Presentation on theme: "Marco Songini, Director Diabetes Unit - Azienda Ospedaliera “G.Brotzu” Cagliari – Sardinia, Italy The Center for Immunology."— Presentation transcript:
Marco Songini, Director Diabetes Unit - Azienda Ospedaliera “G.Brotzu” Cagliari – Sardinia, Italy The Center for Immunology and Transplantation University of Florida, Gainesville, July 5th, 2005 type 1 diabetes and related ADs in Sardinia
Gene and diseases in the founder population of Sardinia
Isolation Insularity and geographical position Physical geography Low population density Language Romance (the most archaic neo-latin language spoken so far) Early Latinization Isolated location Resistance to innovation Any lexical innovation mostly regards some Southern and Northern areas Paulis (1995) Stable population About 300,000 inhabitants from 3rd About 300,000 inhabitants from 3rd 800 b.C. Phoenicians and century b.C. to 17th century century b.C. to 17th century Carthaginians No real colonization in terms of 238 b.C. Romans agent of demographic development 456 A.D. Vandals No large-scale admixture between 534 A.D. Eastern Roman populations from costal to internal empire (Byzantium) regions 1258 A.D. Pisans The invaders were not inclined 1323 A.D. Catalan-Aragoneses towards permanent inhabitation of 1479 A.D. Spanish the island 1720 A.D. Italians – Piedmont Little genetic flow from invaders (Savoys) Genes Uniformly distributed Frequencies unique for Sardinia RH- ; MNS-M ; DIA2 , HLA B18 Cavalli-Sforza et al. (1994) Consanguinity Kinship = 12.26% 1945 = 8.21% Today = very rare Moroni et al (1972) Stable population Struggle for survival i.e. not to become extinct Famine and malnutrition Endemic illness (Malaria and other major infections) Sardinia and the genetic map of Europe According to Cavalli-Sforza et al Different colours indicate genetic distances 24,000 sq. Km popul Lat. 39°-41° N Long.8°-10° E Life expectancy The oldest man in the world lives currently in Sardinia at birth 1year (National Institute of Statistics) Genetic drift Paleolitic: inhabitants ( b.C.; about 750 generations ago) Small number of founders Same ancestral gene pool Skewing effect of selection Considerable drift Matrimonial mobility (average distances of birth place of the spouses) 1850 = 13.3 Km = 20 Km = 39.9 Km Nowadays > 40 < 50 Km Gatti (1990)
SARDEGNA GRE LAZ LOM BAS CAL PUG LAP FINLANDIA DAN SVE NOR SCO FMG IRI DUT GER AUS SWI CZE FRE HUN MAR TOS CAM SIC UMB PIE SPA POR LIG VEN EMI GENETIC DISTANCE AMONG POPULATIONS
Neighbor-joining tree of 16 European and North-African populations using DRB1-DQA1- DQB1 haplotype frequencies FRA CZE US WHITE NOR CRE GB SPA ITAMOR TUN GRE BULG ROM SARD ALG TUR ALG, Algerians; BULG, Bulgarians; CRE, Cretan; CZE, Czech; FRA, French; GB, Britons; GRE, Greeks; ITA, Italians; MOR, Moroccan; NOR, Norwegians; ROM, Romanians; SARD, Sardinians; SPA, Spanish; TUN, Tunic: TUR, Turks; US-WHITE, American Whites. (Courtesy of F. Cucca)
Neighbor-joining tree of 7 Sardinian sub-populations and continental Italians using DRB1-DQA1-DQB1 haplotype frequencies LANUSEICAGLIARI CARBONIA ORISTANO SORGONO SASSARI TEMPIO ITALY 1 Cagliari 2 Carbonia 3 Lanusei 4 Oristano 5 Sassari 6 Sorgono 7 Tempio (Courtesy of F. Cucca)
Sardinians Caucasians haplotype frequency (%) Latin American Blacks Chinese DRB1* DQA1 DQB1* haplotypes in 5 ethnic groups Lampis, Cucca et al % of Sardinians
Genetic clusters for T1D in Sardinians Cappello et al Vona et al Genetic tree of the Sardinian and Italian populations for HLA Genetic tree for the 21 linguistic domains in Sardinia for 12 polymorphisms
