Seroprevalence of Trypanosoma cruzi in kidney transplant donors and recipients in Mexico City.

Infectious diseases are common causes of morbidity and mortality among kidney transplant recipients. Chagas disease (CD) has been recognized as an emerging infectious complication of transplantation caused by the parasite Trypanosoma cruzi. CD is prevalent in Mexico, particularly in the southern coastal region. The impact on Mexican kidney transplant programs has not been previously studied prospectively. From 2009 through 2010, serum samples from 59 kidney transplant donors and 405 renal transplant recipients were screened for antibodies against T. cruzi. Serum was initially screened using a locally developed ELISA test; positive results were confirmed by an indirect immunofluorescense test, in accordance with Panamerican Health Organization/World Health Organization guidelines. None of the donors were seropositive for T. cruzi, while 8 (1.97%) kidney transplant recipients were confirmed to be seropositive for T. cruzi. None of them have developed clinical manifestations of CD, although specific screening of recipients was not performed. A prospective study is planned to define the epidemiology and outcome of CD among kidney transplant donors and recipients in Mexico more thoroughly.

DNA-binding property of Sm nuclear antigen.

Antibodies in the sera of patients with systemic lupus erythematosus reacted with a nuclear acidic protein called Sm antigen, and these antibodies were used as reagents to identify Sm antigen in preparative fractionation procedures. DNA affinity chromatography showed that Sm antigen was associated with nuclear protein fractions which had DNA-binding capacity. Evidence was also presented that Sm antigen showed preferential binding for single-strand DNA over double-strand DNA. These studies demonstrate that spontaneously occurring anti-nuclear antibodies in disease states may be used to study the properties of cellular proteins which are present in trace amounts.

Takayasu arteritis: clinical features in 110 Mexican Mestizo patients and cardiovascular impact on survival and prognosis.

OBJECTIVE: Takayasu Arteritis (TA) is a rare disease that mainly affects large elastic arteries. It is more frequently seen in Asia, the Mediterranean basin, South Africa and Latin America. We have characterized its clinical manifestations and identified the cardiovascular mortality predictors in a cohort of 110 Mexican Mestizo patients. MATERIAL AND METHOD: Retrospective review of 110 charts of TA patients complying with the American College of Rheumatology (ACR) criteria, seen in a single hospital between 1976 and 2003. Demographic, clinical, and radiological characteristics were described. With the use of actuarial table analysis at 2, 5, and 10 years, and Kaplan Meier methods applying t function for probability, plus Cox regression analysis, the following factors were identified as mortality predictors: systemic arterial hypertension, coronary heart disease and aortic valve regurgitation. Informed consent and approval from the institutional Internal Review Board (IRB) were obtained. RESULTS: We observed a slowly progressive widespread obstructive arterial disease with cardiovascular (48%), neuro-ophthalmic (36%), and skin morbidity (13%). Systemic hypertension and heart disease were significant mortality predictors. Twenty-six percent of cases died due to myocardial infarction, chronic renal failure, stroke, or surgical complications. CONCLUSION: TA in Mexican Mestizos shows a clinical pattern similar to the one recognized in the Far East. Management strategies must be directed at reducing the identified mortality risk factors.

Phase I clinical trial in healthy adults of a nasal vaccine candidate containing recombinant hepatitis B surface and core antigens.

