Cryoglobulins in New Zealand Black mice.

In about a quarter of New Zealand Black mice (NZB mice), aged 4 months or older, cryoglobulins were found, sometimes in large amounts. The frequency was somewhat higher in females than in males. The presence of cryoglobulins was rarely observed in control mice and in these groups the cryocrit always remained low. The majority of the cryoglobulins in NZB mice were macroglobulins with a relatively positive charge. Attempts to elucidate their significance have remained unsuccessful so far.