Can HLA typing predict the outcome of grass pollen immunotherapy?

Objective: The aim of this study was to investigate the relationship between HLA molecules and the positive or negative response of atopic patients to specific immunotherapy (SIT).

Methods: We studied 42 atopic multisensitive patients undergoing grass pollen immunotherapy, 42 parents of patients (30 mothers and 12 fathers) and 173 control individuals. HLA class I and class II antigens were typed by a microlymphocytotoxicity test. The typing of DRB1* alleles for atopic patients and their parents was based on the reverse hybridization principle, while for the control group, DNA-RFLP and PCR-SSP methods were used.

Results: The frequency of B14 and DRB1*1101-4 antigens/alleles, as well as the A2B5DR11 haplotype, showed a statistically significant difference in those patients who responded to immunotherapy. On the other hand, HLA-A28, B8 and DRB1*0301 antigens/alleles, as well as the frequency of the A1B8 and A1B8DR3 haplotypes, were found to be significantly higher in patients who responded poorly to SIT.

Discussion: Our findings support the hypothesis that treatment responsiveness may show an association to HLA molecules, which could thus play a role in the immunological selection and monitoring of atopic patient candidacy for SIT.