ABO and Rh blood group genotypes in a cohort of Saudi stem cell donors.

The ABO and rhesus (Rh) blood group antigens are the most frequently studied genetic markers in a large group of people. Blood type frequencies vary in different racial/ethnic groups. Our objective was to investigate the distribution of the ABO and rhesus (Rh) blood groups by molecular typing method in a population of Saudi stem cell donors. Our data indicate that the most common blood group in our population is group O followed by group A then group B, and finally, the least common is group AB.

A novel HLA-DQ allele, HLA-DQB1*05:48, found in the Saudi Stem Cells Donor Registry.

The allele HLA-DQB1*05:48 differs from HLA-DQB1*05:01:01 by a non-synonymous T to C substitution at nucleotide position 1693 in exon 2.

Severe neurologic syndrome associated with Middle East respiratory syndrome corona virus (MERS-CoV).

BACKGROUND: Since the identification of the first case of infection with the Middle East respiratory syndrome corona virus (MERS-CoV) in Saudi Arabia in June 2012, the number of laboratory-confirmed cases has exceeded 941 cases globally, of which 347 died. The disease presents as severe respiratory infection often with shock, acute kidney injury, and coagulopathy. Recently, we observed three cases who presented with neurologic symptoms. These are so far the first reported cases of neurologic injury associated with MERS-CoV infection. METHODS: Data was retrospectively collected from three patients admitted with MERS-CoV infection to Intensive Care unit (ICU) at King Abdulaziz Medical City, Riyadh. They were managed separately in three different wards prior to their admission to ICU. FINDING: The three patients presented with severe neurologic syndrome which included altered level of consciousness ranging from confusion to coma, ataxia, and focal motor deficit. Brain MRI revealed striking changes characterized by widespread, bilateral hyperintense lesions on T2-weighted imaging within the white matter and subcortical areas of the frontal, temporal, and parietal lobes, the basal ganglia, and corpus callosum. None of the lesions showed gadolinium enhancement. INTERPRETATION: CNS involvement should be considered in patients with MERS-CoV and progressive neurological disease, and further elucidation of the pathophysiology of this virus is needed.

Three new HLA-C alleles (HLA-C*14:02:13, HLA-C*15:72 and HLA-C*15:74) in Saudi bone marrow donors.

Three new HLA-C alleles were identified by sequence-based typing method (SBT) in donors for the Saudi Bone Marrow Donor Registry (SBMDR). HLA-C*14:02:13 differs from HLA-C*14:02:01 by a silent G to A substitution at nucleotide position 400 in exon 2, where lysine at position 66 remains unchanged. HLA-C*15:72 differs from HLA-C*15:22 by a nonsynonymous C to A substitution at nucleotide position 796 in exon 3, resulting in an amino acid change from phenylalanine to leucine at position 116. HLA-C*15:74 differs from HLA-C*15:08 by a nonsynonymous C to T substitution at nucleotide position 914 in exon 3, resulting in an amino acid change from arginine to tryptophan at position 156.

Two novel alleles HLA-A*02:433 and HLA-A*02:434 identified in Saudi bone marrow donors using sequence-based typing.

In this report, we present two novel HLA-A alleles: HLA-A*02:433 and HLA-A*02:434. These alleles were identified by sequence-based typing method (SBT), in two donors for the Saudi Bone Marrow Donor Registry (SBMDR). Allele A*02:433 is identical to A*02:05:01G except for a G to A substitution at nucleotide position 449 in exon 2. This substitution results in glycine to serine substitution at position 83. Whereas, allele A*02:434 is identical to A*02:01:01G except for a C to A substitution at nucleotide position 245 in exon 2, which results in phenylalanine to threonine substitution at position 15. The generation of both alleles appears to be the result of nucleotide point mutation involving 02:01:01 and 02:05:01.

Two novel alleles HLA-DRB1*11:150 and HLA-DRB1*14:145 identified in Saudi individuals.

Two new HLA- DRB1 alleles were identified by sequence-based typing method (SBT) in 1100 participants in the Saudi Stem Cell Donor Registry. HLA-DRB1*11:150 differs from HLA-DRB1*11:01:01G by a single C to A substitution at nucleotide position 5580 in exon 2, resulting in an amino acid change from alanine to glutamic acid at position 74. HLA-DRB1*14:145 differs from HLA-DRB1*14:04 by a C to G substitution at nucleotide position 5511 in exon 2, resulting in an amino acid change from threonine to arginine at position 51.

HLA-A, -B, -C, -DRB1 and -DQB1 allele and haplotype frequencies in Saudis using next generation sequencing technique.

