Idiopathic paraproteinemia. III. Increased frequency of paraproteinemia in thymectomized aging C57BL/KaLwRij and CBA/BrARij mice.

The influence of thymectomy on the appearance of idiopathic paraproteinemia (IP) during aging was investigated in mice of the C57BL/KaLwRij and the CBA/BrARij strains, which under normal conditions develop IP in high and low frequency, respectively. Compared with sham-thymectomized mice, C57BL mice thymectomized at a young adult age showed a markedly increased frequency and an earlier onset of IP during aging; this was even more pronounced in neonatally thymectomized mice. A similar effect of thymectomy was also observed in mice of the CBA strain.

Idiopathic paraproteinemia. II. Transplantation of the paraprotein-producing clone from old to young C57BL/KaLwRij mice.

Transplantation experiments in the C57BL/KaLwRij mouse model of idiopathic paraproteinemia (IP) showed that an IP-producing clone can be further propagated in young, lethally irradiated mice and also equally as well in nonirradiated recipients by a bone marrow and/or spleen cell transfer. The latency period before the original paraprotein was detected in the sera of recipients varied in different experiments between 1 and 9 months after transplantation. With subsequent transplantations, the "take" frequency gradually decreased.

Idiopathic paraproteinaemia. I. Studies in an animal model--the ageing C57BL/KaLwRij mouse.

A search for a suitable animal model for studies on idiopathic paraproteinaemia showed that an age-dependent increase in the appearance of homogeneous immunoglobulins in serum was common to all of the seven mouse strains investigated to date. The highest frequency was found in C57Bl/KaLwRij mice. Further investigations in this strain demonstrated that, except for some quantitative differences, most of the features of human and C57BL Mouse idiopathic paraproteinaemia were essentially the same.

A rapid, simple, and reliable technique for preparation of antisera against idiotypes of homogeneous immunoglobulins.

One-step immunization of guinea pigs with homogeneous immunoglobulins partly purified by micro-agar electrophoresis represents a rapid and reliable microtechnique for the preparation of antisera against the idiotype of the homogeneous immunoglobulins. Testing of these antisera by immunodiffusion techniques requires agar plates containing 3% polyethyleneglycol 6000.