Here we focused on one of the six HLA GWI-protective HLA alleles, DRB1*13:02, which has been found to have a protective role in a broad range of autoimmune diseases (Furukawa et al., 2017), and tested its effects on brain volumes.
A gene dosage effect was observed in the associations of DRB1*13:02 with the protection from systemic autoimmune diseases; thus homozygous individuals are more effectively protected from the systemic autoimmune diseases than heterozygotes.
Furthermore, taken together with our previous observations, the haplotype carrying DRB1*13:02 was suggested to be a shared protective factor against multiple autoimmune diseases.
Previous studies of isolated T1D and of T1D combined with other autoimmune disorders showed genetic susceptibility for alleles in HLA-DQB1 and -DRB1 and also CTLA4 and PTPN22.
On the basis of these results, the HLA alleles DRB1*0101 and DRB1*0404 and the PTPN22 R620W variant are consistently associated with autoimmunity in the T1DGC Autoantibody Workshop data.
Complement component C4 (C4) is a highly variable complement pathway gene situated ∼500 kb from DRB1 and DQB1, the genes most strongly associated with many autoimmune diseases.
This mechanism could provide a robust synergistic action and a differential role of DRB1 and DQB1 in tissues and in the time-steps towards autoimmunity.
Both generalized and localized vitiligo have the same predisposing major histocompatibility complex alleles, i.e., B*44:03 and DRB1*07:01, in both the populations studied, beside the differences in the frequencies of other alleles, suggesting that localized vitiligo too may be an autoimmune disorder.
The increased frequency of DRB1*07:01 in North Indian and Gujarat populations with generalized and localized vitiligo and in several vitiligo populations studied previously suggests that it contributes to autoimmunity and destruction of melanocytes.
While genome studies map a strong MS susceptibility effect to the region of DRB1*1501, our findings offer a rationale for potential involvement of pathogenic DQ6-associated autoimmunity in MS.
In Caucasians, we highlighted the definite protective role of HLA-DRB1*14 and DRB1*07 for MS. DRB1*03 is probably the only risk factor for MS besides DRB1*15 and a common genetic foundation for autoimmune disease.
In addition, the DRB1*0901 haplotype and the risk alleles of ERBB3, CLEC16A and CTLA4 were positively associated with the co-occurrence of thyroid autoimmunity.
These data suggest that the interaction between VDR and HLA alleles is mediated by VDRE present in the promoter region of HLA-DRB1 0301 allele, which may be detrimental for the manifestation of T1D in the absence of 1,25-(OH)(2)D(3) in early childhood due to poor expression of DRB1 0301 in the thymus resulting in autoimmunity.
Compared with those with low GADA titers, patients with high GADA titers had more prominent traits of insulin deficiency and a profile of more severe autoimmunity resulting in higher A1C, lower BMI, a lower prevalence of metabolic syndrome and its components (P < 0.02 for all), a higher prevalence of IA-2As, TPO antibodies (P < 0.003 for both), and DRB1*03-DQB1*0201 (50 vs. 26.8%, P = 0.001), and a decreasing frequency of DQB1*0602 and DRB1*0403 (from type 2 to low and to high GADA titer autoimmune diabetes; P < 0.001 for trend for both comparisons).
Preliminary results showed increased frequencies of DRB1*11- and DRB*16-associated haplotypes that were found to be protective for autoimmune diseases in some populations.
The development of MS is influenced by environmental factors, particularly the Epstein-Barr virus (EBV), and genetic factors, which include specific HLA types, particularly DRB1*1501-DQA1*0102-DQB1*0602, and a predisposition to autoimmunity in general.
It is noteworthy that certain genes and haplotypes, notably HLA-DRB1*0301, DQA1*0501, DQB1*0201 in Caucasians and DRB1*0405, DQA1*03, DQB1*0401 in Asians, as well as PTPN22, seem to be associated with a variety of autoimmune diseases.
The following significant findings were observed: 1) a significant excess of autoimmunity in first-degree relatives of MS patients (p = 0.000), 2) an association of MS with Type 1 diabetes mellitus (T1DM) (p = 0.02), 3) an increase in DR4 expression (namely DRB1*0401) in MS patients from families with multiple autoimmune pathology compared with reference MS patients (p=0.02) and NC (p=0.01).
The aim of this study was to investigate the role of autoimmunity in the etiology of AAAs using a genetic association study approach with human leukocyte antigen (HLA) polymorphisms (HLA-DQA1, -DQB1, -DRB1 and -DRB3-5 alleles) in 387 AAA cases and 426 controls.
In family A, all MS patients and two of five individuals with MS immunopathic trait had HLA DRB1*(15) and in family B, all blood relatives had the rare HLA type DRB1*0103, which is associated with other autoimmune diseases.