Anti-neurofilament protein antibodies in opsoclonus-myoclonus.

Opsoclonus-myoclonus (OM) is a neurological disorder usually occurring in infancy, clinically manifested by various involuntary movements. The pathogenesis of OM is unknown, but since the disease often is associated with viral infection or with neuroblastoma, an immunologic basis for OM has been postulated. We have studied two children with OM whose serum contained antibodies directed against the 210 kDa neurofilament protein; these antibodies were not seen in the serum of 21 children with other neurological disorders. Neurofilament proteins, which are found only in neurons, may be of prime importance in neuronal function, especially during development of the nervous system. Our findings suggest that generation of antibodies to the neurofilament proteins can occur in patients with opsoclonus-myoclonus; the role of the anti-NF210K antibodies in the pathogenesis of OM, however, is uncertain.

Horseradish peroxidase labeled antisera--a diagnostic method for evaluating the percentages of B lymphocytes in peripheral blood.

Horseradish peroxidase labeled antisera supplied commercially was used to evaluate B lymphocytes in peripheral blood. This technique not only gave comparable results to the conventional fluorescein method, but also proved to be more advantageous.

Use of horseradish peroxidase to block nonspecific enzyme uptake in immunoperoxidase microscopy.

Intrinsic tissue peroxidase activity can be more or less successfully destroyed by methanol-H2O2 treatment. It has been found, however, in our laboratory that horseradish peroxidase (HRP) coupled to antibody will bind to some tissue components on a nonspecific basis and remain to take part in the histochemical stain. This contributes considerably to the background. This difficulty can be largely overcome if the tissues are pretreated with a solution of horseradish peroxidase which binds with nonspecific tissue sites. The adsorbed enzyme, along with the intrinsic peroxidase, can then be successfully inactivated by methanol-H2O2 treatment. By this method of blocking, there is considerable reduction in background staining.

Immunofixation electrophoretic techniques applied to identification of proteins in serum and cerebrospinal fluid.

We describe the application of immunofixation staining of agarose-gel electrophoretograms in areas where its use in the clinical laboratory is appropriate. Immunofixation electrophoresis consists of an electrophoretic phase followed by a fixation phase in which antiserum is used to precipitate the protein. As long as the antibody is in slight excess or near equivalency, the antigen/antibody complex remains insoluble. The reaction can be detected by visual inspection in indirect light, by protein staining, or by use of antibodies labeled with fluorescein, enzyme, or isotope. In the method described here we primarily have used protein staining (Coomassie Blue) to accentuate the proteins fixed by antisera. All unreacted proteins are removed by pressing with filter paper and saline washing. In the clinical laboratory, this method expedites immunochemical evaluation of samples and may also supplement immunoelectrophoresis. It has been applied successfully in identifying small obscure monoclonal proteins in the serum and cerebrospinal fluid of patients with multiple sclerosis, subacute sclerosing panencephalitis, biclonal gammopathies, serum monoclonal light chains, and mobility shifts of certain proteins, particularly of the complement series. Immunofixation demonstrates that the protein bands present in spinal fluid from multiple sclerosis and subacute sclerosing panencephalitis patients are of the IgG class of immunoglobulins; and non-IgG protein, such as beta and gamma trace proteins, are not detected. We also comment on reverse immunofixation with labeled antigen as a branch of the procedure that allows detection of function of the immunoglobulins separated by electrophoresis.