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1.
Mar Pollut Bull ; 173(Pt B): 112943, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34562663

ABSTRACT

The Sardinian and Sicilian Channels are considered hotspots of biodiversity and key ecological passages between Mediterranean sub-basins, but with significant knowledge gaps about marine mammal presence and potential threats they face. Using data collected between 2013 and 2019 along fixed transects, inter and intra-annual cetacean index of abundance was assessed. Habitat suitability, seasonal hot spots, and risk exposure for plastic were performed using the Kernel analysis and the Biomod2 R-package. 661 sightings of 8 cetacean species were recorded, with bottlenose and striped dolphins as the most sighted species. The north-eastern pelagic sector, the coastal waters and areas near ridges resulted the most suitable habitats for these species. The risk analysis identified the Tunis, Palermo, and Castellammare gulfs and the Egadi Island as areas of particular risk of plastic exposure. The study represents a great improvement for cetacean knowledge in this region and contributes to the development of effective conservation strategies.


Subject(s)
Cetacea , Plastics , Animals , Biodiversity , Ecosystem , Mediterranean Sea
2.
Mar Environ Res ; 140: 145-151, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29921450

ABSTRACT

Mucilaginous aggregates produced by planktonic or benthic algae are considered ecological threats to marine systems. The study evaluated the effects of the spread of benthic mucilaginous aggregates on the structure of coralligenous assemblages. The assemblage and the quality of a site subjected to a benthic mucilage bloom were compared to those of two reference sites using a Before/After-Control/Impact (BACI) design. Results showed the α and ß-diversity, ESCA and COARSE quality ecological indices and the cover of encrusting algae and bryozoans were lower at the impact site after the mucilage event than at the control sites and at the impact site before the mucilage event. An opposite pattern was observed for the necrosis of gorgonians and the cover of algal turf. This study describes for the first time the impacts of ephemeral mucilage blooms on the whole coralligenous assemblage, identifying a further threat of this habitat and the need of adequate monitoring programs.


Subject(s)
Anthozoa/physiology , Coral Reefs , Microalgae/physiology , Plankton/physiology , Animals , Ecosystem
3.
Mar Pollut Bull ; 128: 318-323, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29571378

ABSTRACT

A modified version of the ALien Biotic IndEX (ALEX) has been recently proposed to evaluate biological invasions in macroalgal assemblages. ALEX was applied in a Marine Protected Area where a recreational-fishing port is present testing the following hypotheses: ALEX increases with the distance from the port, it changes between the two directions off the port and it changes among three different habitats: Cystoseira beds, algal turf and dead matte of the seagrass Posidonia oceanica. A total of 78 native macroalgal taxa and 4 introduced species were found, the Chlorophyta Caulerpa cylindracea and the Rhodophyta Apoglossum gregarium, Acrothamnion preissii and Womersleyella setacea. All study sites were in high quality status highlighting that the assemblages investigated were at an early stage of NIS invasion. However, ALEX detected different values among conditions and habitats within the MPA, suggesting a local dynamics of NIS spread and different resistance to invasion of the investigated habitats.


Subject(s)
Environmental Monitoring/methods , Introduced Species/trends , Seawater/chemistry , Seaweed/growth & development , Biodiversity , Ecosystem , Italy , Seaweed/classification , Ships , Transportation Facilities
4.
Article in English | MEDLINE | ID: mdl-25938688

ABSTRACT

Multiple sclerosis (MS) is a chronic demyelinating disease affecting the central nervous system. Pharmacological therapy of MS includes symptomatic drugs, treatment for relapses (corticosteroid and intravenous immunoglobulin) and disease modifying drugs (DMDs) defined as pharmacological agents that have an impact on relapse rate, disability accumulation and radiological outcomes. Two different therapeutic approaches are widely used in MS: escalation and induction therapy. Escalation therapy consists of an early start with first line DMDs (beta interferon, glatiramer acetate, teriflunomide, dimethyl fumarate) and if DMDs are ineffective or partially effective, switching to second line drugs (mitoxantrone, natalizumab, fingolimod). Induction therapy consists of the early use of immunosuppressant drugs followed by long-term maintenance treatment, generally with immunomodulatory agents. While the use of natalizumab and fingolimod as first line drugs is indicated for aggressive forms of MS, the indication for mitoxantrone as an induction treatment arises from randomized studies demonstrating that induction therapy with mitoxantrone followed by DMD maintenance is more effective than monotherapy with beta interferon. However, the safety profile of induction drugs indicates this is not an acceptable therapeutic strategy for all MS patients in all phases of the disease. The upcoming challenge is to identify patients at high risk of disability development from their clinical characteristics, radiological findings or biomarkers. Furthermore, future studies to establish an individual safety profile stratification are needed.


