Assessment of cell proliferation in normal and pathological bone marrow biopsies: a study using double sequential...

Area of Science:

• Hematology
• Immunohistochemistry
• Oncology

Background:

• Assessing bone marrow cell proliferation is crucial for diagnosing hematological disorders.
• Ki-67 antigen is a widely used marker for cell proliferation.
• Sequential double immunostaining allows simultaneous evaluation of proliferation and cell lineage.

Purpose of the Study:

• To evaluate the proliferative activity of hematopoietic and plasma cells in normal and neoplastic bone marrow conditions.
• To determine the utility of Ki-67 expression in differentiating various myeloproliferative disorders and myeloma.
• To assess the diagnostic value of MIB-1 and lineage-specific markers in routine bone marrow biopsies.

Main Methods:

• Analyzed 58 bone marrow biopsies (11 normal, 47 neoplastic) using sequential double immunostaining.
• Utilized MIB-1 antibody for Ki-67 antigen and antibodies for glycophorin-C, myeloperoxidase, factor VIII-related antigen, and immunoglobulin light chains.
• Quantified Ki-67 positive cells in erythroid precursors, myeloid precursors, megakaryocytes, and plasma cells.

Main Results:

• Normal marrows showed highest proliferation in erythroid cells (mean 90%), followed by myeloid precursors (mean 38%) and megakaryocytes (mean 14%). No Ki-67 positive plasma cells were observed.
• Erythroid cell proliferation was similar in neoplastic disorders compared to controls.
• Myeloid precursor proliferation largely overlapped normal values in myelodysplasia, chronic myeloproliferative disorders, and acute non-lymphoid leukemia (M1/M2).
• Increased Ki-67 expression in megakaryocytes, including micro-megakaryocytes, was observed in chronic myeloproliferative disorders.
• Mature myeloma showed less than 2% Ki-67 positive cells.

Conclusions:

• Erythroid and myeloid proliferative activity evaluation has limited value in differentiating myeloproliferative disorders.
• Increased megakaryocyte proliferation, detected by Ki-67, may aid in diagnosing challenging chronic myeloproliferative disorder cases.
• Ki-67 evaluation is not useful for differentiating myeloma from reactive plasmacytosis.
• Sequential double immunophenotyping is a consistent method for evaluating proliferating cells in routine bone marrow biopsies.