Next generation sequencing (NGS) is a promising technique that can reveal the entire gene sequences and to the highest possible resolution without any phase ambiguities. We have used this technique to investigate the frequencies of HLA-A, -B, -C, -DRB1 and -DQB1 in a Saudi cohort of healthy individuals. We used NGS using the 454 genome sequence (GS) FLX System and Conexio assign atf 454 software to human leukocyte antigen (HLA) genotype eight class I and class II loci. A total of 158 healthy Saudi adults were analyzed. The most frequently observed allele for HLA-A was HLA-A*02:01:01:01 (13.6%); for HLA-B, HLA-B*50:01:01 (15.8%); for HLA-C, HLA-C*06:02:01:01 (18.7%); for HLA-DRB1, HLA-DRB1*07:01:01:01 (26.6%); and for HLA-DQB1, HLA-DQB1*02:01:01 (20.3%). The most common four loci haplotypes in the Saudi population were HLA-A*24:02:01:01-B*08:01:01-C*07:02:01:01-DRB1*03:01:01:01 and HLA-A*23:01:01-B*50:01:01-C*06:02:01:01-DRB1*07:01:01:01.. We have used a highly informative technique for HLA typing of a Saudi healthy cohort to establish allele and haplotype frequencies. These results should prove useful for population studies, disease associations and future planning of the unrelated bone marrow donor registry.

HLA class I and class II polymorphisms in Saudi patients with myasthenia gravis.

Myasthenia gravis (MG) is a rare autoimmune disease of the neuromuscular junction. MG has been shown to be associated with many HLA antigens in different populations. Here we have analysed the frequency of HLA-A, B, DR and DQ in a group of Saudi MG patients and compared their results to a group of healthy controls. MG in Saudi patients is found to be associated with HLA-A*23, B*08, B*18, DRB1*16 and DRB1*13. The strongest association was with HLA-B*08, which was associated with young age at onset and female gender. Our results are in line with other published results from around the world and warrant fine mapping of the area using microsatellite to map the disease gene.

Identification of the novel HLA-A*32:01:01:08 allele in a Saudi individual.

HLA-A*32:01:01:08 differs from HLA-A*32:01:01:01 by a single nucleotide substitution (G → A) at position 2200.

Identification of the novel HLA-B*51:230 allele in a Saudi individual.

One nucleotide replacement at codon 349 of HLA-B*51:01:01:01 results in a new allele, HLA-B*51:230.

HLA class II polymorphism in Saudi patients with multiple sclerosis.

Several studies have investigated the association of different HLA antigens with multiple sclerosis (MS). However, only few studies have considered the association of high-resolution HLA type and MS with none yet from Saudi Arabia. The aim of this study was to investigate the association of HLA class II alleles with MS in the Saudi population. We used next-generation sequencing to investigate HLA association with MS. This study was conducted at King Abdulaziz Medical City in Riyadh, Saudi Arabia. We found that several HLA-DRB1 and DQB1 alleles were associated with MS. These alleles included HLA-DRB1*15:01 (odds ratio [OR]: 3.01; 95%, confidence interval [CI]: 1.68-5.54; P = .0001), HLA-DQB1*02:01 (OR: 1.76; 95% CI: 1.20-2.58; P = .0022), HLA-DQB1*06:02 (OR: 3.52; 95% CI: 1.87-6.86; P < .0001), and HLA-DQB1*06:03 (OR: 2.42; 95% CI: 1.16-5.25; P = 0.01). Interestingly, HLA-DRB1*15:01 was associated with increased risk of previous relapses. In addition, HLA-DRB1*15:01 and HLA-DQB1*06:02 were found to be associated with lower vitamin D levels. This study provides insights on the association of different HLA alleles with clinical characteristics and outcome of MS among Saudis. These insights can have future implications for the clinical management of MS based on the patient genetic profile.

Identification of the HLA-DQB1*06:123 allele in an unrelated stem cell donor from the Saudi Registry.

HLA-DQB1*06:123 differs from HLA-DQB1*06:29 by six nucleotide substitutions resulting in five amino acid changes.

Description of a novel HLA-DQB1 allele, HLA-DQB1*06:126, in the Saudi stem cell donor registry.

HLA-DQB1*06:126 differs from HLA-DQB1*06:02:01 by a nonsynonymous C to T substitution at nucleotide position 1621 in Exon 2.

Neutrophils and lymphoid chimerism after adult living-related liver transplantation from a homozygous donor.

