The metabolism of radioiodinated IgG was studied in a series of 42 @entity1 with @entity2597 (16 @entity1252 , nine @entity309 , five @entity6558 , five @entity1333 , and seven miscellaneous diagnoses). Fractional catabolic rates were increased and survival half-lives were shortened in all diagnostic categories indicating @entity11744 of IgG. This @entity11744 was masked by increased IgG synthesis, resulting in elevated serum concentrations of IgG in @entity1 with @entity1252 and @entity309 and in generally normal concentrations in the others. The metabolism of iodinated IgM was also studied in eight @entity1 with @entity1252 , in seven with @entity309 , and in 12 controls. The fractional catabolic rates were normal in both groups of patients. Serum concentrations of both IgM and IgA were moderately elevated in all diagnostic categories. Serum albumin metabolism was entirely normal in the nine subjects studied who were not receiving corticosteroids; in three who were receiving them, moderate @entity11744 was observed. The @entity11744 of IgG could not be accounted for by factors previously known to alter IgG metabolism. It was not observed in 15 @entity1 with other chronic, inflammatory diseases and was not explained by concomitant administration of adrenal corticosteroids to some @entity1 . Identical results were obtained whether the IgG was obtained from a @entity1 himself or from a normal donor, demonstrating that the @entity11744 is a host defect and not an abnormality of the protein. Thus, @entity1 with connective tissue disease of several different diagnostic categories have been shown to have an @entity2015 : they catabolize normal IgG at an accelerated rate.

@entity11744 of normal IgG; an @entity2015 in the XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity2597 :: ('MESH:D003240', 'Disease') :: ['connective tissue diseases'] @entity1333 :: ('MESH:D014657', 'Disease') :: ['vasculitis'] @entity11744 :: ('MESH:C565476', 'Disease') :: ['hypercatabolism'] @entity1252 :: ('MESH:D008180', 'Disease') :: ['systemic lupus erythematosus'] @entity309 :: ('MESH:D001172', 'Disease') :: ['rheumatoid arthritis'] @entity2015 :: ('MESH:D004406', 'Disease') :: ['unexplained immunoglobulin abnormality'] @entity6558 :: ('MESH:D017285', 'Disease') :: ['polymyositis']
@entity2597 :: (MESH:D003240,Disease) :: ['connective tissue diseases']
