A GHEP-ISFG collaborative study on the genetic variation of 38 autosomal indels for human identification in different continental populations.

A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low FST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents.

The HLA-A, -B and -DRB1 polymorphism in a large dataset of South Brazil bone marrow donors from Rio Grande do Sul.

Human leukocyte antigen (HLA) genes are very informative in population genetics studies and their variability has been widely used to reconstruct the history of geographic and/or demographic expansions of human populations. The characterization of HLA diversity at the population level is also fundamental in clinical studies, particularly for bone marrow transplantation programs. In this study, we investigated the HLA molecular variation in Rio Grande do Sul, South Brazil, in order to identify possible regional differences across this state. More than 97,000 bone marrow donors were typed at the HLA- A, -B and -DRB1 loci and analyzed by considering two kinds of subdivisions based on both self-identified ethnicity and place of residence: (a) the official geographic subdivision defined by the Brazilian Institute of Geography and Statistics and (b) known information about the colonization history of the state. HLA allele and haplotype frequencies were estimated and compared among the defined subgroups. The results indicate a lack of correlation between genetic variation and geography and thus no clear HLA genetic structure based on geographic criteria. On the other hand, major differences were observed regarding ethnicity. In addition, local populations from Rio Grande do Sul were found to be genetically similar to their corresponding parental European populations from Germany, Italy and Portugal, as documented by historical data. Overall, this study provides a thorough characterization of the HLA genetic variation in Rio Grande do Sul and a better understanding of its demographic history, being most useful for the development of more efficient strategies in bone marrow donors' recruitment.

Human platelet antigen genotyping of platelet donors in southern Brazil.

Human platelet antigens (HPA) are immunogenic structures that result from single nucleotide polymorphisms (SNPs) leading to single amino acid substitutions. This study sought to determine the allele and genotype frequencies of HPA-1, HPA-2, HPA-3, HPA-4, HPA-5 and HPA-15 in platelet donors from the state of Rio Grande do Sul (RS), Brazil, and compare their allele frequencies to those observed in other populations. HPA genotyping was performed by PCR-SSP method. The study sample comprised 201 platelet donors (167 Caucasians and 34 non-Caucasians). Allele 'a' was that most commonly found for HPA-1 to 5 in both groups. The HPA-15ab genotype predominated over homozygous genotypes of this system. Fisher's exact test revealed statistically significant differences for the HPA-5 system, with a greater prevalence of the HPA-5b allele in non-Caucasians. The neighbour-joining method and principal components analysis revealed genetic proximity between our Caucasian group and European populations. We conclude that the allele frequencies of HPA-1 to 5 and HPA-15 found in our Caucasian sample are similar to those reported for European populations. These findings corroborate the ethnic makeup of the population of RS. The higher frequency of the HPA-5b allele found in the non-Caucasian group of our sample suggests the possibility of allosensitization in patients who receive platelet transfusions from genetically incompatible donors.

DEFB1 gene 5' untranslated region (UTR) polymorphisms are marginally involved in inflammatory bowel disease in south Brazilians.

The possible association of three DEFB1 gene polymorphisms with susceptibility to develop ulcerative colitis (UC) and Crohn's disease (CD) was investigated in Brazilian patients and controls. Although a clear and strong association between functional 5'-UTR DEFB1 SNPs and susceptibility/protection to IBDs cannot be drawn, our results suggest a possible involvement of DEFB1 gene in inflammatory bowel diseases, especially with the colonic localization of Crohn's disease.

