Genetic risk factors for sclerotic graft-versus-host disease

Sclerotic graft-versus-host disease (GVHD) is a distinctive phenotype of chronic GVHD after allogeneic hematopoietic cell transplantation, characterized by fibrosis of skin or fascia. Sclerotic GVHD has clinical and histopathological similarities with systemic sclerosis, an autoimmune disease whose risk is influenced by genetic polymorphisms. We examined 13 candidate single-nucleotide polymorphisms (SNPs) that have a well-documented association with systemic sclerosis to determine whether these SNPs are also associated with the risk of sclerotic GVHD. The study cohort included 847 consecutive patients who were diagnosed with chronic GVHD. Genotyping was performed using microarrays, followed by imputation of unobserved SNPs. The donor rs10516487 (BANK1: B-cell scaffold protein with ankyrin repeats 1) TT genotype was associated with lower risk of sclerotic GVHD (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.21-0.87; P = .02). Donor and recipient rs2056626 (CD247: T-cell receptor ζ subunit) GG or GT genotypes were associated with higher risk of sclerotic GVHD (HR, 1.57; 95% CI, 1.13-2.18; P = .007 and HR, 1.66; 95% CI, 1.19-2.32; P = .003, respectively). Donor and recipient rs987870 (5'-flanking region of HLA-DPA1) CC genotypes were associated with higher risk of sclerotic GVHD (HR, 2.50; 95% CI, 1.22-5.11; P = .01 and HR, 2.13; 95% CI, 1.00-4.54; P = .05, respectively). In further analyses, the recipient DPA1*01:03∼DPB1*04:01 haplotype and certain amino acid substitutions in the recipient P1 peptide-binding pocket of the HLA-DP heterodimer were associated with risk of sclerotic GVHD. Genetic components associated with systemic sclerosis are also associated with sclerotic GVHD. HLA-DP-mediated antigen presentation, T-cell response, and B-cell activation have important roles in the pathogenic mechanisms of both diseases.