Studies on the biological functions of monoclonal immunoglobulins and their fragments.

Complement-binding ability of three isolated monoclonal proteins of IgG class, their Fab, and Fc fragments was analyzed (including tests for the presence of polymers, aggregated forms and immune complexes), and the influence of two monoclonal IgG lambda proteins on fibrinogen conversion to fibrin was determined. Two proteins--IgG1 lambda and IgG3K--bound small amounts of complement only when tested in native form, but failed to bind complement after thermal aggregation. Papain-digestion of these proteins revealed a significant ability of complement binding by Fc fragments.

Papain hydrolysis products in four M-IgG subclasses.

Four different classes of monoclonal IgG were submitted to papain digestion activated by cysteine. After digestion of subclasses G-1, 3 and 4 about 80% of the initial amount of IgG is converted to fragments Fab and Fc (less in subclass IgG2). In the initial time of digestion subfragments: Fc', Facb-like and nonidentified product of digestion (fraction IV) are also obtained.

[Analysis of the results of treatment of multiple myeloma].

Therapeutic results were analysed in 62 cases of multiple myeloma treated by two-stage method: I. with cyclically non-specific agents (melphalan) in each case. When this treatment was a failure the second step was given: II.

Determination of subclasses of myeloma proteins M-IgG by enzymatic hydrolysis.

Several methods of determine M-IgG subclasses after hydrolysis with papain and pepsin were compared, and the results were checked by the passive hemagglutination test with erythrocytes using specific antisera. For practical purposes, the papain method was preferred to the pepsin method for recognition of IgG-3 subclass. A shortened method of digestion with papain which distinguishes between the papain-sensitive subclasses, i.

[Disorders in the conversion of fibrinogen to fibrin in patients with multiple myeloma].

A prolonged thrombin clotting time was found in 15 of 85 patients with multiple myeloma. Among those with abnormal clotting time in 9 cases (60.0%) the M protein was classified as IgG-lambda, in 1 (6.

[Immunochemical and biological properties of rapid monoclonal proteins of the IgG class].

Four proteins M class IgG were analysed in detail in view of their more rapid electrophoretic migration in starch gel among most proteins in this class. On the basis of these investigations two protein (from sera 212 and 244) corresponded to subclass IgG-4, one (serum 119) probably to IgG-4 with polyclonal impurities from other subclasses, and the fourth protein (from serum 210) to subclass 3 or 1. Since subclass IgG-4 contains the greatest amount of sialic acid residues of the remaining IgG subclasses finding of more rapid migration of the observed proteins seems to be due to this.

Serum levels of IgE in malignant lymphogranulomatosis.

Serum levels of IgE in malignant lymphogranulomatosis (Hodgkin's disease) were lowered in patients who had been intensively treated, without eosinophilic granulocytes, and in less advanced forms of the disease. High levels were observed in untreated patients with eosinophilic granulocytes in their peripheral blood, and in clinically advanced cases.

[M-component of serum formed by lambda-type Bence-Jones protein].

M-component in the serum composed of free light chains occurs rarely as evidenced by literature. In the investigations of the authors it was demonstrated that three M components obtained from patients with plasmocytoma were composed of free light chains type lambda. High concentration of low-molecular protein in serum was due, probably, to coexistent impairment of renal filtration.

[Sera showing the ability of erythrocyte panagglutination].

The properties of a factor causing panagglutination of erythrocytes are described. The factor was found in the sera of three patients when blood was tested for transfusion. Panagglutination appeared in the indirect antiglobulin test when the erythrocytes were being washed with 0.

[Comparison of diagnostic values of immunoelectrophoresis and other methods of determination of the class and type of M protein].

Comparative analysis of immunoelectrophoresis (IEF) and several other laboratory methods used in the diagnosis of protein M showed that IEF is a method of choice in the immunological characterization of this protein, with the exception of IgM macroglobulin where the interpretation of the heavy chain and particularly of the light chain give better results in dilution immunodiffusion or immunochromatography. When the results are uncertain the simplest additional method to IEF seems to be dilution immunodiffusion and the best method is isolation of the observed protein by column chromatography and repeated determination of purified protein by IEF. With all these methods the lambda type of protein M is more difficult to determine than the kappa type.