MICA diversity and linkage disequilibrium with HLA-B alleles in renal-transplant candidates in southern Brazil.

The major histocompatibility complex (MHC) class I chain-related gene A (MICA) is located centromerically to the human leukocyte antigen (HLA)-B. The short distance between these loci in the MHC indicates the presence of linkage disequilibrium (LD). Similarly to the HLA, the MICA is highly polymorphic, and this polymorphism has not been well documented in different populations. In this study, we estimated the allelic frequencies of MICA and the linkage disequilibrium with HLA-B alleles in 346 renal-transplant candidates in southern Brazil. MICA and HLA were typed using the polymerase chain reaction-sequence-specific primer method (PCR-SSO), combined with the Luminex technology. A total of 19 MICA allele groups were identified. The most frequent allele groups were MICA*008 (21.6%), MICA*002 (17.0%) and MICA*004 (14.8%). The most common haplotypes were MICA*009-B*51 (7.8%), MICA*004-B*44 (6.06%) and MICA*002-B*35 (5.63%). As expected from the proximity of the MICA and HLA-B loci, most haplotypes showed strong LD. Renal patients and healthy subjects in the same region of Brazil showed statistically significant differences in their MICA polymorphisms. The MICA*027 allele group was more frequent in renal patients (Pc = 0.018, OR: 3.421, 95% CI: 1.516-7.722), while the MICA*019 allele group was more frequent in healthy subjects (Pc = 0.001, OR: 0.027, 95% CI: 0.002-0.469). This study provided information on the distribution of MICA polymorphisms and linkage disequilibrium with HLA-B alleles in Brazilian renal-transplant candidates. This information should help to determine the mechanisms of susceptibility to different diseases in patients with chronic kidney disease, and to elucidate the mechanisms involved in allograft rejection associated with MICA polymorphisms in a Brazilian population.

HLA-A, HLA-B, and HLA-DRB1 Allele and Haplotype Frequencies in Renal Transplant Candidates in a Population in Southern Brazil.

BACKGROUND: Very few studies have examined the diversity of human leukocyte antigens (HLA) in the Brazilian renal transplant candidates. METHODS: The frequencies of the HLA-A, HLA-B, and HLA-DRB1 alleles, haplotypes and phenotypes were studied in 522 patients with chronic renal failure, renal transplant candidates, registered at the Transplant Centers in north/northwestern Paraná State, southern Brazil. Patients were classified according to the ethnic group (319 whites [Caucasians], 134 mestizos [mixed race descendants of Europeans, Africans, and Amerindians; browns or "pardos"] and 69 blacks). The HLA typing was performed by the polymerase chain reaction sequence-specific oligonucleotide method (PCR-SSO), combined with Luminex technology. RESULTS: In the analysis of the total samples, 20 HLA-A, 32 HLA-B, and 13 HLA-DRB1 allele groups were identified. The most frequent allele groups for each HLA locus were HLA-A*02 (25.4%), HLA-B*44 (10.9%), and HLA-DRB1*13 (13.9%). The most frequent haplotypes were HLA-A*01-B*08-DRB1*03 (2.3%), A*02-B*44-DRB1*07 (1.2%), and A*03-B*07-DRB1*11 (1.0%). Significant differences (P < 0.05) were observed in the HLA-A*68, B*08, and B*58 allele frequencies among ethnic groups. CONCLUSIONS: This study provides the first data on the HLA-A, HLA-B, and HLA-DRB1 allele, phenotype and haplotype frequencies of renal transplant candidates in a population in southern Brazil.

Prevalence of Torque teno virus in healthy donors of Paraná State, southern Brazil

OBJECTIVE: To determine the prevalence of the Torque teno virus in healthy donors in the northern and northwestern regions of the state of Paraná, southern Brazil.METHODS: The Torque teno virus was detected by a nested polymerase chain reaction using a set of oligoprimers for the N22 region.RESULTS: The prevalence of the virus was 69% in 551 healthy blood donors in southern Brazil. There was no statistically significant difference between the presence of the virus and the variables gender, ethnicity and marital status. There was significant difference in the prevalence of the virus regarding the age of the donors (p-value = 0.024) with a higher incidence (74.7%) in 18- to 24-year-old donors.CONCLUSION: A high prevalence of Torque teno virus was observed in the population studied. Further studies are needed to elucidate the routes of contamination and the clinical implications of the virus in the healthy population.