Interleukin-10 gene promoter and NFKB1 promoter insertion/deletion polymorphisms in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease characterized by fibrotic, immunological and vascular abnormalities. Nuclear factor-kB (NFKB), as a key transcription factor involved in the regulation of immune responses, appears to be a good candidate for studies on the pathogenesis of autoimmune diseases, as well as the interleukin-10 (IL-10) polymorphism, which other studies have suggested an association with SSc. Our objective was to study the association of NFKB and IL-10 gene polymorphisms with SSc. One hundred and fifty-one SSc patients and 147 healthy bone marrow donors were enrolled in a case-control study. Blood was collected for DNA extraction; typing of IL-10 genes was made by polymerase chain reaction with sequence-specific primers (PCR-SSP), and NFKB gene typing was made by restriction fragment length polymorphism (RFLP). Patients underwent clinical evaluation, serology, Doppler echocardiography and chest high-resolution computed tomography. The frequency of IL-10 (-1082) GG genotype was found to be significantly higher in SSc patients (36.4%) as compared to healthy controls (22.4%) (P = 0.012). The frequency of heterozygous genotype GA was significantly lower (P = 0.004) in patients (38.4%) in comparison with control subjects (55.8%). A predominance of the high-producing IL-10 phenotype (GCC(+) /GCC(+) ) was observed in SSc patients compared with healthy controls (37.7% versus 24.5%, respectively; OR: 1.87, 95% CI: 1.10-3.19, P = 0.019). No significant difference was found in the allelic and genotype distribution of the NFKB promoter polymorphism between patients and controls. No statistically significant associations were found between IL-10 or NFKB polymorphisms clinical and laboratory features of SSc. Our results confirmed the association of the high-producing phenotype (GCC(+) /GCC(+) ) with increased risk for SSc, but found no correlation with NFKB polymorphisms.

Analysis of KIR gene frequencies and HLA class I genotypes in prostate cancer and control group.

Prostate cancer is the second most common cancer in men, with a significant increase in incidence and mortality in men over 50 years of age. Natural killer cells (NK) are part of the innate immune system recognizing class I HLA molecules on target cells through their membrane receptors, called killer cell immunoglobulin-like receptors (KIR). The aim of our study is to evaluate the association between the KIR genes and HLA alleles in patients with prostate cancer and healthy controls. Two hundred patients with prostate cancer and 185 healthy controls were typed for HLA class I and KIR genes by PCR-SSP. When both groups were compared, no significant differences were found for HLA-C group 1 and group 2, HLA-Bw4, HLA-A3 and A11. No difference was seen either in KIR frequency between patients with prostate cancer and controls. In conclusion, our data suggest no potential role for the KIR gene system in prostate cancer.

Killer cell immunoglobulin-like receptor (KIR) genes in systemic sclerosis.

A previous study has suggested that the combination KIR2DS2(+)/KIR2DL2(-) was related to increased risk for systemic sclerosis (SSc), while others have failed to reproduce this finding. Our objective was to study this matter further and test the association of other KIR genes with SSc. One hundred and ten SSc patients and 115 healthy bone marrow donors were enrolled in a case-control study. Blood was collected for DNA extraction; typing of 15 KIR genes and human leucocyte antigen-C (HLA-C) was made by polymerase chain reaction with sequence specific primers (PCR-SSP), followed by electrophoresis on agarose gel. Patients underwent clinical evaluation, serology, Doppler echocardiography and chest high-resolution computed tomography. The frequency of the inhibitory KIR2DL2 was significantly lower in patients [29.1% versus 65.2% in controls, P < 0.0001; odds ratio (OR) = 0.22, 95% confidence interval 0.12-0.40]. When combinations of activating and inhibitory KIR genes were analysed, the presence of KIR2DS2 in the absence of KIR2DL2 (KIR2DS2(+)/KIR2DL2(-)) was more frequent in patients than in controls (25.5% versus 1.7%, respectively; P < 0.0001; OR = 19.29, 4.24-122.26). However, the presence of both KIR2DS2 and KIR2DL2 (KIR2DS2(+)/KIR2DL2(+)) was more frequent in controls (57.4%) than in patients (28.2%, P < 0.0001), suggesting a preponderant protective effect of KIR2DL2 over KIR2DS2. Stratification for HLA-C1 status did not change these results. No statistically significant associations were found between KIR phenotypes and clinical and laboratory features of SSc. Our results suggest a protective role of KIR2DL2(+) phenotype and confirmed the association of the combination KIR2DS2(+)/KIR2DL2(-) with increased risk for SSc.

Killer cell immunoglobulin-like receptor gene diversity in a Caucasian population of southern Brazil.

