Cumulative incidences of grades II to IV and cortico-resistant acute GvHD according to primary diagnosis and recipient age at the time of transplantation. (A) Cumulative incidence of grades II to IV AGvHD in patients younger than 12 years of age at the time of transplantation was 72% in FA (solid black line; n = 18) versus 13% in non-FA patients (dashed gray line; n = 15; P = .0012). Cumulative incidence of AGvHD for patients of at least 12 years of age at the time of transplantation was 53% in FA (dashed black line, n = 19) versus 52% in non-FA patients (solid gray line, n = 58; P = NS). (B) Probability of requiring systemic corticosteroid therapy for treatment of AGvHD by day +100 after transplantation was 85% in FA patients (thick black line) versus 70% in non-FA patients given CsA alone (thin black line) and 81% in non-FA patients given CsA plus MTX (dashed line) (P = .045 when all 3 groups compared; probability, 74% for all non-FA patients; P = .013 when FA patients compared with all non-FA patients). (C) Cumulative incidence of cortico-resistant AGvHD in patients younger than 12 years of age at the time of transplantation was 56% in FA (solid black line, n = 18) versus 13% in non-FA patients (dashed gray line, n = 15; P = .008). Cumulative incidence of cortico-resistant AGvHD in patients of at least 12 years of age at the time of transplantation was 29% in FA (solid gray line, n = 19) versus 38% in non-FA patients (dashed black line, n = 58; P = NS).