Human Leukocyte Antigen Profiles Research Articles

Polymorphism in MICA rather than HLA-B/C genes is associated with psoriatic arthritis in the Jewish population

The aim of this study was to examine whether the association of psoriatic arthritis (PsA) with human leukocyte antigen (HLA) class I genes is secondary to linkage disequilibrium with a nearby gene. We examined a sample of the Jewish population to investigate whether HLA-B/C and DR polymorphism is associated with susceptibility, or whether other closely related class I loci, such as the major histocompatibility complex class I chain-related gene A (MICA) and tumor necrosis factor (TNF), might play a role in disease development. Comparisons of different populations with different HLA profiles would be of value in identifying the candidate genes involved in PSA. Fifty-two patients with PsA and 73 random matched controls from a Jewish population were selected and DNA typed by polymerase chain reaction–single-strand oligonucleotide probe (PCR-SSOP) (HLA-C), PCR sequence-specific primers (PCR-SSP) (HLA-B, -DR), radioactive PCR (MICA-TM polymorphism in the transmembrane region), and PCR-RFLP (TNF). Some findings can be concluded from the study: (1) the frequency of HLA-B∗5701, B∗3801, B∗39, B∗27, Cw∗0602, Cw∗07, DRB1∗0402, and DRB1∗0701 were not found to be significantly increased in PsA; (2) no significant differences of TNFα promoter alleles at positions −308 and −238 were found between PsA and healthy controls; (3) the trinucleotide repeat polymorphism MICA-A9 was present at a higher frequency in PsA patients, ( p c < 0.009, RR = 3.34, EF = 0.39); and (4) MICA-A9 polymorphism was found in linkage disequilibrium with HLA-B alleles (B∗5701, B∗3801) described to be associated with PsA in Caucasians. These results suggest that the MICA gene or other nearby gene(s) may be involved in the development of PsA, and it would thus appear that psoriasis vulgaris (PsV) and PsA are associated with different MHC susceptibility genes.

HLA in alopecia areata.

The aim of this study was to investigate the human leukocyte antigen (HLA) characteristics of Turkish alopecia areata patients, and the correlation of the HLA profile with age of onset, severity and duration of the disease, presence of ophiasis, and family history. A total of 88 patients with alopecia areata, alopecia totalis, or alopecia universalis were compared with 100 healthy controls. HLA typing was performed by the Terasaki microlymphocytotoxicity method. The frequency of HLA-A1, HLA-B62(15), HLA-DQ1, and HLA-DQ3 was significantly higher in patients than in controls. HLA-DR16 was significantly less common in patients than in the control group, and we concluded that this allele might have a protective role for alopecia areata. Juvenile onset and severe involvement were related with HLA-Cw7 and HLA-DR1, respectively. The HLA profile was independent of the existence of long-standing disease, presence of ophiasis, and a positive family history. In HLA-alopecia areata association, ethnic differences may play a role.

The relation between human leukocyte antigen (HLA) distribution and intestinal obstruction and adhesions in childhood: preliminary report.

To investigate the association between the human leukocyte antigen (HLA) system and adhesions causing intestinal obstruction in childhood in order to determine whether HLA profiles can be used to identify and screen individuals at risk for intestinal adhesions, clinical and laboratory evaluations were done in a total of 42 (F:M = 27:15) patients. The mean age was 6.11 +/- 3.2 years (0.6-13 years). The patients were tested for HLA phenotype in two groups; the HLA phenotype distribution and relative risk (RR) for adhesions were determined. The study patients were children operated upon due to acute abdominal emergencies. Group 1 included patients who needed readmission after the surgery due to intestinal obstruction (n = 19), group 2 patients had no readmission for any reason following surgery (n = 23). Of the 19 patients in group 1, 9 were treated only medically and 10 needed surgical intervention. Among the patients in whom medical treatment was initiated (n = 14), 5 needed surgery during follow-up. There was an increased RR for certain HLA subtypes (A24 [9], HLA11, DR11 [5], B22) in patients presenting with intestinal obstruction due to adhesions. Among these, A24 (9) and DR11 (5) were statistically significant (P < 0.05) compared with the control group. Several possible mechanisms could link the HLA system with disease, especially those in which the immune response is suspected to be involved, but the questions of how the inflammatory response is initiated and the role of proinflammatory cytokines remain unclear. Future research developments are likely to focus on increased understanding of the molecular biology of the major histocompatibility complex and its biological function in the immune response and adhesion formation and intestinal obstruction. It is possible that HLA profiles can be used to identify individuals at risk for intestinal adhesions in the future.

Nasopharyngeal carcinoma in two young brothers and its relationship with epstein-barr virus

Nasopharyngeal carcinoma (NPC) has a relatively high incidence in southern China but is a relatively rare tumor in Europe and North and South America. Although the pathogenesis is not known with certainty, it is currently thought that Epstein-Barr virus (EBV) plays a strong role in disease development because of the consistent detection of EBV genome in the tumor cells. Genetic factors may also be important because the incidence of NPC remains high among first generation Chinese who have emigrated to other parts of the world. In addition, there is an increased risk of NPC in Chinese-related human leukocyte antigen profiles. Environmental factors other than EBV, such as ingestion of salted foods and occupational exposures to certain chemicals may also play a role in the pathogenesis.le6 In this report, we present the first case (to our knowledge) of two young brothers diagnosed with NPC within a l-year period in whom we were also able to detect the presence of EBV.