Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report a patient with severe aplastic anaemia found to have a prolonged prothrombin time due to acquired factor VII deficiency. No evidence for a factor VII inhibitor or inactivator was demonstrable. Laboratory studies identified deficiency both of factor VII activity and factor VII antigen. The factor VII deficiency persisted from clinical presentation until approximately 50 d after allogeneic marrow transplantation when restoration of factor VII activity and antigen was noted. The patient's serum could be depleted of factor VII activity by in vitro incubation with Protein A bound to Sepharose, suggesting the presence of an IgG or IgG containing complex able to bind factor VII, but not neutralize its procoagulant activity. A dual specificity solid phase immunoassay identified a factor VII binding immunoglobulin which was detectable throughout the course of factor VII deficiency. The concordant appearance of this factor VII reactive immunoglobulin and the factor VII deficiency suggested the pathologic role of this immunoglobulin in the aetiology of the factor VII deficiency. This factor VII binding immunoglobulin may have induced rapid plasma clearance of the factor VII molecule or, alternatively, may have modified factor VII synthesis. The immunosuppressive therapy and subsequent lymphohaematopoietic engraftment following allogeneic marrow transplant was accompanied by complete resolution of the factor VII deficiency.
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PMID:Acquired factor VII deficiency associated with aplastic anaemia: correction with bone marrow transplantation. 264 42

An immunologic crossreactant of erythropoietin seemed to develop and persist in serum samples from a patient during treatment and remission of idiopathic aplastic anemia. It had a steeper slope to radioimmunoassay log-dose response lines and a larger molecular size than erythropoietin. On fractionation of serum, the apparent crossreactant was bound by staphylococcal Protein A at pH 7.5 and recovered by elution from it at pH 3.0. Adsorption of serum from the patient, and from one of two similarly affected children, with rabbit IgG linked to agarose appeared to remove completely the apparent crossreactant. These treated sera gave radioimmunoassay log-dose response lines essentially parallel to that given by the International Reference Preparation (IRP) for erythropoietin and estimates of immunoreactive erythropoietin appropriate to the normal hemoglobin concentrations. The apparent crossreactant of erythropoietin is thus accounted for by heterophilic antibodies to rabbit IgG. These developed in the patient following treatment with rabbit antilymphocyte globulin but seem to have arisen spontaneously in the children. Thus iatrogenic and idiopathic antibodies to rabbit IgG interfered in a radioimmunoassay for erythropoietin in serum through their ability to react with the radioimmunoassay anti-erythropoietin antiserum raised in rabbits.
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PMID:Invalidity from nonparallelism in a radioimmunoassay for erythropoietin accounted for by human serum antibodies to rabbit IgG. 824 69