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Biomedical subjects

M B Santiago

Publications and source records attributed to M B Santiago.

At least 19 recordsLinked to original sources

Neonatal antiphospholipid syndrome.

Antiphospholipid syndrome (APS) is a clinical entity characterized by arterial and venous thrombosis, adverse obstetric outcome and the presence of antibodies against phospholipids in serum or plasma. The objective of the present study is to describe a rare case of APS that occurred in a neonate born from a patient previously diagnosed as primary APS. A male, preterm born twin infant, whose mother had been diagnosed as primary APS, developed thrombocytopenia, livedo reticularis, pericardial effusion and thrombosis of the left subclavian and external jugular veins concomitantly with severe respiratory tract infection soon after his delivery, that culminated with his death two months after the birth, in spite of the large spectrum antibiotic therapy and all supportive measures. Laboratory findings included high titers of IgM anticardiolipin antibodies and moderate titers of IgG isotype and negative antinuclear antibody, configuring a case of neonatal APS. Neonatal APS is a rare clinical condition, with only a few cases described in the literature. Its occurrence may depend on the passage of antibodies through the placenta or, as it seems to have occurred in the present case, by the production of de novo antibodies by the fetus. The present case illustrates the necessity of a higher surveillance of the neonates born from mothers with primary APS or systemic lupus erythematosus (SLE) for the eventual development of such complication.

Adult↗

An improved anti-C3/IgG ELISA for quantification of soluble immune complexes.

A semi-quantitative ELISA for complement-fixing, IgG-containing immune complexes (IC) is described. The assay is based on the insolubilization of IC by polyethyleneglycol, their capture by solid-phase anti-C3 antibodies, reaction with peroxidase-labeled anti-IgG antibodies and incubation with a chromogenic peroxidase substrate. It was markedly improved by the use of a single-step procedure which simultaneously washed and precipitated the insolubilized immune complexes. Intra-assay and inter-assay coefficients of variation were lower than 8.6 and 14.7%, respectively. As expected, higher levels of circulating immune complexes, in relation to healthy individuals, were found in patients with American visceral leishmaniasis (AVL), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), with prevalences comparable to those described in the literature. The ELISA can be quickly assembled from reagents and plasticware widely available commercially, detects immune complexes fulfilling three different criteria and is more sensitive than a previously published method based on the same principles (detection limit for complement-sensitized aggregated IgG of 2 microg ml(-1) as compared with a detection limit above 16 microg ml(-1)).

Antigen-Antibody Complex↗

[Weight for height of Chilean school children according to age and puberal development].

In a sample of 6371 school age children, aged 9 to 15 years, representative of four Regions of Chile (II,V,IX, and XIII) weight for stature was evaluated, acocording to age and puberal stages of Tanner. The averages and medians of weight for stature between 130 at 170 cm for men and between 130 and 163cm for females are presented. Higher weight for height whith age and puberal stages was found in both sexes, but differences were not always significants. A very low correlation between weight, and chronologic age and low between weight and puberal status was observed. This was reflected for higher differences of weight in the successive puberal stages than in successive ages. We conclude that the puberal development rahter than chronologic age, must be use for a better nutritional evaluation of adolescents. Nevertheless, other parameters with better distribution in puberal poblation, must be considered.

Adolescent↗

Complement activation by anticardiolipin antibodies.

A haemolytic assay was used to test the complement fixation ability of 16 serum samples with high concentrations of anti-cardiolipin antibodies. Fourteen patients had clinical complications usually associated with these antibodies--namely, recurrent abortions, thrombosis, or thrombocytopenia. Complement fixation by anticardiolipin antibodies was shown in only four of these patients and was not directly related to the antibody concentration. Because anticardiolipin antibodies in most of these patients did not activate the complement pathway it is unlikely that the complement cascade has an important role in the clinical complications associated with these antibodies.

Abortion, Habitual↗

Neuropsychiatric manifestations of systemic lupus erythematosus: the value of anticardiolipin, antigangliosides and antigalactocerebrosides antibodies.

In an attempt to find a serological marker for neuropsychiatric manifestations (NPM) of SLE, sera from 66 patients (classified in three groups, according to their NPM-defined, probable and without NPM) were analysed by ELISA for IgG and IgM anticardiolipin, antigangliosides and antigalactocerebrosides antibodies. A strong correlation was found between IgM antigangliosides and antigalactocerebrosides antibodies and NPM, but not with IgG class. IgM and IgG antibodies anticardiolipin were not correlated with NPM in this study. Both IgM antigangliosides and antigalactocerebrosides antibodies disappeared in seven patients with definite but clinically inactive NPM. The analysis of these autoantibodies showed an important role predictive for NPM in SLE; the negative test decreases the chance of the NPM.

Antibodies↗

Antiphospholipid antibodies in syphilis.

