Minor histocompatibility antigen HA‐1 (MiHAg‐HA‐1) disparity between a patient and his or her human leukocyte antigen (HLA) genoidentical donor has been widely associated with an increased risk of graft‐versus‐host disease following allogeneic hematopoietic stem cell transplantation.
To examine the effect of HA‐1 disparity on the incidence of both acute and chronic graft‐versus‐host disease in Tunisian recipients of hematopoietic stem cells.
A total of 60 patients and their 60 respective sibling hematopoietic stem cell donors were enrolled in this study. All patients prophylactically received cyclosporine A and/or methotrexate for graft‐versus‐host disease. An HA‐1 genotyping assay was performed with the SSP‐PCR method, and HLA‐A*0201‐ and/or HLA‐A*0206‐positive samples were identified using the Luminex HLA typing method.
The Luminex HLA typing assay showed that 54 patients were positive for either the HLA‐A*0201 or HLA‐A*0206 alleles. Among these cases, six pairs were mismatched for MiHAg‐HA‐1. Both acute and chronic graft‐versus‐host disease occurred in four mismatched patients (Fisher's p‐values were 0.044 and 0.170, respectively). A univariate logistic regression model analysis showed that only acute graft‐versus‐host disease may be affected by recipient MiHAg‐HA‐1 disparity (p: 0.041, OR: 6.727), while chronic graft‐versus‐host disease correlates with both age and recipient/donor sex mismatch (p: 0.014, OR: 8.556 and p: 0.033, OR: 8.664, respectively).
Our findings support previously reported data suggesting a significant association between HA‐1 disparity and the risk of acute graft‐versus‐host disease following hematopoietic stem cell transplantation.