Subject(s)
Induction Chemotherapy , Interferon-beta/therapeutic use , Maintenance Chemotherapy , Multiple Sclerosis/drug therapy , Animals , Crotonates/therapeutic use , Dimethyl Fumarate/therapeutic use , Fingolimod Hydrochloride/therapeutic use , Glatiramer Acetate/therapeutic use , Humans , Hydroxybutyrates , Mitoxantrone/therapeutic use , Natalizumab/therapeutic use , Nitriles , Randomized Controlled Trials as Topic , Toluidines/therapeutic use , Treatment Outcome
5.
Pharmacogenomics ; 8(11): 1497-509, 2007 Nov.
Article in English | MEDLINE | ID: mdl-18034615

ABSTRACT

To clarify the role of gene polymorphisms on the effect of losartan and losartan plus hydrochlorothiazide on blood pressure (primary end point) and on cardiac, vascular and metabolic phenotypes (secondary end point) after 4, 8, 12, 16 and 48 weeks treatment, an Italian collaborative study - The Study of the Pharmacogenomics in Italian hypertensive patients treated with the Angiotensin receptor blocker losartan (SOPHIA) - on never-treated essential hypertensives (n = 800) was planned. After an 8 week run-in, losartan 50 mg once daily will be given and doubled to 100 mg at week +4 if blood pressure is more than 140/90 mmHg. Hydroclorothiazide 25 mg once daily at week +8 and amlodipine 5 mg at week +16 will be added if blood pressure is more than 140/90 mmHg. Cardiac mass (echocardiography), carotid intima-media thickness, 24 h ambulatory blood pressure, homeostatic model assessment (HOMA) index, microalbuminuria, plasma renin activity and aldosterone, endogenous lithium clearance, brain natriuretic peptide and losartan metabolites will be evaluated. Genes of the renin-angiotensin-aldosterone system, salt sensitivity, the beta-adrenergic system and losartan metabolism will be studied (Illumina custom arrays). A whole-genome scan will also be performed in half of the study cohort (1M array, Illumina 500 GX beadstation).


Subject(s)
Angiotensin II Type 1 Receptor Blockers , Clinical Trials as Topic/methods , Hypertension , Losartan , Pharmacogenetics/methods , Research Design , Adolescent , Adult , Angiotensin II Type 1 Receptor Blockers/administration & dosage , Angiotensin II Type 1 Receptor Blockers/adverse effects , Angiotensin II Type 1 Receptor Blockers/pharmacokinetics , Angiotensin II Type 1 Receptor Blockers/therapeutic use , Blood Pressure/drug effects , Blood Pressure/genetics , Clinical Trials as Topic/standards , Endpoint Determination , Female , Humans , Hydrochlorothiazide/adverse effects , Hydrochlorothiazide/pharmacokinetics , Hydrochlorothiazide/therapeutic use , Hypertension/drug therapy , Hypertension/genetics , Losartan/adverse effects , Losartan/pharmacokinetics , Losartan/therapeutic use , Male , Middle Aged , Multicenter Studies as Topic , Pharmacogenetics/standards , Polymorphism, Genetic
6.
Gut ; 47(4): 520-6, 2000 Oct.
Article in English | MEDLINE | ID: mdl-10986212

ABSTRACT

BACKGROUND: The cytoskeleton actin network of intestinal microvilli has been found to be rapidly impaired after gluten challenge in coeliac disease (CD). The aim of this study was to investigate the presence of an immune reaction towards cytoskeleton structures such as actin filaments in CD. METHODS: Eighty three antiendomysial antibody positive CD patients (52 children and 31 adults) were studied at our outpatient clinics from 1996 to 1998 using indirect immunofluorescence, ELISA, and western blotting for antiactin (AAA) and antitissue transglutaminase (TGA) antibodies before and after a gluten free diet (GFD). Sixteen patients with smooth muscle antibody positive autoimmune hepatitis, 21 with inflammatory bowel diseases, seven with small bowel bacterial overgrowth, and 60 healthy subjects were studied as controls. RESULTS: Fifty nine of 83 CD patients (28/31 adults (90.3%); 31/52 children (59.6%)) were positive for IgA and/or IgG AAA. Seventy seven (92.7%) were positive for IgA TGA. IgA AAA were strongly correlated with more severe degrees of intestinal villous atrophy (p<0.0001; relative risk 86.17). After a GFD, AAA became undetectable within five months. CONCLUSIONS: Apart from the immune reaction against the extracellular matrix, we have described an immune reaction against the cytoskeleton in both children and adults with CD. As AAA are strongly associated with more severe degrees of villous atrophy, they may represent a useful serological marker of severe intestinal atrophy in CD.


