The double gammopathies. Clinical and immunological studies.
A retrospective review of 1135 patients with paraproteinemias recorded 28 (2.5%) as having two M components. This group included 11 patients with myeloma, 6 with lymphoproliferative disease, 5 with a nonlymphoproliferative malignancy, and 6 with a double gammopathy of undetermined significance. In 13 cases in which the M components were measured over a period of time, three distinct patterns were observed, which may reflect the cellular and subcellular origin of the two proteins: 1) In 2 cases the minor component remained relatively stable while the dominant protein changed with time and treatment, suggesting the origin to be two cell lines--the minor arising from a quiescent clone of the monoclonal gammopathy of undetermined significance, and the major M component arising from a more rapidly proliferating plasma cell line; 2) a discordant pattern was seen in 4 patients, suggesting that the two M components arose from two separate plasma cell clones; 3) seven cases in which the proteins behaved in a concordant manner probably arose from a single plasma cell clone with incomplete class switching, producing two M components with different heavy chains.
Riddell
S
S
Traczyk
Z
Z
Paraskevas
F
F
Israels
L G
LG
D000368:Aged; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D008137:Longitudinal Studies; D008232:Lymphoproliferative Disorders / Q000150:complications* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications; D009369:Neoplasms / Q000150:complications; D010265:Paraproteinemias / Q000150:complications* / Q000276:immunology; D011087:Polycythemia Vera / Q000150:complications; D012189:Retrospective Studies
D007136:Immunoglobulins