HLA polymorphisms as incidence factor in the progression to end-stage renal disease in Brazilian patients awaiting kidney transplant

Chronic renal failure (CRF) leads in the majority of instances to end-stage renal disease (ESRD) requiring renal replacement therapy. Age, gender, genetics, race, hypertension, and smoking among others are factors associated with ESRD. Our interest was to evaluate the possible associations of class I and II HLA antigens with ESRD renal disease independent of other factors, among patients with CRF, having various diagnoses in the Brazilian population of the Sao Paulo state. So 21 HLA-A, 31 HLA-B, and 13 HLA-DR were detected in 105 patients who were compared with 160 healthy controls of both sexes who were not related to the patients evaluated until 2005. We calculated allelic frequencies, haplotypes frequencies, etiological fractions (EF), preventive fractions, and relative risks (RR). We compared demographic data of patients and controls. The antigens positively associated with ESRD were: HLA-A78 (RR = 30.31 and EF = 0.96) and HLA-DR11 (RR = 18.87 and EF = 0.65). The antigens HLAB14 (RR = 29.90 and EF = 0.75) was present at a significantly lower frequency among patients compared with controls. In contrast, no haplotype frequency showed statically significant associations. Further molecular studies may clarify types and subtypes of alleles involved with ESRD progression.

Superoxide anion production by neutrophils is associated with prevalent clinical manifestations in systemic lupus erythematosus

To determine the relation between neutrophil function and the clinical characteristics of systemic lupus erythematosus ( SLE), the superoxide anion (O(2)(-)) production by neutrophils, mediated by Fc gamma R and Fc gamma R/CR cooperation, was studied in 64 SLE patients classified according to their prevalent clinical manifestations. Three clinically distinct patterns were designated: ( 1) manifestations associated with the occurrence of cytotoxic antibodies ( SLE-I group); ( 2) manifestations associated with circulating immune complexes ( IC; SLE-II group), and ( 3) manifestations associated with IC and cytotoxic antibodies ( SLE-III group). O(2)(-) production was evaluated by a lucigenin-dependent chemiluminescent assay in neutrophils stimulated with ICIgG opsonized or not with complement. No difference in O(2)(-) production was observed when neutrophil responses from healthy controls were compared to the unclassified patients. However, when the SLE patient groups were considered, the following differences were observed: ( 1) SLE-I neutrophils showed lower O(2)(-) production mediated by the IgG receptor ( Fc gamma R) with the cooperation of complement receptors ( Fc gamma R/ CR) than observed in the SLE-II, SLE-III, and healthy groups; ( 2) neutrophils from the SLE-II group showed a decreased O(2)(-) production mediated by Fc gamma R/ CR compared to the SLE-III group, ( 3) SLE-III neutrophils produced more O(2)(-) than neutrophils from the SLE-II and control groups, and ( 4) CR showed inefficiency in mediating the O(2)(-) production by neutrophils from the SLE-I group. Comparative experiments on the kinetics of chemiluminescence ( CL; T(max) and CL(max)) disclosed differences only for the SLE- I group. Taken together, these results suggest that differences in oxidative metabolism of neutrophils mediated by Fc gamma R/ CR may reflect an acquired characteristic of disease associated with distinct clinical manifestations.

Antibody-targeted horseradish peroxidase associated with indole-3-acetic acid induces apoptosis in vitro in hematological malignancies

Indole-3-acetic acid (IAA), when oxidized by horseradish peroxidase (HRP), is transformed into cytotoxic molecules capable of inducing cell injury. The aim of this study was to test if, by targeting hematopoietic tumors with HRP-conjugated antibodies in association with IAA treatment, there is induction of apoptosis. We used two lineages of hematologic tumors: NB4, derived from acute promyelocytic leukemia (APL) and Granta-519 from mantle cell lymphoma (MCL). We also tested cells from 12 patients with acute myeloid leukemia (AML) and from 10 patients with chronic lymphocytic leukemia (CLL). HRP targeting was performed with anti-CD33 or anti-CD19 antibodies (depending on the origin of the cell), followed by incubation with goat anti-mouse antibody conjugated with HRP. Eight experimental groups were analyzed: control, HRP targeted, HRP targeted and incubated with 1, 5 and 10 mM IAA, and cells not HRP targeted but incubated with 1, 5 and 10 mM IAA. Apoptosis was analyzed by flow cytometry using annexin V-FITC and propidium iodide labeling. Results showed that apoptosis was dependent on the dose of IAA utilized, the duration of exposure to the prodrug and the origin of the neoplasia. Targeting HRP with antibodies was efficient in activating IAA and inducing apoptosis. (C) 2010 Elsevier Ltd. All rights reserved.