BACKGROUND: The nasal vaccine candidate (NASVAC), comprising hepatitis B virus (HBV) surface (HBsAg) and core antigens (HBcAg), has been shown to be highly immunogenic in animal models. METHODS: A phase I double-blinded, placebo-controlled randomized clinical trial was carried out in 19 healthy male adults with no serologic markers of immunity/infection to HBV. This study was aimed at exploring the safety and immunogenic profile of nasal co-administration of both HBV recombinant antigens. The trial was performed according to Good Clinical Practice guidelines. Participants ranged in age from 18 to 45 years and were randomly allocated to receive a mixture of 50 microg HBsAg and 50 microg HBcAg or 0.9% physiologic saline solution, as a placebo, via nasal spray in a five-dose schedule at 0, 7, 15, 30, and 60 days. A total volume of 0.5 ml was administered in two dosages of 125 microl per nostril. Adverse events were actively recorded 1 h, 6 h, 12 h, 24 h, 48 h, 72 h, 7 days and 30 days after each dose. Anti-HBs and anti-HBc titers were evaluated using corresponding ELISA kits at days 30 and 90. RESULTS: The vaccine candidate was safe and well tolerated. Adverse reactions included sneezing (34.1%), rhinorrhea (12.2%), nasal stuffiness (9.8%), palate itching (9.8%), headache (9.8%), and general malaise (7.3%). These reactions were all self-limiting and mild in intensity. No severe or unexpected events were recorded during the trial. The vaccine elicited anti-HBc seroconversion in 100% of subjects as early as day 30 of the immunization schedule, while a seroprotective anti-HBs titer (>or=10 IU/l) was at a maximum at day 90 (75%). All subjects in the placebo group remained seronegative during the trial. CONCLUSION: The HBsAg-HBcAg vaccine candidate was safe, well tolerated and immunogenic in this phase I study in healthy adults. To our knowledge, this is the first demonstration of safety and immunogenicity for a nasal vaccine candidate comprising HBV antigens.

Trypanocidal drugs for late stage, symptomatic Chagas disease (Trypanosoma cruzi infection).

BACKGROUND: People with Chagas disease (American Trypanosomiasis) may develop progressive and potentially lethal heart conditions. Drugs to eliminate the causative parasite, Trypanosoma cruzi, currently in use have limited therapeutic value and are used in early stages of the disease. Extending the use of these drugs to treat symptomatic chronic parasitism with chronic Chagasic cardiopathy (CCC) and progressive dilated cardiomyopathy has been proposed. OBJECTIVES: To assess the effects (harms and benefits) of nitrofurans and imidazolic trypanocidal drugs for treating late stage chronic Chagas disease and CCC. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 3, 2004), MEDLINE (1985-2004), EMBASE (1985-2004), BIREME (1985-2004), LILACS (1985-2004), ARTEMISA (1985-2004), SCIELO (1985-2004). Indexing terms in English and Spanish were used. References obtained were assessed for relevance by two reviewers independently. SELECTION CRITERIA: We included randomized controlled clinical trials (RCTs), single or double blind using trypanocidal drugs versus placebo or no treatment in CCC. DATA COLLECTION AND ANALYSIS: All articles retrieved were assessed using a predefined check list to determine if they met the inclusion criteria. Two independent reviewers collected data using a pre-designed form piloted on three articles before the review process started. Disagreements were resolved by a third reviewer. If the information was unavailable the articles were excluded. We planned a quantitative analysis of reduction of parasite load whether recorded as a categorical variable or the reduction of specific antibody titers. However insufficient data were available for quantitative analysis. We prepared a qualitative description of data identified. MAIN RESULTS: We found only one randomized double blind placebo controlled trial. We also found six uncontrolled or non-randomized studies which were of some relevance and were therefore described. We found insufficient evidence to define the effects of drug treatment for people with CCC. AUTHORS' CONCLUSIONS: There is insufficient evidence to support the efficacy of nitrofurans or imidazolic drugs as recommended treatment in CCC and chronic T.cruzi infections, specifically if overt heart disease is present. A well designed randomized controlled trial is necessary to establish if new drugs are suitable for treatment of cardiac patients with CCC.

Acute rheumatic fever.

The diagnosis of acute rheumatic fever has become difficult. A growing number of diseases that were not recognized in the past could fulfill its diagnostic criteria. We emphasize its changing incidence, current knowledge of its pathogenesis, and lesser known clinical features such as pneumonitis, encephalitis and glomerulonephritis.

Humoral nitric oxide levels and antibody immune response of symptomatic and indeterminate Chagas' disease patients to commercial and autochthonous Trypanosoma cruzi antigen.