1. An enzyme-linked immunosorbent assay was used to determine the phospholipid specificity of antibodies present in sera from 35 syphilis patients. 2. Based on the cross-reaction obtained against a mixture of cardiolipin, phosphatidylcholine and cholesterol that is standard for flocculation tests according to the Venereal Disease Research Laboratory (CECON, São Paulo, Brazil), all 35 patients tested positive for antibodies of the IgG class whereas 13 (37%) also had IgM antibodies for the same mixture of lipids. IgG antibodies to cardiolipin were demonstrated in 2 patients (6%) and IgM antibodies in 5 (15%). Significant levels of IgG anti-phosphatidylcholine were detected in 3 patients (9%) and IgM antibodies in 4 (11%). IgG anti-phosphatidylethanolamine antibodies were found in 1 patient (3%) and IgM antibodies in 3 (9%). Antibody binding to cardiolipin plus cholesterol or cardiolipin plus phosphatidylcholine was as effective as when the standard mixture of all 3 lipids was used. 3. A comparison with serum from systemic lupus erythematosus patients and inhibition studies using liposomes of cardiolipin or the mixture of 3 lipids suggests that there are at least 3 groups of anticardiolipin antibodies.

Antibodies, Anti-Idiotypic↗

Anticardiolipin antibodies in patients with infectious diseases.

IgG or IgM anticardiolipin antibodies were present in the sera of 67% of 33 patients with Hansen's disease, in 53% of 30 patients with tuberculosis and in 50% of 16 patients with endocarditis. Despite the high frequency of these antibodies, no patient had a history of thrombosis or abortion. Anti-denatured DNA antibodies were tested in patients with tuberculosis and patients with Hansen's disease. Only in the latter group did we observe a statistically significant association between anticardiolipin and anti-denatured DNA antibodies. Anticardiolipin binding activity, however, could not be inhibited by preincubation of sera with a variable concentration of denatured DNA. These data suggest that: a) Anticardiolipin antibodies in infectious diseases do not necessarily participate in the pathogenesis of thrombotic or obstetric complications; b) Anti-denatured DNA and anticardiolipin antibodies in the population studied do not have a cross-reaction.

Adolescent↗

Spinal cord compression by ectopic calcinosis in scleroderma.

Systemic sclerosis (SS) is a chronic, multisystemic disease, characterized by inflammation associated with fibrosis. Calcinosis is one of the manifestations of this disorder, observed in 10 to 20% of cases. It is usually located on the extensor surface of the phalanges, peri-articular tissue and near the bone prominences. There are only a few cases reported of SS with vertebral column involvement and spinal cord compression by calcinosis causing serious neurological complications. We describe a fatal case of SS who showed tetraplegia secondary to ectopic calcinosis in the cervical medulla and present a review of the literature on the subject.

Calcinosis↗

Anticardiolipin antibodies and disease activity in systemic lupus erythematosus.

We studied a group of 80 unselected patients with systemic lupus erythematosus (SLE). Twenty six (32.5%) of them were considered in clinical activity using criteria based on clinical features and laboratory abnormalities. Using an isotype specific enzyme linked immunosorbent assay (ELISA) for anticardiolipin antibodies we found IgG anticardiolipin in 28/80 (35%) and IgM anticardiolipin in 20/80 (25%) patients. Antibodies to native DNA by immunofluorescence were found in 11/80 (14%) patients, whereas antibodies to denatured DNA by ELISA were found in 51/80 (64%) patients. There was an association between disease activity and the presence of anticardiolipin and anti-DNA antibodies particularly of the IgG isotype. We also found an association between anticardiolipin and anti-DNA suggesting a cross reaction between these antibodies, but we are not able to exclude the possibility of a simple coincidental phenomenon due to polyclonal synthesis of immunoglobulin observed during periods of disease activity.

Adolescent↗

[Clinical and biochemical characterization of isoniazid-induced auto-antibodies].

Isoniazid (INH) is one among many drugs capable of inducing autoantibodies and, in some cases, a lupus-like syndrome (LE). A longitudinal study was performed in 24 tuberculosis patients treated with INH to detect antibodies (A-AH) to total histones and fractions. Antinuclear antibodies were observed in two patients after treatment. Higher frequency of IgM-AH was also observed. IgM-AH binding to all fractions were observed in those serum samples exhibiting stronger ELISA reactivity. Conversely, binding to only H1 occurred when lower IgM-AH activity was tested. Correlations with clinical expressions of LE were not observed in the present study.

Adolescent↗

Association of anti-DNA and anticardiolipin antibodies in systemic lupus erythematosus.

Recent studies have shown that anti-DNA and anticardiolipin antibodies in patients with SLE may cross-react. Using an ELISA for determination of these antibodies, a strong association between IgG anti-denatured DNA and IgG anticardiolipin antibodies was found. Eight sera samples with the highest levels of both antibodies were selected to determine the possibility of a cross-reaction. The levels of anticardiolipin were not affected by denatured DNA in concentrations adequate to inhibit the anti-DNA binding. These data did not confirm previous studies using monoclonal antibodies showing cross reactivity between the two groups of antibodies. Nevertheless, a population of antibodies that may cross-reacts, in some special cases, cannot be ruled out.

Antibodies, Antinuclear↗