[Chagasic cardiopathy in Tehuantepec. Preliminary report]. / Cardiopatía chagásica en Tehuantepec. Informe preliminar.

UNLABELLED: American trypanosomosis was described in the state of Oaxaca, Mexico in 1936, and is probably endemic in rural areas. However, there is no information regarding chronic disease in the Isthmus of Tehuantepec, previous to this report. OBJECTIVE: To identify the prevalence of American trypanosomosis and its consequences, such as the chronic chagas cardiomyopathy (CCC) among patients who were evaluated by the cardiology service in two general hospitals in Salina Cruz in the state of Oaxaca which is the main city of the Tehuantepec Region. MATERIAL AND METHODS: Consecutive patients referred to the two cardiology services were identified as primary dilated myocardiopathy after a complete clinical and epidemiological history, chest roengentgram, EKG and echocardiogram. Blood was obtained through venipuncture and samples were studied for anti-Trypanosoma cruzi antibodies using validated indirect immunofluorescence, ELISA and Western blot assays. RESULTS: Over a two period in which 540 cardiologic patients were examined, 16 (2.4% cases) of primary dilated cardiomyopathy were diagnosed and 13 (81%) of these were seropositive for anti-T. cruzi and therefore, fulfilled epidemiological and clinical criteria for chronic chagasic cardiomyopathy (CCC). CONCLUSIONS: American trypanosomosis and CCC were diagnosed in cases of dilated cardiomyopathy within a geographical area where, there is an important distribution of triatomine bugs infected and Trypanosoma cruzi. Infection caused a progressive heart disease in this population exposed to insect vectors due to poor housing and sanitary conditions. The present study points out the need for further epidemiological studies in the Tehuantepec region.

American trypanosomiasis (Chagas' disease) and blood banking in Mexico City: seroprevalence and its potential transfusional transmission risk.

BACKGROUND: American trypanosomiasis (Chagas' disease), an anthropozoonosis fairly common in rural Latin America, has become an urban disease due to continuous migration, intra- and internationally. Blood transfusion, the second important pathway for transmission, increases its impact. Recognition of seropositive subjects among blood donors is now recommended, and clinical and serological screening enforced. Maneuvers to inactivate or remove Trypanosoma cruzi present in collected blood are recommended. METHODS: We surveyed voluntary donors at the National Institute of Cardiology in Mexico City in search of anti-T. cruzi by indirect immunofluorescence, ELISA, and Western blot analysis. Seropositive donors were identified and tested for immunoglobulin. We used types and fractions of donated blood to extract DNA and perform the PCR technique using kinetoplast primers seeking parasite DNA in blood. RESULTS: After 3,300 donors were screened, we identified 10 seropositive subjects (0.3%). These subjects were considered as indeterminate chagasic patients, came mainly from rural areas, and had IgG (100%) and IgA (30%) antibodies against a crude extract as well as a recombinant T. cruzi antigen. Identification of parasite DNA in red cell and platelet fraction was achieved from eight blood units. CONCLUSIONS: The present data provide evidence that blood donors at an urban hospital are seropositive for T. cruzi and at least 50% of donors carry the parasite potentially able to transmit T. cruzi in their cellular blood products. Serological screening should be included in routine blood-making. It is also necessary to adopt measures to inactivate or eliminate organisms in donated blood.

[Vector electrocardiographic findings in chronic Chagas cardiomyopathy]. / Hallazgos electrovectocardiográficos en la miocardiopatía chagásica crónica.

