhong)(zhong)疊(die)可(ke)同時(shi)發生,好病(bing)人在同一(yi)時(shi)間(jian)符合(he)兩(liang)種或兩(liang)種以上結締(di)(di)(di)組織(zhi)病(bing)的診斷;亦(yi)可(ke)在不同時(shi)期先(xian)后發生另一(yi)種結締(di)(di)(di)組織(zhi)病(bing);或先(xian)有某一(yi)種結締(di)(di)(di)組織(zhi)病(bing),以后移行(xing)轉變(bian)為另一(yi)種CTD。這(zhe)(zhe)種轉變(bian)可(ke)呈連續性(xing)(xing)或間(jian)隔一(yi)定(ding)時(shi)間(jian)后進(jin)行(xing)。OS通常發生于6個彌漫性(xing)(xing)CTD,即SLE、RA、DM/PM、PSS、結節性(xing)(xing)多動(dong)脈炎(PN)及風濕熱(RF)的重(zhong)(zhong)疊(die),亦(yi)可(ke)由6個CTD與近緣病(bing)如白塞(sai)病(bing)、干燥(zao)綜合(he)征(zheng)、脂膜(mo)炎相(xiang)重(zhong)(zhong)疊(die),此外尚可(ke)與其他自身(shen)免疫病(bing)如慢(man)性(xing)(xing)甲狀膽狀腺炎、自身(shen)免疫性(xing)(xing)溶血性(xing)(xing)貧血等重(zhong)(zhong)疊(die)。