Chimerism and graft-versus-host disease (GVHD) pose significant risks to liver transplant patients. The risk of chimerism and GVHD is higher among cases of living-related liver transplant (LRLT). Donors homozygous at all HLA loci carry a higher risk for GVHD. Herein we present a case of LRLT. The recipient suffered from end-stage liver disease and received a right lobe graft from his son. After 8 months posttransplant, the patient developed profound bone marrow depression. The patient was negative for CMV, Brucella, HHV6, HHV8, HBV, HCV, and parvovirus. No skin or GI signs of GVHD were noted. The patient and donor were HLA typed by SSP. The donor was homozygous for all HLA loci while the patient shared the class II homozygosity and was class I heterozygous. Chimerism studies were prompted after noting that the neutrophil compartment of the patient was homozygous for all HLA loci. This initiated further studies of the PMN and lymphocytes by microsatellite analysis. A total 15 microsatellites were analyzed. The results suggest that the majority (75%) of the PMNs and 45% of the lymphocytes were of donor origin. The patient was treated with G-CSF; his WBC counts returned to normal. At 2.5 years posttransplant the patient had not developed GVHD, despite the large number of donor lymphocytes circulating in his bloodstream. The only complaint he had was severe arthritis, which was treated with steroids. It must be investigated whether this was the result of GVHD.

Tumour necrosis factor c2 microsatellite allele is associated with the rate of HIV disease progression.

BACKGROUND: The rate of immunological deterioration and progression to AIDS differs markedly between HIV-positive individuals, and may be influenced by cofactors, HIV phenotype and host T-cell response. Tumour necrosis factor (TNF)-alpha and lymphotoxin stimulate HIV replication and may induce apoptosis of HIV-infected and uninfected lymphocytes in vitro, thus accelerating disease progression and CD4 depletion. Variability in TNF production between individuals is to a degree genetically determined and may be predicted from polymorphisms of microsatellite regions surrounding the human TNF gene locus. METHODS: We examined TNf microsatellite polymorphisms in 24 HIV-positive patients with slower disease progression (CD4 count > 400 x 10(6)/l at > or = 6 years), 20 HIV-positive patients with faster progression (CD4 count < 200 x 10(6)/l within 5 years) and 109 healthy controls resident in north-west England. Typing was performed by polymerase chain reaction amplification of TNF a, b, c and d microsatellites and alleles were defined using fluorescence-based semi-automated microsatellite mapping techniques. RESULTS: No significant differences in TNF a, b and d allele frequencies were observed between faster and slower progressors, or with healthy controls. The frequency of the TNF c2 allele was significantly different between HIV-positive slower (60.9%) and faster (15%) progressors (P = 0.002) with an odds ratio of 0.1 (95% confidence interval, 0-0.6). TNF c2 was also less frequent in faster progressors than in healthy controls (45.9%, P = 0.006) with an odds ratio of 0.2 (95% confidence interval 0-0.8). CONCLUSIONS: This is the first report demonstrating a strong association between the TNF c2 allele and the rate of HIV progression. Although it is possible that this finding may have arisen as a result of linkage disequilibrium with other alleles within the major histocompatibility complex that exert a more powerful effect upon progression, evidence is mounting to suggest that both TNF-alpha and lymphotoxin are closely involved in HIV disease progression and CD4 depletion. Our results serve to highlight the potential importance of genetic polymorphism, particularly of the TNF locus, in influencing the progression of HIV infection.

Chemokine RANTES promoter polymorphism affects risk of both HIV infection and disease progression in the Multicenter AIDS Cohort Study.

OBJECTIVE: To examine whether polymorphism in the RANTES gene is associated with HIV disease outcome. DESIGN: RANTES, a ligand of the major HIV co-receptor, CCR5, is known to block HIV-CCR5 interactions. Recently, two single nucleotide polymorphisms in the RANTES gene promoter region, designated -403G/A and -28C/G, have been described. Both polymorphisms can affect in-vitro promoter activity, and the RANTES -403A, -28G haplotype has been associated with a slower CD4 cell count decline rate in a Japanese cohort. METHODS: We compared RANTES compound genotype frequencies between HIV-positive and exposed-uninfected participants of the Multicenter AIDS Cohort Study (MACS) and rates of progression to AIDS for MACS seroconverters. RESULTS: We found that the two most common RANTES promoter compound genotypes, G1 (-403G/G, -28C/C) found in 67% of Caucasians, and G4 (-403G/A, -28C/C) found in 23% of Caucasians, were associated with altered risk of HIV transmission and progression, particularly in individuals who lacked the protective CCR5 mutation, CCR5delta32. In this study, individuals with a G4 compound genotype were more likely to acquire HIV than individuals with a G1 compound genotype (OR 1.72, P = 0.016) and the risk increased when individuals possessing CCR5delta32 were omitted from consideration (OR 2.13, P = 0.005). Among seroconverters lacking CCR5delta32, those who had the G4 compound genotype progressed significantly slower to AIDS-1993 than those with the G1 compound genotype (median time to AIDS 7.6 versus 5.4 years; RH 0.65; P = 0.007). CONCLUSIONS: These data implicate the RANTES-403A allele as a risk factor for HIV transmission and as a protective factor for HIV progression.