Dilated Cardiomyopathy (DCM) is associated with many diseases. By means of epidemiologic, clinical and invasive diagnostic techniques, the etiology of DCM is identified almost in 50% of the cases. Chronic infection with Trypanosoma cruzi is recognized as a cause of DCM in Latin America. A blind study of 40 cases of DCM explores the electrovectorcardiographic data obtained in chronic chagasic cardiomyopathy (CCC). Twenty one of 40 patients fulfilled epidemiologic and seroimmunologic criteria for CCC, 19 had DCM. There were not differences between these groups in regard to sex or age. Patients suffering DCM had in addition diabetes mellitus, systemic hypertension or ischemic heart disease. Those with CCC had not comorbid diseases in 50% of the cases. Arrhythmias and conduction blocks were equally recognized in both groups, as well as ECG evidence of injury or necrosis (p > 0.05). However, ECG signs of subepicardial ischemia were a dominant feature in patients with CCC and normal epicardial coronary arteries (p < 0.05). Probably this finding is due to a small vessels damage, a pathogenic mechanism proposed in CCC.

Intron 2 and exon 3 sequences may be involved in the susceptibility to develop Takayasu arteritis.

We studied Major Histocompatibility Complex (MHC) Class I and Class II genes in seven Mexican Mestizo patients with Takayasu arteritis. Takayasu arteritis is an uncommon condition in Mexican Mestizo, however, previous studies report association of the disease in this population with Human Leukocyte Antigen (HLA)-B39 and HLA-DRB1*1301. The results in the present study show that the haplotypes of the Mexican Mestizo patients with Takayasu arteritis are very heterogeneous, even when the disease is much more rare in Mexico than in Japan. The sequence analysis of HLA-B39 shows that Mexican patients exhibit the HLA-B*39061 and HLA-B*39062 subtypes. These subtypes are more common in Mexico than in Japan, where the predominant subtype is HLA-B*3901. Interestingly, HLA-B*39061 and B-39062 share the 3' end of intron 2 and the 5' end of exon 3 with HLA-B*5101 and B*52012, alleles associated to Takayasu arteritis in Japanese. This fact suggests that Takayasu arteritis patients may share a specific sequence rather than a specific allele, even when the gene involved in the susceptibility to develop Takayasu arteritis may be a neighboring gene located between the genes related at present time with the disease, i.e. a gene located between MHC Class I and Class II regions.

Circulating lymphocyte subpopulations and activated T and B cells in patients with chagasic and non-chagasic myocardiopathy.

Trypanosoma cruzi causes a profound immune depression in the infected host, and a small proportion of chagasic patients will develop a chronic disease characterized by myocardiopathy. There is evidence suggesting that dilated non-chagasic cardiomyopathy may be mediated by an immunological mechanism. In an attempt to distinguish abnormal immunoregulatory cell patterns in both dilated myocardiopathies, total and activated T and B lymphocyte subpopulations were measured by flow cytometry and double-labeling in whole blood samples from patients with dilated myocardiopathy, 10 with positive serological tests for T. cruzi and 9 with different non-chagasic cardiomyopathies. Several significant differences were found between both groups of patients and 13 sex- and age-matched apparently healthy controls. Chagasic patients besides showing clear decrease in absolute numbers of CD3+/CD71+ and CD8+/CD25+ cell populations also had a significant increase in CD19+, CD10+, and CD19+/HLA-DR+ cell subsets, as well as high helper/ suppressor cell ratio. These findings suggest that concurrently with T cell diminution, which involved activated T lymphocytes displaying suppressor/cytotoxic immunophenotype, chronic chagasic patients with myocardiopathy showed elevated numbers of total and activated B lymphocytes. Patients with dilated non-chagasic myocardiopathy had significantly increased numbers of activated T cells (CD3+/CD25+, CD8+/CD25+, and CD8+/HLA-DR+) and total and activated B lymphocytes (CD10+, CD19+, CD19+HLA-DR+). These data support the notion that dilated myocardiopathies other than the chagasics may be associated with immunological abnormalities.

Chronic chagasic cardiopathy with parasitemic state (preliminary report).

Seven patients with diagnosis of dilated myocardiopathy, who fulfilled epidemiological, clinical, and serological criteria for chronic American Trypanosomosis, were submitted to hemoculture. Parasites were isolated in two patients (29%) confirming diagnosis and indicating an infection. Antibody titers did not show any relationship with the presence or absence of parasitemia nor were clinical differences noticed. Isolated Trypanosoma cruzi parasites belonged to biodeme III.

