RESUMEN
The complete amino acid structure of the variable regions of two monoclonal human rheumatoid factors (RF), antibodies that bind to the Fc portion of IgG, is presented. Although these RFs are of different isotypes, IgG (SFL) and IgM (RIV), they are highly related. They probably derive from the same KIII light chain variable region used, but the heavy chains are derived from genes of the VHIII family that are probably evolutionarily related. An analysis of the level of somatic mutation reveals that antigen selection was probably involved in the maturation of these clones. These antibodies, although highly related, are not merely IgM to IgG switch variants which occurred independently in different individuals. Little is currently known about the structure of IgG RFs and this study indicates that the level of somatic mutation of SFL is similar to other autoantibodies or antiviral antibodies of the IgG isotype.
Asunto(s)
Inmunoglobulina G/química , Cadenas Pesadas de Inmunoglobulina/química , Cadenas Ligeras de Inmunoglobulina/química , Inmunoglobulina M/química , Región Variable de Inmunoglobulina/química , Factor Reumatoide/química , Secuencia de Aminoácidos , Crioglobulinemia/genética , Crioglobulinemia/inmunología , Humanos , Inmunoglobulina G/genética , Cadenas Pesadas de Inmunoglobulina/genética , Idiotipos de Inmunoglobulinas/genética , Cadenas Ligeras de Inmunoglobulina/genética , Inmunoglobulina M/genética , Región Variable de Inmunoglobulina/genética , Datos de Secuencia Molecular , Mutación , Mapeo Peptídico , Púrpura Hiperglobulinémica/genética , Púrpura Hiperglobulinémica/inmunología , Factor Reumatoide/genética , Factor Reumatoide/inmunologíaRESUMEN
Data from a study carried out on a group of 18 patients with hypergammaglobulinemic purpura of Waldenström (HPW) followed-up for 3-14 years are reported in this paper. In 11 patients the syndrome was considered to be idiopathic, while in the remaining 7 it was associated with Sjögren's syndrome (SS). A marked (17/1) female prevalence was observed. Purpura was the presenting clinical manifestation in 9 patients, but it occurred at different points during the course of the disease; Raynaud's phenomenon was present in one third of patients. Serum gammaglobulin levels were higher than 2.2 g/dl in all the cases and higher than 3 g/dl in 9 cases. Immune complexes were detected in all patients. A significant serologic finding in our case series was represented by the frequency of anti-Ro (16/16) and anti-La (14/15) antibodies, clearly higher than that reported in SS patients. HLA typing showed a marked increase of B8 and DR3 antigens as well as A1,B8,DR3 haplotype, never reported in other autoimmune diseases. On the basis of serologic and immunogenetic features, HPW seems a clearly distinguishable entity among autoimmune vasculitis.
Asunto(s)
Púrpura Hiperglobulinémica/inmunología , Adulto , Anticuerpos Antinucleares/análisis , Femenino , Marcadores Genéticos , Antígenos HLA/genética , Haplotipos , Humanos , Inmunogenética , Masculino , Persona de Mediana Edad , Púrpura Hiperglobulinémica/clasificación , Púrpura Hiperglobulinémica/genética , Factor Reumatoide/metabolismo , Síndrome de Sjögren/inmunologíaRESUMEN
Uniovular twin sisters have been diagnosed 10 years ago as having hyperglobulinemic purpura (Waldenström) at age 12. The diagnosis was documented by purpura of the lower extremities, increased gamma-globulin after serum electrophoresis, and increased 7S component upon ultracentrifugation. In addition, there was an elevated ESR, a positive rheumatoid arthritis latex test, and their LE prep. was negative at that time. At a later date, however, both of them developed polyarthritis. After 9 years for the one and 10 years for the other, their LE prep. became strongly and constantly positive, while their gamma-globulin remained within abnormal limits.