Prevalencia de anticuerpos anti envoltura nuclear y sus isotipos en sueros positivos para anticuerpos antinucleares / Prevalence of antinuclear envelope antibodies and their isotypes in sera positive for antinuclear antibodies

Antinuclear antibodies detected in HEp-2 cells by indirect immunofluorescence assay display a great variety of images, including the nuclear envelope pattern. This is quite a less frequent finding. Two thousand five hundred and ninety-four sera were processed, and 37.6% of ANA were detected. The prevalence of anti-nuclear envelope antibodies (ANEA) was of 1.2%, with a high association with autoimmune liver diseases (83%) and a low association with systemic lupus erythematosus. In 21 sera of patients with ANEA, no anti-DNAn antibodies were found; but 28.6% of anti-smooth muscle antibodies and 19% of anti-mitochondrial antibodies were detected. The triple rodent tissue section proved to be a less sensitive substrate than HEp-2 for the detection of ANEA. When using conjugates against different isotypes of antibodies for the detection of ANA, 90.5% of IgG, 66.6% of IgA and 9.5% of IgM. Two patients had ANEA-IgA at high titers (> or = 1:160) without ANEA-IgG. In this work, the importance of performing complementary tests for the detection of anti-smooth muscle antibodies, anti-mitochondrial antibodies and anti-DNAn is highlighted in order to apply these tests as guidelines for the clinical diagnosis of patients with ANEA. Besides, this study expresses the need of using total anti-Ig antibodies as conjugate for IIF-HEp-2 instead of anti-lgG; until the role of IgA antibodies in these autoimmune diseases is clarified.

Prevalencia de anticuerpos anti envoltura nuclear y sus isotipos en sueros positivos para anticuerpos antinucleares / Prevalence of antinuclear envelope antibodies and their isotypes in sera positive for antinuclear antibodies

Antinuclear antibodies detected in HEp-2 cells by indirect immunofluorescence assay display a great variety of images, including the nuclear envelope pattern. This is quite a less frequent finding. Two thousand five hundred and ninety-four sera were processed, and 37.6% of ANA were detected. The prevalence of anti-nuclear envelope antibodies (ANEA) was of 1.2%, with a high association with autoimmune liver diseases (83%) and a low association with systemic lupus erythematosus. In 21 sera of patients with ANEA, no anti-DNAn antibodies were found; but 28.6% of anti-smooth muscle antibodies and 19% of anti-mitochondrial antibodies were detected. The triple rodent tissue section proved to be a less sensitive substrate than HEp-2 for the detection of ANEA. When using conjugates against different isotypes of antibodies for the detection of ANA, 90.5% of IgG, 66.6% of IgA and 9.5% of IgM. Two patients had ANEA-IgA at high titers (> or = 1:160) without ANEA-IgG. In this work, the importance of performing complementary tests for the detection of anti-smooth muscle antibodies, anti-mitochondrial antibodies and anti-DNAn is highlighted in order to apply these tests as guidelines for the clinical diagnosis of patients with ANEA. Besides, this study expresses the need of using total anti-Ig antibodies as conjugate for IIF-HEp-2 instead of anti-lgG; until the role of IgA antibodies in these autoimmune diseases is clarified.(AU)

Prevalencia de anticuerpos anti envoltura nuclear y sus isotipos en sueros positivos para anticuerpos antinucleares / Prevalence of antinuclear envelope antibodies and their isotypes in sera positive for antinuclear antibodies

Antinuclear antibodies detected in HEp-2 cells by indirect immunofluorescence assay display a great variety of images, including the nuclear envelope pattern. This is quite a less frequent finding. Two thousand five hundred and ninety-four sera were processed, and 37.6% of ANA were detected. The prevalence of anti-nuclear envelope antibodies (ANEA) was of 1.2%, with a high association with autoimmune liver diseases (83%) and a low association with systemic lupus erythematosus. In 21 sera of patients with ANEA, no anti-DNAn antibodies were found; but 28.6% of anti-smooth muscle antibodies and 19% of anti-mitochondrial antibodies were detected. The triple rodent tissue section proved to be a less sensitive substrate than HEp-2 for the detection of ANEA. When using conjugates against different isotypes of antibodies for the detection of ANA, 90.5% of IgG, 66.6% of IgA and 9.5% of IgM. Two patients had ANEA-IgA at high titers (> or = 1:160) without ANEA-IgG. In this work, the importance of performing complementary tests for the detection of anti-smooth muscle antibodies, anti-mitochondrial antibodies and anti-DNAn is highlighted in order to apply these tests as guidelines for the clinical diagnosis of patients with ANEA. Besides, this study expresses the need of using total anti-Ig antibodies as conjugate for IIF-HEp-2 instead of anti-lgG; until the role of IgA antibodies in these autoimmune diseases is clarified.(AU)

Detection of human Toxoplasma-specific immunoglobulins A, M, and G with a recombinant Toxoplasma gondii rop2 protein.