Subject(s)
Celiac Disease/immunology , Cytoskeleton/immunology , Adolescent , Adult , Autoantibodies , Blotting, Western , Case-Control Studies , Celiac Disease/diet therapy , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Female , Fluorescent Antibody Technique, Indirect , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Infant , Male , Middle Aged , Transglutaminases/immunology
7.
Hum Mutat ; 14(5): 394-400, 1999.
Article in English | MEDLINE | ID: mdl-10533065

ABSTRACT

Alagille syndrome (AGS) is an autosomal dominant disorder with developmental abnormalities affecting the liver, heart, eyes, vertebrae, and craniofacial region. The Jagged-1 (JAG1) gene, which encodes a ligand of Notch, has recently been found mutated in AGS. In this study, mutation analysis of the JAG1 gene performed on 20 Italian AGS patients led to the identification of 15 different JAG1 mutations, including a large deletion of the 20p12 region, six frameshift, three nonsense, three splice-site, and two missense mutations. The two novel missense mutations were clustered in the 5' region, while the remaining mutations were scattered throughout the gene. The spectrum of mutations in Italian patients was similar to that previously reported. We also studied in detail a complex splice site mutation, 3332dupl8bp, which was shown to lead to an abnormal JAG1 mRNA, resulting in a premature stop codon. With the exception of the missense mutations, the majority of the JAG1 mutations are therefore likely to produce truncated proteins. Since the phenotype of the patient with a complete deletion of the JAG1 gene is indistinguishable from that of patients with intragenic mutations, our study further supports the hypothesis that haploinsufficiency is the most common mechanism involved in AGS pathogenesis. Furthermore, our data confirmed the absence of a correlation between the genotype of the JAG1 gene and the AGS phenotype.


Subject(s)
Alagille Syndrome/genetics , Mutation , Proteins/genetics , Amino Acid Sequence , Base Sequence , Calcium-Binding Proteins , Child , Codon, Nonsense , DNA/genetics , DNA Mutational Analysis , DNA Primers/genetics , Female , Frameshift Mutation , Genes, Dominant , Genotype , Humans , Intercellular Signaling Peptides and Proteins , Italy , Jagged-1 Protein , Male , Membrane Proteins , Molecular Sequence Data , Mutation, Missense , Phenotype , RNA Splicing/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence Deletion , Serrate-Jagged Proteins
8.
Clin Exp Immunol ; 111(1): 76-80, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9472664

ABSTRACT

IgA deficiency (IgA-D) has been associated with the HLA region, in particular with the North European haplotype HLA-A1, -B8, -DR3, but the exact location of the susceptibility gene(s) is unknown. Some reports suggest that a susceptibility gene is encoded in the class II region, while others implicate the class III region. We exploited differences between the common Sardinian and North European HLA-DR3 haplotypes to help localize the IgA-D susceptibility gene(s). With the knowledge that approximately 13% of HLA-DR3 homozygous individuals of North European origin are IgA-D, we examined 43 HLA-DR3 homozygous Sardinians to find that all had normal serum IgA, IgG and IgM levels. A detailed analysis of their MHC haplotypes indicated a common Sardinian HLA-DR3 haplotype TAP1A, TAP2A, HLA-DQB1*0201, -DQA1*0501, -DRB1*0301, LH1-(Z + 2), D3A-(Z + 2), C4B-0, C4A-L, G11-15, Bf-0-4, C2-a, HSP70-7.5, 9N3-(Z + 10), 82I-(Z - 2), TNFalpha-9, 62-(Z - 20), HLA-B18, -Cw5, -A30 which diverges from the common North European HLA-DR3 haplotype telomeric to the HLA-DR region. In parallel studies of five Sardinians with IgA-D, two of the 10 HLA haplotypes (20%) contained HLA-DR3, a frequency similar to that observed in the background population. One of these was the HLA-DR3- B8 North European haplotype, which occurs rarely in Sardinia. Our data favour the hypothesis that a class III region allele, present on the common North European but not on the Sardinian HLA-DR3 haplotype, confers susceptibility to IgA-D.


