Chronic Graft Versus Host Disease (cGVHD) Following Unrelated Donor Hematopoietic Stem Cell Transplantation (HSCT): Higher Response Rate in Recipients of Unrelated Donor (URD) Umbilical Cord Blood (UCB).

The nature of chronic graft versus host disease (cGVHD) after umbilical cord blood (UCB) transplant has not been well characterized. We analyzed clinical presentation and response to treatment in 170 patients with cGVHD (123 following transplant from an unrelated donor (URD) and 47 following transplant from UCB). URD transplant recipients were significantly younger (median age 25 (0.5–57) versus 39 (0.2–61) years, p = 0.002; and were less likely to receive a transplant from an HLA mismatched donor (33% versus 90%, p<0.0001). Seven% and 43% of patients underwent a transplant using a non myeloablative conditioning in the URD and UCB groups, respectively (p< 0.001). Progressive onset of cGVHD was seen in 27% and 19% of patients in URD and UCB cohorts (p =0.15) and platelet count of < 100,000/μl was seen in 36% and 15% of patients (p =0.014), respectively. The median follow up was 5 (0.14–10.8) and 1.5 (0.02–8.8) years in the 2 groups, respectively. A higher rate of response (CR+PR) to treatment was seen in UCB group across all time periods. Rates of response were 48% versus 74% at 2 months (p =0.005); 49% versus 78% at 6 months (p =0.001) and 51% versus 72% at 1 year (p =0.03) in the URD and UCB groups, respectively. Overall survival at 2 years was 59% (50–67%) versus 71% (53–83%) at 2 years and at 5 years was 54% (44–63%) versus 64% (42–79%) (p=0.17). In multivariate analysis, progressive onset of CGVHD (RR=2.3, 95% CI 1.4–3.8−2.3,p=0.002), platelet count of <100,000/μl (RR=3.5, 95% CI 1.7–7.3,p=0.0009), liver involvement (RR=2.5, 95% CI 1.4–4.6,p=0.002), and no CR or PR at 2 months (RR=3.5, 95% CI 2.1–5.9,p<0.0001) were associated with significantly increased mortality. These data suggests that among patients undergoing transplant from unrelated donor or cord blood, despite similar clinical presentation, higher rates of response to treatment were seen in UCB recipients. Early identification of high risk groups (progressive onset, less than PR at 2 months, platelet count < 100,000/μl and liver involvement should facilitate timely assignment of intensified therapy.