[Immunosecretory cells in human bone marrow. Immunofluorescence study on histological sections]

The authors report on a method for studies using immunofluorescence with total and anti-light chain anti-immunoglobuline immune serums of bone marrow specimens previously fixed, decalcified, and embedded in paraffin. The semi-quantitative counts of plasmocytes on histological sections are in agreement with those performed by other authors on smears of bone marrow punctures. The results of this method are in agreement with those of serum electrophoresis. It provides a distinction between polyclonal and monoclonal plasmocytosis and an exact identification of clonal proliferation of a frank tumorous nature (myeloma and Waldenström). Applicable to autopsies performed within 24 hours, it reveals the existance in the vast majority of amyloid diseases of monoclonal dysglobulinemia, without the abnormal clone being necessarily present in the other immunocyte area (spleen and ganglions).