Killer immunoglobulin-like receptors (KIR) regulate the activity of natural killer and T cells through an interaction with specific human leucocyte antigen (HLA) class I molecules on target cells. Diversity in KIR gene content, KIR allelic and haplotype polymorphism has been observed between different ethnic groups. However, most population studies on KIR variability have focused on Europe and Asia, while Americas, Oceania and Africa remain poorly studied. The aim of this study was to analyse the variability of KIR genes in 200 healthy nonrelated individuals from the Southern Brazilian population. KIR genes and HLA-A, -B and -Cw were genotyped using polymerase chain reaction-sequence-specific primers. Southern Brazilian population demonstrated several similarities to states that are closer geographically and distinct differences with Northern Brazil in the frequency of genes KIR2DS1, 2DS2, 2DS3, 2DS5, 3DL1, 3DS1, 2DL1 and 2DL2. The activating gene KIR2DS5 was the least frequent locus found in our group. Interaction of KIR/HLA was more common in the 2DS1-/2DL1+/C2+ association. This study demonstrated the diversity of KIR genes and of KIR/HLA association in a Caucasian group of Southern Brazil, establishing differences and similarities to other different populations.

A study of the killer cell immunoglobulin-like receptor gene KIR2DS1 in a Caucasoid Brazilian population with psoriasis vulgaris.

Psoriasis is a chronic inflammatory skin disease whose pathogenesis and genetic background remain unclear. Considering that previous studies have suggested an association of psoriasis vulgaris (PV) and killer cell immunoglobulin-like receptors (KIRs), we typed 15 KIR genes and human leukocyte antigen (HLA)-Cw in 79 Brazilian Caucasoid patients with PV and 110 healthy controls by polymerase chain reaction (PCR) using sequence-specific oligonucleotides and sequence-specific primers. We did not observe a relevant increase in the frequency of the activating KIR2DS1 gene in the PV group [KIR2DS1, 46 of 79 cases (58.2%) vs 40 of 110 controls (36.4%)]. However, an association of KIR2DS1 with Cw*0602+ in 26.5% of PV patients was observed, while it was present in only 5.4% of controls. These results suggest that activating KIR2DS1 gene may not confer susceptibility to PV, and an association of KIR2DS1 gene with the HLA-Cw*0602+ was observed in these patients.

Association between the presence of anti-HLA antibodies with acute rejection and chronic allograft nephropathy in the first year after kidney transplantation.

The clinical relevance of anti-HLA antibodies following kidney transplantation has been a recent focus of research. Patients who present anti-HLA antibodies in the posttransplantation period have shown higher incidences of acute rejection episodes (ARE) and chronic allograft nephropathy (CAN). The objective of this study was to evaluate the presence of anti-HLA antibodies during the first year after kidney transplantation and their association with the occurrence of ARE and CAN. Eighty-eight kidney transplant recipients were evaluated for the presence of IgG anti-HLA antibodies using an enzyme-linked immunosorbent assay (LAT-M and LAT-1240, One Lambda Inc, Calif, United States). Protocol kidney biopsies were performed in consenting patients. ARE and CAN were diagnosed by clinical, laboratory, and histopathological criteria. Anti-HLA antibodies were observed in 20 (22.7%) patients. At 1 year follow-up, 26.1% presented ARE and 51.2% developed CAN. Nine patients (45%) with antibodies developed ARE as opposed to 20.6% without antibodies and 64.7% developed CAN as opposed to 47.8% of those without antibodies. In the histological analysis, the anti-HLA antibodies were associated with Banff IIA ARE (P = .001) and Banff grade II CAN (P = .012). Routine posttransplantation search for antibodies may identify cases at higher risk for acute and chronic rejection, and perhaps help to tailor the immunosuppressive regimen.

Occult hepatitis B in renal transplant patients.