Natural Host Relationships and Genetic Diversity of Rodent-Associated Hantaviruses in Southeastern Brazil

Objective: Hantaviruses are rodent-borne RNA viruses that have caused hantavirus cardiopulmonary syndrome in several Brazilian regions. In the present study, geographical distribution, seroprevalence, natural host range, and phylogenetic relations of rodent-associated hantaviruses collected from seven counties of Southeastern Brazil were evaluated. Methods: ELISA, RT-PCR and phylogenetic analysis were used in this study. Results: Antibodies to hantavirus were detected in Bolomys lasiurus, Akodon sp. and Oligoryzomys sp., performing an overall seroprevalence of 5.17%. All seropositive rodents were associated with grasslands or woods surrounded by sugar cane fields. Phylogenetic analysis of partial S- and M-segment sequences showed that viral sequences isolated from B. lasiurus specimens clustered with Araraquara virus. However, a sequence from Akodon sp. shared 100% similarity with Argentinian/Chilean viruses based on the partial S- segment amino acid sequence. Conclusion: These results indicate that there are associations between rodent reservoirs and hantaviruses in some regions of Southeastern Brazil, and suggest the existence of additional hantavirus genetic diversity and host ecology in these areas. Copyright (C) 2008 S. Karger AG, Basel

Efficiency of the DNA repair and polymorphisms of the XRCC1, XRCC3 and XRCC4 DNA repair genes in systemic lupus erythematosus

Impaired DNA repair efficiency in systematic lupus erythematosus (SLE) patients has been reported ill some studies, mainly regarding the repair of oxidative damage, but little is known about repair kinetics towards primarily single-stranded DNA breaks. In the present study, we aimed to investigate: (a) the efficiency of SLE peripheral blood leucocytes in repairing DNA damage induced by ionizing radiation and (b) the association of DNA repair gene (XRCC1 Arg399Gln, XRCC3 Thr241Met and XRCC4 Ile401Thr) polymorphisms in SLE patients, considering the whole group, or stratified sub-groups according to clinical and laboratory features. A total of 163 SLE patients and 125 healthy control were studied. The kinetics of DNA strand break repair was evaluated by the comet assay, and genotyping for DNA repair genes was performed by PCR-RFLP. Compared with controls. SLE leucocytes exhibited decreased efficiency of DNA repair evaluated at 30 min following irradiation. A significant association with DNA repair gene polymorphisms was not observed for the whole group of SLE patients; however, the XRCC1Arg399Gln polymorphism was associated with the presence of anti-dsDNA antibody. The concomitance of two DNA repair polymorphic sites was associated with the presence of neuropsychiatric manifestations and antiphospholipid antibody syndrome. Taken together, these results indicated that SLE leucocytes repair less efficiently the radiation-induced DNA damage, and DNA repair polymorphic sites may predispose to the development of particular clinical and laboratory features. Lupus (2008) 17, 988-995.

Sustained Ventricular Tachycardia Is Associated with Regional Myocardial Sympathetic Denervation Assessed with (123)I-Metaiodobenzylguanidine in Chronic Chagas Cardiomyopathy

Cardiac sympathetic denervation and ventricular arrhythmia are frequently observed in chronic Chagas cardiomyopathy (CCC). This study quantitatively evaluated the association between cardiac sympathetic denervation and sustained ventricular tachycardia (SVT) in patients with CCC. Methods: We prospectively investigated patients with CCC and left ventricular ejection fraction (LVEF) greater than 35% with SVT (SVT group: n = 5 15; mean age +/- SD, 61 +/- 8 y; LVEF, 51% +/- 8%) and patients without SVT (non-SVT group: n = 11; mean age +/- SD, 55 +/- 10 y; LVEF, 57% +/- 10%). Patients underwent myocardial scintigraphy with (123)I-metaiodobenzylguanidine ((123)I-MIBG) for the evaluation of sympathetic innervation and resting perfusion with (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) for the evaluation of myocardial viability. A visual semiquantitative score was attributed for regional uptake of each radiotracer using a 17-segment left ventricular segmentation model (0, normal; 4, absence of uptake). A mismatch defect was defined as occurring in segments with a 99mTc-MIBI uptake score of 0 or 1 and a (123)I-MIBG score of 2 or more. Results: Compared with the non-SVT group, the SVT group had a similar (99m)Tc-MIBI summed score (6.9 +/- 7.5 vs. 4.4 +/- 5.2, respectively, P = 0.69) but a higher (123)I-MIBG summed score (10.9 +/- 7.8 vs. 22.4 +/- 9.5, respectively, P = 0.007) and a higher number of mismatch defects per patient (2.0 +/- 2.2 vs. 7.1 +/- 2.0, respectively, P < 0.0001). The presence of more than 3 mismatch defects was strongly associated with the presence of SVT (93% sensitivity, 82% specificity; P = 0.0002). Conclusion: In CCC, the amount of sympathetically denervated viable myocardium is associated with the occurrence of SVT. Myocardial sympathetic denervation may participate in triggering malignant ventricular arrhythmia in CCC patients with relatively well-preserved ventricular function.

Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection

As the mechanisms leading to the persistence of hepatitis B virus (HBV) infection are poorly understood and as the histocompatibility leucocyte antigen (HLA)-G is well described as a tolerogenic molecule, we evaluated HLA-G expression in 74 specimens of HBV liver biopsies and in 10 specimens obtained from previously healthy cadaver liver donors. HBV specimens were reviewed and classified by the METAVIR score, and HLA-G expression was assessed by immunohistochemistry. No HLA-G expression was observed in control hepatocytes. In contrast, 57 (77%) of 74 HBV specimens showed soluble and membrane-bound HLA-G expression in hepatocytes, biliary epithelial cells or both. No associations between the intensity of HLA-G expression and patient age or gender, HBeAg status, severity of liver fibrosis, and grade of histological findings were observed. Although significance was not reached (P = 0.180), patients exhibiting HLA-G expression presented a higher median HBV DNA viral load (105 copies/mL) than those who did not express HLA-G (103.7 copies/mL). These results indicate that HLA-G is expressed in most cases of chronic HBV infection in all stages and may play a role in the persistency of HBV infection.

High expression of AURKA and AURKB is associated with unfavorable cytogenetic abnormalities and high white blood cell count in patients with acute myeloid leukemia

In the present study, we analyzed AURKA and AURKB gene expression in 70 acute myeloid leukemia (AML) patients. There was no difference between leukemic samples and bone marrow mononuclear cells (BMMCs, n = 8) or CD34(+) progenitors (n = 10) from healthy donors. High white blood cells (WBC) counts were observed in the AURKA(+) and AURKB(+) groups, but no significant differences regarding age, gender, platelet counts or frequency of FLT3-ITD mutations. AURKA, but not AURKB, expression was independently associated with high WBC counts (OR: 3.15, 95% CI 1.07-9.24, p = 0.03). Moreover, the majority of cases that overexpressed AURKA and AURKB presented unfavorable cytogenetic abnormalities (p < 0.001). In conclusion, we described a significant association between overexpression of AURKA/B and cytogenetics findings in AML, which may be relevant to new therapeutic approaches, based on Aurora kinase inhibitors. (C) 2010 Elsevier Ltd. All rights reserved.

TNF microsatellite alleles may confer protection against the development of lipodystrophy syndrome in Brazilian HIV patients

P>The aim of this study was to evaluate the frequency of TNFa-e microsatellites and the promoter region (TNF-308 and TNF-238) in HIV/AIDS-infected patients presenting or not lipodystrophy syndrome (LS). The design is the genetic case-control association study. Microsatellite and the TNF promoter region polymorphisms were amplified by PCR and submitted to polyacrylamide gel electrophoresis. The genotypes and allele frequencies for 67 HIV-positive patients with lipodystrophy were compared with 50 HIV-positive patients with no evidence of lipodystrophy and with 131 healthy HIV-negative individuals. The presence of the TNFa5 allele could provide HIV/AIDS patients with protection against developing LS. The presence of TNF-308G allele, as well as of its homozygote TNF-308GG, were associated with susceptibility to developing LS. In addition, the presence of the haplotype TNFe3-d3-238G-308A-c1-a5-b7 suggests protection against developing that syndrome. This study highlights that polymorphic sites spanning the region nearby the TNF locus are associated with LS development in HIV/AIDS patients.