[Detection of Trypanosoma cruzi in experimental samples by the DNA polymerase chain reaction method]. / Detección de Trypanosoma cruzi en muestras experimentales por el método de reacción en cadena de la ADN polimerasa.

Chagas' disease (American Trypanosomiasis) affects more than 20 million people in Latin America. Almost 30% of those people may develop a chronic disease, which is expressed mainly as a chronic chagasic cardiopathy (CCC). Recent studies in Mexico have shown that 40% of patients suffering dilated cardiomyopathy do have serum antibodies against Trypanosoma cruzi. It is well known the difficulties of parasitologic diagnosis of CCC, which in less extent does exist for serologic diagnosis. Here we report a diagnostic method based on a molecular approach. It is able to recognize parasite DNA, and may have a clinical application. Two oligonucleotides (KNS1 and KNS2) designed from kinetoplast minicircle DNA, were used to amplify the hypervariable region by PCR technology. The method allowed an amplification of 0.8 to 1.5 minicircle DNA molecules, which equals 1/12,000 of parasite. When tissue DNA samples from mice infected with T. cruzi were subjected to amplification, a product was obtained that was recognized by a DNA probe specific for minicircle. These results correlate with immunohistochemical studies showing tissular parasites. Molecular diagnosis of American Trypanosomiasis, could be applied in human studies.

[Detection of antibodies against Trypanosoma cruzi in blood donors]. / Detección de anticuerpos contra Trypanosoma cruzi en donadores de sangre.

American trypanosomiasis is an endemic disease in Mexico. Blood transfusion has been recognized as the second main mechanism of transmission in South American countries. There is no definitive information available for Mexico. We obtained the prevalence of IgG antibodies against Trypanosoma cruzi among 1076 blood donors at the Instituto Nacional de Cardiología "Ignacio Chávez" in Mexico City. We used an antigen freshly prepared from local isolates, and the complete and soluble antigen preparations were analyzed with the Western blot technique using sera previously characterized as reactive. Blood donors' antibodies were studied with DOT-ELISA and Western blot. All donors were asked in regard to place of birth, and blood samples were serologically tested as usual in transfusion practice. The presence of IgG antibodies to T. cruzi, confirmed with a high-specificity test, showed a prevalence of 0.28 per cent. Screening for antibodies to T. cruzi; should be included in the evaluation of blood donors in Mexico.

[Mechanisms of innate and acquired resistance to Trypanosoma cruzicruzi]. / Mecanismos de resistencia innata y adquirida al Tripanosoma cruzi.

Defense mechanisms against the parasite Trypanosoma cruzi, the etiologic agent for dilated myocardiopathy and Chagas disease are reviewed, in vitro studies and experimental models are described and commented. Applying new techniques derived from Molecular Biology for the study of Chagas disease, both at experimental and clinical level could be rewarding and maybe useful to design effective treatment for this irreversible heart disease in humans.

[Infectious endocarditis caused by Staphylococcus. Study at the Ignacio Chavez National Institute of Cardiology 1977-1987]. / Endocarditis infecciosa por estafilococo. Estudio en el Instituto Nacional de Cardiología I. Chavez 1977-1987.

This is a descriptive survey of infectious endocarditis (EI) due to Staphylococci, collected at the Instituto Nacional de Cardiología "Ignacio Chávez", in a ten years period. All had anatomical and bacteriological diagnosis. There were 21 cases, this disease in not rare, and both coagulase-positive or negative Staphylococci were represented in similar proportion as etiologic agents. Coagulase positive organisms produce a clinical picture of septicemia and systemic boxicity, therefore early diagnosis and prompt therapy is forthcoming. Instead coagulase negative EI cause an insidious illness with late diagnosis, focal intramyocardial abscesses and low responsiveness to therapy explain the poor prognosis. It is impossible to differentiate with our present resources between Staphylococcal bacteremia and EI. We recommend, combined antimicrobial therapy and if necessary early surgical treatment.

