T. Del Beato

Correlation between genetic HLA class I and II polymorphisms and anthropological aspects in the Chaouya population from Morocco (Arabic speaking)

The aim of this study was to provide genetic and anthropological information on the Chaouya (CH), an Arabic-speaking population living in West Morocco, Atlantic coast (Settat). In 98 unrelated healthy CH volunteers, we first investigated the human leukocyte antigen (HLA) class I and II allele polymorphisms using a sequence-based typing method and examined haplotypes and relatedness of this group to other African and Mediterranean populations. The study showed the close relatedness with Tunisian population and other North Africans, together with a strong influence of various immigrations, mainly Spaniards, French, and Portuguese, as expected. Nevertheless, analysis of class II allele frequencies (afs) showed that Oromo and Amhara Ethiopian groups cluster together with the Berbers and other North Africans, confirming the relationship between these populations (Afro-Asiatic linguistic group, Hamites). South and sub-Saharan Africans cluster separately at a great distance from CH, except the sub-Saharan Bantu population from Congo Kinshasa, which shows a relatively close genetic relationship ascribable to the effect of a diversifying selection. On the other hand, considering HLA class I afs analyses, it was noteworthy that CH grouped together with sub-Saharans, showing a close genetic distance mainly with Ugandas and Kenians Luo.

A new HLA-A allele identified in a leukemic patient attending hematopoietic cell transplantation: A*2318.

Sequence-based typing procedure (SBT) procedure permitted us to identify a new human leukocyte antigen-A allele in a patient attending hematopoietic stem cell transplantation.

Identification of the novel HLA-A*9250 allele by sequence-based typing in a Caucasian bone marrow donor from Italy.

HLA-A*9250 allele was identified by SBT in a Caucasian bone marrow donor. It differs from the closest A*020101 by only one nucleotide (A-->G) at position 124 in exon 2 (Arg to Gly at codon 18); this is an uncommon variation at a highly conserved nucleotide position, located on the loop between S1-S2 beta-sheets in alpha1 domain.

HLA class I residue mismatch and renal graft outcome

Abstract Donor‐recipient HLA matching was retrospectively evaluated in 111 cadaveric renal transplants using Takemotos ten‐residue model in which HLA class I antigens are clustered by crossreactive group (CREGs) on the basis of amino acid sequence homology and the sharing of a particular public epitope. The grade and type of HLA residue mismatching were correlated to post‐transplant, class I donor‐specific antibody production (monitored by flow cytometry crossmatch), rejection occurrence and clinical outcome during the 1st year posttransplant. In 52 patients with 0 mis‐matchings (MMs) we observed a low incidence of rejection (11.1%) and antibody production (11.1 %) for 0 CREG MM grade, while 1 MM was enough to increase immune response against graft (rejection 35%; antibodies 30%). Moreover, a significant correlation was observed between Q144, E163, Q62 and L82/R82 epitopes and the incidence of acute rejection and antibody production (“immunogenic” residues) in patients grouped for a single residue mismatch.

Increased CD1D polymorphism: identification of two novel alleles, CD1D*03 and *04, in individuals from Morocco.

Two novel CD1D alleles were identified in unrelated individuals from Morocco. They differ each from the common CD1D*01 allele by one nucleotide substitution in exon 2 resulting in one amino acid change in the G‐ALPHA1‐LIKE domain. According to the IMGT unique numbering for G domain, CD1D*03 has one nucleotide transition c136 > t in codon 46, with an arginine‐to‐cysteine amino acid change (R46 > C) in the D‐STRAND, whereas CD1D*04 has one transition c98 > t in codon 33, with a threonine‐to‐methionine amino acid change (T33 > M) in the C‐STRAND. This suggests that CD1D is more polymorphic than previously assumed.