The H63D genetic variant of the HFE gene is independently associated with the virological response to interferon and ribavirin therapy in chronic hepatitis C

Background Conflicting results have been reported in studies evaluating the relationship between serum markers of iron overload, liver iron deposits, and HFE mutations (C282Y and H63D) in chronic hepatitis C patients, and also their impact on the response to therapy in these patients. Aim To evaluate the role of HFE mutations in the severity of liver disease and in the response to therapy in chronic hepatitis C. Methods Two hundred and sixty-four hepatitis C patients treated with standard interferon and ribavirin were divided into two groups according to type of antiviral response: sustained virological response (SVR) and nonresponse or relapse. We evaluated the relationship between HFE mutation and the type of antiviral response, clinical data, biochemical tests, liver histopathology, virological data, and HFE mutations. Results Of the 264 patients, 88 (32.1%) had SVR whereas 67.9% had nonresponse or relapse. Liver iron deposits were observed in 49.2% of the patients. The factors associated with SVR were hepatitis C virus genotype 2 or 3, transferrin saturation value of 45% or less, and detection of the H63D mutation. HFE mutation was more frequent in patients with iron deposits, but without association with serum iron biochemistry or severity of liver disease. Steatosis was more frequent in patients with liver iron deposits. Conclusion The H63D mutation was an independent factor associated with SVR in chronic hepatitis C patients, as also were hepatitis C virus genotype 2 or 3 and transferrin saturation value of 45% or less. Moreover, the H63D mutation was associated with liver iron deposits. Eur J Gastroenterol Hepatol 22: 1204-1210 (C) 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Low Expression of Human Histocompatibility Soluble Leukocyte Antigen-G (HLA-G5) in Invasive Cervical Cancer With and Without Metastasis, Associated With Papilloma Virus (HPV)

Human leukocyte antigen-G (HLA-G) is a non-classical major histocompatibility complex class lb molecule that acts as a specific immunosuppressor. Some studies have demonstrated that human papillomavirus (HPV) seems to be involved in lower or absent HLA-G expression, particularly in cervical cancer. In this study, we performed a cross-sectional study, systematically comparing the qualitative expression of the HLA-G5 isoform in invasive cervical carcinoma (ICC), stratifying patients according to the presence [ICC with metastasis (ICC(W))) and absence [ICC without metastasis (ICC(WT))] of metastasis, correlating these findings with interference of HPV and demographic and clinical variables. Seventy-nine patients with a diagnosis of ICC were stratified into two groups: ICC(WT) (n=52 patients) and ICC(W) (n=27). Two biopsies were collected from each patient (one from the tumor lesion and one from a lymph node). Immunohistochemistry analyses were performed for the HLA-G5 isoform, for HPV detection, and virus typing. HLA-G5 isoform molecules were detected in 25 cases (31.6%), 17 (32.7%) without metastasis and 8 (29.6%) with metastasis. HPV was detected in the cervical lesions of 74 patients (93.7%), but low expression of the HLA-G5 isoform was observed in all HPV-related cases. These findings are important; however, additional studies are necessary to identify the influence of HPV with HLA-G5 isoform expression on invasive cervical malignancies. (J Histochem Cytochem 58:405-411, 2010)

Segmental amplification of MLL gene associated with high expression of AURKA and AURKB genes in a case of acute monoblastic leukemia with complex karyotype

We report a case of acute monoblastic leukemia showing a jumping translocation with the MLL gene in a 17-year-old male. Classic cytogenetic and spectral karyotyping revealed a complex karyotype, and fluorescence in situ hybridization (FISH) demonstrated amplification of the MLL gene followed by translocation to chromosomes 15q, 17q, and 19q. In addition, molecular analyses showed a high expression of AURKA and AURKB genes. It is already known that overexpression of Aurora kinases is associated with chromosomal instability and poor prognosis. The formation of jumping translocations is a rare cytogenetic event and there is evidence pointing toward preferential involvement of the heterochromatin region of donor chromosomes and the telomere ends of recipient chromosomes. Jumping translocation with the MLL gene rearrangement is an uncommon phenomenon reported in leukemia cytogenetics. (C) 2010 Elsevier Inc. All rights reserved.

