it is a chronic enteropathy , with genetic , environmental and autoimmune components , triggered by the ingestion of wheat gluten and other related proteins . hla - dq2 is found in up to 95% of cd patients , and the hla - dq8 in most of the remaining patients . clinically , cd varies greatly , and is now considered to resemble a multisystemic rather than a gastrointestinal disorder . it can be found in classical , atypical , silent and latent forms . while the classical form is characterized by chronic diarrhea and malnutrition , in the atypical form of cd extraintestinal features such as osteoporosis , infertility , anemia , short stature and neurological problems can also be found . the development of accurate serological tests for cd over the last decades , such as the antiendomysial and anti - tissue transglutaminase antibodies provided a valuable tool for screening individuals , in as much as the general population as in cd high risk groups . cd was considered to be of low - prevalence until the 1950s , but currently , due to the availability of high sensitivity and specificity diagnostic tests , its prevalence has been shown to be much higher than previously thought . cd has a worldwide distribution , being described in different ethnic groups from north and south america , europe , south and west asia , australia and new zealand . the disease is rare among africans and not expected among populations with no hla dq2 , like chinese and japanese , except in individuals presenting hla dq8 . although several autoimmune diseases have been described in native indian populations from around the world , studies evaluating the occurrence of cd among those individuals are scarce . described clinical and serological features of cd in patients and relatives of a chilean population carrying amerindian traits . in addition , galvo et al . reported twenty cases of cd in north of brazil in a mixed population ( europeans and local indians ) . on the other hand , high prevalence and more severe disease , as well as increased comorbidity and mortality rates , were demonstrated in different indian populations for other autoimmune diseases , such as rheumatoid arthritis , systemic lupus erythematosus , primary biliary cirrhosis[1618 ] , systemic sclerosis and type i diabetes , amongst others . both genetic and environmental components have been considered as the main factors influencing the development of these autoimmune disorders in native indians . although kaingang and guarani represent the two largest amerindian tribes living in south brazil and some areas of paraguay and argentina , they are both culturally and genetically distinct from each other[2224 ] . while kaingang are semi - nomads and cultured , the guarani are nomads and preserve secular customs and the tupy native language . several studies have evidenced genetic differences between kaingang and guarani indians , specially related to mhc genes , also when compared with other south american indians and other ethnic groups , such as europeans and africans[2528 ] . the general brazilian population is known to present a high degree of miscigenation between europeans , africans and native indians , with a predominance of european ancestry in the south . recent data has shown prevalence for cd of 1:273 to 1:417 in this region . the present study aimed to screen the anti - endomysial antibody ( iga - ema ) in kaingang and guarani indians from southern brazil , in order to evaluate clinically the occurrence of cd in these individuals . a total of 321 indians ( 196 female and 125 male ) , from mangueirinha reserve ( latitude 255628s ; longitude 521032o ) , in the state of parana , south brazil , were studied . amongst them , 158 were kaingang , 98 guarani and 65 mixed races ( kaingang and euro - brazilian individuals ) . as a comparison group , 180 healthy , voluntary non indian subjects , from european ancestry all individuals belong to the same geographic area and were matched for age and sex . a structured questionnaire was used to collect socio - demographic data and symptoms and signs related to diseases . some features related to their occupational activities , individual customs and some complaints or symptoms were summarized ( table 2 ) . general characteristics from the studied populations the study was approved by the ethical committee of the clinical hospital of the federal university of parana , national council of research ( conep ) , national foundation of indians ( funai ) and by the local leaders of the tribes . anti - endomysial antibodies ( iga - ema ) were evaluated in all serum samples , by indirect immunofluorescence assay ( fitc ) , according to volta et al .. cryostatic sections of human umbilical cord were used as substrate and fitc anti - iga human as conjugate ( inova , san diego , usa ) . sera were considered positive if fluorescence was observed at a dilution of 1:2.5 , and titred up to the end - point . similarly , indian individuals presenting complaints of diarrhea ( n=12 ; table 2 ) were also evaluated to the anti - endomysial antibodies class igg ( igg - ema ) , using fitc anti - igg human conjugate ( dako , denmark ) . statistical analysis was performed with statistical ( microsoft usa ) software , using the fisher exact test . the serological screening for cd based on iga - ema , performed in the kaingang and guarani indians as well as in the non - indian subjects , is in table 3 . the analysis of igg - ema in those indians who informed in the structured questionnaire the occurrence of diarrhea with frequency also showed negative results ( table 3 ) . the population of native indians in brazil at the time of its discovery in 1500 was approximately 6 million individuals . however , recent data estimates this number to be only 460000 . during the centuries , millions of native indians were exterminated due to the colonization process , slavery and diseases . this is the first report of serological and clinical evaluation of cd in kaingang and guarani indians from southern brazil . the results showed