HLA-Cw*1701 is associated with two sub-Saharan African-derived HLA haplotypes: HLA-B*4201, DRB1*03 and HLA-B*4202 without DRB1*03

Different extended haplotypes have been described for many ethnic groups, such as African-Americans. The complotype FC(1,90)0 is in linkage disequilibrium with HLA-B42, DRB1*0302 in African-Americans and Southern African Xhosa individuals, suggesting a common ancestry. In order to analyze the distribution of Cw*17 alleles (Cw*1701, 1702) in relation to this African-derived extended haplotype, we studied a large panel of samples from African-American individuals and additionally a group of selected samples carrying HLA-B42, DR3 and HLA-B42, non-DR3 antigens. HLA alleles were assigned using sequence-specific amplification (SSP) and sequence-specific oligonucleotide probe hybridization (SSOP). We have found that all haplotypes (10 in total) carrying the extended haplotypes [HLA-B42, FC(1,90)0, DRB1*0302] were positive for HLA-Cw*1701. Interestingly, HLA B*4201 was found in all samples (17 in total) carrying HLA-B42, DR3, Cw*1701, whereas HLA-B*4202 was found in 10 out of 13 samples from individuals carrying HLA B42, Cw*1701 non-DR3. These findings suggest that HLA-Cw*17 polymorphism is conserved in different ethnic populations and that HLA-B42 alleles seem to separate at least different African-derived haplotypes. The historical context of these findings are important for the study of human evolution and they may be useful for the development of strategies in the search for possible donors in organ transplantation for African-derived populations.     

Discovery of a novel HLA‐DRB1*04:05 variant,DRB1*04:05:15, in a Taiwanese and the probable HLA haplotype in association with DRB1*04:05:15

Here, we report a novel HLA‐DRB1*04 allele, DRB1*04:05:15, found in a Taiwanese unrelated volunteer bone marrow hematopoietic stem cell donor by a sequence‐based typing (SBT) method. The DNA sequence of DRB1*04:05:15 is identical to the sequence of DRB1*04:05:01 in exon 2, except the nucleotide at the position 198 where C is substituted by T (TAC→TAT at codon 37). Due to the silent mutation, the nucleotide replacement generated no amino acid variation in comparison with DRB1*04:05:01. We postulate the allele DRB1*04:05:15 was probably derived from DRB1*04:05:01 via a nucleotide point mutation event. The probable HLA‐A, ‐B, ‐C, ‐DRB1 and ‐DQB1 haplotype in association with DRB1*04:05:15 may be deduced as A*02:01‐B*48:01‐C*08:03‐DRB1*04:05:15‐DQB1*04:01.     

Four novel HLA alleles,DRB1*04:11:03, DRB1*10:05, DRB1*15:94 and DRB1*16:22, identified in Brazilian individuals

Four novel human leucocyte antigen (HLA) class II alleles were identified by sequencing‐based typing (SBT) and analysis of the closest‐matching alleles from volunteer subjects from the Brazilian Bone Marrow Donor Register (REDOME, Brazil). The new HLA alleles discovered include DRB1*04:11:03, DRB1*10:05, DRB1*15:94 and DRB1*16:22. Three of the novel alleles had single‐nucleotide substitution polymorphisms when compared to their most homologous allele. Of these, one harboured a single‐nucleotide polymorphism (SNP) identified as a silent substitution.     

