Cristina Capittini

HLA haplotypes and birth weight variation: Is your future going to be light or heavy?

Birth weight is known to be a direct indicator of perinatal mortality and a clear predictor of adult pathologies too. It has been correlated with several causes of mortality in adulthood: low birth weight with diabetes, nephropathy and cardiovascular diseases and high birth weight with autoimmune diseases and cancer. In genome-wide studies, an extended human leucocyte antigen (HLA) region has been linked to birth weight variation. We focused our attention on the HLA haplotypes marked by HLA-A, HLA-B and HLA-DRB1 polymorphisms in 1206 healthy Caucasian newborns belonging to the Cord Blood Bank of Pavia (Italy) and their mothers, aiming to investigate the association between this restricted HLA region and birth weight variation. In our study, the HLA-B*38;DRB1*13 haplotype showed an ascending trend among centiles addressing to the high foetal weight. The HLA-A*02;B*15 haplotype showed a descending trend among centiles addressing to the low foetal weight. Besides the acknowledged correlation between the HLA-A*02 and HLA-B*15 alleles (as well as low birth weight) and type I diabetes and between the HLA-B*38 and HLA-DRB1*13 alleles (as well as high birth weight) and several autoimmune diseases, we cannot predict if our babies, healthy at birth, will suffer from these pathologies during life. Nevertheless, our data point to the HLA telomeric end for markers linked to the low birth weight and to the HLA centromeric end for markers linked to the high birth weight, thus limiting the region involved in birth weight variation, which still represents a useful predictor of disease risk in adulthood.

Genetic epistasis between killer immunoglobulin-like receptors and human leukocyte antigens in Kawasaki disease susceptibility.

Kawasaki disease (KD) is a pediatric acute multisystemic vasculitis complicated by development of coronary artery lesions. The breakthrough theory on KD etiopathogenesis points to pathogens/environmental factors triggered by northeastern wind coming from China. Natural Killer cells and T lymphocytes express the inhibitory/activating Killer Immunoglobulin-like Receptors (KIR) to elicit an immune response against pathogens by binding to human leukocyte antigens (HLA) class I epitopes. We first report on the role of KIR/HLA genetic epistasis in a sample of 100 Italian KD children. We genotyped KIR, HLA-A, HLA-B and HLA-C polymorphisms, and compared KD data with those from 270 Italian healthy donors. The HLA-A*11 ligand for KIR2DS2/2DS4/3DL2 was a KD susceptibility marker by itself (odds ratio (OR)=3.85, confidence interval (CI)=1.55–9.53, P=0.004). Although no epistasis between HLA-A*11 and KIR2DS2/S4 emerged, HLA-A*11 also engages KIR3DL2, a framework gene encoding for a pathogen sensor of CpG-oligodeoxynucleotides (CpG-ODN), and KD blood mononuclear cells are actually prone to pathogen CpG-ODN activation in the acute phase. Moreover, carriers of KIR2DS2/HLA-C1 and KIR2DL2/HLA-C1 were more frequent among KD, in keeping with data demonstrating the involvement of these HLA/KIR couples in autoimmune endothelial damage. The highest KD risk factor was observed among carriers of KIR2DL2 and two or more HLA ligands (OR=10.24, CI=1.87–56.28; P=0.007).

The plasma levels of soluble HLA-G molecules correlate directly with CD34+ cell concentration and HLA-G 14bp insertion/insertion polymorphism in cord blood donors.