Visual manifestations of giant cell arteritis. Trends and clinical spectrum in 161 patients.

Giant cell (temporal) arteritis (GCA) is the most common systemic vasculitis in Western countries. It involves large and medium-sized vessels with predisposition to the cranial arteries in the elderly. Cranial ischemic complications, in particular permanent visual loss, constitute the most feared aspects of this vasculitis. Although the use of corticosteroids and a higher physician awareness may have contributed to a decrease in the frequency of severe ischemic complications, permanent visual loss is still present in 7%-14% of patients. To investigate further the incidence, trends, and clinical spectrum of visual manifestations in patients with GCA, we examined the features of patients with biopsy-proven GCA diagnosed at the single reference hospital for a defined population in northwestern Spain during an 18-year period. Predictive factors for the development of any visual manifestation, not only permanent visual loss, were also examined. Between 1981 and 1998, 161 patients were diagnosed with biopsy-proven GCA. Visual ischemic complications were observed in 42 (26.1%), and irreversible blindness, mainly due to anterior ischemic optic neuropathy and frequently preceded by amaurosis fugax, was found in 24 (14.9%). Despite a progressive increase in the number of new cases diagnosed, there was not a significant change in the proportion of patients with visual manifestations during the study period (p = 0.37). Patients with visual ischemic complications had lower clinical and laboratory biologic markers of inflammation. Indeed, during the last years of the study, anemia was associated with a very low risk of visual complications. Also, HLA-DRB1*04-positive patients had visual manifestations more commonly. Patients with other ischemic complications developed irreversible blindness more frequently. The best predictors of any visual complication were HLA-DRB1*04 phenotype (odds ratio [OR] 7.47) and the absence of anemia at the time of admission (OR for patients with anemia = 0.07). The best predictors of irreversible blindness (permanent visual loss) were amaurosis fugax (OR 12.63) and cerebrovascular accidents (OR 26.51). The present study supports the claim that ocular ischemic complications are still frequent in biopsy-proven GCA patients from southern Europe. The presence of other ischemic complications constitutes an alarm for the development of irreversible blindness. In contrast, a higher inflammatory response may be a protective factor against the development of cranial ischemic events.

Influence of TNFalpha gene polymorphisms on TNFalpha production and disease.

Tumor necrosis factor alpha (TNFalpha) is a potent inflammatory cytokine. In human, the TNFalpha gene is located within the highly polymorphic major histocompatibility complex (MHC) region on chromosome 6p21.3. TNF gene cluster contains many polymorphisms including microsatellites and single nucleotide polymorphisms (SNPs). Many of these polymorphisms were found to be in linkage disequilibrium with HLA class I and II alleles. Some of the TNFalpha gene polymorphisms were found to influence TNFalpha production in vitro, for example the -308 SNP. Many studies have shown that this SNP and others within the TNFalpha gene associate with different inflammatory conditions. Whether this phenomenon is due to the direct influence of the SNP in question and/or due to linkage disequilibrium with other polymorphisms within the TNFalpha gene or the HLA system is still controversial.

Association of IL-10 genotype with sudden infant death syndrome.

Sudden infant death syndrome (SIDS) is a major cause of infant death of unknown etiology. We propose that SIDS results from a genetically determined imbalance in the production of inflammatory and anti-inflammatory cytokines in response to the infant's microbial flora. We were especially interested to know the relationship between SIDS and genetically determined higher or lower production of IL-10, an anti-inflammatory cytokine. Biallelic polymorphisms in the promoter region of the IL-10 gene associated with higher or lower production of IL-10 were determined in a SIDS and in a control group using a sequence-specific oligonucleotide approach. One particular allele of the IL-10 gene, the IL-10-592*A allele, was significantly associated with SIDS. Indeed, 70% of the SIDS babies carried the IL-10-592*A allele (p = 0.007 compared with control). In addition, there was a significant reduction in the frequency of homozygosity for the allele IL-10-592*C (p = 0.001 compared with control). Carrying the A allele (either A/A or A/C) had an odds ratio of 3.3 (95% confidence interval 1.4-8.0). In the same patients there was no association with other IL-10 gene polymorphisms nor with other cytokine (TNF-alpha, TGF-beta 1) genotypes, emphasizing the particular relationship between SIDS and the IL-10-592*A allele.