Frequency distribution of XbaIG > T and HaeIIIT > C GLUT1 polymorphisms among different Brazilian ethnic groups

GLUT is the major glucose transporter in mammalian cells. Single nucleotide polymorphisms (SNP) at GLUT1 promoter and regulatory regions have been associated to the risk of developing nephropathy in different type 1 and type 2 diabetic populations. It has been demonstrated that differences in allelic and genotypic frequencies of GLUT1 gene (SLC2A1) polymorphisms occur among different populations. Therefore, ethnic differences in distribution of GLUT1 gene polymorphisms may be an important factor in determining gene-disease association. In this study, we investigated the XbaIG > T and HaeIIIT > C polymorphisms in six different Brazilian populations: 102 individuals from Salvador population (Northern Brazil), 56 European descendants from Joinville (South Brazil), 85 Indians from Tiryi tribe (North Brazil) and 127 samples from Southern Brazil: 44 from European descendants, 42 from African descendants and 41 from Japanese descendants. Genotype frequencies from both sites did not differ significantly from those expected under the Hardy-Weinberg equilibrium. We verified that the allele frequencies of both polymorphisms were heterogeneous in these six Brazilian ethnic groups.

T allele of-344C/T polymorphism in aldosterone synthase gene is not associated with resistant hypertension

Resistant hypertension (RH) is the maintenance of elevated blood pressure concurrent with the use of three different antihypertensive drugs, one of which is a diuretic. The Renin-Angiotensin-Aldosterone System plays a major role in volume-dependent hypertension. Therefore, its components are interesting targets for genetic association studies. This work focused on the -344 C/T polymorphism in the CYP11b2 gene, which encodes aldosterone synthase. This work evaluates the association between T allele and resistance to anti-hypertensive treatment. Genotyping analysis included 88 subjects with RH, 142 who were responsive to anti-hypertensive treatment and 110 subjects as a control group. Plasmatic concentrations of aldosterone, renin and cortisol, carotid intima-media thickness and carotid-femoral pulse wave velocity were assessed in a smaller subset of hypertensive patients. An association was found between T allele and hypertension (P < 0.005), but there was no difference in allele frequencies between both hypertensive groups. There was no difference in plasmatic parameters either, in remodeling indicators between the genotypic groups.

Activation of the ET-1/ETA Pathway Contributes to Erectile Dysfunction Associated with Mineralocorticoid Hypertension

The cavernosal tissue is highly responsive to endothelin-1 (ET-1), and penile smooth muscle cells not only respond to but also synthesize ET-1. Considering that ET-1 is directly involved in end-organ damage in salt-sensitive forms of hypertension, we hypothesized that activation of the ET-1/ET(A) receptor pathway contributes to erectile dysfunction (ED) associated with mineralocorticoid hypertension. Wistar rats were uninephrectomized and submitted to deoxycorticosterone acetate (DOCA)-salt treatment for 5 weeks. Control (Uni [uninephrectomized control]) animals were uninephrectomized and given tap water. Uni and DOCA-salt rats were simultaneously treated with vehicle or atrasentan (ET(A) receptor antagonist, 5 mg/Kg/day). Cavernosal reactivity to ET-1, phenylephrine (PE), ET(B) receptor agonist (IRL-1620) and electric field stimulation (EFS) were evaluated in vitro. Expression of ROCK alpha, ROCK beta, myosin phosphatase target subunit 1 (MYPT-1), and extracellular signal-regulated kinase 1/2 (ERK 1/2) were evaluated by western blot analysis. ET-1 and ET(A) receptor mRNA expression was evaluated by real-time reverse-transcriptase polymerase chain reaction. Voltage-dependent increase in intracavernosal pressure/mean arterial pressure (ICP/MAP) was used to evaluate erectile function in vivo. ET(A) receptor blockade prevents DOCA-salt-associated ED. Cavernosal strips from DOCA-salt rats displayed augmented preproET-1 expression, increased contractile responses to ET-1 and decreased relaxation to IRL-1620. Contractile responses induced by EFS and PE were enhanced in cavernosal tissues from DOCA-salt hypertensive rats. These functional changes were associated with increased activation of the RhoA/Rho-kinase and ERK 1/2 pathways. Treatment of rats with atrasentan completely prevented changes in cavernosal reactivity in DOCA-salt rats and restored the decreased ICP/MAP, completely preventing ED in DOCA-salt rats. Activation of the ET-1/ET(A) pathway contributes to mineralocorticoid hypertension-associated ED. ET(A) receptor blockade may represent an alternative therapeutic approach for ED associated with salt-sensitive hypertension and in pathological conditions where increased levels of ET-1 are present. Carneiro FS, Nunes KP, Giachini FRC, Lima VV, Carneiro ZN, Nogueira EF, Leite R, Ergul A, Rainey WE, Webb RC, and Tostes RC. Activation of the ET-1/ETA pathway contributes to erectile dysfunction associated with mineralocorticoid hypertension. J Sex Med **;**:**-**.