HLA DRB1*1503 allelic haplotype predominance and associated immunodysregulation in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic, relapsing, and remitting disease affecting primarily African American females of child bearing age. Familial aggregation of this disease suggests that at least part of the susceptibility for this disease is genetic, although environmental and hormonal influences are also likely to play a role. Early studies of genetic susceptibility to SLE revealed several of the major histocompatibility complex molecules, namely HLA DR, to be linked to SLE. Meta-analysis of genome scans has yielded loci significant for lupus patients, one of which includes the MHC region.Regulatory T cells are immunoregulatory cells that modulate activated immune cells. These cells play a large role in homeostasis of the immune responses and maintenance of immunologic tolerance, i.e., prevention of autoimmunity. Decreased numbers of regulatory T cells have been described in many autoimmune diseases, including systemic lupus erythematosus.Autoantibody production in systemic lupus erythematosus and the resulting immune complex formation and complex deposition into tissues are arguably the central core of immune dysregulation leading to disease manifestations and symptoms. Inability of the immune system to recognize and inhibit autoreactive immune cells in this particular autoimmune disease may be the result of inappropriate numbers and function of regulatory T cells.This study aims to characterize the immune cell population in patients from our community suffering from systemic lupus erythematosus and to prove that these patients exhibit a unique cellular profile compared to healthy age, race and gender matched control subjects. Surprisingly, our findings demonstrate that patients from the local Mississippi area exhibit increased proportions of CD25⁺ FoxP3⁺ regulatory T cells and CD25⁺ FoxP3⁻ T cells (of CD45⁺ CD3⁺ CD4⁺ helper T cells) as compared to healthy controls.HLA tissue-typing of these lupus patients revealed a prominent subgroup (~ 30%) of patients possessing the HLA DRB1*1503 allele. The investigation of this subgroup demonstrated regulatory T cell composition similar to that of the total lupus group and to that of the non-HLA DRB1*1503 subgroup.Genetic analysis for molecular gene expression levels of various lupus-associated genes by real-time PCR demonstrated a unique profile as compared to healthy controls. Increased gene expression of FoxP3 together with decreased gene expression levels of GATA3, TNFAIP3, and TNFSF4 suggest that variations in gene products compared to healthy controls may be playing a role in the immune cell dysregulation and disproportionate CD25⁺ FoxP3⁺ regulatory T cells.     

Discovery of the novel HLA-DRB1*03:77 allele in a Taiwanese unrelated hematopoietic stem cell donor by a sequence-based typing method and identification of the probable HLA haplotype in association with DRB1*03:77

Here, we report a novel human leucocyte antigen (HLA)-DRB1 allele, DRB1*03:77, discovered in a Taiwanese unrelated volunteer hematopoietic stem cell donor by a sequence-based typing (SBT) method. The DNA sequence of DRB1*03:77 is identical to the DNA sequence of DRB1*03:01:01 in exon 2 except one nucleotide at position 223 (G→C). The nucleotide substitution caused an amino acid replacement at residue 46 (E→Q). The formation of DRB1*03:77 was thought as the result of a nucleotide point mutation. The probable HLA-A, HLA-B and HLA-DRB1 haplotype in association with DRB1*03:77 may be deduced as A*33-B*58-DRB1*03:77. The donor was a Minna Taiwanese whose ancestors came from mainland China.     

Susceptible and protective associations of HLA DRB1*/DQB1* alleles and haplotypes with ischaemic stroke

Stroke has emerged as the second commonest cause of mortality worldwide and is a major public health problem. For the first time, we present here the association of human leucocyte antigen (HLA)‐DRB1*/DQB1* alleles and haplotypes with ischaemic stroke in South Indian patients. Ischaemic stroke (IS) cases and controls were genotyped for HLA‐DRB1*/DQB1* alleles by polymerase chain reaction sequence‐specific primers (PCR‐SSP) method. The frequencies of HLA class II alleles such as DRB1*04, DRB1*07, DRB1*11, DRB1*12, DRB1*13, DQB1*02 and DQB1*07 were high in IS patients than in the age‐ and gender‐matched controls, suggesting that the individuals with these alleles are susceptible to ischaemic stroke in South India. The frequencies of alleles such as DRB1*03, DRB1*10, DRB1*14, DQB1*04 and DQB1*05 were less in IS cases than in the controls, suggesting a protective association. Haplotypes DRB1*04‐DQB1*0301, DRB1*07‐DQB1*02, DRB1*07‐DQB1*0301, DRB1*11‐DQB1*0301 and DRB1*13‐DQB1*06 were found to be high in IS patients conferring susceptibility. The frequency of haplotype DRB1*10‐DQB1*05 was high in controls conferring protection. IS‐LVD and gender‐stratified analysis too confirmed these susceptible and protective associations. Thus, HLA‐DRB1*/DQB1* alleles and haplotypes strongly predispose South Indian population to ischaemic stroke. Further studies in different populations with large sample size or the meta‐analysis are needed to explain the exact mechanism of associations of HLA gene(s) with IS.     

