Efficacy of allogeneic hematopoietic cell transplantation for autoimmune diseases

Abstract Background Allogeneic hematopoietic cell transplantation (HCT) may be efficacious for autoimmune diseases (AIDs), but the efficacy for each AID is unknown. Factors influencing the likelihood of relapse for each AID are also unknown. Objective To determine the likelihood of relapse for each common AID, and to generate hypotheses about factors influencing the likelihood of relapse. Methods We reviewed charts of adult patients with nonhematologic AIDs who had undergone HCT in Alberta (n=21) and patients described in the literature (n=67). We used stringent inclusion criteria to minimize the inclusion of patients whose AID may have been cured pretransplant. We also used stringent definitions of AID relapse and remission. Results AID relapsed in 2/9 (22%) patients with lupus, 4/12 (33%) with rheumatoid arthritis (RA), 0/4 (0%) with systemic sclerosis (SSc), 3/16 (19%) with psoriasis, 1/12 (8%) with Behcet's disease (BD), 1/15 (7%) with Crohn's disease (CD), 0/5 (0%) with ulcerative colitis (UC), 4/8 (50%) with multiple sclerosis (MS), and 3/3 (100%) with type 1 diabetes (T1DM). Among highly informative patients (followed for >1 year after discontinuation of immunosuppressive therapy if no relapse, or donor AID status known if relapse), relapse occurred in 0/3 patients with lupus, 2/7 with RA, 0/2 with SSc, 3/6 with psoriasis, 0/3 with BD, 0/10 with CD, 0/3 with UC, 2/3 with MS, and 2/2 with T1DM. There appeared to be no relation of AID relapse to low intensity of pretransplant chemoradiotherapy, multiple lines of AID therapy (surrogate for AID refractoriness) except perhaps for lupus, absence of serotherapy for graft-vs-host disease (GVHD) prophylaxis, lack of GVHD except perhaps for lupus, or incomplete donor chimerism. Conclusions Despite remission commonly occurring after HCT in lupus, RA, SSc, psoriasis, BD, CD, and UC, HCT is efficacious for only a subset of patients. The efficacy appears unrelated to pretransplant therapy, GVHD, or chimerism. Large studies are needed to determine for each AID the characteristics of patients likely to benefit from HCT.