Serologic characteristics of subjects with silent red blood cell autoantibodies according to the associated condition or disorder. (1) Autoimmune disorders: Hashimoto thyroiditis, 4 cases; anti-phospholipid syndrome, 5; systemic lupus erythematosus, 1; autoimmune glomerulonephritis, 1. (2) Lymphoproliferative disorders: bone marrow involvement with MBL, 6 cases, marginal cell lymphoma, 1. (3) Cancers: breast cancer, 2; thyroid cancers, 3.