Enfermedad por aglutininas frías: proceso diagnóstico, tratamiento y seguimiento de un paciente / Cold agglutinin disease: diagnosis, treatment and follow-up of a patient

La enfermedad por crioaglutininas es una anemia hemolítica autoinmune que se caracteriza, en la gran mayoría de los casos, por la hemólisis mediada por autoanticuerpos de tipo IgM y complemento C3d, contra los antígenos de la membrana del eritrocito, que conduce a hemólisis extravascular con propensión a la trombosis, y que afecta principalmente al sexo femenino y personas mayores. Su diagnóstico se realiza con la prueba de Coombs directo y fraccionado, y la titulación de aglutininas frías >1:64 a 4 °C. Se describe el caso clínico de una mujer de 89 años con un síndrome constitucional y una anemia de 3 años de evolución, en quien se determinó el diagnóstico de enfermedad por aglutininas frías. Asimismo, se describe el abordaje diagnóstico, el tratamiento instaurado, y se hace una breve revisión de la literatura publicada

Cold agglutinin disease (CAD) is an autoimmune hemolytic anemia characterized in the vast majority of cases by hemolysis mediated by IgM autoantibodies and complement C3d against erythrocyte membrane antigens, leading to extravascular hemolysis with propensity to thrombosis, affecting mainly females and older individuals. It is diagnosed by direct and fractionated Coombs test and a cold agglutinin titer >1:64 at 4 °C. We describe the case of an 89-year-old woman with a constitutional syndrome and a 3-year history of anemia, who was diagnosed with cold agglutinin disease. Also, we include the diagnostic and treatment approach, and a brief review of the literature

Immunohistochemical analysis for C3d, C4d, IgG, IgG4, and CD123 in diagnosis of autoimmune skin diseases / 中南大学学报(医学版)

To assess the value of immunohistochemical analysis for expressions of C3d, C4d, IgG, IgG4, and CD123 in the diagnosis of autoimmune skin diseases.
 Methods: We investigated the expressions of C3d, C4d, IgG, IgG4, and CD123 in paraffin-embedded, formalin-fixed tissues from 27 lupus erythematosus cases, including 8 discoid lupus erythematosus (DLE) cases, 4 subacute cutaneous lupus erythematosus (SCLE) cases, and 15 systemic lupus erythematosus (SLE) cases. Tissues from 15 dermatomyositis (DM) cases, 15 bullous pemphigoid (BP) cases, and 15 pemphigus cases were examined by immunohistochemical analysis. The differences in expression rates of C3d, C4d, IgG, IgG4, and CD123 between immunohistochemical staining and direct immunofluorescence were compared in the diagnosis of these diseases.
 Results: In the lupus erythematosus group, the positive rates of C3d and C4d deposited along the dermoepidermal junction were 85.2% and 51.9%, respectively. In the dermatomyositis group, the positive rates of C3d and C4d deposited along the dermoepidermal junction were 40% and 0, respectively. The expressions of C3d and C4d in lupus erythematosus tissues were significantly higher than those in DM tissues (P<0.05). The expression of CD123 protein in skin lesions of the lupus group was significantly higher than that in the DM group (P<0.05). In the BP group, the positive rates of C3d and C4d deposited along the dermoepidermal junction were 100% and 86.7%, respectively. In the pemphigus group, the positive rates of C3d and C4d deposited in the intercellular space of keratinocytes were 100% and 60%, respectively. The expressions of IgG and IgG4 in pemphigus tissues were higher than those in BP tissues (P<0.05). And the ratios of IgG4 to IgG in the pemphigus group was significantly higher than that in the BP group (P<0.05).
 Conclusion: The assays of C3d and C4d define an important diagnostic adjunct in evaluation of lupus erythematosus, BP and pemphigus. In some cases, it may even replace the direct immunofluorescence as a diagnostic adjunct. The expression of CD123 possesses certain clinical significance for the differential diagnosis of lupus erythematosus, and IgG4 and IgG expressions have adjunctive diagnostic significance for pemphigus.

