Undifferentiated connective tissue disease

In recent years, undifferentiated connective tissue disease (UCTD) has gradually been recognized by people. The disease has some clinical manifestations of connective tissue disease, but it does not meet the diagnostic criteria for any particular disease. It may belong to the early stage or frustration of a diffuse connective tissue disease, and may be an independent disease in some patients. So far, no characteristic clinical manifestations and specific laboratory indicators of UCTD have been found. The diagnosis of UCTD mainly depends on clinical manifestations. Whether this disease is another connective tissue disease still needs further research in academia. The concept of UCTD was first proposed by LeRoy et al. In 1980. However, it was not until 1989 that relevant clinical studies gradually increased. The names in the literature are still inconsistent, and some people call them occult lupus, incomplete or frustrated lupus, early undifferentiated connective tissue disease, and undifferentiated connective tissue syndrome. The diagnostic criteria recommended by each investigator are not completely consistent. In the past ten years, more researches have been done on the clinical characteristics, laboratory abnormalities and outcomes of this disease abroad. There are also many cases of UCTD in China, but there are few systematic reports.