Dapsone provides an alternative treatment for patients with chronic autoimmune thrombocytopenic purpura (AITP) who had inadequate response to conventional therapy. However, the efficacy of this treatment is achieved in only 50% of patients. Dapsone is partly metabolized by the polymorphic N-acetyltransferase 2% and 50% of Caucasian patients show a genetically determined slow acetylator phenotype. The aim of our study was to investigate the influence of the acetylator status on dapsone efficacy in patients with chronic AITP. Nineteen caucasian adults with chronic AITP, previously treated by dapsone, were included in the study. Acetylator phenotype was determined by using a caffeine urinary test. Among the fourteen fast acetylator patients, eight patients exhibited positive response to dapsone and six patients did not. Among the five slow acetylator patients, one patient displayed a positive response to dapsone. Comparison of data by using the Fisher's exact test did not reach statistical significance. Our results do not support a relationship between dapsone efficacy and acetylator status in adults with chronic AITP.
Abstract There are two forms of orosomucoid (ORM) in the sera of most individuals. They are encoded by two separate but closely linked loci, ORM1 and ORM2. A number of variants have been identified in various populations. Duplication and nonexpression are also observed in some populations. Thus, the ORM system is very complicated and its nomenclature is very confusing. In order to propose a new nomenclature, ORM variants detected by several laboratories have been compared and characterized by isoelectric focusing (IEF) followed by immunoprinting. A total of 57 different alleles including 17 new ones were identified. The 27 alleles were assigned to the ORM1 locus, and the others to the ORM2 locus. The designations ORM * F1 , ORMI * F2 , ORMI * S and ORM2 * M were adopted for the four common alleles instead of ORM1 * 1 , ORM1 * 3 , ORM1 * 2 and ORM2 * 1 ( ORM2 * A ), respectively. The variants were designated alphanumerically according to their relative mobilities after IEF in a pH gradient of 4.5‐5.4 with Triton X‐100 and glycerol. For the duplicated genes a prefix is added to a combined name of two alleles, e.g. ORM1 * dB9S . Silent alleles were named ORM1 * Q0 and ORM2 * Q0 conventionally. In addition, the effects of diseases to ORM band patterns after IEF are also discussed.
