Common, Intermediate and Well-Documented HLA Alleles in World Populations: CIWD Version 3.0.0

A catalog of common, intermediate and well-documented (CIWD) HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1 and -DPB1 alleles has been compiled from over 8 million individuals using data from 20 unrelated hematopoietic stem cell volunteer donor registries. Individuals are divided into seven geographic/ancestral/ethnic groups and data are summarized for each group and for the total population. P (two-field) and G group assignments are divided into one of four frequency categories: common (≥1 in 10 000), intermediate (≥1 in 100 000), well-documented (≥5 occurrences) or not-CIWD. Overall 26% of alleles in IPD-IMGT/HLA version 3.31.0 at P group resolution fall into the three CIWD categories. The two-field catalog includes 18% (n = 545) common, 17% (n = 513) intermediate, and 65% (n = 1997) well-documented alleles. Full-field allele frequency data are provided but are limited in value by the variations in resolution used by the registries. A recommended CIWD list is based on the most frequent category in the total or any of the seven geographic/ancestral/ethnic groups. Data are also provided so users can compile a catalog specific to the population groups that they serve. Comparisons are made to three previous CWD reports representing more limited population groups. This catalog, CIWD version 3.0.0, is a step closer to the collection of global HLA frequencies and to a clearer view of HLA diversity in the human population as a whole

Public Awareness on Cord Blood Banking in Saudi Arabia

Background. In the last decade, cord blood (CB) has proven to be a valuable source of hematopoietic stem cells for transplantation to treat many hematological disorders. Since then, many CB banks have been established worldwide. Our aim was to estimate the level of public awareness of CB banking in Saudi Arabia. Study Design and Methods. A self-administered questionnaire of 22 multiple choices was conveniently distributed, consisting of demographics, awareness measure, attitude toward banking preference, and donation for research data. Results. A total of 1146 participants have completed the questionnaire. The majority were young female 19–25 years old (26%), who are college graduates (57%) with middle class socioeconomic status (82%). The subjective assessment of the overall knowledge was inadequate (66%). For the objective assessment, 12 questions were asked about CB source, collection, storage, and usage. Only half of the subjects (52%) knew that CB is a source of stem cells. More than half did not know the main use of CB. About half did not know about the method of collection nor the condition of storing. Conclusion. This study shows a high lack of knowledge about CB banking. More than half of the subjects were unaware of CB banking and its uses. However, most subjects are accepting CB storage, which anticipates great impact and efficacy on educational programs. Moreover, the data demonstrated that health professionals were not the source of knowledge. We recommend having comprehensive educational campaigns with clear information about CB banking to facilitate positive perspectives towards donation and scientific research

Public Awareness on Cord Blood Banking in Saudi Arabia

Background. In the last decade, cord blood (CB) has proven to be a valuable source of hematopoietic stem cells for transplantation to treat many hematological disorders. Since then, many CB banks have been established worldwide. Our aim was to estimate the level of public awareness of CB banking in Saudi Arabia. Study Design and Methods. A self-administered questionnaire of 22 multiple choices was conveniently distributed, consisting of demographics, awareness measure, attitude toward banking preference, and donation for research data. Results. A total of 1146 participants have completed the questionnaire. The majority were young female 19–25 years old (26%), who are college graduates (57%) with middle class socioeconomic status (82%). The subjective assessment of the overall knowledge was inadequate (66%). For the objective assessment, 12 questions were asked about CB source, collection, storage, and usage. Only half of the subjects (52%) knew that CB is a source of stem cells. More than half did not know the main use of CB. About half did not know about the method of collection nor the condition of storing. Conclusion. This study shows a high lack of knowledge about CB banking. More than half of the subjects were unaware of CB banking and its uses. However, most subjects are accepting CB storage, which anticipates great impact and efficacy on educational programs. Moreover, the data demonstrated that health professionals were not the source of knowledge. We recommend having comprehensive educational campaigns with clear information about CB banking to facilitate positive perspectives towards donation and scientific research

HLA-A, -B, -C,-DRB1,-DQB1, and-DPB1 Allele and Haplotype Frequencies of 28,927 Saudi Stem Cell Donors Typed by Next-Generation Sequencing