HLA-DRB1*03, DRB1*11 or DRB1*12 and their respective DRB3 specificities in clinical variants of sarcoidosis

Determination of DRB1 and DRB3 specificities in sarcoidosis patients identified that the presence of DRB1*03 and the absence of DRB1*11 and/or DRB1*12 favors a course of disease that is associated positively with L?fgren's syndrome (DRB1*03) and negatively with stage I disease (DRB1*11 and/or 12). In common with normal controls, DRB1*03 was associated with DRB3*0101 and DRB1*11/12 with DRB3*0201/2. An analysis of DRB1 and DRB3 associations in variants of sarcoidosis revealed that DRB1*03 and DRB3*0101 were associated with L?fgren's syndrome in a combined association fashion. Conversely, a lack of DRB1*11 and/or DRB1*12 but not DRB3*0201/2 favored the clinical course of sarcoidosis.     

Association of hypersensitivity to the nematode Anisakis simplex with HLA class II DRB1*1502-DQB1*0601 haplotype

Anisakiasis as well as allergic and anaphylactoid reactions to Anisakis simplex antigens are recently identified clinical entities. They are relatively frequent in countries with habitual raw food consumption, often in the form of large amounts of fish and sea food products. In this communication the relationship between HLA class II alleles and the IgE-specific immune response to A. simplex allergen was studied in a defined population in Northern Spain. Individuals with immediate-type Anisakis hypersensitivity and healthy controls were examined for HLA-DRB1, DQB1 and DQA1 alleles by sequence-specific oligonucleotide probe typing. Analysis of the HLA data among patients revealed increased phenotypic frequencies for DRB1*1502 and DRB1*0404 compared to healthy controls (p < 1 x 10(-7) and < 0.01, respectively). Analysis of haplotypic frequencies showed that the DRB1*1502-DQB1*0601 haplotype is significantly higher in patients with Anisakis hypersensitivity in comparison with the control population from the same region (p < 4 x 10(-8)). The data suggest that this haplotype can be considered to be a susceptibility factor for hypersensitivity to A. simplex antigens.     

HLA DRB1*130101-DQB1*060101 haplotype is associated with acute chest syndrome in sickle cell anemia patients

We investigated the association of human leukocyte antigens (HLA) class II alleles and haplotypes with the pathogenesis of acute chest syndrome (ACS) in 186 sickle cell anemia (SCA) patients, of whom 58 had documented ACS (new pulmonary infiltrate, fever, and other associated clinical events) and 128 with a negative history of ACS, serving as controls. HLA DRB1* and -DQB1* genotyping was performed by polymerase chain reaction–sequence-specific priming. Of the DRB1* and DQB1* alleles analyzed, only DRB1*130101 ( Pc  < 0.001) was positively associated with ACS. DRB1*130101-DQB1*060101 haplotype was more prevalent among ACS patients ( P  = 0.018), thus conferring disease susceptibility. Specific HLA alleles and haplotypes may influence ACS risk in SCA patients, and specific HLA genotypes may be useful markers for identifying high-risk SCA ACS patients.     

