1996 Volume 23 Issue 1 Pages 63-82
The etiology of mixed connective tissue disease(MCTD)still remains unknown and the disease entities named MCTD is not definitely but empirically constructed by the prescribed combination of the signs and symptoms and laboratory findings(SS)which are frequently observed in so-called collagen diseases. Using a clustering technique, internal structure of MCTD has been studied on a mathematical model as to whether it can be divided into smaller groups. Each MCTD case was represented in the form of multidimensional vector shown by the existence or non-existence of 32 SS. The results are as follows: 1. We could not divide MCTD into several subgroups with good reproducibility. 2. However, we sometimes obtained the subgroups which could be characterized by clinical features. It was concluded that the approach shown in this paper could give a working hypothesis to help the further classification of diverse MCTD patients.