ABSTRACT
Abstract: Background: Alopecia areata (AA) is a common disorder of unknown etiology that affects approximately 0.7% to 3.8% of patients among the general population. Currently, genetic and autoimmune factors are emphasized as etiopathogenic. Studies linking Human Leukocyte Antigens (HLA) to AA have suggested that immunogenetic factors may play a role in the disease's onset/development. Objectives: To investigate an association between AA and HLA class I/II in white Brazilians. Methods: Patients and control groups comprised 33 and 112 individuals, respectively. DNA extraction was performed by column method with BioPur kit. Allele's classification was undertaken using the PCR-SSO technique. HLA frequencies were obtained through direct counting and subjected to comparison by means of the chi-square test. Results: Most patients were aged over 16, with no familial history, and developed partial AA, with no recurrent episodes. Patients showed a higher frequency of HLA-B*40, HLA-B*45, HLA-B*53 and HLA-C*04 compared with controls, although P was not significant after Bonferroni correction. Regarding HLA class II, only HLA-DRB1*07 revealed statistical significance; nevertheless, it featured more prominently in controls than patients (P=0.04; Pc=0.52; OR=0.29; 95%; CI=0.07 to 1.25). P was not significant after Bonferroni correction. Conclusions: The development of AA does not seem to be associated with HLA in white Brazilians, nor with susceptibility or resistance. The studies were carried out in populations with little or no miscegenation, unlike the Brazilian population in general, which could explain the inconsistency found.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Young Adult , Histocompatibility Antigens Class I/genetics , Histocompatibility Antigens Class II/genetics , Brazil , Histocompatibility Antigens Class I/blood , HLA-B Antigens/genetics , HLA-B Antigens/blood , HLA-C Antigens/genetics , HLA-C Antigens/blood , Histocompatibility Antigens Class II/blood , Case-Control Studies , Cross-Sectional Studies , White People , Alopecia Areata/genetics , Alopecia Areata/immunology , HLA-DRB1 Chains/genetics , HLA-DRB1 Chains/blood , Gene Frequency/geneticsABSTRACT
BACKGROUND: To monitor the performance of histocompatibility testing laboratories, HLA proficiency survey in Korea has been conducted biannually since 1996. In this report, we summarized the results of the surveys performed in recent two years (2005-2006). METHODS: A total of four proficiency surveys were performed, in which 59-61 laboratories participated. Each survey included three tests for HLA class I (serology and DNA) and class II (DNA) typing and six tests for HLA crossmatch. RESULTS: The overall concordance of serologic typing was 98.9% (355/359) for HLA-A, 97.5% (350/ 359) for HLA-B, and 94.7% (337/356) for HLA-C. The antigens assigned correctly by less than 95% of the participating laboratories were A26 (93.8%), B38 (94.2%), Cw3/Cw10 (90.9%), Cw6 (94.4%), and Cw8 (74.3%). The overall concordance rates of DNA typing were 99.6% (533/535) for HLA-A, 99.8% (539/540) for HLA-B, and 100% (392/392) for HLA-C. Correct assignment of HLA-DRB1 and -DQB1 was reported by 99.2% (98.1-100%) and 96.7% (88.9-100%) for the generic level and 100% and 95.8% (75-100%) for the allelic level, respectively. On the average 3.8% (0-7.7%) of the total laboratories showed unacceptable results in the crossmatch tests. CONCLUSIONS: The rates of correct antigen identification and of unacceptable crossmatch were similar to those of previous surveys, which were considered satisfactory. The Korean proficiency survey program may have contributed to a high quality of HLA tests today and should be continued for further improvements of the tests tomorrow.
Subject(s)
Humans , Alleles , Data Collection , HLA Antigens/blood , HLA-A Antigens/blood , HLA-B Antigens/blood , HLA-C Antigens/blood , HLA-DQ Antigens/blood , HLA-DR Antigens/blood , Haplotypes , Histocompatibility Testing/standards , Korea , Laboratories , Quality ControlABSTRACT
This is the first study of HLA class I antigens among Bahrainis, which will indicate the HLA -A, -B, and -C amongst Bahrainis in correlation with sex of the population. Six hundred and five Bahrainis were included in the study [303 males: 302 females]. The complement-dependent microcytotoxicity [CDC] was used. The study showed that there are unique HLA antigens, which show Bahrainis relation to the Middle East, with the following characteristics of high frequencies: A2, Al, A19, A9, Al0, All, B12, B7, B8, B2, B5, B13, Cw4, Cw3, Cw1, Cw2, and Cw6. Some of the antigens were shared with other countries. The results showed that some HLA -A, -B and -C antigens are sex associated