An HLA-A*02:01-B*13:01-DRB1*14:01:03 haplotype conserved in Taiwanese and a possible close relationship between DRB1*14:01:03 and DRB1*14:54

We here report sequence confirmation and analysis of the variant HLA-DRB1*14:01:03 on three voluntary bone marrow donors and the conserved haplotype carrying DRB1*14:01:03 allele in Taiwanese population. In exon 2, the DNA sequence of DRB1*14:01:03 is identical to HLA-DRB1*14:01:01 except a silent nucleotide substitution at position 192. However, sequence specific primer (SSP) reaction pattern of DRB1*14:01:03 matched with the pattern of DRB1*14:54 instead of DRB1*14:01:01, 14:01:02 or 14:01:03. In exon 3, at position 421, DRB1*14:01:03 has an identical nucleotide as DRB1*14:54 but differs from DRB1*14:01:01. We think the discrepancy of the allele assignment by SSP typing protocol and by sequence-specific oligonucleotide probe (SSO) and sequence-based typing methods should be addressed. We assume DRB1*14:54 is probably the parental allele for DRB1*14:01:03.     

The DQA1*0104 allele is carried by DRB1*1001- and DRB1*1401-positive haplotypes in Caucasians, Africans and Orientals

Abstract: The DQA1*0104 allele is known to differ from DQA1*0101 by a single nucleotide in the sequenced part of the first exon. DQA1*0104 has a guanine in the second position of the second expressed codon, whereas DQA1*0101 and all other sequenced DQA1 alleles have an adenine in that position, changing aspartic acid to glycine. The DQA1*0104 allele was originally described in African Americans with the DRB1*12, DRB3*0101, DQA1*0104, DQB1*0501, DRB1*12, DRB3*0202, DQA1*0104, DQB1*0605 or DRB1*14, DQA1*0104, DQB1*0503 haplotypes. When developing DQA1 typing by PCR amplification with sequence-specific primers (PCR-SSP), we observed that all DR10- and DR14-positive samples carried the DQA1*0104 allele, wheres all DRB1*01 -positive DNAs carried the closely related DQA1*0101 allele. In the present study, samples representing the major ethnic groups with DR-DQ haplotypes known to carry the DQA1*0104 allele or the very similar DQA1*0101 allele were investigated by Taq I RFLP analysis, PCR-SSP typing and nucleotide sequencing. The DQA1*0104 allele was found to differ from DQA1*0101 not only in the second expressed codon, but also by a productive mutation in the signal peptide. All investigated DRB1*1001 -(n = 24) and DRB1*1401 -positive (n = 25) haplotypes, defined by homozygosity or association, of Caucasian, African or Oriental origin carried the DQA1*0104 allele, whereas the DQA1*0101 allele was found on all DRB1*01 -positive (n = 32) haplotypes. These findings demonstrate that in the assignment of HLA class II alleles, polymorphism outside the second exon sometimes must be considered. The maintenance of the DQA1*0104 allele on a few distinct haplotypes indicates that the allele is old and might also be compatible with a functional difference between the DQA1*0101 and DQA1*0104 alleles.     

HLA DRB1 and DQB1 alleles and haplotypes influencing the progression of hepatitis C

Some HLA class II alleles and haplotypes were examined by restriction fragment length polymorphism of corresponding DNA fragments amplified by the polymerase chain reaction in 117 patients with chronic hepatitis C in Japan. The prevalence rates were compared between patients and 1216 controls and in 67 patients with liver cirrhosis, of whom 20 had hepatocellular carcinoma and 50 patients with chronic hepatitis who did not have cirrhosis or hepatocellular carcinoma. Notably, DRB1*0405 (49% [95% confidence range 38-60%] vs. 26% [16-40%]; P < 0.05, relative risk [rr] = 2.8) and DQB1*0401 (43% [33-54%] vs. 22% [13-34%]; P < 0.05, rr = 2.1) were detected more frequently in patients with cirrhosis than in those without cirrhosis. By contrast, DRB1*0901 (11% [6-19%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) and DQB1*0303 (11% [6-19%] vs. 36% [25-49%]; P < 0.01; rr = 0.2) were detected less frequently in patients with cirrhosis than those without cirrhosis. Accordingly, the DRB1*0405-DQB1*0401 haplotype was more common (43% [33-54%] vs. 22% [13-34%]; P < 0.05; rr = 2.7), while the DRB1*0901-DQB1*0303 haplotype was less common (9% [4-17%] vs. 28% [18-40%]; P < 0.05; rr = 0.3) in patients with cirrhosis than in those without cirrhosis. These results suggest that there would be HLA class II alleles and haplotypes which may be associated with an accelerated or slower progression of chronic hepatitis C towards cirrhosis and eventually to hepatocellular carcinoma. © 1996 Wiley-Liss, Inc.     

