[Antiglomerular basement disease in children: Literature review and therapeutic options]. / Syndrome de Goodpasture et maladie des anticorps anti-membrane basale chez l'enfant : revue de la littérature.

Antiglomerular basement membrane glomerulonephritis is a rare autoimmune disease characterized by rapidly progressive glomerulonephritis that may be associated with pulmonary hemorrhage (Goodpasture syndrome). The disease is caused by autoantibodies (classically IgGs) directed against the α3 subunit of type IV collagen. This is a rare disease in the adult population and extremely rare in children, with a reported cumulative annual incidence at 1/106 people/year. Among scarce reported pediatric cases (n=31), most are girls (M/F sex ratio, 1:4), and the mean age at diagnoses is 9.2±4.6 years. A medical diagnosis is an emergency and is based on the identification of specific antibodies in the serum, and pathognomonic linear fixation of IgGs along the glomerular basement membrane. Without appropriate treatment, the disease is generally fulminant, and patient and kidney survival is poor. Indeed, glomerular function strongly correlates with histological lesions. The current guidelines recommend the use of plasma exchanges and immunosuppressive drugs. For the past few years, alternative therapeutics such as specific anti-B-cell antibodies (rituximab) or specific extrarenal cleansing such as immunoadsorption have been successfully used in adults. Immunoadsorptions (IAs) can remove pathogenic IgGs from the circulation and do not require plasma infusions, contrary to plasma exchanges. In this review, we discuss the key points of antiglomerular basement membrane glomerulonephritis diagnosis and conventional or alternative therapeutics.

Tumor-bound immunoglobulins: an in vivo phenomenon of masked specificity.

We examined the specificity of the lg "coating" on murine tumor cells grown in vivo. Cells were treated in vitro for release of cell-bound lg from ascites tumors. Such uncoated cells showed an increased expression of tumor-associated antigens and a parallel decrease in intensity of the lg coat, but displayed no changes in the expressions of other normal membrane antigens. This was shown by a complement-dependent cytotoxicity assay and radioimmunoassay. These changes were attenuated if the tumor originated from animals that had been irradiated before tumor inoculation. No alterations were found with corresponding cells propaged in vitro and submitted to the same treatments. Our findings and others suggest tumor-specific antibodies among the lg coats detected on tumor cells grown in vivo.

Specific IgE antibody responses to ragweed allergens Ra5S and Ra5G associated with distinct HLA-DR beta genes.

Previous studies have established that sensitivity (IgE antibody response) to Ra5S, a 5000 mol. wt protein of short ragweed pollen, is significantly associated with host possession of HLA-DR2. The same allele was implicated [Goodfriend et al. (1985) Molec. Immun. 22, 899-906] in sensitivity to Ra5G, a 4400 mol. wt homologue of Ra5S in giant ragweed pollen, based on frequency of co-sensitivity to both proteins. However, data reported here generated in HLA-DR assays of mono-sensitive individuals demonstrate that sensitivity to Ra5S and Ra5G is associated with separate alleles: DR2 and DRw52 respectively. Results consistent with the same sensitivity/DR associations were obtained in immunoabsorption studies with sera from co-sensitive individuals. As HLA-DR2 and DRw52 have identical alpha but different beta chain types (beta 1 and beta 3), it was considered that IgE antibody responses to Ra5S and Ra5G are associated with distinct DR-beta genes.

Ra5G, a homologue of Ra5 in giant ragweed pollen: isolation, HLA-DR-associated activity and amino acid sequence.

Recent studies [Marsh et al. (1982) J. exp. Med. 155, 1439-1451; Coulter (1983) M.Sc. thesis, McGill University, Montreal, Canada; Coulter et al. (1983) in Genetic and Environmental Factors in Clinical Allergy (Edited by Marsh D.G., Blumenthal M.N. and Santilli J., Jr), University of Minnesota Press, Minneapolis, MN] have shown a highly significant association between HLA-Dw2/DR2 and host sensitivity to the 5000-D, 4-disulfide bonded protein Ra5S of short ragweed pollen. To extend these findings, we isolated Ra5G, an Ra5S-like protein, from giant ragweed pollen by gel and ion-exchange chromatography. The protein was homogeneous by polyacrylamide gel electrophoresis (pH 4.3), reverse-phase high-performance liquid chromatography, and antigenic assays. Its mol. wt and amino acid composition (including 8 half-cystine residues) were closely similar to Ra5S, but the two proteins had little or no antigenic or allergenic cross-reactivity. In a study of 200 ragweed-sensitive individuals, host sensitivity simultaneously to Ra5G and Ra5S was significantly associated with the DR2 allele. The amino acid sequence of Ra5G was determined and showed close homology with Ra5S. The potential function of a highly homologous decapeptidyl sequence stretch is discussed in relation to Ir gene control of immune response to the 2 proteins.