Subject(s)
HLA-DR3 Antigen/genetics , IgA Deficiency/genetics , Disease Susceptibility , HLA-DR3 Antigen/immunology , Haplotypes , Humans , IgA Deficiency/epidemiology , IgA Deficiency/immunology , Italy/epidemiology
9.
Gastroenterology ; 114(2): 324-8, 1998 Feb.
Article in English | MEDLINE | ID: mdl-9453493

ABSTRACT

BACKGROUND & AIMS: Liver disease has been described in 10%-15% of patients with autoimmune polyglandular syndrome type 1 (APS-1). After the discovery of cytochrome P450 1A2 (CYP1A2) as a hepatocellular autoantigen in liver-kidney microsomal autoantibody (LKM)-positive patients with APS-1, the investigation of antiliver antibodies was extended to 11 Sardinian patients with APS-1. METHODS: Indirect immunofluorescence and Western blotting analysis were performed to study the antiliver antibodies. RESULTS: Immunofluorescence revealed LKM antibodies in 3 patients with APS-1, 1 of whom died of fulminant hepatitis. Western blotting showed a liver microsomal protein band of approximately 51 kilodaltons in the LKM-positive sera of these 3 patients. Western blotting performed with recombinant cytochrome P450 enzymes allowed the identification of CYP2A6 as a specific target antigen. CONCLUSIONS: LKM antibodies in APS-1 sera are specifically directed against CYP1A2 or CYP2A6, but their diagnostic and prognostic significance for liver disease remain to be determined.


Subject(s)
Aryl Hydrocarbon Hydroxylases , Autoantibodies/analysis , Autoantigens/analysis , Cytochrome P-450 CYP1A2/analysis , Cytochrome P-450 Enzyme System/analysis , Mixed Function Oxygenases/analysis , Polyendocrinopathies, Autoimmune/immunology , Adult , Autoantibodies/immunology , Autoantigens/immunology , Blotting, Western , Cytochrome P-450 CYP1A2/immunology , Cytochrome P-450 CYP2A6 , Cytochrome P-450 Enzyme System/immunology , Female , Fluorescent Antibody Technique, Indirect , Humans , Male , Mixed Function Oxygenases/immunology , Pedigree , Polyendocrinopathies, Autoimmune/genetics
10.
Hepatology ; 24(6): 1338-41, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8938157

ABSTRACT

To investigate the factors that may confer susceptibility or protection to hepatitis C virus (HCV) infection and to HCV-associated immunological disorders, we designed two studies on 420 Sardinian transfusion-dependent thalassemia patients followed in our department in Cagliari since 1974. The first one was an epidemiological survey aimed to evaluate the prevalence of HCV infection and HCV-associated immunological disorders. In the second study, the distribution of different HLA class II genes was examined by DNA analysis in 116 HCV positive patients, 30 HCV negative patients, and 606 healthy controls. Three hundred fourteen patients became infected with HCV (74.7%) after 5.6 +/- 2.8 years of regular transfusion program. Mixed cryoglobulinemia, purpura, arthritis, proteinuria, decreased complement levels, rheumatoid factor and anti-GOR, smooth muscle antibody (SMA), anti-nuclear antibody (ANA), and liver, kidney microsome (LKM) autoantibodies were significantly more represented in HCV positive patients than in negative ones (P < .05). A significant increase of HLA class II DR2 subtype (DRB1*1601,DQB1*0502) was observed in a group of 30 HCV negative patients who despite 10.3 +/- 2.2 years in a regular blood transfusion program did not show any evidence of HCV infection (Pc < .0092). Our results represent clear evidence for a relationship between HCV infection and immune extrahepatic abnormalities. A gene(s) located in the human major histocompatibility complex (MHC) region may play an important role in conferring protection against HCV infection.