The Toxoplasma gondii rhoptry protein Rop2 was expressed in Escherichia coli as a fusion protein containing 44 kDa of the 55-kDa mature Rop2, supplied with six histidyl residues at the N-terminal end (Rop2196-561). Humoral response during Toxoplasma infection of humans was analyzed by immunoglobulin G (IgG), IgA, and IgM enzyme-linked immunosorbent assay with Rop2196-561 as the antigen substrate. The analyzed sera were divided according to T. gondii-specific serological tests (IgG, IgA, or IgM indirect immunofluorescence and IgA or IgM immunosorbent agglutination assay) as group A (IgG+ IgA- IgM-; n = 35), group B (IgG+ IgA+ IgM+; n = 21), group C (IgG+ IgA+ IgM-; n = 5), and group D (IgG+ IgA- IgM+; n = 16). Twenty-six T. gondii-seronegative sera from individuals with other infections were also included (group E). Anti-Rop2 IgG antibodies were detected in 82.8% of group A sera and in 97.6% of the sera with acute-phase marker immunoglobulins (groups B, C, and D). The percentage of IgA antibody reactivity against Rop2196-561 was 17.1% in group A, 50% in group D, and 80.8% in groups B and C. The percentage of IgM antibody reactivity was 0% in groups A and C and 62% in groups B and D. Sera from group E failed to show IgA, IgM, or IgG antibody reactivity. Since T. gondii Rop2 elicits a strong humoral response from an early stage of infection, it is suggested that recombinant Rop2196-561 would be suitable for use in diagnostic systems, in combination with other T. gondii antigens, to detect specific IgG, IgA, and IgM antibodies.

Diagnosis of toxoplasmosis by joint detection of immunoglobulin A and immunoglobulin M.

An indirect immunofluorescence test with total anti-human immunoglobulin conjugate (IgG,A,M-IIF) can be used for joint detection of immunoglobulin A (IgA) and IgM antibodies, provided serum IgG is previously absorbed with anti-human IgG. To determine the validity of the IgG,A,M-IIF assay with absorbed sera, the results obtained were compared with those obtained by methods routinely used for the detection of acute-phase markers, IgA and IgM IIF and enzyme immunoassay. Accordingly, 114 serum samples were selected from patients showing titers of > or = 1:1,024 by IgG,A,M-IIF. (i) In 90 of the samples, neither IgA nor IgM was detected by any of the methods employed; (ii) the remaining 24 samples showed IgA and/or IgM. In all cases, the IgG,A,M-IIF assay with absorbed sera was positive. These comparative data support the use of IgG,A,M-IIF, performed with absorbed and unabsorbed sera simultaneously, for determining the presence of specific IgG, IgA, and IgM by employing a single technique (IIF), one conjugate (anti-IgG,A,M), and only one sample (with and without previous absorption), thus providing a useful initial tool for the diagnosis of toxoplasmosis.

[Incidence of Chagas infection in pregnant women and newborn infants in a non-endemic area]. / Incidencia de la infección chagásica en embarazadas y en recién nacidos en área no endémica.

The aim of this report was to determine Chagas infection incidence in pregnant women and congenital infection of their children in a hospital of a non-endemic area. From January 1990 to February 1991 we studied: a) 729 pregnant women with the serologic techniques of indirect hemagglutination and indirect immunofluorescence; b) 38 newborns from the 62 babies of seroreactive mothers with the parasitologic microhematocrit method to diagnose the infection. The serological tests were used as an index of the transplacental passage and for the eventual post-treatment control. We found 8.5% of women with Chagas disease, most of whom were born in an endemic area and did not know that they were infected (Table 1). We detected parasitemia in two newborns which represent 5.3% of congenital infection. Both babies were born in good conditions: at term, with normal weight and asymptomatic (Table 2). They were treated with nifurtimox and they showed a good response; the microhematocrit technique became negative a month later. At the end of the treatment the children were in perfect conditions showing an important decrease in the specific antibodies titer (Fig. 1). One of the cases was studied longer than the sixth month of life, maintaining negative serology. Our results in pregnant women are not different from those previously published in Buenos Aires; this points out the need to keep fighting the vector so as to lessen the existing reservoirs. We found a greater incidence of congenital Chagas disease with the microhematocrit technique than that previously published in Buenos Aires with other methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Incidencia de la infección chagásica en embarazadas y en recién nacidos en área no endémica. / [Incidence of Chagas infection in pregnant women and newborn infants in a non-endemic area]

The aim of this report was to determine Chagas infection incidence in pregnant women and congenital infection of their children in a hospital of a non-endemic area. From January 1990 to February 1991 we studied: a) 729 pregnant women with the serologic techniques of indirect hemagglutination and indirect immunofluorescence; b) 38 newborns from the 62 babies of seroreactive mothers with the parasitologic microhematocrit method to diagnose the infection. The serological tests were used as an index of the transplacental passage and for the eventual post-treatment control. We found 8.5

of women with Chagas disease, most of whom were born in an endemic area and did not know that they were infected (Table 1). We detected parasitemia in two newborns which represent 5.3

of congenital infection. Both babies were born in good conditions: at term, with normal weight and asymptomatic (Table 2). They were treated with nifurtimox and they showed a good response; the microhematocrit technique became negative a month later. At the end of the treatment the children were in perfect conditions showing an important decrease in the specific antibodies titer (Fig. 1). One of the cases was studied longer than the sixth month of life, maintaining negative serology. Our results in pregnant women are not different from those previously published in Buenos Aires; this points out the need to keep fighting the vector so as to lessen the existing reservoirs. We found a greater incidence of congenital Chagas disease with the microhematocrit technique than that previously published in Buenos Aires with other methods.(ABSTRACT TRUNCATED AT 250 WORDS)