RESUMEN
OBJECTIVE: To compare the distribution of HLA-B*27 subtypes in healthy controls and in ankylosing spondylitis (AS) patients of different ethnic groups from Pakistan. STUDY DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from April 2016 to October 2017. METHODOLOGY: Forty-nine HLA-B*27 positive, unrelated AS patients and 18 HLA-B*27 positive healthy BMT/renal transplant donors were selected for this study. Typing of the HLA-B27 alleles was performed by the polymerase chain reaction-sequence-specific primer (PCR-SSP). RESULTS: There was a wide number of HLA-B*27 subtypes and an elevated frequency of the B*2707 allele in the AS patients. The allele B*2706 seems to have a protective role in the population studied because it was found only in the healthy controls. HLA-B*27:03 and 07 were found predominant subtypes in Punjabis and Pathans, respectively. CONCLUSION: There were no significant differences for the distribution of B*27 subtypes between patients and controls (p >0.05).