We report here the evaluation of chagasic patients for the presence and/or severity of the disease, antibody to Trypanosoma cruzi, and nitric oxide (NO) serum levels. Serum samples tested by ELISA with autochthonous and commercial antigen revealed that 10% and 7.5% of the individuals were anti-T. cruzi antibody-positive, respectively. Ten of 21 seropositive individuals had no clinical signs, the other 11 cases presented cardiomyopathy and/or mega-gastrointestinal syndromes, and three patients presented a combined form. A statistical difference (P < 0.001) in antibody titer between asymptomatic and symptomatic patients with autochthonous antigen was detected, and serum NO levels was found to be three times higher in cases than in controls. These results suggest that it is recommended to use a sole source of antigen (autochthonous) for the serodiagnosis of Chagas' disease, and that the pathogenic role of NO in this disease should be evaluated.

Ionophoretic-like action of diflunisal.

It is shown that diflunisal, a derivative salicylic acid, causes uncoupling of oxidative phosphorylation owing to its property of carrying hydrogen ions through the inner mitochondrial membrane in such way that a short-circuit of protons is promoted. As a consequence of the above, the drug induces a decrease of the internal negative membrane potential and therefore the release of intramitochondrial calcium. In addition this report presents evidences that diflunisal behaves as a ionophore molecule since it induces cation extraction into an organic phase.

Takayasu's arteritis in Mexico: a clinical review of 44 consecutive cases.

OBJECTIVES: To review our experience in clinical diagnosis of the non-specific arteritis called Takayasu's arteritis (TA), and to assess its possible relationship with previous mycobacterial infections as judged by delayed hypersensitivity skin test. METHODS: We examined 44 consecutive patients in Mexico City. All of them fulfilled the ACR criteria for the classification of TA and had a characteristic panaortogram in the absence of any other arterial or systemic disease. RESULTS: Forty-three of our patients were Mexican mestizos; only one had a Caucasian appearance. 38 were women, and the age at diagnosis ranged from 15 to 64 years with a mean of 32 and a median of 35. Age at onset of the symptoms was under 30 years in most cases. Five patients had type I disease, and 4 had type II. Most had a diffuse arteritis (type III), and in seven cases involvement of the pulmonary artery (type IV) was recognized. All patients showed abnormal peripheral pulses and blood pressure differences, 35 had systemic arterial hypertension and 7 pulmonary hypertension. A noisy vascular auscultation was very common and cardiac ailments were also found in many cases. Systemic complaints such as fever, weight loss and malaise were present in the active stages of the disease. Arthritis did occur in a single case, arthralgia was frequent and inflammatory nodules involving the shin, perimalleolar area, and the antero-external surface of the distal leg were also common. Polyclonal hypergammaglobulinemia was a frequent finding in active and inactive cases; leukocytosis with neutrophilia, accelerated ESR and high fibrinogen, however, did occur when the disease was active. Eight of our patients had a previous diagnosis of tuberculosis, and 81% developed a delayed skin reactivity to PPD (2U old tuberculin). None had a bacteriologic diagnosis of tuberculosis or mycobacterial disease. CONCLUSION: Non-specific arteritis, or Takayasu's disease, frequently affects young women of colored race in Mexico. Late diagnosis is common and cardiovascular features dominate the clinical picture. Arterial compromise is widespread and may involve the pulmonary artery and its branches. Most cases are inactive and morbidity results from systemic arterial hypertension and heart disease; active cases have systemic complaints and laboratory abnormalities suggestive of ongoing inflammation. The close relationship between Takayasu's arteritis and previous contact with Mycobacterium tuberculosis was again confirmed in our series, although further studies are necessary to clarify this probable relationship.

Antiphospholipid syndrome in patients with cyanotic congenital heart disease.

Patients with cyanotic congenital heart disease exhibit an increased incidence of thrombotic episodes and are frequently thrombocytopenic. We studied the sera of 15 patients with this type of heart malformation, searching for anticardiolipin antibodies. 3/15 had positive results. The three of them were adult females; two had thrombotic episodes and a false positive VDRL. Thus, cyanotic congenital heart disease may be another disease entity associated with the antiphospholipid syndrome.

Gender impact in systemic lupus erythematosus.