BACKGROUND Cord blood provides haematopoietic stem cells for allogeneic transplantation and, thanks to the naivety of its immune system, has several advantages over other sources of stem cells. In the transplantation setting, the presence of immunosuppressive human leucocyte antigen (HLA)-G molecules has been advocated to prevent both rejection and Graft-versus-Host disease. HLA-G is physiologically expressed throughout pregnancy and is contained in cord blood at birth. Moreover, it has recently been reported that not only cord blood mesenchymal cells, but also CD34+ cell progenies produce soluble HLA-G (sHLA-G). We tried to identify the largest producer of sHLA-G among 85 healthy cord blood donors at Pavia Cord Blood Bank, correlating the sHLA-G concentration with the HLA-G 14bp insertion/deletion (INS/DEL) genotype and CD34+ cell concentration. MATERIALS AND METHODS We measured sHLA-G levels in 36 cord blood plasma stored at -20 °C for 2 months and 49 cord blood plasma stored at -196 °C for 4-6 years, by enzyme-linked immunosorbent assay. All cord blood donors were genotyped for the HLA-G 14bp INS/DEL polymorphism by polymerase chain reaction. For each cord blood unit, we measured the cell concentration by flow cytometry. RESULTS We did not find differences in sHLA-G levels between cord blood plasma aliquots stored for 4-6 years at -196 °C and cord blood plasma aliquots stored for 2 months at -20 °C. We observed a higher sHLA-G concentration in cord blood plasma donors who carried the HLA-G 14bp INS/INS genotype and had higher CD34+ cell concentrations (P=0.006). DISCUSSION This is the first report showing that the best cord blood stem cell donor is also the best sHLA-G producer, particularly if genetically characterized by the HLA-G 14bp INS/INS genotype. If the therapeutic role of sHLA-G molecules were to be finally established in the transplantation setting, our data suggest that cord blood plasma donors can provide a safe source of allogeneic sHLA-G immunosuppressive molecules ready for transfusion.

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 Behçets 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.

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

BackgroundSpecific 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.MethodsAfter 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.ResultsIn 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.ConclusionThe 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.

An historical approach to the genetic distribution of KIR and HLA ligands in Eastern Sicilians compared to modern descendants of their invaders

A geographical stratification of Killer Immunoglobulin-like Receptors (KIR) has been reported worldwide. We first analyzed the distribution of 15 KIR genes in a sample of 50 East-Sicilians (ES). We used a Principal Component Analysis (PCA) to compare the KIR genetic content among ES and 10 modern populations who are descendants of the ancient invaders of Sicily: Spanish, French, Norwegians, Swedes, Finns, Tunisians, Moroccans, Arabs, Greeks, Turks. We also included a sample of Sardinians, and Senegalese (as outlier group). Then, we also compared the HLA-A, HLA-B and HLA-C allelic frequencies among ES and the same populations investigated for KIR. As to HLA-A and HLA-B polymorphisms, ES are close to Greek population who invaded the island for long time until 827 CE; while HLA-C and KIR distribution in ES are close to Spanish population that invaded Sicily (and Sardinia) starting from 1283. As to KIR, ES are close to Spanish and Sardinians. The immunogenetic fingerprint of ES may be the finely balanced result of the invasions that overwhelmed Sicily over the centuries.

HLA-DRB1 alleles and juvenile idiopathic arthritis: Diagnostic clues emerging from a meta-analysis

Juvenile Idiopathic Arthritis (JIA) is characterized with a variable pattern of articular involvement and systemic symptoms and, thus, it has been classified in several subtypes. Genetic predisposition to JIA is mainly due to HLA class II molecules (HLA-DRB1, HLA-DPB1), although HLA class I molecules and non-HLA genes have been implicated, too. Here, we carried out a meta-analysis including selected studies designed to assess HLA genetic background of JIA patients, compared to healthy controls; particularly, we focused our attention on HLA-DRB1. In summary, our meta-analysis showed four main findings regarding HLA-DRB1 locus as a genetic factor of JIA: i) HLA-DRB1*08 is a strong factor predisposing to JIA, both for oligo-articular and poly-articular forms (oJIA>pJIA); ii) HLA-DRB1*01 and HLA-DRB1*04 may be involved in the genetic predisposition of Rheumatoid Factor (RF) positive forms of JIA; iii) HLA-DRB1*11 was confirmed to be predisposing to oligo-articular JIA; iv) HLA-DRB1*04 was confirmed to have a role in systemic JIA. Importantly, RF positivity seems to select the JIA clinical subset with the strongest immunogenetic similarities with adult rheumatoid arthritis.