Subject(s)
Genes, MHC Class II , HLA-D Antigens/genetics , Hepatitis C/immunology , Immune System Diseases/immunology , Thalassemia/immunology , Adolescent , Adult , Autoantibodies/blood , Blood Transfusion , Child , Child, Preschool , Female , Fluorescent Antibody Technique, Indirect , HLA-DQ Antigens/genetics , HLA-DQ alpha-Chains , HLA-DQ beta-Chains , HLA-DR Antigens/genetics , HLA-DRB1 Chains , Hepatitis B Antibodies/blood , Hepatitis B Surface Antigens/blood , Hepatitis C Antibodies/blood , Humans , Immune System Diseases/etiology , Male , Radioimmunoassay , Reference Values , Thalassemia/complications , Thalassemia/therapy
11.
Gastroenterology ; 111(2): 318-24, 1996 Aug.
Article in English | MEDLINE | ID: mdl-8690196

ABSTRACT

BACKGROUND & AIMS: Inflammatory changes in the rectum of patients with celiac disease after local instillation of gluten have been reported. The aim of this study was to examine rectal mucosa after local gluten challenge in children with celiac disease and their siblings. METHODS: Rectal biopsy specimens were obtained before and 6 hours after rectal challenge with a peptictryptic digest of gliadin in 33 children with treated celiac disease, 12 controls, and 19 siblings of children with celiac disease. Epithelium and lamina propria volumes were determined, and CD3+ and gamma delta + lymphocytes were counted. RESULTS: After local instillation of gliadin, a significant increment in the absolute number of intraepithelial lymphocytes was noted in patients with celiac disease but not in controls. Immunohistochemical analysis showed a significant increase in CD3+ and gamma delta + cells, with the gamma delta/CD3 ratio remaining unchanged after challenge. A discriminant analysis allowed correct classification of 100% of patients with celiac disease and controls. The same analysis was used to classify 6 of 13 siblings as having celiac disease. The positivity was not associated with the presence of the heterodimer encoded by the DQA*0501 DQB1*0201 alleles in any of the siblings. CONCLUSIONS: All patients with celiac disease were identified by rectal gluten challenge. Approximately half of the siblings reacted to rectal instillation of gluten. The genetic background of such sensitization to gluten remains to be elucidated.


Subject(s)
Celiac Disease/immunology , Glutens/immunology , HLA Antigens/metabolism , Immunization , Rectum/immunology , Adolescent , Adult , CD3 Complex/metabolism , Celiac Disease/genetics , Child , Child, Preschool , Discriminant Analysis , Family Health , Female , HLA-DQ Antigens/metabolism , HLA-DQ alpha-Chains , HLA-DQ beta-Chains , Humans , Intestinal Mucosa/immunology , Lymphocytes/immunology , Male , Receptors, Antigen, T-Cell, gamma-delta/metabolism
12.
Clin Exp Rheumatol ; 13 Suppl 13: S149-51, 1995.
Article in English | MEDLINE | ID: mdl-8730496

ABSTRACT

OBJECTIVE: The aim of this study was to determine the frequency of cryoglobulinemia and associated symptoms in transfusion-dependent thalassemia patients at high risk for HCV infection. METHODS: A controlled epidemiological study was used to evaluate the prevalence of clinical, biochemical and immunological abnormalities in a group of 264 HCV-positive and 106 HCV-negative transfusion-dependent thalassemia patients. Haematologic and hepatic function tests were performed according to standard methods. HCV-RNA was detected by PCR analysis. RESULTS: The significant presence of cryoglobulinemia and associated symptoms (purpura, vasculitis, arthritis, asthenia, proteinuria), serum autoantibodies (SMA, anti-GOR, ANA, LKM), low complement and rheumatoid factor were found in HCV-positive compared with HCV-negative patients. CONCLUSIONS: This study demonstrates the role of HCV in inducing cryoglobulinemia and immunological disorders in transfusion-dependent thalassemia patients. HCV infection and associated immune abnormalities are a new clinical aspect of, and deserve particular attention due to their high frequency in, transfusion-dependent thalassemia patients.