Expression of NA of influenza virus and C3d fusion gene in replication-defective recombinant adenovirus and its immune efficacy analysis / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct a replication-defective recombinant adenovirus expressing the fusion gene of neuraminidase (NA) gene in influenza virus A/FM/1/47 and C3d and to evaluate the induced immune efficacy.</p><p><b>METHODS</b>NA-C3d was cloned into shutter vector pAdTrack-CMV, which was cotransformated with adenovirus DNA into E. coli BJ5183. The recombinant adenovirus genomic DNA was generated through homological recombination. The recombinant adenovirus was produced by transfecting 293 cell line with the genomic DNA and the induced immune efficacy in mice were analyzed.</p><p><b>RESULTS</b>The integration of NA-C3d in the adenovirus genomic DNA and its expression were confirmed by PCR and Western-Blot assays respectively. After intranasal immunization, the serum IgG was induced at a titer of 1: 1000 and 1:100 000 in BALB/c mice at primary and secondary immunization respectively. The vaccinated mice were completely survived when challenged with wide influenza virus.</p><p><b>CONCLUSION</b>recombinant adenovirus expressing NA-C3d was successfully constructed and it could induce desired immune efficacy.</p>

Serum C3d levels in tropical pulmonary eosinophilia.

Background & objectives: Results of earlier studies to evaluate the possible role of complement system in tropical pulmonary eosinophilia (TPE) using classical methods like serum haemolyte component CH50, C3 and C4 levels were inconclusive. In this study we determined levels of serum C3d which is a catabolic fragment of C3, to find out any direct evidence of activation of the complement system in TPE. Methods: The study population consisted of 3 groups. Group A consisted of 37 patients with well characterized TPE. In group B, 26 patients with pulmonary eosinophilia had similar respiratory and haemotological features as in Group A but had associated worm infestation in stool. The control group consisted of 39 healthy volunteers. Serum C3d levels were determined by sandwich ELISA technique. Results: The serum C3d levels in TPE patients were not significantly different from those of the patients of group B or the normal controls. Interpretation & conclusions: Absence of significant change in serum C3d goes against the possibility of complement activation in TPE. Results of our study suggest that complement system is unlikely to play a pivotal role in pathogenesis of TPE.

C3d-M28 enhanced DNA vaccination induced humoral immune response to glycoprotein C of pseudorabies virus / 生物工程学报

We studied the immunogenicity of pseudorabies virus gC DNA vaccination by fusing the murine complement C3d receptor binding domain. First, pseudorabies virus gC gene was linked to four copies of C3d receptor binding domain (M284), and then cloned into the vector pcDNA3.1 to construct the recombinant plasmid sgC-M284. Through the experiment of immunized BALB/c mice, we found that the enzyme linked immunosorbent assay (ELISA) antibody titer for sgC-M284 was 17-fold higher than that for sgC alone, and protective rate of mice was augmented from 25% to 88% after lethal dose PrV (316 LD50) challenge. In addition, the IL-4 levels for sgC-M284 immunization approached that for the pseudorabies virus inactivated vaccine. In conclusion, we demonstrated murine C3d receptor binding domain fusion significantly increased Th2-biased immune response by inducing IL-4 production.