Presence of the DRB4*0103102N null allele in different DRB1*04-positive individuals

The DRB4 gene encoding the DR53 antigen is present in DRB1*04-, DRB1*07- and DRB1*09-positive individuals. Eight allelic variants of DRB4 have been recognized, 5 resulting in an expressed DR53 antigen and 3 belonging to the null alleles. So far the DRB4*0103102N null allele had been found exclusively in individuals carrying the haplotype DR7,-DQ9. High-resolution typing of HLA class II by polymerase chain reaction using sequence-specific primers (PCR-SSP) and/or sequence-based typing of kidney patients and their families revealed the presence of the DRB4*0103102N null allele segregating with DRB1*04 and DQB1*03 in 4 different families. Three different haplotypes on which the null allele was located, were recognized by family studies: DRB1*0401, DQB1*0301; DRB1*0402, DQB1*0302 and DRB1*0404, DQB1*0302. Determination of the DR53 specificity of antisera reacting with DR53-positive individuals has always been difficult due to the simultaneous presence of DR4, 7 or 9. Identification of DR4-positive DR53-negative individuals as described here, provided the serological reactions with DR53-antisera and revealed the antibody specificities in the antisera used.     

HLA-DRB1*01 and DRB1*04 alleles in Sardinian rheumatoid arthritis patients

In Sardinia, like in other Caucasoid populations, rheumatoid arthritis (RA) is significantly associated with HLA-DR4 and DR1 antigens. To discover which DR4 and DR1 alleles were associated with the disease we selected 22 Sardinian patients affected by RA. Fifty DR4+ and 28 DR1+ healthy individuals coming from the same geographical area were used as controls. In the Sardinian patients only two DRB1*04 alleles were observed: DRB1*0405 in 11 and DRB1*0403 in three patients. The DRB1*0102 allele was observed in two patients and DRB1*0101 in six patients. Hereditary predisposition to RA in Sardinia therefore seems to be almost exclusively associated with the DRB1*0405 and DRB1*0101 alleles which share the 67LLEQRRAA74-85VG86 epitope in the peptide binding groove.     

HLA DRB1*DQB1* haplotype in HTLV-I-associated familial infective dermatitis may predict development of HTLV-I-associated myelopathy/tropical spastic paraparesis

A possible causal association between infective dermatitis and HTLV-I infection was reported in 1990 and confirmed in 1992. We now report familial infective dermatitis (ID) occurring in a 26-year-old mother and her 9-year-old son. The mother was first diagnosed with ID in 1969 at the age of 2 years in the Dermatology Unit at the University Hospital of the West Indies (U.H.W.I.) in Jamaica. The elder of her 2 sons was diagnosed with ID at the age of 3 years, also at U.H.W.I. Both mother and son are HTLV-I-seropositive. A second, younger son, currently age 2 years, is also HTLV-I-seropositive, but without clinical evidence of ID. Major histocompatibility complex (MHC), class II, human leucocyte antigen (HLA) genotyping documented a shared class II haplotype, DRB1*DQB1* (1101-0301), in the mother and her 2 sons. This same haplotype has been described among Japanese patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and has been associated with a possible pathologically heightened immune response to HTLV-I infection. The presence of this haplotype in these familial ID cases with clinical signs of HAM/TSP may have contributed to their risk for development of HAM/TSP. The unaffected, HTLV-I-seropositive, younger son requires close clinical follow-up. © 1995 Wiley-Liss, Inc.