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.

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.

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.

Effect of the chemokine receptor CCR5 in the development of American cutaneous leishmaniasis in a Southern Brazilian population.

American cutaneous leishmaniasis (ACL) shows a wide spectrum of clinical and immunopathological manifestations. The CCR5 chemokine receptor directs the immune response to a Th1 pattern and the mutant allele of this genotype (Δ32/Δ32) results in a less effective response, thus leading to a milder inflammation. The objective of the present study was to investigate the effect of the CCR5 chemokine receptor in the pathogenesis of ACL in a population of Southern Brazil. The frequency of the genotypes and their association with ACL were studied in 111 patients and compared with 218 control subjects. Genotyping was performed using samples amplified by polymerase chain reaction with sequence specific primers (PCR­SSP). The groups varied in chronological age (P<0.00001), but showed no differences in gender (P=0.0696) or ethnicity (P=0.2944). The frequency of the CCR5/Δ32 genotype did not differ between the patient and control groups (P=0.3009). The Δ32/Δ32 deletion was not observed in any individual involved in the study. The analysis of the genotypes observed no significant difference in the frequency of the CCR5/Δ32 genotype between the ACL and control groups, however the subgroup of patients with a recurrence of the lesion showed a higher frequency of the CCR5/Δ32 mutation (P=0.020), indicating a possible effect of this allele in the pathogenesis of ACL. Nevertheless, more studies are required to elucidate the role of CCR5 in the pathogenesis of ACL.

HLA molecules and nasal carriage of Staphylococcus aureus isolated from dialysis and kidney transplant patients at a hospital in Southern Brazil.

BACKGROUND: Healthy individuals can host Staphylococcus aureus in the nasopharynx, body surface and vagina. Most invasive infections by this bacterium are endogenous, caused by strains spread from the nasopharynx of carriers. S. aureus is a pathogen involved in the etiology of hospital- and community-acquired infections. Transplant and dialysis patients are at risk of colonization or infection by multi-resistant S. aureus. Infection is directly linked to individual immunity, and the major histocompatibility complex (MHC) plays a crucial role in determining susceptibility to diseases. Different MHC specificities have been shown to be more frequent in individuals suffering from certain diseases. This study aimed to investigate the association between HLA class I (HLA-A and -B) and class II (HLA-DRB1) molecules and nasal carriage of S. aureus in dialysis and kidney transplant patients at a hospital in Southern Brazil. RESULTS: The sample consisted of 70 dialysis and 46 kidney transplant patients, totaling 116 patients. All subjects were typed for HLA molecules using LABType® SSO (One Lambda). Nasal swab samples of S. aureus were isolated from the nasal cavity (both nostrils) of patients undergoing dialysis or kidney transplantation.In renal dialysis patients, HLA-A*02 was the most frequent allele in both carriers (25.5%) and non-carriers (21.2%) of S. aureus. Allele A*68 was not observed in the carrier group, but the allele was observed six times in the non-carrier group (p = 0.0097). Regarding HLA-B and HLA-DRB1, no allele was shown to be involved in protection against or susceptibility to carriage of S. aureus. In kidney transplant patients, allele A*03 was more frequent in the non-carrier (20.83%) than in the carrier (5.88%) group (p = 0.0486). HLA-B*15 was present in carriers (5.88%) and non-carriers (25%) (p = 0.0179). Regarding class II alleles, DRB1*03 appeared to be related to susceptibility to carriage of S. aureus (p = 0.0319). CONCLUSIONS: Our findings suggest that HLA-DRB1*03 may be involved in susceptibility to nasal carriage of S. aureus in transplant patients. In addition, HLA-A*68 (dialysis patients) and HLA-A*03 and HLA-B*15 (transplant patients) appear to be associated with increased resistance to S. aureus nasal carriage.