Prevalence of Torque teno virus in healthy donors of Paraná State, southern Brazil.

OBJECTIVE: To determine the prevalence of the Torque teno virus in healthy donors in the northern and northwestern regions of the state of Paraná, southern Brazil. METHODS: The Torque teno virus was detected by a nested polymerase chain reaction using a set of oligoprimers for the N22 region. RESULTS: The prevalence of the virus was 69% in 551 healthy blood donors in southern Brazil. There was no statistically significant difference between the presence of the virus and the variables gender, ethnicity and marital status. There was significant difference in the prevalence of the virus regarding the age of the donors (p-value=0.024) with a higher incidence (74.7%) in 18- to 24-year-old donors. CONCLUSION: A high prevalence of Torque teno virus was observed in the population studied. Further studies are needed to elucidate the routes of contamination and the clinical implications of the virus in the healthy population.

Torque teno virus among dialysis and renal-transplant patients.

Patients who undergo dialysis treatment or a renal transplant have a high risk of blood-borne viral infections, including the Torque teno virus (TTV). This study identified the presence of TTV and its genome groups in blood samples from 118 patients in dialysis and 50 renal-transplant recipients. The research was conducted in a hospital in the city of Maringá, state of Paraná. The viral DNA, obtained from whole blood, was identified by using two nested Polymerase Chain Reactions (PCR). The frequencies of TTV were 17% and 36% in dialysis patients using the methodology proposed by Nishizawa et al . (1997) and Devalle and Niel (2004) , respectively, and 10% and 54% among renal-transplant patients. There was no statistically significant association between the frequency of the pathogen and the variables: gender, time in dialysis, time since transplant, blood transfusions, and the concomitant presence of hepatitis B, for either the dialysis patients or the renal-transplant recipients. Among dialysis patients and renal-transplant recipients, genogroup 5 was predominant (48% and 66% respectively), followed by genogroup 4 (37% and 48%) and genogroup 1 (23% and 25%). Genogroup 2 was present in both groups of patients. Some patients had several genogroups, but 46% of the dialysis patients and 51% of the renal-transplant recipients had only a single genogroup. This study showed a high prevalence of TTV in dialysis patients and renal-transplant recipients.

Analysis of platelet eluate for the elucidation of sensitization to HLA in kidney transplant candidate / Análise do eluato de plaqueta para a elucidação da sensibilização ao HLA em um candidato ao transplante de rim

While a 42-year-old male patient was being prepared for deceased-donor renal transplantation, anti-HLA-A2 antibodies were detected in the serum by enzyme-linked immunosorbent assay (ELISA) method. The patient denied any transfusion history and previous transplant. Crossmatch by complement dependent cytotoxicity (CDC) and CDC with anti -human globulin (CDC-AHG) proved negative with a four-cell panel with positive typing for HLA-A2. Adsorption of antibodies with platelets and analysis of eluate were suggested to elucidate discrepancies in results by ELISA and by CDC-AHG. ELISA showed that adsorbed serum with platelets did not reveal antibodies for HLA-A2 specificity and suggested that they were removed by their specific binding with HLA-A2 antigens on the platelet surface. Eluate analysis by ELISA showed antibodies for HLA-A2 specificity. No antibodies for HLA-A2 specificity in the non-adsorbed serum were detected by CDC-AHG method. Revision of patient's data showed that a previous transfusion had occurred, which may have been the source of HLA sensitization. The suggested method may be a contribution towards the evaluation of sensitivity between CDC-AHG and ELISA methods for characterizing antibodies in the patient's serum.