OBJECTIVE: Systemic Lupus Erythematousus (SLE), an autoimmune disease of unknown etiology manifesting as a pleomorphic systemic disease, affects mostly females, (female:male ratio 9:1). Clinical differences between genders, including a higher death rate in males, has been reported. Here we compared clinical manifestations and the 5-year survival probability in Mexican male and female crossbred cases living under similar socioeconomic conditions. A systematic review of published literature was also carried out. MATERIAL AND METHODS: SLE patients treated at the Instituto Nacional de Cardiología "Ignacio Chávez" México City who fulfilled at least four classification criteria (ACR) were included. The frequency of clinical variables with emphasis on cardiovascular findings before and after the diagnosis were described, disease activity based on a validated scale (SLEDAI) was determined, and the 5-year survival rate was estimated. RESULTS: There were 33 men and 158 women, average age of 31 in both groups ranging from 7 to 65 and from 10 to 75 year in male and female patients respectively; both groups were followed for 3.8 years (median), average activity was of 12 points with a range of 5 to 23 in men, and 11 with a range of 2 to 24 in women. Main clinical characteristics in men were: discoid lupus, psychosis, pericarditis, lymphopenia, thrombocytopenia and SLE kidney disease. Immunological tests showed gender-linked differences in regard auto-antibodies (U1-nRNP, Sm, anticardiolipine and false VDRL) and hypocomplementemia. Cardiovascular features and survival rate were not different between gender. CONCLUSION: Male Mexican SLE patients share clinical findings with other male SLE cases reported everywhere as can be deducted from systematic literature review covering 25-year.

Immunologic studies in patients with Takayasu's arteritis. II. Effects of serum on lymphocyte functions in vitro.

Natural lymphocytotoxic antibodies, circulating immune complexes and their effect on in vitro blast transformation of normal cells were studied in 24 patients with Takayasu's arteritis. Sera with Takayasu's arteritis lacked lymphocytotoxic antibodies, had an inhibitory effect on the formation of EA and EAC rosettes and interfered with normal lymphocyte function in vitro. The absence of lymphocytotoxic antibodies, together with the other epidemiological and histocompatibility studies, would support the notion that Takayasu's arteritis and temporal arteritis are two distinct entities.

Immunogenetics and clinical aspects of Takayasu's arteritis patients in a Mexican Mestizo population.

OBJECTIVE: The aim of the present work was to study the association between HLA alleles and Takayasu's arteritis in Mexican Mestizo patients. METHODS: The study included 26 Mexican Mestizo patients with Takayasu's arteritis and 99 healthy unrelated individuals. HLA-A, -B and -DR alleles were determined by polymerase chain reaction PCR-SSP RESULTS: Increased gene frequencies were demonstrated for HLA-B15(p=0.009,pC=0.020,OR=3.24,EF=11.9%) and HLA-B52 (p=0.008, pC=0.027, OR=5.16, EF=7.7%), and a decreased frequency for the HLA-A24 allele in patients compared to normal controls (p=0.035, pC=NS, PF=11.1%). When HLA typing was correlated to clinicalfeatures in 24 cases, wefound an increasedfrequencies of HLA-DR14 in patients with systemic arterial hypertension (p=0.005, pC=0.004, OR=24.6, EF=38.3%) and HLA-A2 on patients with pulmonary involvement (p=0.034, pC=0.036, OR=3.67, EF=40.4%) when compared to patients without these clinical manifestations. CONCLUSION: These data confirm HLA-B52 as a relevant susceptibility allele for Takayasu's arteritis and suggest that HLA-B15 could be important as a marker of the disease in Mexican patients. Other class I and/or class II alleles could also be relevant as markers for the clinical features present in these patients.

Standardization of micro-enzyme-linked immunosorbent assay (ELISA) and Western blot for detection of Trypanosoma cruzi antibodies using extracts from Mexican strains as antigens.

