HLA ALLELE DISTRIBUTION DISTINGUISHES SPORADIC INCLUSION-BODY MYOSITIS FROM HEREDITARY INCLUSION-BODY MYOPATHIES

We studied the HLA class II associations in patients with sporadic inc lusion body myositis (s-IBM) and hereditary inclusion body myopathies (h-IBM) and attempted to distinguish these myopathies on the basis of HLA allele assignments. Forty-five patients, 30 with s-IBM and 15 with h-IBM, underwent HLA class II allele-specific typing using polymerase chain reaction sequence-specific primers for 71 alleles contained in the DR beta 1, DR beta 3-5, and DQ beta 1 loci. In s-IBM, we found a h igh (up to 77%) frequency of DR beta 10301, DR beta 3*0101 (or DR bet a 30202) and DQ beta 1*0201 alleles. No significant association with alleles in the DR and De haplotypes was found among the 15 h-IBM patie nts. The strong association of prominent alleles with s-IBM, but not h -IBM, suggests that s-IBM is a distinct disorder with an immunogenetic background that differs from h-IBM. Published by Elsevier Science B.V .