[Lymphoproliferative diseases with small molecular (monomere) IgM paraproteinemia (proceedings)]

Phytohemagglutinin P, when used like an antiserum in immunoelectrophoresis, precipitates with pentameric IgM but not with monomeric IgM subunits. In a retrospective study this simple screening method was applied to 180 sera containing monoclonal IgM. Five cases were found to be of the monomeric type of IgM paraproteinemia. Four of these patients had lymphoproliferative diseases with lymphocytic infiltration of the bone marrow. The last case was complicated by acute myelomonocytic leukemia.