BACKGROUND: Occult hepatitis B (HB) is characterized by the presence of HBV-DNA in patients who do not have HB surface antigen (HBsAg) detectable in sera, and is frequently described in patients with hepatitis C virus (HCV) infection. These viral liver diseases are common and may have a negative impact on the survival of renal transplant patients, especially if they are both present. In this study we aimed to evaluate the prevalence of occult HB in renal transplant patients either with or without HCV infection. PATIENTS AND METHODS: In a cross-sectional survey 101 HbsAg-negative renal transplant patients were evaluated; 51 were anti-HCV positive. Sera were analyzed for the presence of the S and core genes of the HBV-DNA by a nested polymerase chain reaction technique. Markers of HBV infection and liver function tests were also analyzed. RESULTS: The core gene was identified in 1 HCV-infected patient and 1 anti-HCV-negative patient who also presented the S gene (prevalence: 2% and 1% for each gene, respectively). HCV-infected patients had longer pre-transplant dialysis time (50.8 +/- 34.6 vs. 32.0 +/- 20.9; P < 0.001). Liver function tests were also increased in the HCV-infected group: alanine aminotransferase (P < 0.001), aspartate aminotransferase (P < 0.05), gamma-glutamyl transpeptidase (P<0.02), and alkaline phosphatase (P < 0.04). Multivariate analysis revealed that HCV infection was the only determinant of the altered results of the liver function tests. CONCLUSION: We found that occult HB is a condition present in our population of renal transplant patients and that HCV infection does not seem to be associated with occult HB infection in this setting.

Polymerase chain reaction for the laboratory diagnosis of aseptic meningitis and encephalitis.

A protocol for testing cerebrospinal fluid specimens using a range of PCR assays for the diagnosis of central nervous system infection was developed and used to test prospectively 383 specimens. PCR assays were used for the detection of adenovirus, Borrelia burgdorferi, enteroviruses, Epstein Barr virus, cytomegalovirus, herpes simplex virus, human herpes virus type 6, JC virus, Leptospira interrogans, Listeria monocytogenes, lymphocytic choriomeningitis virus, measles virus, mumps virus, Mycobacterium sp. , Mycoplasma pneumoniae, Toxoplasma gondii and varicella zoster virus. Of the 383 specimens tested in this study, 46 (12.0%) were found to be positive. The microorganisms detected were CMV, enterovirus, Epstein Barr virus, herpes simplex virus, human herpes virus type 6, JC virus, L. monocytogenes, Mycobacterium genus, Toxoplasma gondii and varicella zoster virus. The introduction of the PCR protocol described has improved the diagnosis of a range of central nervous system infections in our laboratory. We believe however that further evaluation of these assays in immunocompromised patients is necessary to better determine the predictive value of positive PCR results in these patient groups.

Combined carcinoembryonic antigen and cytopathologic examination in ascites.

OBJECTIVE: To investigate use of the combined carcinoembryonic antigen (CEA) test and cytopathologic examination to improve the diagnosis of neoplastic vs. nonneoplastic ascites. STUDY DESIGN: The tests were performed prospectively on 130 patients with ascites whose effusions were submitted for cytologic examination. RESULTS: Sixty-seven patients had epithelial tumors, and the cytologic examination was positive in 39 (58.2%). The CEA level was > or = 11.0 ng/mL in 36 patients (53.73%). CEA was helpful in the diagnosis in 18 cases, increasing to 57 (85.07%) the number of positive diagnoses. Eight samples of nonepithelial tumors had low levels of CEA. In 55 patients with nonneoplasic ascites the cytopathologic examination was negative, but the CEA assay was > 11.0 ng/mL in 3 patients. CONCLUSION: The cytopathologic examination should be performed in all cases, and the CEA assay should be done in suspected cases of epithelial neoplasia in which the cytologic examination was negative, there was uncertainty about the histologic type of neoplasia, or a diagnosis of nonepithelial neoplasia was made. When ascitic leukocytosis or hepatic failure is present, one should be cautious in interpreting the CEA assay because false positivity can occur.

Inhibition of mitogen-activated proliferation of human lymphocytes in vitro by high concentrations of glutamine

We invetigated the influence of hogh concentrations of glutamine and aspargine on in vitro cellular growth of lymphocytes stimulated with phytohaemaglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM), a recognized test of cellular immunocompetence. Human peripheral lymphocytes were cultured in flat-bottomed 96-well microplates at 37§ C for 96 (PHA and Con A) or 144 hours (PWM) in the presence of a mitogen at different concentrations and either glutamine or asparagine supplemented at doses of 2, 4 or 8 mM. Lymphocyte reactivity, meas ured by the incorporation of tritiated thymidine into cellular DNA, was compared to identical cultures in the absence of supplemented amino acids (controls). We found that glutamine in doses of 2 mM and higher inhibited lymphocyte proliferation of mitogen-stimulated human lymphocyes, whereas asparagine caused no effect. These results demonstrate that, although necessary for cellular division in moderate amounts, glutamine in high concentrations has the reverse effect

Ethnic differences in human leukocyte antigen markers of susceptibility to IDDM.

