CDR3 size distribution of TCR BV derived from BM T cells of CyA-dependent AA patients. TCR cDNA of another normal individual with HLA-DRB1*1501 (N3, normal no. 3) and patients no. 5-9 (P5-P9) whose hematopoietic function depended on continuous administration of CyA was analyzed. A large number of BV subfamilies (> 40%) of the patients displayed a skewed or collapsed pattern with a reduced peak number, indicating clonal or oligoclonal proliferation of T cells.