Subject(s)
Cryoglobulinemia/etiology , Hepatitis C/etiology , Transfusion Reaction , beta-Thalassemia/complications , Adolescent , Biomarkers , Child , Child, Preschool , Cryoglobulinemia/epidemiology , Hepatitis C/epidemiology , Humans , Infant , Male , Prevalence , Risk Factors , beta-Thalassemia/physiopathology , beta-Thalassemia/therapy
13.
Hum Immunol ; 43(4): 301-8, 1995 Aug.
Article in English | MEDLINE | ID: mdl-7499178

ABSTRACT

The contribution of genetic variation at HLA class II loci to the susceptibility to and protection from IDDM was investigated by analyzing the distribution of HLA-DRB1*04 haplotypes in 630 Sardinian newborns and 155 Sardinian IDDM patients. The different RRs and ARs of the various DR4-DQB1*0302 haplotypes, significantly ranging from the strongly associated DRB1*0405, DQB1*0302 to the protective DRB1*0403, DQB1*0302 haplotypes, provides clearcut evidence that the DRB1 locus is crucial in conferring IDDM predisposition or protection. Also, the DQB1 locus influences IDDM predisposition or protection by restricting the disease-positive association to DRB1*0405 haplotypes carrying the susceptibility DQB1*0302 or DQB1*0201 alleles but not the protective DQB1*0301 allele. Haplotype analysis not only suggests that the DRB1 and DQB1 loci influence IDDM risk in the same way, but also that the HLA-linked protection is "dominant" compared with "susceptibility." These results, obtained from a population with one of the highest IDDM incidences in the world, define more clearly the contribution of the various HLA loci to IDDM protection or susceptibility and allow a more precise calculation of AR.


Subject(s)
Diabetes Mellitus, Type 1/genetics , Genetic Linkage/immunology , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , HLA-DR4 Antigen/genetics , Haplotypes/immunology , Adolescent , Child , Child, Preschool , HLA-DQ alpha-Chains , HLA-DQ beta-Chains , HLA-DRB1 Chains , Humans , Infant , Italy
14.
J Pediatr ; 125(1): 123-8, 1994 Jul.
Article in English | MEDLINE | ID: mdl-8021761

ABSTRACT

The purpose of this study was to determine whether interferon-alfa (IFN-alpha) therapy benefits patients with transfusion-dependent thalassemia and chronic active hepatitis C, and whether their iron burden modifies the response to this therapy. We conducted a controlled trial of recombinant IFN-alpha (3 million units per square meter of body surface area, three times a week for 15 months) in 65 patients with thalassaemia major and chronic active hepatitis C; 14 of them were untreated control subjects. In 21 of the 51 treated patients, alanine aminotransferase values returned to normal within 6 months, and hepatitis C virus ribonucleic acid was no longer detected in serum; no changes were detected among control subjects. The response to IFN-alpha therapy was inversely related (p < 0.002) to the liver iron burden as assessed by atomic absorption, the histologic semiquantitative method, or both methods. During 3 years of follow-up, two responder patients had relapses. We conclude that IFN-alpha represents a useful therapeutic option for children with transfusion-dependent thalassemia and chronic active hepatitis C with a mild to moderate iron burden.


Subject(s)
Hemochromatosis/physiopathology , Hepatitis C/therapy , Hepatitis, Chronic/therapy , Interferon-alpha/therapeutic use , beta-Thalassemia/therapy , Adolescent , Adult , Child , Ferritins/blood , Hemochromatosis/etiology , Hepatitis C/etiology , Hepatitis, Chronic/etiology , Humans , Interferon-alpha/adverse effects , Iron/analysis , Liver/chemistry , Transfusion Reaction , Treatment Outcome , beta-Thalassemia/blood , beta-Thalassemia/complications
15.
Hum Immunol ; 40(2): 138-42, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7928444

ABSTRACT

This study reports the HLA-DR and DQ molecular characterization of 62 CD patients of Sardinian descent. Patients were divided in two groups (36 in group I and 26 in group II) according to the clinical features at the disease onset. Among the patients of group I, having the fully expressed form of CD and a mean age of 3 years at disease onset, a significant increase of DRB1*0301, DQA1*0501, DQB1*0201 homozygotes, encoding in cis two DQ (alpha 1*0501, beta 1*0201) susceptibility heterodimers, was observed when compared either with the patients of group II (pIII < 0.012) or with healthy individuals (pI < 10(-6)). On the other hand, in the patients of group II, presenting oligosymptomatic forms and a mean age of 5.7 years at the disease onset, the haplotype combinations encoding in cis or in trans only one DQ (alpha 1*0501, beta 1*0201) heterodimer were significantly increased in comparison either with the patients of group I (pIII < 0.026) or with controls (pII < 10(-6)). These findings suggest that a double dose of DQA1*0501, DQB1*0201 genes may predispose a person to an earlier onset and to more severe disease manifestations. Genotype analysis showed that only three patients (all in group I) failed to form in trans or in cis the DQ (alpha 1*0501, beta 1*0201) heterodimer and carried the DQA1*0101,DQB1*0501 haplotype, suggesting its possible role in CD susceptibility. In addition, a significant increment of DQB1*0501 gene (pc < 0.0065) was found comparing the frequency of DQB1 alleles in CD patients and healthy controls, after exclusion of DQB1*0201 chromosomes.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Celiac Disease/genetics , Celiac Disease/physiopathology , Gene Dosage , HLA-D Antigens/genetics , Adult , Age of Onset , Child , Child, Preschool , Female , HLA-DQ Antigens/genetics , HLA-DQ alpha-Chains , HLA-DQ beta-Chains , HLA-DR Antigens/genetics , HLA-DRB1 Chains , Haplotypes/genetics , Histocompatibility Antigens Class II/genetics , Humans , Male , Middle Aged
16.
Hum Immunol ; 40(2): 143-9, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7928445