Analysis of cell-surface markers with staphylococcal protein A: fluorescence studies on mammalian lymphoid determinants.

Membrane antigens including different classes of immunoglobulins, transplantation antigens, beta2-microglobulin, T lymphocyte specific antigens, and virally determined surface components were investigated using fluorescein-labeled Staphylococcal protein A in combination with cytofluorometric studies. Lymphocytes of seven species: mouse, rat, guinea pig, pig, cow, monkey, and human, and of ten human lymphoma-derived lines were tested. Analysis of the differential expression of surface markers revealed a reproducible reaction of protein A with cell-surface Fc of IgG actively produced by lymphoid cells from human, monkey, guinea pig, and pig, and with passively attached IgG molecules in the form of antibodies, directed against cell surface antigens of all lymphoid cells tested. No surface Ig was detected on so-called T lymphocytes. The distribution of cell-bound Ig density among surface Ig-positive cells was found to be different depending upon the origin of the cells with regard to lymphoid organ; it was parallel among the lymphoma lines tested and on peripheral blood cells from human, monkey, and pig, although large variations in fluorescence intensity among individual cells and among the different lines were recorded. Beta2-microglobulin determinants were found equally well on enriched human T and B cells. Transplantation, and T lymphocyte-specific antigens were detected on the majority of the lymphoid cells and on a restricted population respectively.

A radioimmunoassay of cellular surface antigens on living cells using iodinated soluble protein A from Staphylococcus aureus.

Soluble protein A from Staphylococcus aureus does carry great promise as a marker for cellular surface determinants, due to its specific reaction with, and high affinity for, most subclasses of mammalian IgG. In this article we present the different parameters involved in a radioimmunoassay using 125-I-labelled protein A. Using such an approach the actual technical procedures involved are reported in detail together with tests for mammalian alloantigens, including HL-A in the human, H-2 in the mouse and AgB antigenic sites in the rat, as this presents an unique opportunity to compare them with already widely used assays for transplantation antigens. The different parameters of the assay are analysed in view of measuring with precision quantities of cell-surface IgG molecules, thereby allowing possible determinations of antigenic site numbers in a new and simplified manner.

[Profile of aged traffic victims on the road to Sherbrooke (Quebec)]. / Profil de victimes âgées de la route à Sherbrooke (Québec).

This article draws a portrait of the victims, 65 years of age and over, of road accidents in a mid-size Quebec town. By examining four variables--age, sex, condition of the victims and the type of road users--we measured the magnitude and severity of road accident injuries in senior citizens, and identified those road users most at risk. Results indicate that, in the city of Sherbrooke as elsewhere in Quebec, road accident injuries are increasing slowly but constantly in this age group. Analysis of the severity of injuries and of the category of road users, shows that senior citizens have a high degree of vulnerability and are over-represented in statistics dealing with pedestrians who are victims of accidents. We discuss these results and their impact on public health.

[Abnormal specificities of immune alloantisera]. / Spécificités sérologiques "anormales" des immunsérums allogéniques

Sera from repeatedly immunized with allogenic lymphocytes contain IgG that can be fixed by syngenic tumour cells. When compared to the specific anti-H-2 immune response, the paradoxical tumour reactivity is often very high, suggesting an active immunization process. Selective absorptions have demonstrated that the majority of these "anomalous" IgG are directed against membrane components of tumour cells. The nature of the detected tumour-associated determinants is not well elucidated: they are not found on normal embryonnic or adult tissue, but are highly expressed by all in vitro murine malignant cell lines thus far tested, and to a lesser extent by the corresponding in vitro maintained tumours.

[Allergy has no age]. / L'allergie n'a pas d'âge.

Even though allergic reactions to local anesthesia are rare and even more so among elderly people, the present case demonstrates that a medication can be tolerated for a significant period of time before causing an accident. This illustrative case details the true nature of complications observed following local anesthesia and suggests a way of approaching the same to arrive at a definitive diagnosis. This method consists of a rigorous analysis of the clinical manifestations and allergologic testing. Local anesthesia is indispensable for both the dentist and the patient and anyone with allergies is at risk at being allergic to general anesthesia as well.

Comparative studies on the expression of Fc-receptors, Ia antigens, and beta 2-microglobulin following in vitro herpes simplex virus infection of human lymphoid cells.