Enquanto um paciente do sexo masculino de 42 anos de idade estava sendo preparado para o transplante renal de doador falecido, anticorpos anti-HLA-A2 foram detectados no soro pelo método de ensaio imunoenzimático (ELISA). O paciente negava história de transfusão e transplante anterior. Prova-cruzada por citotoxicidade dependente de complemento (CDC) e CDC com antiglobulina humana (CDC-AGH) foram negativos com um painel de quatro células com tipagem positiva para HLA-A2. O método de adsorção de anticorpos com plaquetas e análise do eluato foi sugerido para explicar as discrepâncias dos resultados de ELISA e CDC-AGH. O método de ELISA mostrou que o soro adsorvido com plaquetas não revelou anticorpos para especificidade HLA-A2, sugerindo que eles foram removidos por meio de sua ligação específica com os antígenos HLA-A2 na superfície das plaquetas. A análise do eluato por ELISA mostrou anticorpos para especificidade HLA-A2. Nenhum anticorpo para especificidade HLA-A2 foi detectada no soro não adsorvido pelo método de CDC-AGH. Revisão dos dados do paciente mostrou que houve transfusão anterior, podendo ter sido a fonte de sensibilização HLA. O método sugerido é uma contribuição para avaliação da sensibilidade entre os métodos de CDC-AGH e ELISA em caracterizar anticorpos no soro do paciente.

Torque teno virus among dialysis and renal-transplant patients

Patients who undergo dialysis treatment or a renal transplant have a high risk of blood-borne viral infections, including the Torque teno virus (TTV). This study identified the presence of TTV and its genome groups in blood samples from 118 patients in dialysis and 50 renal-transplant recipients. The research was conducted in a hospital in the city of Maringá, state of Paraná. The viral DNA, obtained from whole blood, was identified by using two nested Polymerase Chain Reactions (PCR). The frequencies of TTV were 17% and 36% in dialysis patients using the methodology proposed by Nishizawa et al. (1997) and Devalle and Niel (2004), respectively, and 10% and 54% among renal-transplant patients. There was no statistically significant association between the frequency of the pathogen and the variables: gender, time in dialysis, time since transplant, blood transfusions, and the concomitant presence of hepatitis B, for either the dialysis patients or the renal-transplant recipients. Among dialysis patients and renal-transplant recipients, genogroup 5 was predominant (48% and 66% respectively), followed by genogroup 4 (37% and 48%) and genogroup 1 (23% and 25%). Genogroup 2 was present in both groups of patients. Some patients had several genogroups, but 46% of the dialysis patients and 51% of the renal-transplant recipients had only a single genogroup. This study showed a high prevalence of TTV in dialysis patients and renal-transplant recipients.

Evaluation of the humoral immune response to human leukocyte antigens in Brazilian renal transplant candidates.

Pre-transplant sensitization to human leukocyte antigens (HLA) is a risk factor for graft failure. Studies of the immunological profile related to anti-HLA antibodies in Brazilian renal transplant candidates are few. In this study, we evaluated the humoral immune response to HLA antigens in 269 renal transplant candidates, in Paraná State, Brazil. The HLA typing was performed by the polymerase chain reaction sequence-specific oligonucleotide method (PCR-SSO) combined with Luminex technology, using an SSO-LABType commercial kit (One Lambda, Inc., Canoga Park, CA, USA). The percentages of panel-reactive antibodies (PRA) and the specificity of anti-HLA antibodies were determined using the LS1PRA and LS2PRA commercial kits (One Lambda, Inc.). The PRA-positive group consisted of 182 (67.7%) patients, and the PRA-negative group of 87 (32.3%) patients. The two groups differed significantly only with respect to gender. Females were the most sensitized. Among the 182 patients with PRA- positive, 62 (34.1%) were positive for class I and negative for class II, 39 (21.4%) were negative for class I and positive for class II, and 81 (44.5%) were positive for both classes I and II. The HLA-A*02, A*24, A*01, B*44, B*35, B*15, DRB1*11, DRB1*04 and DRB1*03 allele groups were the most frequent. The specificities of anti-HLA antibodies were more frequent: A34, B57, Cw15, Cw16, DR51, DQ8 and DP14. This study documented the profile of anti-HLA antibodies in patients with chronic renal failure who were on waiting lists for an organ in Paraná, and found high sensitization to HLA antigens in the samples.