BACKGROUND: This report describes two assays for the detection of anti-Trypanosoma cruzi antibodies using Mexican strains of the parasite and the concordance with two assays previously evaluated at the Instituto Nacional de Cardiología Ignacio Chávez in Mexico City. METHODS: Micro-enzyme-linked immunosorbent assay (ELISA) and Western blot were used for the detection of T. cruzi antibodies with a total extract of epimastigote from Ninoa and Queretaro, which are Mexican strains of T. cruzi. To standardize these methods, a total of 246 serum samples was used. In addition, sera from six confirmed Mexican chronic individuals in the asymptomatic phase were also used for comparison with the Argentinean antigen. RESULTS: ELISA was 100% specific in that no false positive results were found with sera of both healthy individuals and non-Chagasic cardiopaths. Sera from individuals infected with Leishmania sp. showed approximately 16% of cross-reaction with ELISA. The test showed a positive predictive value of 90% and a negative predictive value of 100%. Western blot was also a highly sensitive test for detecting chronic Chagasic symptomatic patients from Mexico because no false negative results were obtained. Furthermore, it was possible to use Western blot to detect seven immunodominant antigens of approximately 30, 32, 40, 42, 65, 70, and 83 kDa. Concordance with two previous standardized tests at the Instituto Nacional de Cardiología showed a Kappa index of 0.96, indicating high concordance between the results obtained at these two laboratories. Finally, ELISA using Ninoa antigen extract was more sensitive than ELISA with an Argentinean extract, which failed to detect individuals in the chronic asymptomatic phase (undetermined phase) of infection. CONCLUSIONS: This study indicates that ELISA and Western blot using Ninoa and/or Queretaro extracts of T. cruzi as antigens are useful tools in the detection of individuals who have been exposed to T. cruzi both in the undetermined/asymptomatic and symptomatic phases. More concordance studies such as this are recommended to obtain an accurate Chagas diagnostic test and to determine the real prevalence of this disease in Mexico.

Molecular analysis of snRNAs and scRNAs using autoantibodies from patients with systemic lupus erythematosus.

Immunoprecipitation analysis of total HeLa cells RNA extract by protein A-Sheparose purified autoantibodies and pCp 32P-3' end labeling RNAs revealed that U1, U2, U4 and U5 snRNAs are related with anti-Sm or U1nRNP autoantibodies, while the hY1, hY3, hY4 and hY5 scRNAs were related to anti-SSA/Ro autoantibodies present in sera of patients with Systemic Lupus Erythematosus. The authors detected molecular snRNAs and scRNAs specificities by autoantibodies in 71 sera, the molecular RNA specificity for anti-Sm (U1, U2, U4 and U5 snRNAs) was present in 39%; anti-SSA/Ro sera reacted against scRNAs (hY1, hY3, hY4 and hY5) in 36%, then anti-U1nRNP sera recognized U1 snRNA in 13% of sera and anti-rRNP related with rRNA were recognized in 8%. Twenty-nine SLE sera were RNA negative. A molecular characterization of the autoantibodies in sera from SLE patients may be a useful tool for clinical and laboratory diagnosis of SLE, and the use of autoantibodies as molecular probes allows to continue exploring some basic mechanism of gene expression.

Persistence of Trypanosoma cruzi in chronic chagasic cardiopathy patients.

BACKGROUND: Although patients with chronic chagasic cardiopathy do have a strong immune response against Trypanosoma cruzi, they have transient and low parasitemia as well as tissue amastigote nests. When conventional studies were carried out, demonstration of such abnormalities is minimally achieved. Molecular biology may provide the best tools to demonstrate parasite persistence, which could be pathogenic in this progressive disease. METHODS: We studied 16 patients with chronic chagasic cardiopathy (CCC) at the Instituto Nacional de Cardiología Ignacio Chávez in Mexico City. Patients had undergone a complete clinical evaluation, and had antibodies against Trypanosoma cruzi. They came from different rural areas in Mexico. Blood samples were obtained and processed for hemoculture and PCR technique. A CCC necropsy case was also sought for the presence of parasite antigen or DNA, using immunohistochemistry and PCR methods in archival tissues. RESULTS: Five of 16 (31%) hemocultures demonstrated circulating T. cruzi; 60% occurred in persons between 25 and 40 years old. In contrast, we found a positive PCR amplification in 81%; therefore, molecular biology tools appear to be more sensitive for demonstrating parasite persistence. There were no correlations between parasitemic state and clinical findings or specific antibody titer. The autopsy case had parasite antigens and DNA in heart tissues. CONCLUSIONS: Chronic chagasic cardiopathy patients do have persistence of parasite even when parasitemia is low or absent. The continuous presence of a parasite load could maintain immune stimulus and perhaps enhance a pathogenic immune or autoimmune tissue damage in susceptible hosts.