Characteristics of the specificity and affinity of surface Fc-receptors induced on Raji (a Burkitt's lymphoma derived B cell line) and Molt-4 (a T cell line derived from a leukaemic patient) after herpes simplex virus (HSV) infection were studied, together with the expression of other surface markers. Inhibition experiments of EA-rosetting suggested that Raji cells infected by HSV had a higher affinity for soluble aggregated IgG than for IgG serologically adsorbed onto erythrocytes; an opposite pattern was noted with Molt-4, a non-Burkitt's lymphoma cell line. Using radiometric and microspectrofluorometric techniques, the expression of Fc-receptors, as detected by their capacity to fix aggregated IgG, paralleled the expression of serologically detectable Fc-receptors and Ia determinants. In contrast to beta 2-microglobulin, both Fc-receptor and Ia antigen expression increased following Hsv infection: this suggests a specific induction of these markers on human lymphoid cells following HSV infection. To our knowledge, this is the first report showing a specific induction of both Fc-receptors and Ia antigens by HSV following in vitro infection of human lymphoid cells.

[Studies on tumour--associated immunoglobulins in human cancer]. / Analyse des spécificités des immunoglobulines associées aux cancers humains

Human sarcomas, carcinomas and brain tumours were assayed for the presence of immunoglobulins IgG. Among 16 tumours tested, 14 had detectable amount of IgG that could be released when incubated in culture conditions. Addition of iodoacetamide--a metabolic inhibitor--inhibited this " uncoating process ". The uncoated cells rebound IgG if incubated subsequently with any of the cancer sera tested. However, when the autologous serum was present during the uncoating incubation, subsequent rebinding at 4 degree C of IgG from the same or other cancer sera was significantly decreased compared to alquots pre-incubated in other sera.

Cytotoxic effector cells from infectious mononucleosis patients in the acute phase do not specifically kill Epstein-Barr virus genome-carrying lymphoid cell lines.

We describe a study in which we investigated the cytotoxic activities of thymusderived (T) lymphocytes and natural killer cells against Epstein-Barr virus (EBV) genome-carrying lymphoid cell lines. Purified subpopulations of lymphocytes from eight patients with infectious mononucleosis and six healthy normal EBV-seropositive donors were tested. Enriched T-cells were obtained by passing purified whole blood lymphocyte preparations through human immunoglobulin-anti-immunoglobulin-coated glass bead columns. The cytolytic activity of effector cells was determined by the ability of these cells to lyse human target cells that were internally labeled with (51)Cr. These targets included cells from both EBV genome-carrying and EBV genome-negative lymphoid lines derived from malignant tumors, as well as from lymphocytes transformed in vitro by EBV, and were chosen to represent a wide spectrum of EBV-associated membrane antigens. We found that cytotoxic T-cells from patients with infectious mononucleosis showed no EBV-related specific cell killing per se, although a trend for increased killing of cell lines derived from spontaneous in vivo growing tumors, EBV genome carrying or not, was noted; however, this trend was not observed with cell lines derived from cord blood lymphocytes after EBV infection in vitro. In addition, our data suggest that natural killer cells may play an important role in controlling EBV infection in patients with infectious mononucleosis in the acute phase of the disease, particularly since T-cells (obtained after removal on immunoglobulin-anti-immunoglobulin columns of natural killer cells presumably bearing Fc receptors) were less efficient killers than whole blood lymphocytes; furthermore, lysis by whole blood lymphocytes was also greatest against cell lines derived from malignant tumors (as opposed to in vitro EBV-transformed cord blood lymphoid lines), irrespective of whether these targets were EBV genome positive or negative.

Epstein-Barr virus interactions with human lymphocyte subpopulations: virus adsorption, kinetics of expression of Epstein-Barr virus-associated nuclear antigen, and lymphocyte transformation.

In order to further understand Epstein-Barr virus (EBV)-lymphocyte interactions, we investigated a chain of events including: (i) EBV binding to human lymphocyte subpopulations; (ii) the earliest appearance of EBV-determined nuclear antigen (EBNA) in the lymphocytes after EBV infection; and (iii) establishment of continuous lymphoblastoid cell lines (LCL) by infecting with EBV different types of lymphocyte preparations from the same as well as from different donors. By using direct membrane immunofluorescence assay, we found that only a small fraction of human peripheral blood and cord blood lymphocytes (CBL), and possibly less than 31% of the T cell-depleted lymphocyte population, carry receptors for P3HR-1 strain of EBV. The number of cells carrying receptors for EBV did not vary considerably among different blood lymphocyte populations from several normal donors. EBV adsorption on lymphocyte subpopulations showed that purified thymus-dependent (T) cells and thymocytes did not adsorb EBV, in contrast to T cell-depleted lymphocyte populations and lymphoid cells from fetal liver and spleen. In CBL infected with EBV strain B95-8, EBNA was detected by anti-complement immunofluorescence as early as 18 h after infection. This indicates that EBNA is the earliest detectable EBV-determined intracellular antigen to appear after infection and before or during lymphocyte transformation by EBV. Transformation was observed only in lymphocyte cultures containing detectable thymus-independent B cells but not in cultures of purified T cells. With one exception (es-b-1), all the EBV-transformed LCL from different origins carried surface-bound immunoglobulins (a B cell marker). These included also the 10 LCL obtained by infecting cultures of adherent cells from different donors. With regard to its surface markers, ES-B-1 appeared to be an exceptional EBV genome-carrying line, and it also lacked the ability to form spontaneous rosettes with sheep erythrocytes (a T cell marker). Therefore, it is possible that ES-B-1 was derived from an atypical B cell or B cell precursor or from a so-called "null cell" transformed by EBV.

