CD8A and autoimmune thrombocytopenic purpura: The percentage of T cells was elevated in corticosteroid‐resistant CTD‐ITP than corticosteroid‐sensitive CTD‐ITP (71.38% and 64.70%, respectively, p = 0.004), mainly the CD3+CD8+ T cell increasing significantly (38.55% and 28.95%, respectively, p = 0.003).