Mosca M, Baldini C, Bombardieri S
Department of Internal Medicine, University of Pisa, Italy.
Clin Exp Rheumatol. 2004 Jan-Feb;22(3 Suppl 33):S14-8.
The existence of patients with signs and symptoms suggestive of a systemic autoimmune disease but not fulfilling the classification criteria for defined diseases is a common experience in clinical practice. The first description of these diseases dates back to 1980, when LeRoy proposed the term "Undifferentiated Connective Tissue Syndromes" (UCTS) to define the early phases of connective tissue diseases that at their onset are undefined, as opposed to mixed or overlapping syndromes in which the disease appears well defined. LeRoy also raised the fundamental question as to whether a proportion of patients with an undifferentiated profile may see their condition remain undifferentiated or even experience a remission of all pathologic features, rather than evolving to a definite connective tissue disease (CTD). Many studies conducted on undifferentiated diseases have shown that up to 75% of patients will not develop a defined CTD and that these conditions exhibit typical clinical and serological manifestations and a good prognosis. We and others have defined these conditions as Undifferentiated Connective Tissue Diseases (UCTD) and it is our opinion that the UCTD represent distinct clinical entites. UCTD could offer an ideal clinical model for the study of single autoantibody specificities, the effects of various factors (such as pregnancy) on the disease course, and the general pathogenesis of autoimmune conditions. Before they can be so used, more must be discovered about their nature and characteristics, and studies will be necessary to improve the sensitivity and specificity of the existing preliminary classification criteria.
临床上，常有一些患者出现提示系统性自身免疫性疾病的体征和症状，但不符合特定疾病的分类标准。这些疾病最早在1980年被描述，当时勒罗伊提出了“未分化结缔组织综合征”（UCTS）这一术语，用于定义结缔组织疾病的早期阶段，这些疾病在发病时不明确，与疾病表现明确的混合或重叠综合征形成对比。勒罗伊还提出了一个基本问题，即一部分未分化型患者的病情是否会一直保持未分化状态，甚至所有病理特征都缓解，而不是发展为明确的结缔组织病（CTD）。许多针对未分化疾病的研究表明，高达75%的患者不会发展为明确的CTD，这些病症表现出典型的临床和血清学表现，且预后良好。我们和其他人将这些病症定义为未分化结缔组织病（UCTD），我们认为UCTD代表了不同的临床实体。UCTD可为研究单一自身抗体特异性、各种因素（如妊娠）对病程的影响以及自身免疫性疾病的一般发病机制提供理想的临床模型。在能够如此应用之前，必须更多地了解它们的性质和特征，还需要开展研究以提高现有初步分类标准的敏感性和特异性。