Staphylococcal protein A in immunoferritin techniques.

Protein A (pA) of Staphylococcus aureus, by virtue of its reactivity with the Fc portion of a variety of mammalian immumoglobulins (IgG), can be used for electron-microscopical immunoferritin techniques. The conjugation of pA with ferritin (pA-F) by means of bis(4-fluoro-3-nitrophenyl) sulfone results in a highly specific marker for IgG in indirect labeling experiments. Native pA can be used as a noncovalent bridging agent between specific antibodies and antiferritin capturing the marker molecule. The use of pA and pA-F is demonstrated with a model system involving human erythrocytes and two rabbit antisera directed against different surface antigens of the human erythrocyte membrane.

Quantitation of beta2-microglobulin and HLA on the surface of human cells. I. T and B lymphocytes and lymphoblasts.

Relative amounts of beta2-microglobulin (beta2m) and of HLA specificities were analysed on the surface of resting unfractionated peripheral human lymphocytes, enriched B and T cells, and on in-vivo- and in-vitro-stimulated lymphoblasts. Single-cell cytofluorometry and a very sensitive radioimmunoassay were used to determine as closely as possible the absolute amounts of membrane-bound beta2m/HLA antigens. B and T "resting" and "stimulated" lymphoid cells express very similar numbers of beta2m and HLA antigenic determinants, respectively, per unit of surface area when compared with each group, although beta2m was found to exist in two- to three-fold excess of HLA.

Tumor-bound immunoglobulins. I. Further analysis of the characteristics of binding of immunoglobulins to in vivo-grown tumor cells.

Immunoglobulin (Ig) "coating" on different in vivo growing mouse tumors was investigated using several approaches. Radioiodine-labelled purified protein A from Staphylococcus aureus, a specific reagent for Fc of IgG, and/or iodinated purified antibodies against mouse immunoglobulins, were fixed by various in vivo-grown mouse tumor cells, but not by the corresponding in vitro-cultivated tumor cells. Removal of host macrophages from the in vivo tumor-cell preparations did not affect the fixation of anti-mouse Ig reagents by the tumor cells. After an initial lag period in vivo, the intensity of the Ig coating of tumor cells increased with time after tumor inoculation. Conversely, the detectable coating decreased rapidly as a function of time after ascites tumor cells were explanted in vitro at 37 degrees C. Iodoacetamide did partially block this 37 degree C in vitro-induced "uncoating process". Surface-bound Ig could also be released from in vivo-coated tumor cells treated at low pH in vitro. Analysis of the behavior of tumor-bound Ig indicated a composite pattern. At the membrane level, uncoating was best shown with in vitro incubation favorable to cellular metabolism; however IgG was detected equally well in the supernatants of the cells, whether they were incubated at 37 degrees C or at 4 degrees C, and so far has failed to display antibody activity towards uncoated tumor cells. This was in contrast to the case of IgG released from ascites tumor cells cultured at low pH in vitro: such eluted Ig, when neutralized, could rebind to the "same" uncoated tumor cells. Under favorable metabolic conditions, the fate of tumor-bound Ig might be one of internalization and/or of degradation.

Immune complexes in psoriasis with and without arthritis.

Two different assays were employed to detect soluble immune complexes in the serum of a large group of patients with psoriasis and psoriatic arthritis. Using a Raji cell assay no evidence of complexes was found. However, with the Clq deviation method, sera from 29% of the patients with psoriasis alone and 35% of those with associated arthritis, exhibited Clq reacting material.

Immunofluorescence assay for antinuclear factor: a nonspecific test in hospitalized medical patients.

Serum from 149 randomly selected hospitalized medical patients was tested for the presence of antinuclear factor (ANF) by the conventional immunofluorescence technique. Patients with positive and negative results were then compared as to clinical history, particularly previous drug exposure, physical findings, and levels of C-reactive protein and immune complexes in the serum. The frequency of ANF positivity was found to be very high (23%). Although the presence of ANF was significantly correlated (P less than 0.02) with a higher age, it was not significantly related to any other clinical or laboratory feature assessed. It was concluded that ANF testing cannot serve as a blind diagnostic screening tool for connective tissue diseases because of its nonspecificity.