Is There Any Relationship Between Human Leucocyte Antigen Class II and Chronic Urticaria? (Chronic Urticaria and HLA Class II)

Human Leukocyte Antigen (HLA) typing of large groups of patients with various autoimmune diseases has demonstrated that some HLA alleles occur at higher frequencies in specific diseases than in the general population. Chronic urticaria has been shown to have an autoimmune basis by a previous study which found an association between chronic urticaria and specific HLA groups. We investigated the HLA subtypes of Turkish chronic urticaria patients. For this purpose 42 Turkish patients with chronic urticaria and 115 healthy controls were typed for HLA-DR and DQ by PCR-SSP (Polymerase Chain Reaction Sequence Specific Primers) low resolution DNA technique. We found an increased frequency of DR4 (42.9%, p=0.01) in chronic urticaria patients in comparison with that in healthy controls. This study supports the hypothesis that HLA alleles may be involved in the pathogenesis of chronic urticaria and that they appear to be directly involved in the initiation of the immune response.

Idiopathic focal segmental glomerulosclerosis and HLA antigens

The objective of the present study was to investigate a possible association between HLA class II antigens and idiopathic focal segmental glomerulosclerosis (FSGS), HLA-A, -B, -DR and -DQ antigens were determined in 19 Brazilian patients (16 white subjects and three subjects of Japanese origin) with biopsy-proven FSGS. Comparison of the HLA antigen frequencies between white patients and white local controls showed a significant increase in HLA-DR4 frequency among FSGS patients (37.7 vs 17.2 percent, P<0.05). In addition, the three patients of Japanase extraction, not included in the statistical analysis, also presented HLA-DR4. In conclusion, our data confirm the association of FSGS with HLA-DR4 previously reported by others, thus providing further evidence for a role of genes of the HLA complex in the susceptibility to this disease.

Restriction fragment length polymorphisms in HLA-DR4-DQ3 haplotypes associated with rheumatoid arthritis.

Restriction fragment length polymorphism (RFLP) patterns were studied in serologically confirmed DR4-DQ3 positive patients with rheumatoid arthritis by Southern blot analysis using full length cDNA probes specific for DRB, DQA and DQB hybridized with genomic DNA digested with informative restriction endonucleases. The RFLP patterns correlated with serology confirming all patients to be DR4+ve. The DQB1*0302 (DQ8) allele identified by 12.0kb BamHI, 3.3kb Hind III and 1.8kb Taql fragments was present in all patients suggesting them to be DR4-DQB1*0302. Hybridization of Taq 1 and PVU II digested genomic DNA with DQA cDNA probe revealed four informative RFLP patterns. While three of them correlated with known DR4 subtypes, one was a new polymorphism observed specifically in Indian patients with rheumatoid arthritis. The study further indicated that two of the several known subtypes of DR4, viz., DRB1*0401-DW4-DQB1*0302 and DRB1*0404-DW14-DQB1*0302 may be implicated in susceptibility to rheumatoid arthritis in the Indian population.