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Heterogeneity of myelomatous and nonmyelomatous monoclonal IgG 1 proteins was investigated by isoelectric focusing experiments in thin-layer polyacrylamide gels. It appears from this study that nonmyelomatous monoclonal IgG 1 proteins possess the same individuality and limited heterogeneity as myelomatous monoclonal IgG 1 proteins.

An antiserum was developed with specificity for the VkIII subgroup, as evidenced by a precipitin reaction with reference protein Man. The antiserum reacted specifically with 4 of 26 monoclonal IgM, 3 of 57 monoclonal IgG, and 2 of 44 monoclonal IgA immunoglobulins. N-terminal amino acid sequence analysis was performed on kappa chains from 8 of these M-components. All were found to belong to the VKIII subgroup, and J of them had valine in position 2. This high frequency (37%) of valine in position 2 is discussed.

Human IgG from 24 normal sera, and from 24 sera containing IgG M-components, were quantitated by rocket immunoelectrophoresis at pH 8.6 using carbamylated antigen as described by Weeke, and at pH 5.0 using carbamylated antibodies. The latter method which is introduced in this paper gives results equal to Weeke's method and hence to the single radial immunodiffusion, the single linear immunodiftusion and the rocket method performed at pH 8.6. The main advantages of utilizing carbamylated antibodies: for quantitation of IgG in routine laboratory work is (a) the method is fast (3 h), (b) it does not involve chemical modification of the antigen and (c) it can be applied to both polyclonal and monoclonal IgG.

Non-myelomatous monoclonal IgG-L gammapathy has been proved in the synovial fluid and blood serum of a 58-year-old woman patient with rheumatoid arthritis. An analysis of synovial fluid by gel filtration demonstrated IgG-L paraprotein in the second peak of the elution curve; the activity of the rheumatoid factor was found only in the first peak of the curve.

No correlations were found between the complement fixing capacity of aggregated IgG immunoglobulins and their carbohydrate content. The techniques of periodate oxidation for removal of carbohydrates proved not to be useful for evaluating the role of carbohydrates in complement fixation because of alterations in the protein portion of the molecule. Further studies that employ milder methods for the removal of carbohydrates are needed to elucidate the possible role of carbohydrates in immunoglobulins.

Description of a case of diffuse pulmonary amyloidosis and benign monoclonal gammopathy in a 59-year-old woman. It was diagnosed by transbronchial lung biopsy. The patient was observed for three years.

Summary Serum, urine and saliva of forty patients with paraproteinaemia were studied by immunodiffusion and immunoelectrophoresis. In the saliva of twenty-two out of twenty-seven patients with monoclonal IgG, in one out of seven cases with monoclonal IgA, in all four with monoclonal IgM and in one patient with monoclonal lambda-type Bence-Jones-protein in the serum the M-component was also found in the saliva in very small amounts (about 1 mg/100 ml). These results are interpreted and discussed as supporting the hypothesis of local production of immunoglobulins.

Sera of some patients with monoclonal IgG gammapathy have been shown to contain a factor producing long-lasting vascular permeability in guinea pig skin. Skin reactions became positive 2 h after the intradermal injections of the sera and persisted for at least 8 h. Such activity could not be demonstrated in the sera of patients with macroglobulinemia, monoclonal IgA gammapathy, or light chain disease. This activity was associated with IgG but not IgM or IgA fractions of the patient’s serum. The activity was abolished by heating the serum at 63°C for 30 min or by treatment of the serum with ME and MIA. The activity, however, was not influenced by treatments with antihistaminics, trypsin inhibitor, or di-isopropyl-fluorophosphate.

Three patients with hypercalcemia had serum IgG monoclonal gammopathies. In none of the cases could a diagnosis of multiple myeloma be established, and other clinical findings were most co...

Twenty-nine sera containing monoclonal IgG proteins have been examined by radial immunodiffusion using commercially available plates. Double precipitation by IgG myeloma sera was demonstrated to be due to the deficiency of specific antibody determinants to the Fd fragment of the monoclonal proteins. Quantitation of polyclonal- and monoclonal IgG in myeloma sera, based on ring size measurements of the two precipitation rings, leads to erroneous values. The quotient of the ring areas, however, may be useful in the evaluation of chemotherapeutic treatment.