[Heavy chain disease: humoral and cellular findings in six patients with mu chain disease (author's transl)].

Clinical and chemical findings in 6 patients with mu-chain disease are reported. In all of these patients a lymphoproliferative disease was observed which by its symptoms resembled CLL. This similarity was underlined by the finding of an impaired response of PBL of the patients to mitogens as PHA, PWM, and Con A. A substantial result of our studies lies in the fact that the presence of mu-chains in the serum does not correlate with a clinically defined entity. Moreover, mu-chains have been observed in a case of benign lymphadenopathy. In one case a good remission of 4 years duration could be induced by the application of cytostatic agents.