ABSTRACT

This study, performed in individuals of Sardinian descent, reports an epidemiologic and molecular analysis of the recently identified DQB1*0304 and DQB1*0305 alleles. These two alleles having a gene frequency of 0.017 and 0.005, respectively, are not uncommon in Sardinia and are distributed fairly uniformly on the island. The analysis of DQB1 second and third exons of the two alleles revealed that although they have always been found included within the same DRB1*0403-DQA1*03 haplotype, they had a different origin. The sequence pattern of DQB1*0305 confirmed that it originated from the DQB1*0302 "recipient" gene by the insertion of a DQB1*0402 nucleotide stretch, within its beta-sheet region, while that of DQB1*0304 suggested that it originated from the DQB1*0301 gene, either by a single point mutation at codon 57 (GCC instead of GAC) or, alternatively, by a segmental transfer of a DQB1*0302 motif, including codon 57, within its alpha-helic region. Independently from the mechanism of generation, the fact that DQB1*0304 originated from DQB1*0301 allele was intriguing considering that, in over 1500 HLA class II Sardinian haplotypes examined, neither the putative parental DRB1*0403-DQA1*03-DQB1*0301 haplotypes were found. Finally, since the assignment of DQB1*0305 may be inaccurate with the traditional panel of probes commonly used for DQB1 oligotyping, the use of an additional oligonucleotide probe is recommended.


Subject(s)
Gene Frequency , HLA-DQ Antigens/genetics , Haplotypes/genetics , Alleles , Amino Acid Sequence , Base Sequence , Exons , HLA-DQ beta-Chains , Humans , Infant, Newborn , Italy , Molecular Sequence Data , Thalassemia/genetics
17.
Hum Immunol ; 37(2): 85-94, 1993 Jun.
Article in English | MEDLINE | ID: mdl-8226139

ABSTRACT

The Sardinian population has an extremely high incidence of IDDM (30.2 of 100.000 in the age group of 0-14 years). This study reports the molecular characterization of HLA class II genes in 120 IDDM sporadic patients and 89 healthy subjects of Sardinian origin. Compared with other Caucasians, both Sardinian patients and controls had an unusual distribution of haplotypes and genotypes. In particular, there was a high gene frequency of the DRB1*0301, DQA1*0501, DQB1*0201 susceptibility haplotype both in patients (0.58) and controls (0.23) while a reduction of the DRB1*1501, DQA1*0102, DQB1*0602 protective haplotype (0.03) was observed in the healthy population. This distribution may partially explain the high incidence of IDDM reported in Sardinia. The analysis of the DQ beta 57 and DQ alpha 52 residues showed that the absence of Asp 57 and the presence of Arg 52 were associated with IDDM in a dose-response manner. On the other hand, we found that (a) a very similar distribution of these residues was found when comparing Sardinians with another healthy Caucasian population from the same latitude but with a lower rate of IDDM incidence; (b) several genotypes encoding the identical DQ alpha 52/DQ beta 57 phenotype carried very different relative risks; and (c) the DRB1*0403, DQA1*0301, DQB1*0304 haplotype (DQ beta 57 Asp-neg and DQ alpha 52 Arg-pos) was found in 40% of the DR4-positive controls but not in patients (p = 0.00034), while the DRB1*0405, DQA1*0301, and DQB1*0302 haplotype carrying the same residues at the same positions was found in 70% of the DR4-positive patients and in only one control (p = 0.00003). These findings suggest that IDDM susceptibility cannot be completely explained by the model in which only DQ alpha 52 and DQ beta 57 residues are taken into account.


