Incidence and prognostic value of eosinophilia in chronic graft-versus-host disease after nonmyeloablative hematopoietic cell transplantation.

Data from a number of cohorts indicate that eosinophilia (Eo) could be associated with better outcomes following allogeneic hematopoietic cell transplant (HCT). However, little is known about its significance and prognostic value in chronic graft-versus-host disease (cGVHD) after nonmyeloablative (NMA) transplantation. Data were collected from 170 patients who underwent HCT using the same preparative regimen and GVHD prophylaxis. Donors were 6/6 HLA-matched siblings and stem cell source was peripheral blood. An eosinophil count of ≥0.5 × 10(9)/L was defined as Eo. Patients were transplanted mainly for lymphoproliferative disorders. Median age and follow-up were 54 years and 58 months, respectively. Incidents of grade II-IV acute GVHD (aGVHD) and cGVHD were 8.2% and 81.2%. Median time from HCT to cGVHD diagnosis was 142 days. Organs involved were: mouth in 80% of patients, skin in 75%, liver in 57%, eyes in 37%, gut in 14%, lungs in 5%, others in 5%. Eo was found in 44% of patients at diagnosis of cGVHD (range: 0.5-4.4 × 10(9)/L). Median time between first appearance of Eo and diagnosis of cGVHD was 4.5 days. We found no correlation between organ involvement and Eo but a lower prevalence of Eo in cGVHD associated with thrombocytopenia (P = .023). Nevertheless, we observed no association among Eo and overall survival (OS), relapse incidence, or nonrelapse mortality (NRM) in the overall cohort, nor in subsets of patients with multiple myeloma and follicular non-Hodgkin lymphoma. Although Eo is observed frequently in cGVHD following NMA transplantation, we report no correlation beween Eo and outcome.