Lack of association between the HLA-DRB1 locus and post-streptococcal reactive arthritis and acute rheumatic fever in Italian children.

Objective: Post-streptococcal reactive arthritis (PSReA) may be a variant of acute rheumatic fever (ARF), but there still is debate on the relationship between the 2 entities. Possible associations with HLA class II antigens of PSReA (DRB1*01) and ARF (DRB1*16) were described previously in white Americans. To confirm these findings, we studied DRB1 alleles in a group of Italian children with PSReA and ARF.

Methods: We performed low-resolution HLA-DRB1 typing by a sequence-specific primer polymerase chain reaction method in 33 children with PSReA and 25 children with ARF. We also compared the DRB1 genotypes of our patients with 200 normal subjects from the same geographic area and typed in the same laboratory with the same methods.

Results: The allele distributions at the DRB1 locus observed in PSReA patients, ARF patients, and controls were not significantly different from each other (chi-square test with small numbers, P = .65). The positivity for each of the 13 HLA-DRB1 alleles was compared in disease groups (PSReA and ARF) and controls, and failed to show any significant association. Comparisons of the frequency of the DRB1*01 allele among PSReA, ARF, and controls did not show any statistical differences. No significant difference in the frequency of DRB1*16 was present between ARF vs the control group, between ARF vs PSReA, and in PSReA patients when compared with controls.

Conclusions: Our data do not confirm in Italian patients the previously reported associations of DRB1*01 and DRB1*16 with PSReA and ARF, respectively.