Subject(s)
Diabetes Mellitus, Type 1/genetics , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , Histocompatibility Antigens Class II/genetics , Adolescent , Adult , Alleles , Child , Child, Preschool , Diabetes Mellitus, Type 1/epidemiology , Female , Genotype , HLA-DQ alpha-Chains , HLA-DQ beta-Chains , HLA-DRB1 Chains , Haplotypes , Humans , Incidence , Infant , Infant, Newborn , Italy/epidemiology , Male , Middle Aged , Polymerase Chain Reaction
19.
Tissue Antigens ; 39(5): 262-5, 1992 May.
Article in English | MEDLINE | ID: mdl-1412411

ABSTRACT

In the Sardinian population a very high incidence of insulin-dependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high frequency of the A2, Cw7, B17, 3F31, DR2, DQw1 extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB1*0502 allele at the DR2-linked DQB1 locus, with no statistically significant difference between the two groups. All DQA1 genes were the ones expected, with only two exceptions. Nine out of 10 of the DR2-positive patients were compound heterozygotes for DQB1*0201/DQB1*0502 alleles; only this allele combination was significantly increased (p less than 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound heterozygous state between the neutral DQA1*0102/DQB1*0502 and the susceptibility DQA1*0501/DQB1*0201 alleles.


Subject(s)
Autoimmune Diseases/genetics , Diabetes Mellitus, Type 1/genetics , Genes, MHC Class II , HLA-DQ Antigens/genetics , Adolescent , Adult , Alleles , Autoimmune Diseases/epidemiology , Autoimmune Diseases/immunology , Base Sequence , Diabetes Mellitus, Type 1/epidemiology , Diabetes Mellitus, Type 1/immunology , Disease Susceptibility/immunology , Female , Gene Frequency , Genetic Predisposition to Disease , HLA-DQ beta-Chains , Heterozygote , Humans , Italy/epidemiology , Male , Middle Aged , Molecular Sequence Data
20.
Tissue Antigens ; 39(2): 78-83, 1992 Feb.
Article in English | MEDLINE | ID: mdl-1349446

ABSTRACT

This study characterizes by serological and molecular methods the HLA class I and class II alleles in a group of celiac disease children, their parents and a control group of Sardinian descent. We found the DR3-DQw2 haplotype in all patients which was, in almost all cases (84%), associated with the HLA-A30, B18, DR3, DRw52, DQw2 extended haplotype named "Sardinian haplotype" because of its frequency (12-15%) in this Caucasian population. This is the first time that this DQw2-linked haplotype has been reported with such a high frequency in CD. However, no different distribution of "Sardinian haplotype" was found comparing CD patients with 91 haplotyped DQw2-positive controls. This finding indicates that the DQw2 antigen in Sardinians is almost always associated with the A30, B18, DR3, DRw52, DQw2 extended haplotype. The DQA1 and DQB1 second exon sequence analysis of the B18,DR3 and B8,DR3 haplotypes showed the DQA1*0501 and DQB1*0201 alleles which shared the already published sequences. DPB1 subtyping showed the DPB1*0301 allele more frequently (p less than 0.005) in CD patients but this difference was no longer significant when patients and controls, both heterozygous for the DR3-DQw2 haplotype, were compared. We suggest that the divergent HLA extended haplotypes and DP allele associated with CD, described in different Caucasian populations, can be explained by the particular DQw2 linkage disequilibrium in each population.


Subject(s)
Celiac Disease/genetics , Gene Frequency/genetics , HLA-A Antigens/genetics , HLA-B Antigens/genetics , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , HLA-DR3 Antigen/genetics , Haplotypes/genetics , Adult , Celiac Disease/epidemiology , Celiac Disease/immunology , Child , Disease Susceptibility , Gene Amplification/genetics , Gene Frequency/immunology , HLA-A Antigens/immunology , HLA-B Antigens/immunology , HLA-B18 Antigen , HLA-DQ Antigens/immunology , HLA-DQ alpha-Chains , HLA-DR Antigens/immunology , HLA-DR Serological Subtypes , HLA-DR3 Antigen/immunology , Haplotypes/immunology , Humans , Italy/epidemiology , Linkage Disequilibrium , Middle Aged , Polymorphism, Restriction Fragment Length
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