Genetic diseases G6PD deficiency (favism). Prevalence (%) among males Silvetti et al. 1969
Genetic diseases Beta thalassemia in Sardinia Epidemiology of beta-thalassemia (95% beta39=founder effect): 13% beta-thalassemia carrier rate 1:70 couple is at risk for 1:250 newborns would be affected but they are reduced to 1:4,000 thanks to prenatal diagnosis Rosatelli et al. 1992; Cao et al. 1996
Genetic diseases Wilson’s Disease Incidence: Sardinia 1-2:10,000 Other countries1-2:100,000 Heterozygous in Sardinia: 3.4% Heterozygous in other countries: 1.1% Loudianos et al 1999
Genetic diseases Wilson’s Disease mutations in Sardinian population (founder effect) Loudianos et al. 1999
Other diabetes-related autoimmune diseases in Sardinia
Other autoimmune diseases APECED (APS1) Autoimmune Polyendocrinopathy Candidiasis Ectodermal Dystrophy Autosomal recessive disorder Incidence: Finns 1:25,000 Iranian Jews1:9,000 Sardinians1:14,400 Genetic: Mutation of AIRE ( autoimmune regulator ) gene: R139X (18/20 indipendent mutations found are R139X= founder effect) Heterozygous in Sardinia for R139X: 1.7% Rosatelli et al. 1998
Population Number Prev. (95% C.I. ) Ref. North Sardinia 1, % ( ) Meloni et al Schoolchildren Italy - Marche 3, % ( ) Catassi et al Schoolchildren Finnish sibs % ( ) Saukkonen et al 2001 of T1D (mean age 12yrs) Finnish adults 1, % ( ) Kolho et al * biopsy proven Other autoimmune diseases Celiac disease (CD)* in background population
Population Number Prev. (95% C.I. ) Ref. NorhtSardinian % ( ) Frongia et al. (unpubl.) Schoolchildren T1D Italian 4, % ( ) Pocecco et al Schoolchildren % ( ) Barera et al Sardinian adults % ( ) Songini et al T1D patients Italian adults % ( ) Sategna-Guidetti et al T1D patients % ( ) De Vitis et al * biopsy proven Other autoimmune diseases CD* among T1D patients
Population Number Prev*. Incid*. Ref. North Sardinia Aiello et al.1997 Whole Sardinia 1.5mil Giagheddu et al Denmark 2.8mil Christensen et al Whole Norway 4.5mil Storm-Mathisen et al Italian adults BO D’Alessandro et al FE * x Other autoimmune diseases Myasthenia gravis (MG) in background adult populations
Other autoimmune diseases Thyroid autoantibodies (TA) in background population Population Number Prev. (95% C.I. ) Ref. Sardinian 8, % ( ) Mariotti et al Schoolchildren Italian % ( ) Aghini et al Schoolchildren % ( ) Fenzi et al Sardinian mothers 2, % ( ) Olivieri et al at delivery Mothers at 4, % ( ) Sakaihara et al delivery (Japan, USA) % ( ) Stagnaro et al.1990
Other autoimmune diseases Thyroid autoantibodies among T1D patients Population Number Prev. (95% C.I. ) Ref. T1D Sardinian % ( ) Ricciardi et al. Schoolchildren (unpubl.) T1D Italy/Europe % ( ) Lorini et al Schoolchildren % ( ) Holl et al T1D Sardinian % ( ) Songini et al adults patients T1D European % ( ) Mangendre et al adults patients % ( ) Fernandez-Castaner et al, 1999
The new concept of T1D as a cluster of autoimmune-related diseases: the example of MS and T1D in Sardinia Sardinia: Giants’ tomb
Prevalence of MS x in Europe (MS pts= 2.5 mil ww) J Cl Nurology and Neurosurgery 104 (002)
Other autoimmune diseases Multiple Sclerosis (MS) and T1D Population Number MS ( Prev) (95% C.I. ) Reference Sardinians 270, % ( ) Granieri et al (NW,all ages ) Italians (all ages) 0.05 % Granieri et al Sardinian T1D % ( ) Songini et al. (unpubl) adults (15-50 yrs) Sardinian T1D % ( ) Chessa et al. (unpubl) schoolchildren Population Number T1D ( Prev) (95% C.I. ) Reference Sardinian 1, % ( ) Marrosu et al MS pts (9-65 yrs) Sardinian pop 6, % ( ) Muntoni et al (20-59yr)