Complement-dependent cytotoxicity (CDC) to detect Anti-HLA antibodies: old but gold.

BACKGROUND: The criterion (gold) standard to detect anti-human leukocyte antigen (HLA) antibodies is the complement-dependent cytotoxicity (CDC) assay. Recently, more sensitive methods have been used for the same purpose. METHODS: This study analyzed 70 serum samples of patients with end-stage renal disease using CDC, CDC with the addition of anti-human globulin (CDC-AHG), CDC with the addition of dithiothreitol (CDC-DTT), and the recent solid-phase immunoassay (SPI; Labscreen PRA) to detect anti-HLA antibodies. RESULTS: Mean percent panel reactive antibodies (PRA) detected by SPI was 37.5% (±34.2) higher than the values detected by the other methods. Comparative analyses revealed significant difference between CDC and CDC-AHG, and between CDC and SPI (P < 0.0001), but not between CDC-AHG and SPI (P = 0.8026). CONCLUSION: Although the CDC-AHG method is "old," its performance to detect anti-HLA antibodies in the samples analyzed was comparable to the SPI in the evaluation of percent class I PRA.

Polymorphism of leukocyte and erythrocyte antigens in chronic kidney disease patients in southern Brazil.

We investigated the polymorphism of human leukocyte antigens (HLA) and Duffy erythrocyte antigens in chronic kidney disease (CKD) patients in southern Brazil. One hundred and eighty-three CKD patients, over 18 years old, on hemodialysis, were included. HLA-A, -B and -DRB1 typing was performed using the LABType®SSO (One Lambda, Inc.). Duffy phenotypes were determined by gel column agglutination using anti-Fy(a) and anti-Fy(b) monoclonal anti-sera. The patients' predominant ages ranged between 51 and 70 years (43%) and the predominant gender, ethnic group and dialysis period were, respectively, male (62%), white (62%) and 1-3 years (40%). The highest and lowest frequencies of Duffy phenotypes were Fy(a+b+) and Fy(a-b-), respectively. Nineteen HLA-A, 30 HLA-B and 13 HLA-DRB1 allele groups were identified. The most frequent HLA allele groups were HLA-A*01, -A*02, -A*03, -A*11, -A*24; HLA-B*07, -B*15, -B*35, -B*44, -B*51; HLA-DRB1*03, -DRB1*04, -DRB1*07, -DRB1*11 and -DRB1*13. Statistically significant differences were observed in the Duffy and HLA polymorphisms compared between CKD patients and healthy subjects. The Fy(a+b-) phenotype (p<0.0001, OR = 2.56, 95% CI = 1.60-4.07) was the most frequent in the patients (p<0.05), and the Fy(a+b+) phenotype (p = 0.0039, OR = 1.71, 95% CI = 1.18-2.51) was the most frequent in the healthy subjects in the same region of Paraná state (p<0.05). Regarding HLA, the HLA-B*42, -B*45, -B*51 and -DRB1*03 allele groups were the most frequent in the patients (p<0.05), and the HLA-B*44 allele group was the most frequent in the healthy subjects in the same region of Brazil (p<0.05). The polymorphism of these two markers among CKD patients in southern Brazil and healthy subjects of other studies, suggests that these markers might be involved with CKD development. Further studies should be undertaken to analyze the markers' influence on CKD and the long-term results from kidney transplantation.

Terapia dialítica em mulheres do estado do Paraná, município de Maringá e região metropolitana / Dialysis therapy in women from Parana State, Maringa city and metropolitan region

O objetivo deste estudo foi analisar a prevalência de diálise em mulheres no estado do Paraná, município de Maringá e região metropolitana. Estudo quantitativo, descritivo, de corte transversal. Foi estudada a prevalência de diálise em mulheres no estado do Paraná, município de Maringá e região metropolitana, no período de 1999 a 2007, através do Sistema de Informações Ambulatoriais do Sistema Único de Saúde (SIA/SUS), no programa do Departamento de Informática do Sistema Único de Saúde (DATASUS).Houve aumento da taxa de prevalência de diálise em mulheres no estado do Paraná, município de Maringá e região metropolitana no período de 1999 a 2007. No estado do Paraná, houve um crescimento de 1,71 mulheres em diálise por 100.000 habitantes do sexo feminino anualmente (p≤0,05), as faixas etárias 30 a 59 anos e 60 anos e mais se revelaram como fatores de risco para realizar diálise no sexofeminino. No município de Maringá e região metropolitana, houve um crescimento de 0,88 de mulheresem diálise por 100.000 habitantes do sexo feminino anualmente (p≤0,05), a faixa etária 60 anos e mais se revelou como fator de risco para realizar diálise no sexo feminino.

