Intragenomic conflict of maternal HLA haplotypes: a potential link between vigorous intrauterine growth and risk of autoimmunity in adulthood.

Scientific lette

Targeting the Immunogenetic Diseases with the Appropriate HLA Molecular Typing: Critical Appraisal on 2666 Patients Typed in One Single Centre

We compared the immunogenetic data from 2666 patients affected by HLA-related autoimmune diseases with those from 4389 ethnically matched controls (3157 cord blood donors CBD, 1232 adult bone marrow donors BMD), to verify the appropriateness of HLA typing requests received in the past decade. The frequency of HLA-B*27 phenotype was 10.50% in 724 ankylosing spondylitis, 16.80% in 125 uveitis (3.41% BMD, 4.24% CBD, P<0.0001); HLA-B*51 allele was 15.57% in 212 Behçet’s disease (12.91% BMD, 9.88% CBD, P<0.0001); the HLA-DRB1-rheumatoid arthritis (RA) shared epitope was 13.72% in 554 RA (10.85% BMD, 13.48% CBD, P=0.016); the carriers of almost one of HLA-DQB1 susceptibility alleles were 84.91% in 795 celiac disease (CD) and 59.37% in 256 insulin-dependent diabetes mellitus (IDDM) (46.06% in 875 CBD, 42.75% in 662 BMD P<0.0001). Overall, our results show that the HLA marker frequencies were higher in patients than controls, but lower than expected from the literature data (excluding CD and IDDM) and demonstrate that, in complex immunogenetic conditions, a substantial number of genetic analyses are redundant and inappropriate, burdening to the public health costs. For this reason, we suggest the Italian Scientific Society of Immunogenetics to establish guidelines to improve the appropriateness of typing requests

The distribution of KIR-HLA functional blocks is different from north to south of Italy

The killer cell immunoglobulin-like receptor (KIR)-human leukocyte antigen (HLA) interaction represents an example of genetic epistasis, where the concomitant presence of specific genes or alleles encoding receptor-ligand units is necessary for the activity of natural killer (NK) cells. Although KIR and HLA genes segregate independently, they co-evolved under environmental pressures to maintain particular KIR-HLA functional blocks for species survival. We investigated, in 270 Italian healthy individuals, the distribution of KIR and HLA polymorphisms in three climatic areas (from cold north to warm south), to verify their possible geographical stratification. We analyzed the presence of 13 KIR genes and genotyped KIR ligands belonging to HLA class I: HLA-C, HLA-B and HLA-A. We did not observe any genetic stratification for KIR genes and HLA-C ligands in Italy. By contrast, in a north-to-south direction, we found a decreasing trend for the HLA-A3 and HLA-A11 ligands (P = 0.012) and an increasing trend for the HLA-B ligands carrying the Bw4 epitope (P = 0.0003) and the Bw4 Ile80 epitope (P = 0.0005). The HLA-A and HLA-B KIR ligands were in negative linkage disequilibrium (correlation coefficient -0.1211), possibly as a consequence of their similar function in inhibiting NK cells. The distribution of the KIR-HLA functional blocks was different along Italy, as we observed a north-to-south ascending trend for KIR3DL1, when coupled with HLA-B Bw4 ligands (P = 0.0067) and with HLA-B Bw4 Ile80 (P = 0.0027), and a descending trend for KIR3DL2 when coupled with HLA-A3 and HLA-A11 ligands (P = 0.0044). Overall, people from South Italy preferentially use the KIR3DL1-HLA-B Bw4 functional unit, while those from the North Italy equally use both the KIR3DL2-HLA-A3/A11 and the KIR3DL1-HLA-B Bw4 functional units to fight infections. Thus, only KIR3DL receptors, which exert the unique role of microbial sensors through the specific D0 domain, and their cognate HLA-A and HLA-B ligands are selectively pressured in Italy according to geographical north-to-south distribution

HLA-DQ genetics in children with celiac disease: A meta-analysis suggesting a two-step genetic screening procedure starting with HLA-DQ β chains

Background: Specific HLA-DQ genes have been recognized as necessary - but not sufficient - factors for the occurrence of Celiac Disease (CD). Through a meta-analysis, evaluating the distribution of CD-related HLA genotypes in children, we aimed at providing insights for a potential widened screening strategy. Methods: After a systematic search on the association between class II HLA genes and CD in children, 46 publications were obtained and assessed for eligibility. A total of 13 eligible studies were submitted to data extraction and analysis (10 case-control studies and 3 cohort studies). Case-control studies collectively enrolled 740 CD patients and 943 controls. Results: In the population-stratified analysis, the following alleles conferred a significantly increased risk for CD: HLA-DQB1*02 (odds ratio [OR]=10.28) and HLA-DQB1*03:02 (OR=2.24). By drafting a risk gradient to develop CD according to HLA genetic background, the highest risk is confirmed to exist for DQ2/DQ2 homozygous subjects, regardless of the ethnicities (OR=5.4). Actually, the genotype DQ2/β2 showed basically the same risk (OR=5.3). Indeed, no differences have been found in CD risk between DQ2/β2 and DQ2/DQ2, as well as between DQ8/β2 and DQ2/DQ8, and between β2/DQX and DQ2/X. Conclusion: The HLA-DQB1*02:01 allele is present in more than 90% CD children. In the perspective of a widened pediatric population screening for CD, a double-step process might be suggested: HLA-DQB1*02:01 might be investigated first and, only if this result is positive, children might be candidate for a prospective serologic screening, as a second step

The relationship between frailty and delirium: insights from the 2017 Delirium Day study.

Background: although frailty and delirium are among the most frequent and burdensome geriatric syndromes, little is known about their association and impact on short-term mortality. Objective: to examine, in hospitalized older persons, whether frailty is associated with delirium, and whether these two conditions, alone or in combination, affect these patients' 30-day survival. Design: observational study nested in the Delirium Day project, with 30-day follow-up. Setting: acute medical wards (n = 118) and rehabilitation wards (n = 46) in Italy. Subjects: a total of 2,065 individuals aged 65+ years hospitalized in acute medical (1,484 patients, 71.9%) or rehabilitation (581 patients, 28.1%) wards. Methods: a 25-item Frailty Index (FI) was created. Delirium was assessed using the 4AT test. Vital status was ascertained at 30 days. Results: overall, 469 (22.7%) patients experienced delirium on the index day and 82 (4.0%) died during follow-up. After adjustment for potential confounders, each FI score increase of 0.1 significantly increased the odds of delirium (odds ratio, OR: 1.66 [95% CI: 1.45-1.90]), with no difference between the acute (OR: 1.65 [95% CI: 1.41-1.93]) and rehabilitation ward patients (OR: 1.71 [95% CI: 1.27-2.30]). The risk of dying during follow-up also increased significantly for every FI increase of 0.1 in the overall population (OR: 1.65 [95% CI: 1.33-2.05]) and in the acute medical ward patients (OR: 1.61 [95% CI: 1.28-2.04]), but not in the rehabilitation patients. Delirium was not significantly associated with 30-day mortality in either hospital setting. Conclusions: in hospitalized older patients, frailty is associated with delirium and with an increased risk of short-term mortality