To the Editor.
—In the August 1990 issue of the Archives, Suarez-Almazor and Russell1 reported their human leukocyte antigen (HLA) studies on siblings with psoriasis. Their article, as well as the editorial in the same issue, states that there are no previous systematic studies on HLA in families with several psoriatic patients.2 They thus ignore our HLA family studies on psoriasis that were published in 1976.3 This is unfortunate because the results of Suarez-Almazor and Russell disagree with our results based on a larger number of sibling pairs.Suarez-Almazor and Russell analyzed 15 sibling pairs with psoriasis and found that 13 were HLA identical and two shared one HLA haplotype. In our study we showed the pedigrees of 14 families with multiple cases of psoriasis.2 Altogether, 35 sibling pairs could be analyzed when all the possible combinations were included. Of these, 13 were HLA identical, 19 shared
Karvonen J, Tiilikainen A. Human Leukocyte Antigen Haplotype Sharing in Siblings With Psoriasis. Arch Dermatol. 1991;127(4):585. doi:10.1001/archderm.1991.04510010153025