Human leukocyte antigen (HLA) allele and haplotype frequency distribution varies widely between different ethnicities and geographical areas. Matching for HLA alleles is essential for successful related and unrelated stem cell transplantation. Among the Saudi population, data on HLA alleles and haplotypes are limited. A cross-sectional study was performed on 28,927 bone marrow donors. The most frequent HLA alleles were HLA-A*02:01:01G (20.2%), A*24:02:01G (7.5%); B*51:01:01G (19.0%), B*50:01:01G (12.3%); C*06:02:01G (16.7%), C*07:02:01G (12.2%); DRB1*07:01:01 (15.7%), DRB1*03:01:01G (13.3%); DQB1*02:01:01G (29.9%), DQB1*03:02:01G (13.2%); and DPB1*04:01:01G (35.2%), DPB1*02:01:02G (21.8%). The most frequent HLA-A similar to C similar to B similar to DRB1 similar to DQB1 haplotypes were A*02:01:01G similar to C*06:02:01G similar to B*50:01:01G similar to DRB1*07:01:01G similar to DQB1*02:01:01G (1.9%) and A*02:05:01G similar to C*06:02:01G similar to B*50:01:01G similar to DRB1*07:01:01G similar to DQB1*02:01:01G (1.6%). The most frequent HLA-A similar to C similar to B similar to DRB1 similar to DQB1 similar to DPB1 haplotypes were A*02:01:01G similar to C*15:02:01G similar to B*51:01:01G similar to DRB1*04:02 similar to DQB1*03:02:01G similar to DPB1*04:01:0G (1%) and A*02:01:01G similar to C*07:02:01G similar to B*07:02:01G similar to DRB1*15:01:01G similar to DQB1*06:02:01G similar to DPB1*04:01:01G (0.9%). Based on these haplotype frequencies, we provide forecasts for the fraction of patients with full matching and single mismatched donors for 3 to 6 loci depending on the registry size. With one million donors, about 50% of the patients would find an 8/8 match and 90% a 7/8 match. These data are essential for registry planning, finding unrelated stem cell donors, population genetic studies, and HLA disease associations

HLA-C polymorphisms in two cohorts of donors for bone marrow transplantation

The typing for HLA-C in transplantation was rather neglected in the past. However, several recent studies have emphasized its role in transplantation and its association with the outcome. Serological typing of HLA-C could identify only a limited number of HLA-C antigens, resulting in a number of HLA-C blanks. This was mainly due to the low expression of surface HLA-C and the small number of available specific anti-sera. Performing molecular methods has identified new HLA-C alleles and filled the blank of most serological typed antigens. In this study, we compared serological and molecular typing of HLA-C in two cohorts of healthy Saudis. Our serological typing method identified HLA-C1-7 with different frequencies, 23.5% of the alleles were not identified and thus defined as blank. Using the SSP molecular method, all samples were typed and all alleles were defined. Both methods showed that CFNx0107 and CFNx0106 have the highest frequency in the Saudi population. Our study emphasizes the importance of molecular methods in identifying all possible HLA-C alleles

Association of HLA-DRB1*15 and HLA-DQB1*06 with SLE in Saudis

BACKGROUND AND OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by humoral autoimmunity. The etiology of SLE is thought to be multifactorial including environmental, hormonal, and genetic factors. The human leukocyte antigen (HLA) has extensively been associated with the susceptibility to SLE; however, the association is heterogeneous among different ethnic groups. The aim of this study was to determine the association of HLA-A, HLA-B, HLA-DRB1, and HLA-DQB1 with SLE susceptibility in the Saudi population

Free Fatty Acids’ Level and Nutrition in Critically Ill Patients and Association with Outcomes: A Prospective Sub-Study of PermiT Trial

Objectives: The objectives of this study were to evaluate the clinical and nutritional correlates of high free fatty acids (FFAs) level in critically ill patients and the association with outcomes, and to study the effect of short-term caloric restriction (permissive underfeeding) on FFAs level during critical illness. Patients/Method: In this pre-planned sub-study of the PermiT (Permissive Underfeeding vs. Target Enteral Feeding in Adult Critically Ill Patients) trial, we included critically ill patients who were expected to stay for ≥14 days in the intensive care unit. We measured FFAs level on day 1, 3, 5, 7, and 14 of enrollment. Of 70 enrolled patients, 23 (32.8%) patients had high FFAs level (baseline FFAs level >0.45 mmol/L in females and >0.6 mmol/L in males). Results: Patients with high FFAs level were significantly older and more likely to be females and diabetics and they had lower ratio of partial pressure of oxygen to the fraction of inspired oxygen, higher creatinine, and higher total cholesterol levels than those with normal FFAs level. During the study period, patients with high FFAs level had higher blood glucose and required more insulin. On multivariable logistic regression analysis, the predictors of high baseline FFAs level were diabetes (adjusted odds ratio (aOR): 5.36; 95% confidence interval (CI): 1.56, 18.43, p = 0.008) and baseline cholesterol level (aOR, 4.29; 95% CI: 11.64, 11.19, p = 0.003). Serial levels of FFAs did not differ with time between permissive underfeeding and standard feeding groups. FFAs level was not associated with 90-day mortality (aOR: 0.49; 95% CI: 0.09, 2.60, p = 0.40). Conclusion: We conclude that high FFAs level in critically ill patients is associated with features of metabolic syndrome and is not affected by short-term permissive underfeeding