Immunologic studies in patients with Takayasu's arteritis. III. Immunoregulatory changes.

Study of cellular immune function in 14 patients with Takayasu's arteritis (TKA) revealed markedly decreased active E rosettes and CD4+ cells and slightly diminished CD8 + and autologous rosette-forming T cells. They were also found to have decreased production of interleukin-2 and decreased response to interleukin-1. Patients with active disease were also found to have decreased response to IL-2. Conversely, patients with inactive disease were found to have a normal response to interleukin-2. Patients with TKA, whether active or inactive, had normal production of interleukin-1, normal concanavalin-A-induced and spontaneously expanded suppression, normal NK cell function and normal enhancement of NK cell function by interleukin 2. The findings indicate that the immunoregulatory disturbance of TKA is different from that occurring in connective tissue disorders.

[Etiology of infectious endocarditis at the Instituto Nacional de Cardiologia Ignacio Chavez from 1976 to 1986]. / La etiologia de la endocarditis infecciosa en el Instituto Nacional de Cardiologia "Ignacio Chavez" 1976-1986.

We studied 85 cases of infectious endocarditis (IE) with an anatomical diagnosis (biopsy or necropsy). Most cases occur between the second and fourth decade of life; male/female ratio was 1/0.8; 45 had IE in a natural valve; 40 had prosthetic IE. Clinical diagnosis was established or at least suspected in 61 cases (72%); the most common misdiagnosis was acute rheumatic fever. Blood cultures were positive in 25 cases of natural valve IE (56%) and in 25 cases of prosthetic IE (63%). Half of those negative culture cases had a history of antimicrobial use before their arrival at the hospital. Those microorganisms which cause natural valve IE were: staphylococci (9), streptococci (8), Gram negatives (5), Candida sp (1), and two non-identified cases; 1 patient had a polymicrobial infection. Prosthetic IE was divided into early and late infections. The former was due to: staphylococci (4), streptococci (1), Candida sp (1); the latter: staphylococci (7), streptococci (4), Gram negatives (4), Candida sp, Mycobacterium fortuitum and Peptococcus (1 each), and in a single case Lactobacillus sp, presumably a contaminant.

[The heart in systemic lupus erythematosus. Study in 32 non-selected patients (author's transl)]. / El corazón en el lupus eritematoso sistémico. Estudio en 32 pacientes no sistémico.

Cardiovascular manifestations of Systemic Lupus Erythematosus (SLE) in 32 unselected patients, with active disease were reviewed. Primary cardiac disease manifested as pericarditis (22%), myocarditis (16%), and valvular disease (9%), was recognized along with secondary disease as heart failure with or without systemic hypertension. Comparison with previous work by others, suggest that our cases are more representative of actual clinical picture of cardiac SLE. It is interesting to notice tht 9% of our patients had valvular disease, and this alteration is only occasionally found in other Hospitals. Valvular disease is rarely noticed during life, although is highly prevalent in autopsy series. We stress the diagnosis and management of the cardiac manifestations of SLE, in order to lower the morbidity and mortality of this condition.

[Immunologic studies in Takayasu's arteritis. I. Circulating antibodies to mycobacterial products and circulating immune complexes]. / Estudios inmunológicos en la arteritis de Takayasu. I. Anticuerpos circulantes a productos de micobacterias y complejos inmunes circulantes.

Takayasu's arteritis (TA) is an arteriopathy of unknown origin that affects young women preferentially and shows a characteristic geographical distribution. Previous reports suggested immune related pathogenesis and certain relationship with mycobacterial infections. Therefore we look for humoral antibodies against four different mycobacterial products as well as for immune complexes which react with human Clq, in 24 patients suffering TA in chronic inactive phase (22) and with relapsing erythema nodosum (2). No single case showed circulating immune complexes and only 3 (12.4%) had antimycobacterial antibodies, including a young female with relapsing erythema nodosum. The presence of immunopathogenic mechanisms in chronic TA is not supported in this work. Further studies using different approaches are now in progress.