PubMed Health⌕ Search

Biomedical subjects

G Genkins

Publications and source records attributed to G Genkins.

53 records · Page 3Linked to original sources
PubMedDate not supplied

Multiple forms of anti-acetylcholine receptor antibody in myasthenia gravis.

Sera of patients with myasthenia gravis (MG) contain anti-acetylcholine receptor (AChR) IgG antibodies (Ab) which have different antigenic specificities. Three Ab types were detected: (1) MG-I, which forms immune complexes with AChR; (2) MG-C, which decreases binding of AChR to concanavalin A; and MG-B, which blocks alpha-bungarotoxin binding to AChR. Sera from 152 MG patients were screened for the Ab types. Sixty-one percent contained MG-I, 26% contained MG-C, 10% contained MG-B, and 5% contained both MG-C and MG-B. The latter Ab types were associated with more severe forms of MG but showed no other clinical correlations. IgG antibodies of defined type were purified, and their interaction with unlabeled and toxin-prelabeled AChR from denervated rat muscle was studied in detail. Receptors are homogeneous with respect to determinants recognized by MG-I, but heterogeneous with respect to determinants recognized by MG-C (3 subpopulations, 22%, 28%, and 50% of AChR) and by MG-B (2 subpopulations, 30% and 70% of AChR). The stoichiometry of AChR interaction with the antibodies indicates that for each toxin-binding site, the receptor is divalent as an antigen for MG-I and MG-C but is tetravalent for MG-B. Denervated muscle AChR appears to be a mixture of at least 3 molecular forms of AChR, each of which has distinct immunological features as well as components common to all the receptor subpopulations.

Acetylcholine↗
PubMedDate not supplied

Acetylcholine receptor antibodies in myasthenia gravis.

A multivariate statistical analysis of levels of serum acetylcholine receptor antibody (AChR Ab) obtained from 197 patients with various clinical forms of myasthenia gravis (MG) was performed. Elevated AChR Ab levels are specific for MG, but normal AChR Ab levels do not rule out MG. Patients in remission or with purely ocular MG had the lowest incidence of elevation of serum AChR Ab levels, while patients with generalized, severe MG, particularly in the presence of thymoma, tended to have the greatest antibody elevations. Corticosteroids depressed AChR Ab levels, but thymectomy did not exert a consistent effect on antibody levels within a 24- to 30-month postoperative period. The relatively low 55% positivity of antibody elevations in all 197 patients probably reflects the use of heterologous (rat) AChR.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Case report: Thymectomy-induced remission of acquired autoimmune hemolytic anemia in an adult with myasthenia gravis.

A 57-year-old woman with diabetes mellitus, hypothyroidism, idiopathic thrombocytopenic purpura, myasthenia gravis, systemic lupus erythematosus, atopy, and basal cell cancer of the skin developed a severe Coombs'-positive autoimmune hemolytic anemia which was resistant to treatment with large doses of azathioprine, cytoxan, and prednisone. One year after transcervical thymectomy the hemolytic anemia disappeared and the patient has maintained a normal hemoglobin and negative Coombs' test without immunosuppressants even since. We believe this case report to be the first recorded instance of thymectomy-induced remission of autoimmune hemolytic anemia in an adult.

Anemia, Hemolytic, Autoimmune↗