Construction and eukaryotic expression of recombinant plasmid encoding fusion protein of goat complement C3d and foot-and-mouth disease virus VP1 / 生物工程学报

We constructed a recombinant plasmid encoding VP1 gene of O type foot-and-mouth disease virus fused to a molecular adjuvant, goat complement C3d gene. The goat C3d gene was cloned and three copies were tandem-linked with the linker (G4S)2 sequence. VP1 gene of O type foot-and-mouth disease virus was linked to three tandem repeats of C3d through the linker sequence and cloned into pUC19 to obtain the recombinant plasmid pUC19-VP1-C3d3. The VP1-C3d3 fusion gene was then subcloned into the eukaryotic vector pcDNA3.1(+) that had been modified to contain the tissue plasminogen activator (tPA) leader sequence to obtain pcDNA3.1-tPA-VP1-C3d3. HeLa cells were transfected with pcDNA3.1-tPA-VP1-C3d3 by Lipofectamine 2000. Indirect immunofluorescent assay and Western blot assay showed that VP1-C3d3 fusion gene was successfully expressed in HeLa cells. The fusion protein with the expected size 133 kD could be secreted outside the cells. This study laid a good foundation to further research on the novel vaccine against foot-and-mouth disease virus by using goat C3d as a molecular adjuvant to enhance the immunogenicity of VP1.

Determinación de la actividad anti-C3d en reactivos antiglobulina humana / Determination of the anticomplement activity in human antiglobulin reagent

La evaluación de la actividad de anti-C3d en reactivos de Coombs poliespecíficos, con los procedimientos clásicos presenta, según la experiencia de los autores, dificultades técnicas y falta de reproductibilidad. El objetivo de este trabajo fue describir una técnica para controlar la actividad de los reactivos antiglobulina humana (AGH) poliespecíficos y monoespecíficos anti-C3d, utilizando glóbulos rojos de carnero (GRc) sensibilizados con fragmentos de complemento (C'). La obtención de GRc sensibilizados con C3d, se evaluó con reactivos de calidad certificada por la firma comercial. Se obtuvieron reacciones de aglutinación francamente positivas con reactivos de Coombs poliespecíficos y con reactivos anti-C3d, -C3d monoespecíficos. La sensibilidad, especificidad y sencillez de esta técnica induce a proponerla dentro del protocolo de Control de Calidad de los antisueros AGH poliespecíficos y anti-C3d, -C3d, utilizados de rutina en los Servicios de Medicina Transfusional

A sequential study of circulating immune complexes, complement and immunoglobulins in borderline tuberculoid leprosy patients with and without reactions.

Sequential estimates of the levels of circulating immune complexes (CIC), complement catabolic fragment C3d, complement-mediated immune complex solubilization (CMS) and immunoglobulins were made in 24 newly diagnosed with borderline tuberculoid leprosy over a 20 month period after initiation of chemotherapy. Fourteen of these patients had not suffered from reversal reactions either at the time of presentation or during the follow-up. The levels of CIC were evaluated in them from the third to the eleventh month after starting chemotherapy and immunoglobulin G (IgG) levels were evaluated up to eight months. The concentrations of C3d and immunoglobulins A (IgA) and M (IgM) were normal in these patients. The other ten patients had reversal reaction at the time of diagnosis which subsided by the third month after starting treatment. They did not have reversal reactions later. The levels of CIC and IgG were elevated and those of CMS were depressed throughout the study period. Serum C3d level was initially elevated but came down to normal by the third month while IgA and IgM levels were within normal limits. The relevance of these findings to the genesis of reversal reaction is discussed in this communication.

The possible role of circulating immune complexes in the deficiency of cell-mediated immunity in paracoccidioidomycosis

1. The nature and extent of immune abnormalities was studied in 28 untreated patients with a chronic moderate form of paracoccidioidomycosis (PCM). 2. The patients presented hyporeactivity to skin tests, diminished lymphocyte transformation by mitogens such as phytohamgglutinin-P and concanavalin A and by Paracoccidioides brasiliensis protein antigen. They also presented peripheral blood leukocytosis but normal absolute numbers of T-cell and T-cell subsets. 3. The patients had increased serum levels of C3d, as well as high levels of circulating immune complexes (CIC) detected by C1q-binding and protein A-binding assays. 4. There was a significant negarive correlation between lymphocyte transformation by mitogens and CIC levels which suggested that CIC may be involved in the genesis of the depressed cell-mediated immunity in PCM patients