Other autoimmune diseases Genetic association of MS with: In Northern Europeans: DRB1*1501-DQB1*0602 (DR2)* * Protective for T1D then T1D and MS occur together very rarely In Sardinians: DRB1*0301-DQB1*0201 (DR3)* DRB1*0405-DQB1*0301 (DR4)* * Also predisposing to T1D, DR2 is very rare then T1D and MS may coexist Marrosu et al. 2000
Multiple Sclerosis (MS) and T1D in Sardinia Population Number MS ( Prev) (95% C.I. ) Reference Sardinians 270, % ( ) Granieri et al (NW,all ages ) Italians (all ages) 0.05 % Granieri et al Sardinian T1D % ( ) Songini et al. (unpubl) adults (15-50 yrs) Sardinian T1D % ( ) Chessa et al. (unpubl) schoolchildren Population Number T1D ( Prev) (95% C.I. ) Reference Sardinian 1, % ( ) Marrosu et al MS pts (9-65 yrs) Sardinian pop 6, % ( ) Muntoni et al (20-59yr)
Genetic association of MS with T1D In Northern Europeans: DRB1*1501-DQB1*0602 (DR2)* * Protective for T1D then T1D and MS occur together very rarely In Sardinians: DRB1*0301-DQB1*0201 (DR3)* DRB1*0405-DQB1*0301 (DR4)* * Also predisposing to T1D, DR2 is very rare then T1D and MS may coexist Marrosu et al. 2000
MS with T1D: together at last (Allegheny County, US) Dorman JS, Songini M et al. Diabetes Care,november 2003 Characteristics T1DSiblings†Parents† Males (n=148) Females (n=149) Males (n=143) Females (n=187) Males (n=84) Females (n=140) Age (yrs) Duration T1D (yrs) Observed MS prev.0%2.0%0%0.5%0% Expected MS prev.n/a0.1%n/a0.1%n/a Relative increased risk of MS n/a20fold*n/a5 foldn/a *p<0.01 † unaffected with T1D n/a non applicable
NUORO SASSARI Tuscany 15% Corse (F) 20% Barbagia 50% Gallura 20% Mediterranean sea MS prevalence gradient Gallurese-speaking communes A B 11 CAGLIARI The two Sardinian provinces under study: Sassari and Nuoro; the south- western to north-eastern gradient of MS prevalence in the province of Sassari (Pugliatti et al., 2002b), correspond to significant differences of genetic and linguistic domains (prevalence is expressed as number of cases per 100,000 population for each commune of the province: black communes >150, grey communes >130 and <150, blank communes < 130 MS cases). B. Polymorphisms of mitochondrial genes in Barbagia (central, “archaic” Sardinia), Gallura (norther Sardinia), Corse (insular France) and Tuscany (mainland Italy) (Morelli et al., 2000) and subdivision of the island in 23 linguistically and genetically domains (Cappello et al., 1996);
Sassari Ferrara rate per 100,000 Nuoro A Figure 4. A. Temporal trends of MS incidence rates in the province of Nuoro, Sassari and Ferrara, in the period 1965 to 1993.
Figure Mean population (x 1000) MS incidence rate (100,000) Five-years periods 1) Average annual incidence rates (per 100,000 per year, right Y axis) of MS in Macomer, Sardinia, from 1912 through 1981 (5-years periods). Left Y axis expresses the population growth (per 1,000). Adapted from reference .
Sardinians Caucasians haplotype frequency (%) Latin American Blacks Chinese DRB1* DQA1 DQB1* haplotypes in 5 ethnic groups Lampis,R et al MSMS and T1DM MS Protetctive T1DM
HLA alleleT1DM effectMS effect DRB1*1501 (DR2) – DQA DQB Dominant protection Predisposition in Caucasians DRB1* 0301(DR3) – DQA DQB PredispositionPredisposition in Sardinians other loci outside the MHC region may be shared between MS and T1DM and contribute to the susceptibility to both the diseases.
