Expression of multiple myeloma associated markers in bone marrow spicules using a novel immunohistochemical technique.

Immunohistochemistry (IHC) is an important tool used for diagnosis and prognosis of several hematological malignancies, and it frequently is used for quantitative and qualitative analysis of expression of different protein biomarkers in tissue sections. To understand the histopathological alterations in multiple myeloma (MM), IHC analysis of bone marrow (BM) biopsy is commonly used. Owing to the harsh decalcification process generally used for processing of bone marrow biopsies, however, protein epitopes occasionally are rendered unsuitable for IHC detection. We have developed a novel technique for processing BM spicule samples into a fibrin clot matrix that allows IHC detection of MM protein markers. This method does not require decalcification and results in a consistent, reliable assay. Using paired BM spicule-clot and BM core biopsies from patients diagnosed with multiple myeloma, we studied six MM related antibodies including kappa and lambda immunoglobulin light chains, CD56, CD138, CYR61 and DKK1.