OBJECTIVE: To determine whether genetic differences explain the lower risk of developing insulin-dependent diabetes mellitus (IDDM) for Hispanic versus non-Hispanic white children in Colorado. RESEARCH DESIGN AND METHODS: Hispanic (n = 62) and non-Hispanic white (n = 82) subjects with IDDM identified from the Colorado IDDM Registry and healthy, nondiabetic control subjects were recruited. Human leukocyte antigen (HLA) serologic typing and sequence-specific oligonucleotide typing of DQA1 and DQB1 alleles were performed. RESULTS: HLA and allele associations with IDDM were similar in both ethnic groups. HLA-DR3 and HLA-DR4 were more common in IDDM subjects in both ethnic groups. Subjects with DQBl alleles encoding aspartic acid (Asp) in position 57 were less likely to have IDDM, irrespective of ethnic background. HLA-DR3 was less common among Hispanic subjects than non-Hispanic white control subjects (4.4 vs. 17.5%, Hispanics vs. non-Hispanic whites, P = 0.04). CONCLUSIONS: These data suggest that the lower prevalence of HLA-DR3 in the Hispanic population, a pattern consistent with the presence of Amerindian admixture, may explain the lower rate of IDDM in the Hispanic population.

Early exposure to cow's milk and solid foods in infancy, genetic predisposition, and risk of IDDM.

Using a case-control study design, we examined the hypothesis that early exposure to cow's milk and solid foods increased the risk of IDDM. An infant diet history was collected from 164 IDDM subjects from the Colorado IDDM Registry with a mean birth year of 1973, and 145 nondiabetic population control subjects who were frequency matched to diabetic subjects on age, sex, and ethnicity. Early exposure was defined as exposure occurring before 3 mo of age. After controlling for ethnicity, birth order, and family income, more diabetic subjects were exposed early to cow's milk (OR 4.5, 95% CI 0.9-21.4) and solid foods (OR 2.5, CI 1.4-4.3) than control subjects. To examine this association while accounting for the genetic susceptibility to IDDM, we defined individuals as high and low risk by an HLA-DQB1 molecular marker. Early exposure to cow's milk was not associated with elevated risk for IDDM in low-risk individuals. Relative to unexposed low-risk individuals, early exposure to cow's milk was strongly associated in individuals with a high risK marker (OR 11.3, CI 1.2-102.0). Similar findings were observed for early exposure to solid foods. These data indicate that early exposure to cow's milk and solid foods may be associated with increased risk of IDDM. The inclusion of HLA-encoded risk in the analyses demonstrates the combined effect of genetic and environmental factors.

The HLA polymorphism in five Brazilian populations.

A total of 977 White individuals living in five Brazilian cities, as well as 173 Black individuals from two of these cities have been studied in relation to HLA-A and HLA-B. Allele frequency similarities among these populations are much more impressive than dissimilarities, and the differences, considering putative ancestors, are not remarkable. This limited variability can be only partially explained in terms of racial admixture, estimates of the latter using different alleles in the various populations showing disparate results. Linkage disequilibrium values vary between groups, that for A1-B8 being the most consistent, independent of sample or race. But four other haplotypes observed to be in significant disequilibrium in Portugal showed the same pattern in at least one of the five Brazilian White samples.

Angioedema hereditario: revisao,apresentacao de uma familia com 15 individuos afetados e correlacao com sistema HLA. / Hereditary angioedema: review, report of a family with 15 affected subjects and correlation with the HLA system

Os autores apresentam sua experiencia com o angiodema hereditario, descrevendo diversos casos no Rio Grande do Sul. As familias acometidas foram investigadas com dosagem de C4, tipagem HLA, grupo sanguineo e Rh. Conclui-se que nao existe relacao entre o surgimento da doenca e antigenos de histocompatibilidade, grupos sanguineos ABO e Rh. A dosagem de C4 e importante na confirmacao do diagnostico clinico