The strong effect of having multiple MS affected relatives suggests that genetic variability in risk for diabetes is linked to genetic loading for MS, which is substantially increased in these individuals. These findings suggest that loci or genes predisposing to familial MS aggregation also contain an enrichment of diabetes predisposing genes.
Taken together, these data suggest: that common genes, either within the HLA region or outside it, influences susceptibility to both MS and T1DM that genetic structure of Sardinians might contain a particular combination of etiologic or a lack of protective genes for these diseases. Thus, Sardinians appears to be a very suitable population for studying what genes contribute to trigger and sustain autoimmunity in humans.
To sum up (1) T1D has started to rise around the middle of the 20th century and keeps increasing ww in younger ages mainly in low risk countries (catch-up phenomenon) Whether it’s an earlier presentation or a true increase it’s not clear yet Sardinia is confirmed to be a hot spot for clinical T1D and islet-related autoimmunity, as for some other autoimmune- related diseases (CD, MS, not TD) An increasing T1D incidence in the Island has been found rising dramatically since the years 60’ as in other countries No defined geographical clustering for T1D was found across the island
To sum up (2) The combination of more than 1 islet-related autoantibody (rather than which) is the best predictor for the development of T1D in the Sardinian background population (SC) None of the classical ecological variables considered so far has shown any firm influence towards the etiopathogenesis of T1D in Sardinia; however other variables need to be further investigated Migrants data seems to support a different role of genetic vs environmental determinants There’s still a long way in front of us to possibly prevent type 1 diabetes…
What we are doing now with the help of so many (1) Trying to further improve the prediction of T1D in the general population by studying the immunological and genetic markers for T1D and other autoimmune diseases in Sardinian population and migrants and their relatives Investigating other putative environmental factors which can play a role towards the etiopathogenesis of T1D (e.g., chemicals, toxins, vaccinations, viral infections, etc.)
Broadening the original investigation for T1D on the prevalence of others autoimmune diseases and to study their associations Comparing data from Sardinia and other areas by new collaborative studies(RIDI,TRIGR,ENDIT, SARDINIAN DIABFIN) Sensitizing Sardinian Health Autorities & population towards primary prevention of T1D and autoimmune diseases …..and by this way... improving the current care of diabetes in Sardinia! What we are doing now... (2)
Acknoledgements Anthropology: G. Vona (Sardinia-Italy) Other autoimmune diseases: GF Bottazzo and coworkers (Rome-Italy) S. Mariotti and coworkers (Cagliari-Italy) T. Meloni and coworkers (Sardinia-Italy) M. Marrosu and coworkers (Sardinia-Italy) Epidemiology:The Sardinian Epidemiology Study Group Eurodiab TIGER Study Group IDA Study Group RIDI Study Group Z. Laron, I. Askenazi (Israel) L. Bernardinelli and C. Pascutto (Pavia-Italy) P. Contu, L. Minerba (Cagliari-Italy) Genetic: F. Cucca and coworkers (Sardinia-Italy) E.A.M. Gale and coworkers (UK) I. Loudianas (Sardinia-Italy)
Acknoledgements Echological studies: G.F. Bottazzo (Rome-Italy) M. Fadda (Sardinia-Italy) B. Elliot (New Zeland) P. Pozzilli (Rome-Italy) A. Contu, M. Carlini (Sardinia-Italy) Prediction Study:G.F. Bottazzo & M. Locatelli (Rome- Italy) S. Carta, M. Sorcini, A. Olivieri (Rome-Italy) GF Bottazzo, A. Loviselli and the Sardinian SchooIchildren Study Group (Sardinia-Italy) GF Bottazzo,R. Cirillo and the Sardinian Newborn Study Group (Sardinia-Italy) A. Dolei, G. Delitala (Sardinia-Italy) M.T. Tenconi, G. Devoti (Pavia-Italy) The League of Sardinian Migrant Associations ASRIS (Association for Study and Research of IDDM in Sardinia): M. Porceddu (secretary)Tina Carboni President: G.F. BottazzoVicePresident: M.Songini C. Putzu, A. Casu R. Cavallo R.A.S. (Regione Autonoma della Sardegna)European Union Italian Ministry of Healh, ADCTNational Institute of Health GPs&Pediatricians from Sardinia….and many more!