Takayasu arteritis in Mexico: a 38-year clinical perspective through literature review.

A literature search covering national reports since the first published in Mexico (1957), discloses 237 adults and 55 children with a definitive diagnosis of Takayasu's arteritis. This condition was first recognized by an ophtalmologist in 1946, and it was communicated 10 years after his observation. Since 1957, 11 clinical papers on Takayasu's arteritis had been published in Mexico and abroad; in contrast few papers were published in other Latinamerican countries and even in North America. Takayasu's arteritis in Mexico follows the clinical pattern described in Asian reports, it affects mainly non-caucasic young women, is a chronic disease which causes prominent cardiovascular complaints. Children developed a systemic disease with higher morbility and mortality. Uncommon diseases, such as Takayasu's arteritis represent an unique opportunity to compare clinical and biological profile among different populations to gain valuable knowledge and understanding of ethiopathogenesis.

Antiaorta antibodies and Takayasu arteritis.

A search for antibodies reactive against a total human aorta extract and its main protein components such as elastin, fibronectin and collagen was attempted by electroimmunetransference and ELISA. Thirty five sera from clinically and angiographically proven diagnosis of Takayasu Arteritis patients were compared with 32 sera from people without abnormalities. Non specific binding was found on electroimmune transference and no difference was shown in optical density readings in ELISA, therefore, we did not demonstrate the presence of antiaorta specific antibodies in this vasculitic condition. Our findings are in agreement with several authors, the contribution of humoral immunity to pathogenesis of Takayasu Arteritis has not been proved yet.

Absence of antiphospholipid/co-factor antibodies in Takayasu arteritis.

UNLABELLED: There are anecdotal reports and small series describing the presence of anticardiolipin antibodies in patients with Takayasu Arteritis. This communication describes a systematic study searching for non-organ specific autoantibodies which includes antinuclear antibodies, anticardiolipin and anti-beta(2) GP(1) antibodies in a cohort of 28 Mexicans with angiographic definitive diagnostic of Takayasu Arteritis. MATERIAL AND METHODS: Twenty-eight consecutive patients, who fulfilled classification and diagnostic criteria for Takayasu Arteritis and had a diagnostic panaortogram, were bled to study the presence of circulating autoantibodies in a cross-sectional design. RESULTS: There were no antinuclear antibodies, although a few sera had faint cytoplasm fluorescent deposit and reacted with cell extract. We did not recognize a distinct pattern. Also, there was no IgG nor IgM anticardiolipin antibodies nor anticofactor antibodies of clinical interest. DISCUSSION AND CONCLUSIONS: The presence of circulating non-organ specific autoantibodies is not a characteristic feature in Takayasu Arteritis when strict diagnostic criteria are applied. The occasional presence of such immune markers could be due to technical differences in sample management, less strict diagnosis or biological variability in certain cases, but has no diagnostic value.

Antinuclear antibodies in scleroderma, mixed connective tissue disease and "primary" Raynaud's phenomenon.

The diversity of antibodies in patients with scleroderma, mixed connective tissue disease or "primary" Raynaud's phenomenon could be used as a laboratory aid in the clinical diagnosis. In serum samples of 75 patients we screened for antinuclear antibodies (HEp 2 cells), anti DNA, soluble nucleoprotein and extractable nuclear antigens (Sm, rRNP, U1-nRNP, SSA/Ro, SSB/La and Scl-70). Distinctive antinuclear antibodies pattern was identified in each group of patients. This immunologic profile is valuable for clinical diagnosis and the preferential association of certain autoantibodies with some diseases and not with others, suggest an antigen-driven stimulus for its production.