A need to adopt new strategies for organ donation in Saudi Arabia.

BACKGROUND: HLA matching in kidney transplantation is a major factor in long-term survival of the graft. In Saudi Arabia, most deceased donors are non-Saudi, making it difficult to achieve minimal HLA mismatches between donor and recipient. OBJECTIVE: To analyze HLA types of 200 deceased donors and compare them with the Saudi population's HLA types. MATERIALS AND METHODS: In a retrospective study analyzing HLA types of the last 398 deceased donors processed in a tertiary hospital in Riyadh, Saudi Arabia, HLA types of all donors were compared with HLA types from a control group of healthy Saudi persons. RESULTS: HLA types were significantly different between the deceased donor group and the Saudi population. In all deceased donors, zero mismatches was never achieved. The major differences in HLA types were in HLA-A*02, HLA-B*15, B*40, B*50, HLA-DRB1*14, DRB1*15, and DRB1*04. CONCLUSIONS: As most of our deceased donors are non-Saudis, it is difficult to match for HLA-A, HLA-B, and HLA-DR. HLA matching should be attempted nationwide by adopting different strategies, including typing donors centrally and distributing results to all centers, agreeing on a national point system for allocating organs from deceased donors, and making HLA matching a priority, especially for highly sensitized patients.

Chances of finding an HLA-matched sibling: The Saudi experience.

Hematopoietic cell transplantation (HCT) remains the fundamental procedure to treat many diseases. Its success depends greatly on the degree of HLA matching between donor and recipient. Although the number of successful HCT procedures carried out worldwide increases every year, many patients remain unable to receive this treatment because of the difficulty of finding an HLA-matching donor. In our center, we identified the HLA types for all HCT candidates and their siblings in an attempt to determine the chance of finding a full HLA-matching sibling. Overall, 60% of patients had a chance of finding an HLA-matching sibling. The chance of finding a matching sibling was 43% in patients aged birth to 5 years, compared with 68% in those aged 20+ years. In our Saudi population, patients in need of HCT have a greater chance of finding an HLA-matching sibling than is reported in most Western countries. This is mainly because of the larger number of siblings in most Saudi families. Younger children requiring HCT have a lesser chance of finding an HLA-matching sibling. Our data demonstrate that even in a country with relatively large families, it is still essential to consider alternative donor strategies, such as adult unrelated donors, unrelated umbilical cord blood units, and haploidentical donors.

Association of HLA-DRB1*15 and HLADQB1*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. DESIGN AND SETTINGS: A total of 86 consecutive SLE patients attending the rheumatology clinic at King Abdulaziz Medical City, Riyadh, were recruited for this study. METHODS: HLA types were determined by the polymerase chain reaction sequence-specific oligonucleotide (PCR-SSP) method in 86 patients and 356 control subjects. RESULTS: The following HLA alleles were found to be positively associated with SLE: HLA-A*29 (OR=2.70; 95% CI=1.03-7.08; P=.0035), HLA-B*51 (OR=1.81; 95% CI=1.17-2.79; P=.0066), HLA-DRB1*15 (OR=1.45; 95% CI=0.98-2.29; P=.063), and HLA-DQB1*06 (OR=1.67; 95% CI=1.19-2.36; P=.0032), whereas HLA-DRB1*16 was negatively associated with the disease (OR=0.18; 95% CI=0.02-1.3; P=.055). HLA-DRB1*15 haplotypes were significantly associated with SLE (OR=2.01, 95% CI=1.20-3.68, P=.008); this was mainly due to the HLADRB1*15-DQB1*06 association. CONCLUSIONS: Our data suggest an association between MHC class I and class II (HLA-A*29, HLA-B*51, HLA-DRB1*15, and HLA-DQB1*06) and susceptibility to SLE in the Saudi population. HLA-DRB1*15-DQB1*06 haplotype showed the highest risk factor for the disease that is similar to what was seen in the African American patients, suggesting shared susceptibility genetic factors among these ethnic groups.

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 C∗07 and C∗06 have the highest frequency in the Saudi population. Our study emphasizes the importance of molecular methods in identifying all possible HLA-C alleles.