The aim of this study was to analyze the prevalence of dialysis in women in the state of Paraná, Maringá and metropolitan region. It is a quantitative, descriptive and transversal cut study. We studied the prevalence of dialysis in women from Parana state, Maringa city and metropolitan region in the period1999 to 2007 through the Outpatient Information System of the Unified Health System (SIA / SUS), theprogram of the Department of Informatics Unified Health System (DATASUS). Increased prevalence ofdialysis in women from Parana state, Maringá and metropolitan region in the period 1999 to 2007. In the Paraná state, an increase of 1,71 women per 100,000 dialysis females annually (p ≤ 0.05), ages 30 to 59 years and 60 years and more were revealed as factors risk to perform dialysis in females. In Maringa and the metropolitan region, an increase of 0,88 women per 100,000 dialysis females annually (p ≤ 0.05),age 60 years and more was revealed as a risk factor to perform dialysis in females.

Chronic kidney disease: information on southern brazilian patients with kidney disease / Insuficiência renal crônica: conhecendo o paciente nefropata sulbrasileiro

The profile of patients undergoing haemodialysis in the dialysis unit of Hospital Santa Casa de Maringá, Maringá PR Brazil, is provided. A questionnaire on social and economic data and underlying diseases prior to the Chronic Kidney Disease (CKD) identified the patients' profile. The project was approved by the Ethics Committee of the institution. Eighty-three patients, with 54.21% males, were interviewed. Age bracket ranged between 20 and 59 years in 65.06% of patients. Only 27.71% maintained jobs after the diagnosis and the start of treatment; 63.86% had an average personal income between 1 and 3 minimum wages; 63.85% did not practice any physical activity. Moreover, 53.01% belonged to the European-Brazilian white group; 20.48% to the Afro-Brazilian brown group; 19.28% to the Afro-Brazilian Negro group; 6.02% to other ethnic groups. Further, 85.54% patients reported having an underlying disease prior to the CKD, namely, 61.45% were hypertensive; 31.33% were diabetics and 20.48% had other diseases. Results show the need of a greater attention to these patients' health care to reduce the negative impacts related to the chronic disease focused.

Este estudo teve como objetivo identificar o perfil dos pacientes em tratamento hemodialítico do setor de diálise do Hospital Santa Casa de Maringá - Paraná, Brasil. Para a identificação do perfil destes pacientes foi utilizado um questionário contendo questões que abrangem dados socioeconômicos e doenças de base anteriores à Insuficiência Renal Crônica (IRC). O projeto foi aprovado pelo Comitê de Ética em Pesquisa da instituição. Entre os 83 pacientes entrevistados, 54,21% eram do sexo masculino. A faixa etária variou de 20 a 59 anos para 65,06% dos pacientes. Somente 27,71% continuaram trabalhando após o diagnóstico e início do tratamento. A renda pessoal média ficou entre um e três salários mínimos para 63,86% dos indivíduos. A atividade física está ausente em 63,85%. Quanto à etnia, foi verificado que 53,01% eram brasileiros descendentes de europeus/brancos, 20,48% brasileiros afrodescendentes/pardos, 19,28% brasileiros afrodescendentes/negros e 6,02% declararam como pertencentes à outras etnias. Entre os pacientes, 85,54% declararam possuir outra doença de base anterior à IRC sendo: 61,45% hipertensão arterial, 31,33% diabetes e 20,48% outras doenças. Estes resultados indicam a necessidade de uma melhor atenção ao cuidado da saúde desses pacientes para a redução dos impactos negativos relacionados à cronicidade da doença.