Ambiguous allele combinations at group level of HLA-A, -C, and -B genes in Macedonian population using reverse line strip typing method.

The aim of this study was to investigate the occurrence of ambiguous allele combinations at the allele group level of HLA-A, -C and -B loci in the Macedonian population. The DNA samples of 214 healthy unrelated Macedonian volunteers were obtained from our DNA Bank. HLA typing was performed using the IHWG-RLS method (Reverse Line Strip, Roche Molecular Systems, USA) consisting of PCR amplification of exon 2 and 3 of HLA-A, -B and -C genes, followed by hybridization. The statistical analysis of the observed ambiguity frequency was performed by using the Arleqin Software. At the HLA-A locus only one ambiguous allele combination at the allele group level in 214 samples was observed with a frequency of 0.467% (1/214 = 0.467%). A total of 6 different HLA-C ambiguous allele combinations at the allele group level in twelve samples with a frequency of 5.607% (12/214 = 5.607%) and 11 different for HLA-B locus in nineteen samples with a frequency of 8.879% (19/214 = 8.879%) were observed in 214 samples. In conclusion we can say that analysis of the frequency of allele ambiguities revealed that the ambiguities involved some of the most common alleles in our population, obviating the need to introduce ambiguity resolution technique(s)/strategies in the HLA laboratory.