an absence of cd in these native indigenous , as well as in the control group of non - indians from southern brazil . none of the individuals were positive to iga - ema , although approximately 6% of guarani and mixed group had complaints of diarrhea ( table 2 ) . this group of individuals was also negative for igg - ema ( table 3 ) . probably the high frequency of intestinal parasitosis and lack of nutritional diets of some indians may be the cause of diarrhea in these individuals to subjects . the presence of other autoimmune disease markers like rheumatoid factor and anti - nuclear antibodies , in association with clinical manifestations of rheumatic diseases , as to was previously described in these individuals by the authors , who observed complaint of arthralgy in almost 30% of the subjects ( table 2 ) . observed the occurrence of autoantibodies in kaingang and guarani indians from rio das cobras and ivai indigenous reserve in south brazil . recent reports have showed the occurrence of cd among ethnic minorities and therefore there was reason to believe that this disease be under- diagnosed in those groups , as described by brar et al . in african - american patients . although the disease has been considered uncommon in india until recently , sood et al . observed a prevalence of 1:310 in school children of the punjab , showing that cd is not rare in wheat - eating areas of north india . similarly , freeman described cd in 14 adult asian individuals from a single canadian teaching hospital , living in north america , including 10 patients from punjab , two from japan and one from china . in addition , butterworth reported clinical and laboratorial features on 40 cd patients of south asian origin living in the united kingdom . according to the authors , special attention needs to be given to methods that encourage adherence to gluten - free diet in affected individuals of minority groups . interestingly , the differences in hla alleles observed in cd patients from south asia when compared with caucasian patients , suggested that non - hla genes play a stronger role in the susceptibility and presentation of the disease in the former group . analyses of hla - dqa1 and hla - dqb1 class ii gene polymorphism in kaingang and guarani amerindians from southern brazil , showed four different dqa1-dqb1 haplotypes : dqa1 * 0401-dqb1 * 0402,dqa1 * 0501-dqb1 * 0301 , dqa1 * 03-dqb1 * 0302 and dqa1 * 03-dqb1 * 03032 . in this context , considering that cd is closely associated with genes that code for hla - dq2 in 95% of the patients ( dqa1 * 05/dqb1 * 02 ) and hla - dq8 in most of the remainder ( dqa1 * 0301/dqb1 * 0302 ) , it is reasonable to suppose a certain degree of susceptibility to cd in these investigated populations , especially in the mixed group , due to the inter ethnic marriages that have occurred in the last centuries . in addition , the gradual change in the traditions , cultural practices and nutritional habits amongst indians have introduced several factors that might represent a risk to autoimmune diseases in this population . among these , it must be emphasized the ingestion of wheat gluten and related cereal proteins ( rye , barley ) by individuals whose nutrition was formerly based on foods , such as fruits , meat and fish . although none of the indian individuals analyzed in the present study showed positivity to ema - iga , the authors consider it important that physicians who attend indigenous populations stay alert and follow up children or adults that present persistent gastrointestinal complaints or other symptoms related to cd . the genetic background , allied to hormonal and immunological factors , besides the changing of habits or even occupational activities , may gradually lead to the occurrence of diseases previously not seen in these native populations , as observed in other ethnic minorities[3841 ] . it must be considered also , that individuals previously negative to the serological markers of cd may become positive in the future . furthermore , in cases with uncertain diagnosis it is important there is an assessment of hla dq2 and dq8 , since absence of those alleles make cd unlikely . finally , the involvement of non - hla genes among asiatic cd patients also suggests their importance in ethnic related populations , such as amerindians , which must also be considered in future studies .
background : celiac disease has been described in populations from around the world , with recent data emphasizing the occurrence of the disease in ethnic minorities . 
 there are only a few studies evaluating celiac disease in native indians.aims:this study aimed to screen the anti - endomysial antibody ( iga - ema ) in kaingang and guarani indians from southern brazil , in order to establish a clinical serological evaluation of celiac disease in these individuals.material and methods : serum samples from 321 individuals ( 125 male and 196 female ; 4 - 86 years old ) from mangueirinha indigenous reserve , state of parana , brazil , and 180 non - indigenous healthy individuals ( 62 male and 118 female ; 2 - 81 years old ) were analysed to the presence of anti - endomysial antibody class iga by indirect immunofluorescence assay . amongst the indians , 158 were kaingang , 98 guarani and 65 of mixed race . 
 indians presenting complaints of diarrhea ( n=12 ) were also evaluated to the igg class of anti - endomisyal antibody.results:none of the individuals showed positive results either to iga or igg anti - endomysial antibodies.conclusions:although the results indicate an absence of celiac disease in kaingang and guarani indians , the authors call attention to the importance of following up indigenous children or adults presenting gastrointestinal complaints or other symptoms related to the disease . 
 consideration should be given to the genetic background of these individuals , allied to the inter ethnic marriages and the changing habits or occupational activities , that have gradually introduced diseases previously not described in indigenous populations .