Longitudinal analysis of serum cytokines in a Behcet's patient during 9 months of IVIG infusions: how does CXCL8 bridge the immune and neuroendocrine systems?

Behcet’s Disease (BD) is a systemic vasculitis of unknown aetilogy with a protean range of manifestations and diagnosed only n the basis of clinical criteria [1,2]. A specific laboratory test has not yet been validated to idenify BD, however, starting from 1993, several studies have reported hat in serum of BD patients the levels of CXCL8 directly correlated o both severity and duration of symptoms, including the numer of involved organs and active clinical manifestations [3,4]. In articular, CXCL8 levels have been found to be high in sera of BD atients who showed mucosal and neurological signs [5]. CXCL8 is n inflammatory cytokine that attracts and activates neutrophils to he site of infection or tissue damage and, although the pathogenic echanisms are still unknown, BD is in fact a systemic neurophilic perivasculitis characterised by recurrent inflammatory ares, mainly due to the hyper-activation of circulating neutrophils 6,7] Here we report for the first time a long term longitudinal nalysis of 7 serum cytokines in a 39-years old female affected y BD treated with cyclic IntraVenous ImmunoGlobulins (IVIG) nfusions. The patient presented mucocutaneous, articular, ocular nd intestinal manifestations, without clear signs of neurological nvolvement. After the failure of the first-line treatment based on rednisone (25 mg/day) and colchicine (1 mg/day), any immunouppressive therapy was contraindicated because of recurrent evere Varicella-Zoster Virus reactivations. Besides the well-known se of IVIG for protecting patients with primary or secondary mmunodeficiency from infections, IVIG are a recognized treatent for several immune-mediated diseases, including BD. Then, he therapeutic choice fell on IVIG, that the patient started at the osage of 0.4 g/kg/day for three consecutive days in a month for 3 onths, then fortnightly for 3 times, then every three weeks for 9 onths. The inflammatory milieu was monitored by measuring the erum levels of IL-1, IL-2, IL 6, IL-10, CXCL8, IFN, and TNF. Before ach IVIG infusion, the cytokine concentrations were assessed by nzyme-linked immunosorbent assay kits following the manufacurer’s instructions (R&D Systems, USA). Before treatment, mucocutaneous and articular symptoms were resent and we found high levels of CXCL8 (253.83 pg/ml; normal alue: 0–31 pg/ml), detectable levels of IL-6, IL-10, IFN, whereas L-1 and IL-2 were undetectable. After 15 days from the first infuion, CXCL8 rapidly decreased (7.82 pg/ml) and symptoms started o improve. During the nine months of therapy, the use of cyclic infusions of VIG maintained the remission of BD symptoms, and cytokines levls only slightly increased even during an upper airways infection [

An immune-molecular hypothesis supporting infectious aetiopathogenesis of Kawasaki disease in children

The competitive binding between CpG-ODN (single-stranded DNA from pathogens) and HLA-B and HLA-A ligands for the inhibitory Killer Immunoglobulin-like Receptors (KIR)3DL1/2 may lead to possible hypo-sensing of pathogens and ineffective clearance. We observed an overabundance of HLA ligands for inhibitory KIR with three domains in KD subjects.

HLA-A, -B, -DRB1 allele and haplotype frequencies of 674 cord blood donors from North Italy

http://dx.doi.org/10.1016/j.humimm.2017.04.009 0198-8859/ 2017 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved. ⇑ Corresponding author at: IRCCS Policlinico San Matteo Foundation, viale Golgi 19, 27100 Pavia, Italy. E-mail address: cristina.capittini@libero.it (C. Capittini). C. Capittini a,⇑, A. De Silvestri , M. Guarene , A. Pasi , C. Tinelli , C. Perotti b