Enzymecytochemistry and Immunohistochemistry in Monoclonal Gammopathy and Reactive Plasmacytosis

Abstract

Peripheral blood smears and bone‐marrow smears from 29 patients with malignant M‐components (25 with multiple myeloma and 4 with malignant lymphoma), 13 patients with benign monoclonal gammopathy (BMG), and 20 patients with polyclonal reactive plasmacytosis were examined by leucocyte alkaline phosphatase score (LAP‐score) and by acid phosphatase score in plasma cells from bone‐marrow smears. Furthermore, tissue sections from marrow biopsies from all patients were examined by the three‐layer unlabelled immunoperoxidase technique to detect cytoplasmic immunoglobulin. The LAP‐score was significantly higher in patients with malignant M‐components than in patients with BMG and also higher in IgA and IgG myeloma than in IgA and IgG BMG, but the latter difference was not significant. Furthermore, a significant positive correlation between paraprotein concentration and LAP‐score was found in multiple myeloma. Acid phosphatase score in plasma cells showed no clear distinction between multiple myeloma and BMG. Immunohistochemical examination showed a distinct monoclonal pattern in both multiple myeloma and BMG, allowing identification of the M‐cxsomponent which in all cases corresponded to the M‐component detected by serum examination. Cells producing immunoglobulin classes not matching the M‐component were more rare in multiple myeloma than in BMG, but the difference between the two conditions was quantitative and allowed no clear distinction.

Introduction

“…The suggested readings show the number of publications produced in 1975 on the topic of in situ hybridization or immunohistochemistry; note that there were eight such papers [1] , [2] , [3] , [4] , [5] , [6] , [7] , [8] . Compare this to the list of publications produced in 1980 on in situ hybridization or immunohistochemistry; note that there were 34 [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] . These references are included to give homage to the pioneers in these two fields.…”